Timothy Omara

@boku.ac.at

Institute of Chemistry of Renewable Resources, Department of Chemistry
University of Natural Resources and Life Sciences Vienna (BOKU)



                       

https://researchid.co/proftimo

Timothy is with University of Natural Resources and Life Sciences, Vienna (BOKU), Austria and an Assistant Lecturer of Chemistry at Makerere University, Uganda
He was previously with the Department of Chemistry and Biochemistry, Moi University, Kenya and the Center of Excellence II in Phytochemicals, Textile and Renewable Energy (PTRE) hosted at the same University. He has proven research assiduity and track record of publications and refereeing across international peer-reviewed journals, with research interests including-but not limited to-food toxicology, analytical, natural products and environmental chemistry employing modern analytical techniques.
As of November 2023, he has over 70 publications and a book chapter to his name, and is serving as an Academic Editor in PLoS ONE, Journal of Food Quality, PeerJ Analytical Chemistry, Evidence-Based Complementary and Alternative Medicine and VEGETOS (Springer)

RESEARCH, TEACHING, or OTHER INTERESTS

Analytical Chemistry, Food Science, Environmental Science

26

Scopus Publications

1146

Scholar Citations

17

Scholar h-index

26

Scholar i10-index

Scopus Publications


  • Physicochemical and Microbial Quality of Water from the Ugandan Stretch of the Kagera Transboundary River
    Daniel Nimusiima, Denis Byamugisha, Timothy Omara, and Emmanuel Ntambi

    MDPI AG
    Increasing global pollution of water resources undermines the efforts invested in the realisation of Sustainable Development Goals. In developing countries, for example, water pollution is exacerbated by poor regulatory structures and improper waste disposal. This study, for the first time, investigated the physicochemical and microbial parameters of surface water from the Ugandan stretch of the Kagera transboundary river. Surface water (n = 135) from downstream, midstream and upstream of the river was sampled between February 2021 and June 2021, and analysed following standard methods for the examination of water and wastewater. Further, the samples were analysed using flame atomic absorption spectroscopy for the presence of heavy metals: nickel, lead, chromium, cadmium and copper. The obtained results showed that turbidity (24.77 ± 5.5–43.99 ± 6.87 mg/L), colour (118 ± 8.90–145.2 ± 30.58 Pt-co units), Escherichia coli (4.96 ± 7.01 CFU/100 mL), lead (23.0 ± 11.0–43.0 ± 12.0 µg/L) and cadmium (3.3 ± 1.0–10.1 ± 10.0 µg/L) were at levels that surpassed their permissible limits as per World Health Organization guidelines for potable water. These results are lower than previously reported for the Rwandese stretch of this river, but still present potential health risks to the population whose livelihoods depend on the river. Measures should therefore be instituted by the East African Community member states to mitigate riverine pollution and ensure sustainable use of the Kagera transboundary river.

  • Health Risks from Intake and Contact with Toxic Metal-Contaminated Water from Pager River, Uganda
    Patrick Onen, Robin Akemkwene, Caroline K. Nakiguli, Daniel Nimusiima, Daniel Hendry Ruma, Alice V. Khanakwa, Christopher Angiro, Gadson Bamanya, Boniface Opio, Allan Gonzaga,et al.

    MDPI AG
    Pollution of water resources is one of the major impediments to the realization of Sustainable Development Goals, especially in developing countries. The aim of this study was to investigate the physicochemical quality and potentially toxic element (lead and cadmium) concentrations in surface water sampled from Pager River, a tributary of the Nile River in Northern Uganda. Water samples (n = 18) were taken from six different points upstream (A, B, and C) and downstream (D, E, and F) of the river and analyzed following standard methods for their physiochemical properties. Atomic absorption spectroscopy was used to quantify lead and cadmium concentrations. Human health risks from ingestion and dermal contact with potentially toxic metal-contaminated water were calculated. The results obtained indicated that the mean temperature (27.7 ± 0.5–29.5 ± 0.8 °C), turbidity (40.7 ± 2.1–50.1 ± 1.1 NTU), lead (0.296 ± 0.030–0.576 ± 0.163 mg/L) and cadmium (0.278 ± 0.040–0.524 ± 0.040 mg/L) occurred at levels that surpassed their permissible limits as per World Health Organization guidelines for drinking water. Human health risk assessment showed that there are potential non-cancer risks from the ingestion of water from Pager River by adults, as the total hazard quotients were greater than one. These results emphasize the urgency to restrict the dumping of wastes into the river to minimize chances of impacting the Nile River, which flows northwards to the Mediterranean Sea. Further studies should perform routine monitoring of the river during both dry and wet seasons to establish the spatiotemporal variations of physicochemical, microbial, and trace metal profiles of the river and the associated health risks.

  • Ethnomedicinal plants used for malaria treatment in Rukungiri District, Western Uganda
    Hannington Gumisiriza, Eunice Apio Olet, Paul Mukasa, Julius B. Lejju, and Timothy Omara

    Springer Science and Business Media LLC
    Abstract Background Malaria remains a major global health challenge and a serious cause of morbidity and mortality in sub-Saharan Africa. In Uganda, limited access to medical facilities has perpetuated the reliance of indigenous communities on herbal medicine for the prevention and management of malaria. This study was undertaken to document ethnobotanical knowledge on medicinal plants prescribed for managing malaria in Rukungiri District, a meso-endemic malaria region of Western Uganda. Methods An ethnobotanical survey was carried out between May 2022 and December 2022 in Bwambara Sub-County, Rukungiri District, Western Uganda using semi-structured questionnaire. A total of 125 respondents (81 females and 44 males) were randomly selected and seven (7) key informants were engaged in open interviews. In all cases, awareness of herbalists on malaria, treatment-seeking behaviour and herbal treatment practices were obtained. The ethnobotanical data were analyzed using descriptive statistics, informant consensus factor and preference ranking. Results The study identified 48 medicinal plants belonging to 47 genera and 23 families used in the treatment of malaria and its symptoms in the study area. The most frequently cited species were Vernoniaamygdalina, Aloevera and Azadirachtaindica. Leaves (74%) was the most used plant organ, mostly for preparation of decoctions (41.8%) and infusions (23.6%) which are administered orally (89.6%) or used for bathing (10.4%). Conclusions Indigenous knowledge of medicinal plants used as prophylaxis and for treatment of malaria still exist among the local communities of Bwambara Sub-County. However, there is a need to investigate the antimalarial efficacy, phytochemical composition and safety of species (such as Digitariaabyssinica and Berkheyabarbata) with high percentage use values to validate their use.

