Antihyperglycemic activity of the bark methanolic extract of Syzygium mundagam in diabetic rats

The present study was designed to investigate the free radical defence and antihyperglycemic property of S. mundagam. Petroleum ether, ethyl acetate, methanol and hot water extracts of bark were determined for the total phenolic, tannin, flavonoid content and antioxidant property using DPPH, ABTS+, phosphomolybdenum, FRAP, superoxide, nitric oxide and metal chelating assays. The antioxidant response was best observed in ABTS+ (109686.87 μM TE/g extract), phosphomolybdenum (268.54 g AAE/100 g extract) and superoxide radical scavenging assays (84.30%). Bark methanol extract was found highly efficient in scavenging the free radicals than other extracts. The higher phenolic content (54.44 g GAE/100 extract) could be attributed to this effect. The glucose homeostasis was observed till 180th min in glucose loaded rats treated with the bark methanol extract. The extract could also induce potent hypoglycaemia in STZ induced diabetic rats. The antioxidant defence system could be one of the prime mechanisms of S. mundagam leaf and bark extracts that needs to be studied further for the exact molecular action leading to antidiabetic effect.