Effect of ethyl acetate fraction of Costus afer on glycaemic control and essential haematological and biochemical indices of streptozotocin-induced diabetic rats

Diabetes mellitus is a common global cause of sudden unpredictable death if undiagnosed and untreated. Costus afer (Costaceae) is a tropical plant with quite a lot of pharmacological properties. This study investigated the prophylactic and antidiabetic properties of ethyl acetate fraction of C. afer in streptozotocin-induced diabetic rats.

Acute toxicity (LD50) test was done using Lorke’s method. Haematological indices were determined using haematology autoanalyser. The biochemical assays were done using standard diagnostic methods.

The lethal dose was 3807.9 mg/kg. There was a significant reduction (P < 0.05) in the fasting blood glucose concentration from week one to week four in the group that was pre-treated and later post-treated with 200 mg/kg body weight (bw) of the ethyl acetate fraction of C. afer leaves compared with the untreated diabetic control. The result of the hematological parameters revealed a significant increase (P < 0.05) in the hemoglobin, packed cell volume (PCV), and platelet count of the group pretreated and treated with 200 mg/kg of the fraction compared with the untreated diabetic control. The result of the biochemical assays revealed a far much better recovery from the disruptions caused by the induction of experimental diabetes as seen in the groups that were initially pretreated with 100 and 200 mg/kg before the induction of diabetes compared with the groups treated with the same dose but without pretreatment.

C. afer might be used for the prevention and management of diabetes mellitus. Its safety is evidenced by its effects on the hematological and biochemical indices.