  • Medicinal plants used for treatment of malaria by indigenous communities of Tororo District, Eastern Uganda
    John R. S. Tabuti, Samuel Baker Obakiro, Alice Nabatanzi, Godwin Anywar, Cissy Nambejja, Michael R. Mutyaba, Timothy Omara, and Paul Waako

    Springer Science and Business Media LLC
    Abstract Background Malaria remains the leading cause of death in sub-Saharan Africa. Although recent developments such as malaria vaccine trials inspire optimism, the search for novel antimalarial drugs is urgently needed to control the mounting resistance of Plasmodium species to the available therapies. The present study was conducted to document ethnobotanical knowledge on the plants used to treat symptoms of malaria in Tororo district, a malaria-endemic region of Eastern Uganda. Methods An ethnobotanical study was carried out between February 2020 and September 2020 in 12 randomly selected villages of Tororo district. In total, 151 respondents (21 herbalists and 130 non-herbalists) were selected using multistage random sampling method. Their awareness of malaria, treatment-seeking behaviour and herbal treatment practices were obtained using semi-structured questionnaires and focus group discussions. Data were analysed using descriptive statistics, paired comparison, preference ranking and informant consensus factor. Results A total of 45 plant species belonging to 26 families and 44 genera were used in the preparation of herbal medicines for management of malaria and its symptoms. The most frequently mentioned plant species were Vernonia amygdalina, Chamaecrista nigricans, Aloe nobilis, Warburgia ugandensis, Abrus precatorius, Kedrostis foetidissima, Senna occidentalis, Azadirachta indica and Mangifera indica. Leaves (67.3%) were the most used plant part while maceration (56%) was the major method of herbal remedy preparation. Oral route was the predominant mode of administration with inconsistencies in the posology prescribed. Conclusion This study showed that the identified medicinal plants in Tororo district, Uganda, are potential sources of new antimalarial drugs. This provides a basis for investigating the antimalarial efficacy, phytochemistry and toxicity of the unstudied species with high percentage use values to validate their use in the management of malaria.


  • Deposition, Dietary Exposure and Human Health Risks of Heavy Metals in Mechanically Milled Maize Flours in Mbarara City, Uganda
    Herbert Kariitu Mugume, Denis Byamugisha, Timothy Omara, and Emmanuel Ntambi

    MDPI AG
    Consumption of maize and maize-based products contributes a significant percentage to the total food energy intake in Uganda. However, the production of maize-derived foodstuffs is performed traditionally or by small- and medium-scale processors using different processing techniques. This can lead to differences in the quality of these products from processors, raising food safety concerns. In this study, the effects of mechanical processing (milling) methods on deposition of heavy metals into milled maize flour and the associated consumption health risks were assessed. Atomic absorption spectrophotometry was used to quantitatively establish the concentration of iron (Fe), manganese (Mn), zinc (Zn), cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu), cobalt (Co) and nickel (Ni) in 100 samples of maize milled using a wooden mortar (n = 2), a metallic mortar (n = 2), diesel engine−powered mills (n = 48) and electric motor−powered mills (n = 48). Results showed that the mean concentrations of heavy metals in mg/kg were Fe (11.60–34.45), Cu (0.50–8.10), Ni (0.50–1.60), Mn (0.70–25.40), Zn (4.40–15.90), Pb (0.53–10.20), Cd (0.51–0.85), Cr (0.50–1.53) and Co (0.50–1.51). The highest concentrations were found in flour milled using a traditional metallic mortar while the lowest levels were in those samples milled using a wooden mortar. The Fe, Pb and Cd contents of flours produced using the metallic mortar and some commercial mills was found to be higher than the permissible limits set by WHO/FAO. Human health risk assessment showed that there are potential carcinogenic health risks from adults’ intake of heavy metals in maize flour milled using a metallic mortar. Therefore, processing of maize flour needs to be monitored by the relevant statutory bodies in Uganda to minimize the possibility of heavy metal contamination of food products and animal feeds.


  • Albizia coriaria Welw ex Oliver: a review of its ethnobotany, phytochemistry and ethnopharmacology
    Timothy Omara, Ambrose K. Kiprop, and Viola J. Kosgei

    Springer Science and Business Media LLC

  • Deciphering the antimycobacterial, cytotoxicity and phytochemical profile of Entada abyssinica stem bark
    Samuel Baker Obakiro, Timothy Omara, Ambrose Kiprop, Lydia Bunalema, Isaac Kowino, and Elizabeth Kigondu

    Springer Science and Business Media LLC

  • Design and assembly of a domestic water temperature, pH and turbidity monitoring system
    Diana Rita Nanyanzi, Gilbert Gilibrays Ocen, Timothy Omara, Felix Bwire, Davis Matovu, and Twaibu Semwogerere

    Springer Science and Business Media LLC
    Abstract Objective The aim of this study was to design a domestic water temperature, pH and turbidity monitoring system that could constantly log temperature, pH and turbidity of water and give alerts in case the parameters are outside the acceptable limits for potable water. Results The system was designed, assembled and performed as expected. The study indicates that the proposed and designed system outperforms the existing manual monitoring system as it can constantly track and store changes in water quality. This could be used to prepare better treatment processes as well as identify problems in the water distribution system early enough.

