Protective Effect of Galactomannan Extracted from Iraqi Lycium barbarum L. Fruits against Alloxan-Induced Diabetes in Rats

Lycium barbarum L. (Solanaceae) is widely used in Iraqi Ayurvedic medicine for the treatment of diabetes mellitus. The present investigation was done to evaluate the effects of polysaccharide (galactomannan) from Lycium barbarum L. Fruits (GLBF) on serum blood glucose, serum lipid profile and lipid peroxidation and antioxidant defence system in liver and kidney of alloxan-induced diabetic rats. GLBF was found to be non-toxic at 1000 mg kg^-1, as no deaths or hazardous signs were recorded during treatment or the observation period (24 and 72 h) in either control or treated groups of mice. In GLBF (500 mg kg^-1), the onset was 4 h, the peak effect was 6 h but the effect waned at 24 h. In the chronic study, repeated administration (once a day for 21 days) of the glibenclamide and GLBF caused a significant reduction in the serum glucose level as compared to the diabetic control group. GLBF (500 mg kg^-1) treatment prevented a decrease in the body weight of the diabetic rats. Moreover, the results revealed that GLBF (500 mg kg^-1) treatment for 21 days significantly (p<0.01) reduced the levels of lipid profile, lipid peroxidation, improving kidney and liver functions, enhanced insulin level and increased the levels of enzymatic and non-enzymatic antioxidants. The findings in this study suggest that polysaccharide (galactomannan) from Lycium barbarum L. Fruits (GLBF) possess good pharmacological activities, which might be helpful in controls the blood glucose level, improves body weight, lipid metabolism and prevents diabetic complications associated with lipid peroxidation and also maintains the antioxidant enzymatic and non-enzymatic in experimental diabetic rats. The extract seems promising for the development of a phytomedicine for diabetes mellitus.