Antidiabetic Potential of Stem Bark Extract of Enantia chlorantha and Lack of Modulation of Its Therapeutic Efficacy in Diabetic Rats Co-Administered with Lisinopril.

This study validates the antidiabetic efficacy of Enantia chlorantha stem bark and the possible therapeutic implications of the co-administration of lisinopril and E. chlorantha in type 2 diabetic rats. E. chlorantha stem bark was extracted by cold maceration. The inhibitory effect of the plant on carbohydrate metabolizing enzymes and its antioxidative potentials were assessed in vitro. The extract exhibited α-amylase and α-glucosidase inhibitory activities and also showed antioxidative properties in vitro. Administration of the extract normalized fasting hyperglycemia in vivo by showing 47.24 % reduction in blood glucose levels relative to untreated diabetic rats. Co-administration of E. chlorantha and lisinopril restored serum glucose and serum lipid profile levels. E. chlorantha stem bark displayed antidiabetic potentials as compared with a standard antidiabetic drug (metformin). The study also showed that the plant contained some bioactive compounds which we hypothesize might be responsible for the observed activities. Co-administration of the plant with lisinopril conferred no significant therapeutic advantage on the serum glucose level and lipid profile.

KINETICS OF MODULATORY ROLE OF Cyperus esculentus L. ON THE SPECIFIC ACTIVITY OF KEY CARBOHYDRATE METABOLIZING ENZYMES.

BACKGROUND: The continuous search for new lead compounds as viable inhibitors of specific enzymes linked to carbohydrate metabolism has intensified. Cyperus esculentus L. is one of the therapeutically implicated botanicals against several degenerative diseases including diabetes mellitus. MATERIALS AND METHODS: This study evaluated the antioxidant and mechanism(s) of inhibitory potential of aqueous extract of C. esculentus on α-amylase and α-glucosidase in vitro. The extract was investigated for its radical scavenging and hypoglycaemic potentials using standard experimental procedures. Lineweaver-Burke plot was used to predict the manner in which the enzymes were inhibited. RESULTS: The data obtained revealed that the extract moderately and potently inhibited the specific activities of α-amylase and α-glucosidase, respectively. The inhibition was concentration-related with respective IC50 values of 5.19 and 0.78 mg/mL relative to that of the control (3.72 and 3.55 mg/mL). The extract also significantly scavenged free radicals and the effects elicited could be ascribed to its phytoconstituents. CONCLUSION: The respective competitive and non-competitive mode of action of the extract is due to its inhibitory potentials on the activities of α-amylase and α-glucosidase. Going forward, in addition to completely characterize the exact compound(s) responsible for the elicited activity in this study, pertinent attention will be given to the in vivo evaluation of the identified constituents.