Hypoglycemic effects of MDG-1, a polysaccharide derived from Ophiopogon japonicas, in the ob/ob mouse model of type 2 diabetes mellitus

Abstract

Ophiopogon japonicus is a traditional Chinese medicine used to treat diabetes mellitus. We investigate the anti-ischemic properties of a water-soluble β-d-fructan (MDG-1) from O. japonicus, and assess the antidiabetic effects of MDG-1. In the study, ob/ob mice were treated with 150mg/kg or 300mg/kg MDG-1 by gavage for 23d. Blood glucose levels were measured regularly. An oral glucose tolerance test (OGTT) was preformed on day 21. The levels of insulin, total cholesterol and triglyceride in the serum were measured at the end of administration. The liver triglyceride content and tissue weights were also determined. Results show that MDG-1 (300mg/kg) was demonstrated to exert acute and long-term hypoglycemic effects on fed blood glucose in ob/ob mice. However, only a marginal hypoglycemic effect on fasting blood glucose levels was observed. MDG-1 (300mg/kg) improved oral glucose tolerance and reduced serum insulin levels and triglyceride content in the liver in ob/ob mice. Furthermore, a reduction in body weight gain and the weight of subcutaneous fat were observed following treatment with MDG-1 (150mg/kg) compared with the control group. MDG-1 had no significant effects on the total cholesterol and triglyceride levels, food intake and other adipose and organ tissues. These data suggest that MDG-1 exhibits hypoglycemic activity and reduces insulin resistance.