  • Medicinal plants used as snake venom antidotes in east african community: Review and assessment of scientific evidences
    Timothy Omara, Caroline Kiwanuka, Rania Awad Naiyl, Florence Atieno Opondo, Sadia Benard Otieno, M. L. Ndiege, Immaculate Mbabazi, Winfred Nassazi and Edmond Etimu

    International Society of Communication and Development Between Universities (ISCDBU)
    Poisonous snake envenomation is a complex neglected health problem implicated in mortality, disability, psychological morbidity, and socio-economic losses recorded worldwide. An antivenin serum, the only medically recommended treatment for snakebites, has several drawbacks including, hypersensitivity, inability to prevent local tissue damage, are scarce and unaffordable in most snakebite endemic areas. In many rural communities all over the world, plants have been utilized for managing snakebites. This review seeks to identify plants reported as antivenom remedies in the East Africa and the scientific studies thereof which could support their use in the treatment of snake envenomation. A review of scientific articles was undertaken to identify information on traditional knowledge of medicinal plants used to treat snake envenomation in East Africa and their antivenom efficacy. A total of 361 plant species were retrieved to have been reported as traditional therapies for snakebites in East Africa. The review identified distinct cases of doctrine of signatures and zoopharmacognosy in snakes using Opilia amentacea, Hugonia castaneifolia and Microglossa pyrifolia respectively. Evaluations of the antivenom efficacy of 44 species (12.2%) have been done globally, and most species found to be effective in neutralizing the lethal activities of snake venoms. Ethnomedicinal plants play a revered holistic role in East African antisnake venom therapy. Conyza sumatrensis, Hyptis pectinata, Justicia betonica, and Maesa lanceolata used to treat specific snakebites merit further studies.

  • Intraspecific Variation of Phytochemicals, Antioxidant, and Antibacterial Activities of Different Solvent Extracts of Albizia coriaria Leaves from Some Agroecological Zones of Uganda
    Timothy Omara, Ambrose K. Kiprop, and Viola J. Kosgei

    Hindawi Limited
    Albizia coriaria Welw ex. Oliver is a customary African medicinal plant, which has a long history of utilization in the management of oxidative stress-induced and bacterial diseases. However, there is no report on the phytochemicals, antioxidant, and antibacterial activities of its leaves. The aim of this study was therefore to compare the phytochemicals, antioxidant, and antibacterial potential of A. coriaria leaves from Jinja, Kole, and Mbarara districts of Uganda. Shade-dried leaf samples were ground into powder and successively extracted with ethyl acetate, ethanol, and distilled water. Phytochemical screening indicated the presence of alkaloids, phenols, saponins, flavonoids, cardiac glycosides, tannins, and terpenes as the major secondary metabolites in the extracts. Total phenolic and flavonoid contents and total in vitro antioxidant activity were found to be the highest for ethanolic extracts, with the highest contents (101.72 ± 0.22 mg GAE/g DW; 13.23 ± 0.03 mg QE/g DW) and antioxidant potential (IC50 = 18.65 ± 0.06 mg/mL) being for leaves from Mbarara district. Antibacterial activity of the extracts determined by agar disc diffusion method revealed that ethanolic extracts had higher antibacterial activities with mean zones of inhibition of 6.00 ± 1.73 to 10.00 ± 1.73 mm, 5.00 ± 1.00 to 12.30 ± 1.53 mm, 17.00 ± 0.00 to 25.00 ± 2.65 mm, and 9.00 ± 1.73 to 16.00 ± 1.73 mm for Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella typhi, respectively. Ethyl acetate extracts of A. coriaria leaves from Kole and Mbarara had lower antibacterial activities, while aqueous extracts and ethyl acetate extract of leaves from Jinja showed no antibacterial activity. The current study for the first time established that A. coriaria leaves possess therapeutic phytochemicals with significant in vitro antioxidant and antibacterial activities, which lend credence to their use in traditional management of oxidative stress-induced conditions and bacterial diseases in Uganda. Structural elucidation of the responsible pure compounds for the observed bioactivities as well as toxicity studies of the extracts is recommended.

  • Traditional Medicinal Uses, Phytoconstituents, Bioactivities, and Toxicities of Erythrina abyssinica Lam. ex DC. (Fabaceae): A Systematic Review
    Samuel Baker Obakiro, Ambrose Kiprop, Elizabeth Kigondu, Isaac K’Owino, Mark Peter Odero, Scolastica Manyim, Timothy Omara, Jane Namukobe, Richard Oriko Owor, Yahaya Gavamukulya,et al.

    Hindawi Limited
    Background. Many studies have been undertaken on the medicinal values of Erythrina abyssinica Lam. ex DC. (Fabaceae). The details, however, are highly fragmented in different journals, libraries, and other publication media. This study was therefore conducted to provide a comprehensive report on its ethnobotany, ethnomedicinal uses, phytochemicals, and the available pharmacological evidence supporting its efficacy and safety in traditional medicine. Method. We collected data using a PROSPERO registered systematic review protocol on the ethnobotany, phytochemistry, and ethnopharmacology of Erythrina abyssinica from 132 reports that were retrieved from electronic databases. Documented local names, morphology, growth habit and habitat, ethnomedicinal and nonmedicinal uses, diseases treated, parts used, method of preparation and administration, extraction and chemical identity of isolated compounds, and efficacy and toxicity of extracts and isolated compounds were captured. Numerical data were summarized into means, percentages, and frequencies and presented as graphs and tables. Results. Erythrina abyssinica is harvested by traditional herbal medicine practitioners in East, Central, and South African communities to prepare herbal remedies for various human and livestock ailments. These include bacterial and fungal infections, tuberculosis, malaria, HIV/AIDS, diarrhea, cancer, meningitis, inflammatory diseases, urinary tract infections, wounds, diabetes mellitus, and skin and soft tissue injuries. Different extracts and phytochemicals from parts of E. abyssinica have been scientifically proven to possess anti-inflammatory, antibacterial, antioxidant, antiplasmodial, antiproliferative, antifungal, antimycobacterial, antidiarrheal, anti-HIV 1, antidiabetic, and antiobesity activities. This versatile pharmacological activity is due to the abundant flavonoids, alkaloids, and terpenoids present in its different parts. Conclusion. Erythrina abyssinica is an important ethnomedicinal plant in Africa harboring useful pharmacologically active phytochemicals against various diseases with significant efficacies and minimal toxicity to mammalian cells. Therefore, this plant should be conserved and its potential to provide novel molecules against diseases be explored further. Clinical trials that evaluate the efficacy and safety of extracts and isolated compounds from E. abyssinica are recommended.

