β-Caryophyllene, a natural sesquiterpene, modulates carbohydrate metabolism in streptozotocin-induced diabetic rats

The study was designed to evaluate the antihyperglycemic effects of β-caryophyllene (BCP), a natural sesquiterpene from spices on streptozotocin (STZ) induced diabetic rats. Diabetes mellitus was induced by a single intraperitoneal injection of STZ (40 mg/kg b.w.) in adult male Wistar rats. Diabetic rats exhibited an increase in glucose and HbA1c with a significant fall in insulin and hemoglobin levels. Aberrations in carbohydrate metabolic enzymes were noticed in liver, kidney and skeletal muscle of diabetic rats. A fall in liver and skeletal muscle glycogen with alterations in glycogen synthase and phosphorylase activities was also observed. Oral administration of BCP in dose dependent manner and glibenclamide (600 μg/kg b.w.), a standard oral hypoglycemic drug to diabetic rats for 45 days significantly decreased glucose with increased plasma insulin levels and ameliorated the altered activities of carbohydrate metabolic enzymes to near normal. The insulinotropic effect of BCP was supported by immunohistochemical studies. BCP at a dose of 200 mg/kg b.w. exerted significant antidiabetic effects than other two doses (100 and 400 mg/kg b.w.). We conclude that administration of BCP has beneficial effects in glucose homeostasis in diabetic rats.