Syzygium cumini ameliorates insulin resistance and β-cell dysfunction via modulation of PPARγ,dyslipidemia,oxidative stress,and TNF-α in type 2 diabetic rats

Syzygium cumini (sc) is well known for its anti-diabetic potential,but the mechanism underlying its amelioration of type 2 diabetes is still elusive. therefore,for the first time,we investigated whether sc aqueous seed extract (100,200,or 400 mg/kg) exerts any beneficial effects on insulin resistance (ir),serum lipid profile,antioxidant status,and/or pancreatic β-cell damage in high-fat diet / streptozotocin-induced (hfd-stz) diabetic rats. wistar albino rats were fed with hfd (55% of calories as fat) during the experiment to induce ir and on the 10th day were injected with stz (40 mg/kg,i.p.) to develop type 2 diabetes. subsequently,after confirmation of hyperglycemia on the 14th day (fasting glucose level > 13.89 mm),diabetic rats were treated with sc for the next 21 days. diabetic rats showed increased serum glucose,insulin,ir,tnf-α,dyslipidemia,and pancreatic thiobarbituric acid-reactive substances with a concomitant decrease in β-cell function and pancreatic superoxide dismutase,catalase,and glutathione peroxidase antioxidant enzyme activities. microscopic examination of their pancreas revealed pathological changes in islets and β-cells. these alterations reverted to near-normal levels after treatment with sc at 400 mg/kg. moreover,hepatic tissue demonstrated increased pparγ and pparα protein expressions. thus,our study demonstrated the beneficial effect of sc seed extract on ir and β-cell dysfunction in hfd-stz-induced type 2 diabetic rats. © the japanese pharmacological society.