Early maternal separation enhances melanoma progression in adult female mice by immune mechanisms Francisco Stefânio Barreto, Wesley Lyeverton Correia Ribeiro, Bruno Coêlho Cavalcanti, Paulo Goberlânio de Barros Silva, Caren Nádia Soares de Sousa, et al. Annals of the New York Academy of Sciences, 2021 Maternal separation (MS) is a risk factor for major depressive disorder. Both cancer and depression seem to share a common biological link. Here, we evaluated the progression of melanoma and the underlying mechanisms related to this progression, namely cell proliferation and apoptosis, in adult female mice exposed to MS. Female C57BL/6 mice were exposed to MS for 60 min/day during the first 2 postnatal weeks (here called MS mice) or left undisturbed (here called non‐MS mice). Melanoma cells were inoculated subcutaneously into the axillary region of adult animals, and tumor progression was evaluated for 25 days. Adult MS mice presented depressive‐like behavior and working memory deficits. MS accelerated murine melanoma growth by mechanisms related to decreased apoptosis and increased cell proliferation rate, such as increased expression of IL‐6 and mTOR. MS stimulated eukaryotic elongation factor 2 expression and increased the number of circulating monocytes and DNA damage in peripheral blood leukocytes, an effect associated with oxidative DNA damage. In conclusion, MS accelerated the progression of murine melanoma by mechanisms related to tumor proliferation and apoptosis, revealing a relationship between adverse childhood experiences and cancer progression, particularly melanoma.
Chemopreventive effect of troxerutin against hydrogen peroxide-induced oxidative stress in human leukocytes through modulation of glutathione-dependent enzymes Bruno Coêlho Cavalcanti, João Batista de Andrade Neto, Antônio Adailson de Sousa Silva, Francisco Stefânio Barreto, José Roberto de Oliveira Ferreira, et al. Journal of Toxicology and Environmental Health Part A Current Issues, 2021 Troxerutin is a natural flavonoid present abundantly in tea, coffee, olives, wheat, and a variety of fruits and vegetables. Due to its diverse pharmacological properties, this flavonoid has aroused interest for treatment of various diseases, and consequently prompted investigation into its toxicological characteristics. The aim of this study was to evaluate the genotoxic and mutagenic effects and chemoprotective activity attributed to troxerutin using human peripheral blood leukocytes (PBLs) through several well-established experimental protocols based upon different parameters. Data demonstrated that troxerutin (100 to 1000 µM) induced no marked cytotoxic effect on PBLs after 24 hr, and did not produce strand breaks and mutagenicity. Regarding chemoprevention, this flavonoid attenuated cytotoxicity, genotoxicity, and mutagenicity initiated by hydrogen peroxide (H2O2) in human PBLs. Further, troxerutin demonstrated no marked cytotoxic effect on PBLs and exerted a protective effect against oxidative stress induced by H2O2 through modulation of GSH-dependent enzymes.
Red propolis and L-lysine on angiogenesis and tumor growth in a new model of hamster cheek pouch inoculated with Walker 256 tumor cells Camila de Carvalho Juanes, Susana Moreira de Souza, Vanessa Nogueira Lages Braga, Francisco Stefânio Barreto, Gisele Rocha Aguiar, et al. Einstein Sao Paulo Brazil, 2019 Objective: To evaluate the effect of red propolis and L-lysine on angiogenesis and tumor growth in a new model of hamster cheek pouch inoculated with Walker 256 tumor cells. Methods: The study consisted of two experiments with four groups each (total: 57 hamsters). In the experiment 1, the animals were inoculated with Walker tumor cells, followed by administration of test substances (red propolis 200mg/5mL/kg or L-lysine 150mg/kg) or control substances (gum arabic 5mL/kg or water 5mL/kg) for 10 days. The animals in the experiment 2 received red propolis, L-lysine, gum arabic or water at the same doses, for 33 days prior to inoculation of Walker tumor cells, followed by 10 days of treatment with the same substances. Based on single-plane images, angiogenesis was quantified (mean vascular area), in percentage, and tumor area (mm2) and perimeter (mm). Results: In the experiment 1, compared to animals receiving water, the mean vascular area expressed in percentage was significantly smaller in animal treated with propolis (p<0.05) and L-lysine (p<0.001). Conclusion: Both red propolis and L-lysine inhibited tumor angiogenesis in the new hamster cheek pouch model when administered after tumor inoculation.
