Antioxidant effect of Phlomis persica Boiss. in rats with streptozotocin-induced diabetes
A number of Phlomis species (Lamiaceae) are used in folk medicine in Asia, Europe and north Africa as stimulant, tonic, antidiabetic, antipyretic, antiallergic and antiulcer agent [1, 2]. A previous phytochemical study of the aerial parts of Phlomis persica , which is an endemic species in Iran , resulted in the isolation of iridoid, flavonoid and phenylpropanoid glycosides  partially with antioxidant activities . The purpose of this study was to evaluate the antioxidant activity of aerial parts of a P. persica methanolic extract (PPE), in streptozotocin (STZ)-induced diabetic rats. Diabetic male Wistar rats were treated orally by incubation tube with vehicle (water) or extract (100 or 200mg/kg body weight/day) for 10 days. Fasting blood glucose (FBG), total antioxidant capacity using ferric reducing antioxidant power (FRAP) assay, lipid peroxidation using thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalas (CAT), and glutathione peroxidase (GPx) were measured . Statistical analysis was performed with one-way ANOVA followed by Tukey post hoc test for multiple comparisons. P<0.05 was considered significant. PPE at 100 and 200mg/kg significantly reduced the level of FBG in comparison with the diabetic control group. Hepatic total antioxidant capacity increased and TBARS decreased following PPE treatments. In addition, PPE-treated diabetic rats indicated a significant increase in hepatic SOD, CAT and GPx. In conclusion, the results indicate that PPE supplementation is beneficial in controlling the blood glucose level and is effective against the development of complications from lipid peroxidation by antioxidant activity in diabetic rats.
Acknowledgements: The authors are grateful to the PSRC, University of Teharn for the financial support of this work.
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