  • The Scourge of Aflatoxins in Kenya: A 60-Year Review (1960 to 2020)
    Timothy Omara, Ambrose K Kiprop, Phanice Wangila, Alex Paul Wacoo, Sarah Kagoya, Papias Nteziyaremye, Mark Peter Odero, Caroline Kiwanuka Nakiguli, and Samuel Baker Obakiro

    Hindawi Limited
    Aflatoxins are endemic in Kenya. The 2004 outbreak of acute aflatoxicosis in the country was one of the unprecedented epidemics of human aflatoxin poisoning recorded in mycotoxin history. In this study, an elaborate review was performed to synthesize Kenya’s major findings in relation to aflatoxins, their prevalence, detection, quantification, exposure assessment, prevention, and management in various matrices. Data retrieved indicate that the toxins are primarily biosynthesized by Aspergillus flavus and A. parasiticus, with the eastern part of the country reportedly more aflatoxin-prone. Aflatoxins have been reported in maize and maize products (Busaa, chan’gaa, githeri, irio, muthokoi, uji, and ugali), peanuts and its products, rice, cassava, sorghum, millet, yams, beers, dried fish, animal feeds, dairy and herbal products, and sometimes in tandem with other mycotoxins. The highest total aflatoxin concentration of 58,000 μg/kg has been reported in maize. At least 500 acute human illnesses and 200 deaths due to aflatoxins have been reported. The causes and prevalence of aflatoxins have been grossly ascribed to poor agronomic practices, low education levels, and inadequate statutory regulation and sensitization. Low diet diversity has aggravated exposure to aflatoxins in Kenya because maize as a dietetic staple is aflatoxin-prone. Detection and surveillance are only barely adequate, though some exposure assessments have been conducted. There is a need to widen diet diversity as a measure of reducing exposure due to consumption of aflatoxin-contaminated foods.

  • Ethnobotany, ethnopharmacology, and phytochemistry of traditional medicinal plants used in the management of symptoms of tuberculosis in East Africa: A systematic review
    Samuel Baker Obakiro, Ambrose Kiprop, Isaac Kowino, Elizabeth Kigondu, Mark Peter Odero, Timothy Omara, and Lydia Bunalema

    Springer Science and Business Media LLC
    Objective Many studies on the treatment of tuberculosis (TB) using herbal medicines have been undertaken in recent decades in East Africa. The details, however, are highly fragmented. The purpose of this study was to provide a comprehensive overview of the reported medicinal plants used to manage TB symptoms, and to analyze scientific reports on their effectiveness and safety. Method A comprehensive literature search was performed in the major electronic databases regarding medicinal plants used in the management of TB in East Africa. A total of 44 reports were retrieved, and data were collected on various aspects of the medicinal plants such as botanical name, family, local names, part(s) used, method of preparation, efficacy, toxicity, and phytochemistry. The data were summarized into percentages and frequencies which were presented as tables and graphs. Results A total of 195 species of plants belonging to 68 families and 144 genera were identified. Most encountered species were from Fabaceae (42.6%), Lamiaceae (19.1%), Asteraceae (16.2%), and Euphorbiaceae (14.7%) families. Only 36 medicinal plants (18.5%) have been screened for antimycobacterial activity. Out of these, 31 (86.1%) were reported to be bioactive with minimum inhibitory concentrations ranging from 47 to 12,500 μg/ml. Most tested plant extracts were found to have acceptable acute toxicity profiles with cytotoxic concentrations on normal mammalian cells greater than 200 μg/ml. The most commonly reported phytochemicals were flavonoids, terpenoids, alkaloids, saponins, cardiac glycosides, and phenols. Only Tetradenia riparia , Warburgia ugandensis , and Zanthoxylum leprieurii have further undergone isolation and characterization of the pure bioactive compounds. Conclusion East Africa has a rich diversity of medicinal plants that have been reported to be effective in the management of symptoms of TB. More validation studies are required to promote the discovery of antimycobacterial drugs and to provide evidence for standardization of herbal medicine use.

  • Effects of industrial effluents on the quality of water in Namanve stream, Kampala Industrial and Business Park, Uganda
    Christopher Angiro, Patrick P’Odyek Abila, and Timothy Omara

    Springer Science and Business Media LLC
    Abstract Objective Kampala Industrial and Business Park (KIBP) is one of the premier and the most successful Ugandan industrial complexes that impact the inner Murchison bay of Lake Victoria. The current study aimed at evaluating the effect of industrial effluents on the physicochemical and microbiological quality of water taken from four different sites along Namanve stream in KIBP, Wakiso district, Uganda. Results All the water quality parameters were below WHO maximum permissible limits except turbidity, electrical conductivity and Escherichia coli count. Mean values of the monitored water quality parameters increased from the point of effluent discharge downstream of Namanve stream.

  • Antivenin plants used for treatment of snakebites in Uganda: Ethnobotanical reports and pharmacological evidences
    Timothy Omara, Sarah Kagoya, Abraham Openy, Tom Omute, Stephen Ssebulime, Kibet Mohamed Kiplagat, and Ocident Bongomin

    Springer Science and Business Media LLC
    AbstractSnakebite envenomation is a serious public health concern in rural areas of Uganda. Snakebites are poorly documented in Uganda because most occur in rural settings where traditional therapists end up being the first-line defense for treatment. Ethnobotanical surveys in Uganda have reported that some plants are used to antagonize the activity of various snake venoms. This review was sought to identify antivenin plants in Uganda and some pharmacological evidence supporting their use. A literature survey done in multidisciplinary databases revealed that 77 plant species belonging to 65 genera and 42 families are used for the treatment of snakebites in Uganda. The majority of these species belong to family Fabaceae (31%), Euphorbiaceae (14%), Asteraceae (12%), Amaryllidaceae (10%) and Solanaceae (10%). The main growth habit of the species is shrubs (41%), trees (33%) and herbs (18%). Antivenin extracts are usually prepared from roots (54%) and leaves (23%) through decoctions, infusions, powders, and juices, and are administered orally (67%) or applied topically (17%). The most frequently encountered species were Allium cepa, Carica papaya, Securidaca longipedunculata, Harrisonia abyssinica, and Nicotiana tabacum. Species with global reports of tested antivenom activity included Allium cepa, Allium sativum, Basella alba, Capparis tomentosa, Carica papaya, Cassia occidentalis, Jatropa carcus, Vernonia cinereal, Bidens pilosa, Hoslundia opposita, Maytensus senegalensis, Securinega virosa, and Solanum incanum. There is need to identify and evaluate the antivenom compounds in the claimed plants.

