University of Cape Coast, Ghana
Objective: The study investigated hypoglycaemic effect of Abrus precatorius leaf extract (APLE) and its possible mechanisms of action by using in vivo and in vitro models.
Results: At the end of 28 days post STZ/NIC treatment, cumulatively APLE (100, 200 and 400 mg/kg respectively) significantly (P < 0.05) decreased the initial FBG by 55.22, 76.15 and 77.77 % respectively) compared to model (-1.04 %) and metformin (72.29 %) groups. APLE increased median cross-sectional area (x106 μm2) of pancreatic islets compared to that of model group. APLE produced dose-dependent decrease in immune cell infiltration relative to model group. Generally APLE (400 mg/kg; 5.21 ± 0.02 AscAE μg/mL) produced significant (P < 0.05) plasma ascorbic acid equivalent (AscAE μg/mL) TAC compared to model (4.06 ± 0.04 AscAE μg/mL) and metformin (4.87 ± 0.03 AscAE μg/mL) groups. APLE produced concentration-dependent inhibitory activity against α-glucosidase activity at an IC50 of 33.89 ± 0.06 μg/mL comparable to that of acarbose standard at an IC50 37.10 ± 0.45 μg/mL. APLE produced concentration-dependent DPPH scavenging activity though lower in potency compared to ascorbic acid.
Conclusion: APLE produced hypoglycemic effect in STZ/NIC-induced hyperglycemic rats possibly mediated through inhibition of α-glucosidase activity; increased free radical scavenging and antioxidant activities as well as amelioration of pancreatic islet atrophy.