Antidiabetic and antioxidant activity of Rhizophora mucronata leaves (Indian sundarban mangrove): An in vitro and in vivo study

BACKGROUND: Rhizophora mucronata is a salt-tolerant true mangrove which is widely distributed in Indian mangrove forest and traditionally used to treat diabetes and other health ailments. AIM: The aim of this study is to elucidate the role of Indian variety of R. mucronata leaves on glucose impairing metabolism during diabetes by in vitro and in vivo methods. MATERIALS AND METHODS: The ethanolic fraction of R. mucronata leaves extract (RHE) was assessed for DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging and in vitro anti-diabetic action through α-amylase and α-glucosidase activity assessment. Oral glucose tolerance test (OGTT) and insulin sensitivity test (IST) were assessed and their counteraction with RHE (100 and 200 mg/kg, p.o) and glibenclamide (10 mg/kg, p.o) in streptozotocin (STZ) (50 mg/kg, intravenous) induced hyperglycemic rats were also monitored for 28 days. The data were analyzed statistically using t-test. RESULTS: RHE dose-dependently inhibited α-amylase and α-glucosidase enzymes and lowered the area under the curve (AUC) for glucose on both OGTT and IST. RHE also significantly (p < 0.01) controlled glycemic index and thereby reducing diabetic complications as assessed by lipid profiles, atherogenic index, and coronary index in STZ rats. CONCLUSION: RHE at doses of 100 and 200 mg/kg/day for 28 days provided a significant decrease in diabetes complications and metabolic impairment.