  • Physicochemical quality of water and health risks associated with consumption of African lung fish (Protopterus annectens) from Nyabarongo and Nyabugogo rivers, Rwanda
    Timothy Omara, Papias Nteziyaremye, Solomon Akaganyira, Dickens Waswa Opio, Lucy Nyambura Karanja, Decrah Moraa Nyangena, Betty Jematia Kiptui, Remish Ogwang, Stephen Mark Epiaka, Abigael Jepchirchir,et al.

    Springer Science and Business Media LLC
    Abstract Objective To determine the quality of water, heavy metal content of edible muscles of a piscivorous fish (Protopterus annectens) and assess the health risks associated with using water and consumption of P. annectens from Nyabarongo and Nyabugogo rivers of Rwanda. Results All the water quality parameters were within World Health Organization’s acceptable limits except total nitrogen, iron, manganese and lead levels. Edible muscles of Protopterus annectens contained 272.8 ± 0.36, 292.2 ± 0.25, 8.8 ± 0.36, 135.2 ± 0.15, 148.0 ± 0.21 and 432. 0 ± 0.50 mg/kg of iron, manganese, copper, zinc, chromium and lead at Ruliba station and 336.0 ± 0.70, 302.6 ± 1.22, 6.4 ± 0.26, 44.7 ± 0.20, 138.2 ± 0.17 and 302.4 ± 1.50 mg/kg of iron, manganese, copper, zinc, chromium and lead at Kirinda bridge of Nyabarongo river. Health risk assessments indicated that though ingestion and dermal contact with heavy metals in water from the rivers may not cause obvious health effects, consumption of Protopterus annectens from Nyabarongo river may lead to deleterious health effects.

  • Bioaccumulation of priority trace metals in edible muscles of West African lungfish (Protopterus annectens Owen, 1839) from Nyabarongo River, Rwanda
    Papias Nteziyaremye and Timothy Omara

    Informa UK Limited
    Abstract Heavy metal pollution and accumulation in aquatic ecosystems present serious threats to sustainability. In the current study, the heavy metal content of water and edible muscles of a piscivorous fish (Protopterus annectens) as well as bioaccumulation of the heavy metals in fish tissues were evaluated. Samples of water (n = 6) and fish (n = 6) were taken from Kirinda bridge and Ruliba station on Nyabarongo river and analyzed by UV spectroscopy and atomic absorption spectrometry, respectively. The heavy metal concentrations in water were: iron (0.63 ± 0.02 and 1.61 ± 0.03 mg/kg), manganese (0.53 ± 0.002 mg/kg at Ruliba station), chromium (0.06 ± 0.002 mg/kg at Kirinda bridge), cadmium (0.106 ± 0.002 mg/kg at Ruliba station) and lead (0.75 ± 0.02 and 0.051 ± 0.01 mg/kg). Edible muscles of Protopterus annectens contained 336.0 ± 0.70, 302.6 ± 1.22, 6.4 ± 0.26, 44.7 ± 0.20, 138.2 ± 0.17 and 302.4 ± 1.50 mg/kg of iron, manganese, copper, zinc, chromium and lead at Kirinda bridge and 272.8 ± 0.36, 292.2 ± 0.25, 8.8 ± 0.36, 135.2 ± 0.15, 148.0 ± 0.21 and 432. 0 ± 0.50 mg/kg of iron, manganese, copper, zinc, chromium and lead, respectively, at Ruliba station. Most of the heavy metal contents were above the recommended levels. Bioaccumulation factors recorded in Protopterus annectens ranged from 403.2 to 15,130 L/kg, implying that consumption of this fish could pose deleterious health risks. The study suggested that P. annectens could be used as a sentinel organism for biomonitoring of aquatic ecosystems.

  • Antimalarial Plants Used across Kenyan Communities
    Timothy Omara

    Hindawi Limited
    Malaria is one of the serious health problems in Africa, Asia, and Latin America. Its treatment has been met with chronic failure due to pathogenic resistance to the currently available drugs. This review attempts to compile phytotherapeutical information on antimalarial plants in Kenya based on electronic data. A comprehensive web search was conducted in multidisciplinary databases, and a total of 286 plant species from 75 families, distributed among 192 genera, were retrieved. Globally, about 139 (48.6%) of the species have been investigated for antiplasmodial (18%) or antimalarial activities (97.1%) with promising results. However, there is no record on the antimalarial activity of about 51.4% of the species used although they could be potential sources of antimalarial remedies. Analysis of ethnomedicinal recipes indicated that mainly leaves (27.7%) and roots (19.4%) of shrubs (33.2%), trees (30.1%), and herbs (29.7%) are used for preparation of antimalarial decoctions (70.5%) and infusions (5.4%) in Kenya. The study highlighted a rich diversity of indigenous antimalarial plants with equally divergent herbal remedy preparation and use pattern. Further research is required to validate the therapeutic potential of antimalarial compounds from the unstudied claimed species. Although some species were investigated for their antimalarial efficacies, their toxicity and safety aspects need to be further investigated.

