HPLC analysis and antidiabetic effect of Rheum ribes root in type 2 diabetic patients

Background and objective: Rheum ribes (polygonaceae) roots are used traditionally to treat diabetes, hypertension, obesity, ulcer, diarrhea, anthelmintic and expectorant. The purpose of this study was to investigate clinically the antidiabetic activity of Rheum ribes in type 2 diabetes mellitus patients and phytochemical study for the correlation of antidiabetic activity with the active constituents in the plant.   Methods: The antidiabetic activity of Rheumribes given alone and in combination with standard oral hypoglycemic agents was investigated in type 2 diabetes mellitus. The study was conducted on 120 patientswith type 2 diabetes mellitus for a period of 12 weeks. Preliminary phytochemical screening was carried out followed by high performance liquid chromatography analysis for the identification of flavonoid constituents in the root of Rheumribes. Results: Rheumribes root showed significant blood glucose reduction (P <0.01) on 12th weeks of the observation period with 39.63% percent blood glucose reduction. The combination treatment of Rheumribes root and glibenclamide showed a significant difference (P <0.05) with the treatment group of glibenclamide and metforminwith maximum percent of reduction in blood glucose level of 48.91%.The results of preliminary phytochemical screening showed the presence of alkaloids, tannins, flavonoids, anthraquinones, and quinones. Quercetin was identified by high performance liquid chromatography. The proposed high performance liquid chromatography method was validated for linearity, accuracy, precision and limit of quantitation.   Conclusion: Rheum ribes root was found to reduce significantly blood glucose levels in type 2 diabetes mellitus patients.Quercetin was identified by high performance liquid chromatography as an important flavonoid constituent.