Antidiabetic and antioxidant activities of methanol extract of Syzygium operculatum(Roxb.)Niedz.bark

Objective:To evaluate the antidiabetic and antioxidant effects of the methanol extract of Syzygium operculatum bark(MSOB)using in vivo and in vitro models.Methods:Antidiabetic activity was assessed by using alloxan induced(120 mg/kg body weight)diabetic mice.The plant extract(200 mg/kg and 400 mg/kg body weight)was administrated i.p.to diabetic mice in comparison with standard metformin hydrochloride(150 mg/kg body weight).The antioxidant activity of the extract was evaluated by using a range of in vitro assays and results were compared to standards.Results:The extract MSOB 200 mg/kg and 400 mg/kg reduced the blood glucose level 44.05%and 55.53%respectively where the standard drug metformin reduced 69.42%in dose of 150 mg/kg body weight.The extract MSOB showed significant 1,1-diphenyl-2-picrylhydrazyl scavenging activity,total phenol content,total flavonoid content and reducing power capacity compared to standards.The IC_(50)values were found 300.34μg/mL in 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay where 40.31μg/mL for ascorbic acid.The total phenol and flavonoid contents were 197.5 and 267.5 mg of gallic acid equivalent per gram,respectively.Conclusions:The present study indicates that the extract of Syzygium operculatum bark is the potential sources of natural antioxidant and possesses significant antidiabetic activities.