ABSTRACT

Hyperglycemia and its complications represent a major public health problem, and are associated with a high mortality rate. The objective of this study was to evaluate the effect of aqueous extract of Cola anomala nut on hyperglycemia and some associated complications. The effect of the extract on postprandial hyperglycemia was evaluated in normoglycemic rats using the oral glucose tolerance test. Subsequently, the effect of the extract on fasting blood glucose was evaluated in an animal model of hyperglycemia induced by streptozotocin. The extract at both doses (200 and 400 mg/kg.bw (mg/kg. bodyweight)) caused a significant reduction (P= 0.003) of postprandial hyperglycemia with percentages of variations of -4.5% and -14.4% against that of glibenclamide (-30.6%). The extract significantly lowered fasting blood glucose with variations of -68.09% and -65.98% respectively compared to Glibenclamide (-64.7%). There was an increase in superoxide dismutases and catalase activities at the renal level and a decrease in plasma and hepatic malondealdehyde and nitric oxide levels with the extract at different doses. The extract at the dose of 400 mg/kg.BW showed an improvement of the globular filtration as plasma creatinine concentrations were found to be decreased, as well as a hepatoprotective effect through the significant reduction of plasma aspartate amino transferase (AST) and alanine amino transferase (ALT) activities. In conclusion, the aqueous extract of Cola anomala nut has a beneficial effect on the control of hyperglycemia and in the prevention of oxidative stress which is strongly involved in the development of microvascular complications of diabetes.

Keywords: Cola anomala, hyperglycemia, microvascular complications.