Opuntia humifusa stems lower blood glucose and cholesterol levels in streptozotocin-induced diabetic rats

The Opuntia humifusa stem (OHSt) contains high levels of antioxidants including vitamin C, flavonoids, and polyphenols that may prove beneficial in treating diabetes mellitus. The objective of this study was to examine the hypothesis that intake of the OHSt regulates blood glucose levels and hypolipidemic responses in rats with diabetes mellitus induced by injection of streptozotocin. Forty Sprague-Dawley rats (6 weeks of age) were assigned to 5 groups: normal control, rats with streptozotocin-induced diabetes mellitus (DM), DM treated with OHSt 150 mg/kg per day, DM treated with OHSt 250 mg/kg per day, and DM treated with OHSt 500 mg/kg per day. Powdered OHSt was suspended in distilled water and administered orally through the sonde once daily. After 7 weeks of treatment, the fasting blood glucose and triglyceride levels of the OHSt groups were significantly lower when compared with the DM group (P < .05). Treatment with the OHSt also resulted in a significant decrease in serum total cholesterol and low-density lipoprotein cholesterol (P < .05). Decreases in both total cholesterol and low-density lipoprotein cholesterol were accompanied by a significant increase in serum high-density lipoprotein cholesterol (P < .05). Furthermore, levels of alanine aminotransferase and aspartate aminotransferase were significantly lower in the OHSt groups than in the DM group (P < .05). In addition, a significant increase in relative beta cell volume of pancreas was observed in rats treated with 500 mg/kg of OHSt when compared with the untreated DM rats (P < .05). The overall results suggest that the OHSt possesses potential hypoglycemic and hypolipidemic activity in streptozotocin-induced diabetic rats. (C) 2011 Elsevier Inc. All rights reserved.