Polyphenolic constituents in mulberry leaf extract (M. latifolia L. cv. BC259) and its antidiabetic effect in streptozotocin induced diabetic rats.

Mulberry (M. alba L.) has prominent use in traditional Chinese medicine since ancient times but its therapeutic properties have not been sufficiently explored in India. Present study was designed to isolate and identify the polyphenolic constituents present in mulberry leaf (M. latifolia) using HPLC and to evaluate its antihyperglycemic and antihyperlipedemic properties in streptozotocin (STZ) induced diabetic wistar rat models. HPLC analysis identified chlorogenic acid (103mg/100gm), caffeic acid (4.3mg/100gm), coumaric acid (11.61mg/kg), rutin (53mg/100gm) and quercetin (46.19mg/100gm) as the major constituents of crude polyphenolic extracts in M. latifolia. STZ induced diabetic rats administered with mulberry leaf extract at doses 250 and 500mg/kg after 4 weeks of treatment significantly improved their glycemic control (p<0.001). Body weight increased significantly (p<0.001) after administration of BC259 extract at a dose of 500mg/kg. Results also showed that there was a significant decrease in serum urea (p<0.001) and creatinine level (p<0.01). Significant decline was observed in the levels of serum triglycerides (p<0.01), total cholesterol (p<0.001), LDL-cholesterol (p<0.01) and VLDL-cholesterol (p<0.01), while the serum HDL-cholesterol (p<0.01) significantly increased. Results revealed that the leaf extract of M. latifolia (var.BC259) causes significant antidiabetic and antihypercholesterolemic activity. Evidence of identified bioactive polyphenolic compounds present in M. latifolia leaf extract strengthens its antidiabetic property.