Effect of the Methanolic Extract of Algerian Salvia officinalis L. Against Oxidative Stress Associated with Diabetes Mellitus

Background and Objective: Medicinal plants are considered an enormous source of multiple phytotherapeutic substances used to treat various human diseases. Hence, the present study aims to evaluate the effect of the methanolic extract of Salvia officinalis L. against oxidative stress in streptozotocin-diabetic rats. Materials and Methods: Methanolic extract was prepared on the differential solubility of polyphenolic compounds in organic solvents. Diabetes was experimentally induced in rats by streptozotocin (40 mg kg(-1)). The treated groups received, 300 mg kgG1 of methanolic extract and gallic acid. The weight and blood glucose levels were controlled from the beginning of the treatment. In terms of experimentation, the liver was removed and a cytosolic dosage of catalase, superoxide dismutase, glutathione and malondialdehyde were performed to estimate possible oxidative damage caused by the installation of diabetes. Results: The method of extraction adopted yielded a methanolic extract with a percentage of 10.63%. The determination of polyphenols revealed a content of 10.43 +/- 1.01 mg g(-1) EAG/mg of extract and that of flavonoids of 2.26 +/- 1.42 mg g(-1) EQ/mg of extract. Oral administration of the methanolic extract of Salvia officinalis L. lowered blood glucose and MDA and increased GSH, catalase and superoxide dismutase activities. Conclusion: These results suggested an important antioxidant effect of Salvia officinalis L., which can reduce oxidative stress and delay the onset of diabetes complications.