  • Plants Used in Antivenom Therapy in Rural Kenya: Ethnobotany and Future Perspectives
    Timothy Omara

    Hindawi Limited
    Snake envenomation is one of the neglected tropical diseases which has left an intolerable death toll and severe socioeconomic losses in Kenya. In a continued effort to identify some antiophidic East African botanical species, this study generated ethnobotanical information on antivenom plants reported in Kenya, with a view to identify potential species which could be subjected to in vitro and clinical studies for possible development into antivenoms. Data retrieved through searches done in multidisciplinary databases (Scopus, Web of Science, PubMed, Science Direct, Google Scholar, and Scientific Electronic Library Online) indicated that 54 plant species belonging to 45 genera, distributed among 27 families, are used for the management of snakebites in Kenya. Most species belonged to the family Asteraceae (11%), Malvaceae (11%), Fabaceae (9%), Annonaceae (6%), Combretaceae (6%), and Lamiaceae (6%). The main growth habit of the species is as herbs (35%), shrubs (33%), and trees (28%). Ethnomedicinal preparations used in treating snake poisons are usually from leaves (48%), roots (26%), and stem bark (8%) through decoctions, infusions, powders, and juices which are applied topically or administered orally. The most frequently encountered species were Combretum collinum, Euclea divinorum, Fuerstia africana, Grewia fallax, Microglossa pyrifolia, Solanecio mannii, and Solanum incanum. Indigenous knowledge on medicinal antivenom therapy in Kenya is humongous, and therefore studies to isolate and evaluate the antivenom compounds in the claimed plants are required to enable their confident use in antivenom therapy alongside commercial antivenin sera.

  • Medicinal Plants Used in Traditional Management of Cancer in Uganda: A Review of Ethnobotanical Surveys, Phytochemistry, and Anticancer Studies
    Timothy Omara, Ambrose K. Kiprop, Rose C. Ramkat, Jackson Cherutoi, Sarah Kagoya, Decrah Moraa Nyangena, Tsedey Azeze Tebo, Papias Nteziyaremye, Lucy Nyambura Karanja, Abigael Jepchirchir,et al.

    Hindawi Limited
    The burden of neoplastic diseases is a significant global health challenge accounting for thousands of deaths. In Uganda, about 32,617 cancer cases were reported in 2018, accompanied by 21,829 deaths. In a view to identify some potential anticancer plant candidates for possible drug development, the current study was designed to compile the inventory of plants with reported anticancer activity used in rural Uganda and the evidences supporting their use in cancer therapy. An electronic survey in multidisciplinary databases revealed that 29 plant species belonging to 28 genera distributed among 24 families have been reported to be used in the management of cancer in Uganda. Anticancer plants were majorly from the families Bignoniaceae (7%), Caricaceae (7%), Fabaceae (7%), Moraceae (7%), and Rutaceae (7%). Most species occur in the wild (52%), though some are cultivated (48%). The growth habit of the plants is as trees (55%) or herbs (45%). Anticancer extracts are usually prepared from leaves (29%), bark (24%), roots (21%), and fruits (13%) through decoctions (53%), as food spices (23%) or pounded to produce ointments that are applied topically (10%).Prunus africana(Hook.f.) Kalkman,Opuntiaspecies,Albizia coriaria(Welw. ex Oliver), Daucus carotaL.,Cyperus alatus(Nees) F. Muell.,Markhamia lutea(Benth.) K. Schum., andOxalis corniculataL. were the most frequently encountered species. As per global reports,Allium sativumL.,Annona muricataL.,Carica papayaL.,Moringa oleiferaLam.,Opuntiaspecies,Prunus africana(Hook.f.) Kalkman, andCatharanthus roseus(L.) G. Don. are the most studied species, with the latter having vincristine and vinblastine anticancer drugs developed from it. Prostate, cervical, breast, and skin cancers are the top traditionally treated malignancies. There is a need to isolate and evaluate the anticancer potential of the bioactive compounds in the unstudied claimed plants, such asCyperus alatus(Nees) F. Muell.,Ficus daweiHutch.,Ficus natalensisHochst., andLovoa trichilioidesHarms, and elucidate their mechanism of anticancer activity.

  • Exponential Disruptive Technologies and the Required Skills of Industry 4.0
    Ocident Bongomin, Gilbert Gilibrays Ocen, Eric Oyondi Nganyi, Alex Musinguzi, and Timothy Omara

    Hindawi Limited
    The 21st century has witnessed precipitous changes spanning from the way of life to the technologies that emerged. We have entered a nascent paradigm shift (industry 4.0) where science fictions have become science facts, and technology fusion is the main driver. Thus, ensuring that any advancement in technology reach and benefit all is the ideal opportunity for everyone. In this study, disruptive technologies of industry 4.0 were explored and quantified in terms of the number of their appearances in published literature. The study aimed at identifying industry 4.0 key technologies which have been ill-defined by previous researchers and to enumerate the required skills of industry 4.0. Comprehensive literature survey covering the field of engineering, production, and management was done in multidisciplinary databases: Google Scholar, Science Direct, Scopus, Sage, Taylor & Francis, and Emerald Insight. From the electronic survey, 35 disruptive technologies were quantified and 13 key technologies: Internet of Things, Big Data, 3D printing, Cloud computing, Autonomous robots, Virtual and Augmented reality, Cyber-physical system, Artificial intelligence, Smart sensors, Simulation, Nanotechnology, Drones, and Biotechnology were identified. Both technical and personal skills to be imparted into the human workforce for industry 4.0 were reported. The review identified the need to investigate the capability and the readiness of developing countries in adapting industry 4.0 in terms of the changes in the education systems and industrial manufacturing settings. This study proposes the need to address the integration of industry 4.0 concepts into the current education system.

  • Aflatoxins in Uganda: An Encyclopedic Review of the Etiology, Epidemiology, Detection, Quantification, Exposure Assessment, Reduction, and Control
    Timothy Omara, Winfred Nassazi, Tom Omute, Aburu Awath, Fortunate Laker, Raymond Kalukusu, Bashir Musau, Brenda Victoria Nakabuye, Sarah Kagoya, George Otim,et al.

    Hindawi Limited
    Uganda is an agrarian country where farming employs more than 60% of the population. Aflatoxins remain a scourge in the country, unprecedentedly reducing the nutritional and economic value of agricultural foods. This review was sought to synthetize the country’s major findings in relation to the mycotoxins’ etiology, epidemiology, detection, quantification, exposure assessment, control, and reduction in different matrices. Electronic results indicate that aflatoxins in Uganda are produced by Aspergillus flavus and A. parasiticus and have been reported in maize, sorghum, sesame, beans, sunflower, millet, peanuts, and cassava. The causes and proliferation of aflatoxigenic contamination of Ugandan foods have been largely due to poor pre-, peri-, and postharvest activities, poor government legislation, lack of awareness, and low levels of education among farmers, entrepreneurs, and consumers on this plague. Little diet diversity has exacerbated the risk of exposure to aflatoxins in Uganda because most of the staple foods are aflatoxin-prone. On the detection and control, these are still marginal, though some devoted scholars have devised and validated a sensitive portable device for on-site aflatoxin detection in maize and shown that starter cultures used for making some cereal-based beverages have the potential to bind aflatoxins. More efforts should be geared towards awareness creation and vaccination against hepatitis B and hepatitis A to reduce the risk of development of liver cancer among the populace.

