In vitro hypoglycemic effects of molokhia leaves (Corchorus olitorius L.)

Abstract

Background: Corchorus olitorius L., commonly known as molokhia in Arabic, is a leafy vegetable containing large amounts of mucilaginous polysaccharides and reported to exhibit antidiabetic diabetic activity in experimental diabetes. Although antidiabetic effect of molokhia is attributed to the presence of phenolic and non-phenolic compounds, the precise mechanism of action is not explored. Materials and Methods: The present study investigated the ability of molokhia leaves powder (MLP) to modulate starch digestion and glucose diffusion in vitro. Results: MLP at 2% and 4% levels bound significantly higher amount of glucose than wheat bran (2%) and also reduced diffusion of glucose through dialysis membrane as reflected by significantly higher glucose dialysis retardation index. In starch–α-amylase system, MLP (4%) showed complete inhibition of starch digestion and glucose diffusion similar to that of acarbose till 120 min. Further, glucose diffusion was retarded to an extent of 83.7% and 63.5% by MLP (4%) at 180 and 240 min, respectively. On the other hand, MLP (2%) retarded glucose diffusion to an extent of 96%, 65%, and 51% at 120, 180, and 240 min respectively. Furthermore, molokhia leaf extract significantly enhanced uptake of glucose by rat hemidiaphragm in vitro. Conclusion: These findings conclusively demonstrate that the antidiabetic effect of molokhia leaves is mediated through delaying starch digestion and physical adsorption of liberated glucose limiting its diffusion across intestinal lumen and enhancing glucose uptake in peripheral tissues.