ABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Hydrolea zeylanica L. Vahl. (Hydroleaceae) is an aquatic medicinal plant used as leafy vegetable in some parts of India. In south Odisha and Hazaribag district of Jharkhand, India, decoction of leaves is used as household remedy for diabetes. To our knowledge, no prior studies have examined the antidiabetic activity of H. zeylanica to validate its ethnomedicinal claim. PURPOSE: With this aim in mind, we examined the bioactivity of hydroalcohol fraction of leaves of H. zeylanica (HAHZ) in streptozotocin-induced oxidative stress in diabetic rats. MATERIALS AND METHODS: In vitro antidiabetic and free radical scavenging activities of different fractions of H. zeylanica were performed. The most effective bioactive fraction e.g. HAHZ was considered for kinetic studies to understand the mode of inhibition of α-glucosidase and α-amylase. To understand the chemical composition, GC-MS/MS and LC-MS/MS analysis of HAHZ were performed. To find out the molecular mechanism of action of HAHZ, streptozotocin-induced oxidative stress and metabolic changes in diabetic rats were studied. RESULTS: HAHZ demonstrated significantly higher radical scavenging and antidiabetic activities. Kinetic analysis revealed that HAHZ inhibited α-glucosidase competitively, and α-amylase mixed competitively. To understand the chemical composition, GC-MS/MS and LC-MS/MS analysis of HAHZ identified 32 compounds and among which R-limonene (0.52%), perillartine (0.41%), N-formyl-L-lysine (1.49%), limonen-6-ol, pivalate (1.43%), lidocaine (1.70%) and gamolenic acid (2.80%) were reported to have antioxidant and antidiabetic activities. HAHZ-400â¯mg/kg showed significant (p < 0.001) improvement in serum markers (SGOT, SGPT, ALP, total bilirubin, total protein, triglycerides, total cholesterol, HDL-C, LDL-C) and oxidative markers (MDA, SOD, CAT, GSH) in serum, liver and pancreas at effective dose dependent manner. In histopathological observation, HAHZ-400â¯mg/kg showed marked improvement in restoring cellular architecture of liver and pancreas. CONCLUSION: In diabetic rats, the improvement in glycemic control mechanism was achieved upon stimulating insulin secretion by R-limonene, perillartine, N-formyl-L-lysine, limonen-6-ol, pivalate, lidocaine and gamolenic acid of HAHZ.