RECENT SCHOLAR PUBLICATIONS

  • Spatio-temporal Variations and Potential Health Risks of Heavy Metals in Water from River Manafwa, Uganda
    M Opolot, T Omara, C Adaku, E Ntambi
    Letters in Applied NanoBioScience 13 (1), 23 2024

  • Exposure and Health Risks Posed by Potentially Toxic Elements in Soils of Metal Fabrication Workshops in Mbarara City, Uganda
    E Nuwamanya, D Byamugisha, CK Nakiguli, C Angiro, AV Khanakwa, ...
    Journal of Xenobiotics 14 (1), 176-192 2024

  • Urban drainage channels as microplastic pollution hotspots into Lake Victoria, East Africa
    S Ocakacon, PM Nyenje, HM Kalibbala, CB Nagawa, T Omara, ...
    3rd DIFENEW Student International Conference – DISC2023, December 5th, 2023 2023

  • Physicochemical and microbial quality of water from the Ugandan stretch of the Kagera Transboundary River
    D Nimusiima, D Byamugisha, T Omara, E Ntambi
    Limnological Review 23 (3), 157-176 2023

  • Physicochemical and microbial quality of water from the Ugandan stretch of Kagera transboundary river
    D Nimusiima, D Byamugisha, T Omara, E Ntambi
    The 4th Commonwealth Chemistry Posters – Building Networks to Address the 2023

  • Health risks from intake and contact with toxic metal-contaminated water from Pager River, Uganda
    P Onen, R Akemkwene, CK Nakiguli, D Nimusiima, DH Ruma, ...
    Journal of Xenobiotics 13 (4), 544–559 2023

  • Comparative study of the topical wound healing activity of Ash and Aqueous Leaf extracts of Vernonia amygdalina Delile on Adult Wistar Albino rats
    IJ Matovu, J Othieno, C Bogere, W Nakabiri, I Kahwa, CO Ajayi, T Omara, ...
    20th NAPRECA Symposium, Harare Institute of Technology, Harare, Zimbabwe 2023

  • Deciphering the antimycobacterial, cytotoxicity and phytochemical profile of Entada abyssinica stem bark
    SB Obakiro, T Omara, A Kiprop, L Bunalema, I Kowino, E Kigondu
    Vegetos, 1-7 2023

  • Suberosin alleviates thiazolidinedione-induced cardiomyopathy in diabetic rats by inhibiting ferroptosis via modulation of ACSL4-LPCAT3 and PI3K-AKT signaling pathways
    S Iqbal, J Farhat, I Kahwa, T Omara
    Cardiovascular Toxicology 23 (9-10), 295-304 2023

  • Optimization of pyrolysis and selected physicochemical properties of groundnut shells, coffee and rice husks for biochar production
    JC Opedun, W Wanasolo, AO Apita, T Omara
    Jordan Journal of Mechanical and Industrial Engineering 17 (3), 431– 442 2023

  • Ethnomedicinal plants used for malaria treatment in Rukungiri District, Western Uganda
    H Gumisiriza, EA Olet, P Mukasa, JB Lejju, T Omara
    Tropical Medicine and Health 51 (1), 49 2023

  • Albizia coriaria Welw ex Oliver: a review of its ethnobotany, phytochemistry and ethnopharmacology
    T Omara, AK Kiprop, VJ Kosgei
    Advances in Traditional Medicine 23, 631–646 2023

  • Medicinal plants used in the management of sexual dysfunction, infertility and improving virility in the East African Community: a systematic review
    C Kyarimpa, CB Nagawa, T Omara, S Odongo, P Ssebugere, SO Lugasi, ...
    Evidence-Based Complementary and Alternative Medicine 2023 2023

  • Medicinal plants used for treatment of malaria by indigenous communities of Tororo District, Eastern Uganda
    JRS Tabuti, SB Obakiro, A Nabatanzi, G Anywar, C Nambejja, ...
    Tropical Medicine and Health 51 (1), 34 2023

  • Bioethanol production from thermochemically-pretreated water hyacinth via partially consolidated bioprocessing with isolated thermophilic microbial consortium from Kenya
    SS Deffar, A Kumar, A Muliwa, NN Pili, T Omara
    From Laboratory to Industry: Green Chemistry for a Circular Economy 2023

  • Assessment of Contamination Levels of Potentially Toxic Elements in the Sediments of an Urban Industrial and Fish Landing Site in Uganda
    G Baguma, T Omara, P Onen, EJ Marti
    World Environmental & Water Resources Congress 2023, American Society of 2023

  • Comparison of the Wound Healing Activity of the Leaf and Leaf Ash Extracts of Vernonia amygdalina in Rats
    IJ Matovu, C Bogere, J Othieno, W Nakabiri, I Kahwa, CO Ajayi, T Omara, ...
    Research square 2023

  • Lacustrine Cyanobacteria, Algal Blooms and Cyanotoxins in East Africa: Implications for Human and Ecological Health Protection
    T Omara, CB Nagawa, C Kyarimpa, S Bhmdorfer, T Rosenau, SO Lugasi, ...
    Phycology 3 (1), 147–167 2023

  • Pharmacognostic and phytochemical studies as an invaluable approach for correct identification of medicinal plants: The case of Artemisia vulgaris L. substituted for Artemisia
    I Kahwa, CO Ajayi, R Yadav, NS Chauhan, K Shah, AA Abdelgadir, ...
    TMR Integrative Medicine 7, e23004 2023

  • Pollution status, source apportionment, ecological and human health risks of potentially (eco)toxic element‑laden dusts from urban roads, highways and pedestrian bridges in Uganda
    M Opolot, T Omara, C Adaku, E Ntambi
    Pollutants 3 (1), 74-88 2023

