Hypoglycemic and antioxidant effects of Daraesoon (Actinidia arguta shoot) in animal models of diabetes mellitus

BACKGROUND/OBJECTIVES: The primary objective of the treatment of diabetes mellitus is the attainment of glycemic control. Hyperglycemia increases oxidative stress which contributes to the progression of diabetic complications. Thus, the purpose of this study was to investigate the hypoglycemic and antioxidant effects of Daraesoon (Actinidia arguta shoot) in animal models of diabetes mellitus. MATERIALS/METHODS: Rats with streptozotocin-induced diabetes received an oral administration of a starch solution (1 g/kg) either with or without a 70% ethanol extract of Daraesoon (400 mg/kg) or acarbose (40 mg/kg) after an overnight fast and their postprandial blood glucose levels were measured. Five-week-old C57BL/6J mice were fed either a basal or high-fat/high-sucrose (HFHS) diet with or without Daraesoon extract (0.4%) or acarbose (0.04%) for 12 weeks after 1 week of adaptation to determine the effects of the chronic consumption of Daraesoon on fasting hyperglycemia and antioxidant status. RESULTS: Compared to the control group, rats that received Daraesoon extract (400 mg/kg) or acarbose (40 mg/kg) exhibited a significant reduction in the area under the postprandial glucose response curve after the oral ingestion of starch. Additionally, the long-term consumption of Daraesoon extract or acarbose significantly decreased serum glucose and insulin levels as well as small intestinal maltase activity in HFHS-fed mice. Furthermore, the consumption of Daraesoon extract significantly reduced thiobarbituric acid reactive substances and increased glutathione levels in the livers of HFHS-fed mice compared to HFHS-fed mice that did not ingest Daraesoon. CONCLUSIONS: Daraesoon effectively suppressed postprandial hyperglycemia via the inhibition of alpha-glucosidase in STZ-induced diabetic rats. Chronic consumption of Daraesoon alleviated fasting hyperglycemia and oxidative stress in mice fed a HFHS diet.

Chamnamul Pimpinella brachycarpa (Kom.) Nakai ameliorates hyperglycemia and improves antioxidant status in mice fed a high-fat, high-sucrose diet

Chronic consumption of a high-fat, high-sucrose (HFHS) diet increases insulin resistance and results in type 2 diabetes mellitus in C57BL/6J mice. Hyperglycemia in diabetics increases oxidative stress, which is associated with a high risk of diabetic complications. The purpose of this study was to examine the hypoglycemic and antioxidant effects of chamnamul [Pimpinella brachycarpa (Kom.) Nakai] in an animal model of type 2 diabetes. The alpha-glucosidase inhibitory activity of a 70% ethanol extract of chamnamul was measured in vitro. Five-week-old male C57BL/6J mice were fed a basal or HFHS diet with or without a 70% ethanol extract of chamnamul at a 0.5% level of the diet for 12 weeks after 1 week of adaptation. After sacrifice, serum glucose, insulin, adiponectin, and lipid profiles, and lipid peroxidation of the liver were determined. Homeostasis model assessment for insulin resistance (HOMA-IR) was determined. Chamnamul extract inhibited alpha-glucosidase by 26.7%, which was 78.3% the strength of inhibition by acarbose at a concentration of 0.5 mg/mL. Serum glucose, insulin, and cholesterol levels, as well as HOMA-IR values, were significantly lower in the chamnamul group than in the HFHS group. Chamnamul extract significantly decreased the level of thiobarbituric acid reactive substances and increased the activities of superoxide dismutase, catalase, and glutathione peroxidase in the liver compared with the HFHS group. These findings suggest that chamnamul may be useful in prevention of hyperglycemia and reduction of oxidative stress in mice fed a HFHS diet.