The Role of Metformin in Controlling Oxidative Stress in Muscle of Diabetic Rats

Metformin can act in muscle, inhibiting the complex I of the electron transport chain and decreasing mitochondrial reactive oxygen species. Our hypothesis is that the inhibition of complex I can minimize damage oxidative in muscles of hypoinsulinemic rats. The present study investigated the effects of insulin and/or metformin treatment on oxidative stress levels in the gastrocnemius muscle of diabetic rats. Rats were rendered diabetic (D) with an injection of streptozotocin and were submitted to treatment with insulin (D+I), metformin (D+M), or insulin plus metformin (D+I+M) for 7 days. The body weight, glycemic control, and insulin resistance were evaluated. Then, oxidative stress levels, glutathione antioxidant defense system, and antioxidant status were analyzed in the gastrocnemius muscle of hypoinsulinemic rats. The body weight decreased in D+M compared to ND rats. D+I and D+I+M rats decreased the glycemia and D+I+M rats increased the insulin sensitivity compared to D rats. D+I+M reduced the oxidative stress levels and the activity of catalase and superoxide dismutase in skeletal muscle when compared to D+I rats. In conclusion, our results reveal that dual therapy with metformin and insulin promotes more benefits to oxidative stress control in muscle of hypoinsulinemic rats than insulinotherapy alone

Avaliação do uso de Hymenaea stigonocarpa Mart. ex Hayne sobre a atividade adaptogênica e na expressão de biomarcadores do estresse oxidativo em cérebro de animais com estresse induzidos

Hymenaea stigonocarpa Mart. ex Hayne (Fabaceae) known as ―jatobá-do-cerrado‖ is a species native to the Brazilian savannah. The plant is popularly used as fortifier, aphrodisiac and brain stimulant. In this study, we show that Wistar rats treated with H. stigonocarpa for 14 days and subjected to chronic stress by restriction and cold for 7 days, decreased levels of corticosterone and normalized serum biochemical parameters. The treatment of H. stigonocarpa showed no toxicity, promoted an improved redox state in brain regions (cerebellum, cerebral cortex, striatum and hippocampus) and increased total antioxidant capacity, suggesting a potential adaptogenic and neuroprotective effect against stress-induced changes.Fundação de Amparo a Pesquisa do Estado de Minas GeraisMestre em Génetica e BioquímicaHymenaea stigonocarpa Mart. ex Hayne (Fabaceae), conhecida como \"jatobá-do-cerrado\" é uma espécie nativa do Cerrado brasileiro e popularmente usada como fortificante, afrodisíaco e estimulante cerebral. Neste estudo, ratos Wistar tratados com H. stigonocarpa por 14 dias e submetidos ao estresse crônico por restrição e frio durante 7 dias, diminuíram os níveis séricos de corticosterona e normalizou os parâmetros bioquímicos. O tratamento com H. stigonocarpa não causou toxicidade, promoveu uma melhora no estado redox em regiões do cérebro (cerebelo, córtex cerebral, estriado e hipocampo) e aumentou a capacidade antioxidante total, demonstrando um potencial efeito adaptogênico e neuroprotetor em relação às alterações causadas pelo estresse