MOST CITED SCHOLAR PUBLICATIONS

  • Exponential Disruptive Technologies and the Required Skills of Industry 4.0
    O Bongomin, G Gilibrays Ocen, E Oyondi Nganyi, A Musinguzi, T Omara
    Journal of Engineering 2020, 4280156 2020
    Citations: 232

  • Medicinal Plants used in Traditional Management of Cancer in Uganda: A Review of Ethnobotanical Surveys, Phytochemistry, and Anticancer Studies
    T Omara, AK Kiprop, RC Ramkat, J Cherutoi, S Kagoya, DM Nyangena, ...
    Evidence-based Complementary and Alternative Medicine 2020, 3529081 2020
    Citations: 119

  • Antivenin Plants Used for Treatment of Snakebites in Uganda: Ethnobotanical Reports and Pharmacological Evidences
    T Omara, S Kagoya, A Openy, T Omute, S Ssebulime, KM Kiplagat, ...
    Tropical Medicine and Health 48, 6 2020
    Citations: 79

  • Ethnobotany, ethnopharmacology and phytochemistry of traditional medicinal plants used in the management of symptoms of tuberculosis in East Africa: a systematic review
    SB Obakiro, AK Kiprop, I Kowino, E Kigondu, MP Odero, T Omara, ...
    Tropical Medicine and Health 48, 68 2020
    Citations: 65

  • Antimalarial Plants Used across Kenyan Communities
    T Omara
    Evidence-Based Complementary and Alternative Medicine 2020, 4538602 2020
    Citations: 57

  • Aflatoxins in Uganda: an encyclopedic review of the etiology, epidemiology, detection, quantification, exposure assessment, reduction and control
    T Omara, W Nassazi, T Omute, A Awath, F Laker, R Kalukusu, B Musau, ...
    International Journal of Microbiology 2020, 4723612 2020
    Citations: 46

  • Mercuric pollution of surface water, superficial sediments, Nile tilapia (Oreochromis nilotica Linnaeus 1758 [Cichlidae]) and yams (Dioscorea alata) in auriferous areas of
    T Omara, S Karungi, R Kalukusu, BV Nakabuye, S Kagoya, B Musau
    PeerJ 7, e7919 2019
    Citations: 38

  • The Scourge of Aflatoxins in Kenya: A 60-Year Review (1960-2020)
    T Omara, AK Kiprop, P Wangila, AP Wacoo, S Kagoya, P Nteziyaremye, ...
    Journal of Food Quality 2021, 8899839 2021
    Citations: 35

  • Plants Used in Antivenom Therapy in Rural Kenya: Ethnobotany and Future Perspectives
    T Omara
    Journal of Toxicology 2020, 1828521 2020
    Citations: 30

  • Effects of alkali treatment on the mechanical and thermal properties of sisal/cattail polyester commingled composites
    SM Mbeche, T Omara
    PeerJ Materials Science 2, e5 2020
    Citations: 26

  • Effects of industrial effluents on the quality of water in Namanve stream, Kampala Industrial and Business Park, Uganda
    C Angiro, PPO Abila, T Omara
    BMC Research Notes 13, 220 2020
    Citations: 25

  • Intraspecific Variation of Phytochemicals, Antioxidant and Antibacterial Activities of Different Solvent Extracts of Albizia coriaria Leaves from Some Agro-Ecological Zones of
    T Omara, AK Kiprop, VJ Kosgei
    Evidence-based Complementary and Alternative Medicine 2021, 2335454 2021
    Citations: 24

  • Physicochemical quality of water and health risks associated with consumption of African lung fish (Protopterus annectens) from Nyabarongo and Nyabugogo rivers, Rwanda
    T Omara, P Nteziyaremye, S Akaganyira, DW Opio, LN Karanja, ...
    BMC Research Notes 13, 66 2020
    Citations: 23

  • Performance Characteristics of a Cooking Stove Improved with Sawdust as an Insulation Material
    J Okino, AJ Komakech, J Wanyama, H Ssegane, E Olomo, T Omara
    Journal of Renewable Energy 2021 (01), 9969806 2021
    Citations: 20

  • Physicochemical and Microbiological Quality of Springs in Kyambogo University Propinquity
    T Omara, W Nassazi, M Adokorach, S Kagoya
    Open Access Library Journal 6 (1), e5100 2019
    Citations: 19

  • Traditional Medicinal Uses, Phytoconstituents, Bioactivities and Toxicities of Erythrina abyssinica Lam. ex DC. (Fabaceae): A Systematic Review
    SB Obakiro, A Kiprop, E Kigundu, I Ko’wino, MP Odero, S Manyim, ...
    Evidence-based Complementary and Alternative Medicine 2021, 5513484 2021
    Citations: 18

  • Bioaccumulation of priority trace metals in edible muscles of West African lungfish (Protopterus annectens Owen, 1839) from Nyabarongo River, Rwanda
    P Nteziyaremye, T Omara
    Cogent Environmental Science 6 (1), 1779557 2020
    Citations: 18

  • Effects of continuous deep-fat frying on the physicochemical properties of assorted brands of edible cooking oils sold in Greater Metropolitan Kampala
    T Omara, E Kigenyi, F Laker, M Adokorach, G Otim, R Kalukusu, B Musau, ...
    Asian Journal of Applied Chemistry Research 3 (2), 1-13 2019
    Citations: 16

  • Spectroscopic analysis of selected priority trace metals in the extant East African gilled lungfish (Protopterus amphibius) in Lira municipal lagoon and its edibility health risk
    T Omara, R Ogwang, S Ndyamuhaki, S Kagoya, E Kigenyi, B Musau, ...
    Science Journal of Analytical Chemistry 2018
    Citations: 16

  • Bioinsecticidal activity of eucalyptol and 1R-alpha-pinene rich acetonic oils of Eucalyptus saligna on Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae)
    T Omara, FK Kateeba, B Musau, E Kigenyi, E Adupa, S Kagoya
    Journal of Health and Environmental Research 4 (4), 153-160 2018
    Citations: 15