Effect of Ethanol Extract of Tetrapleura tetraptera (Schum and Thonn) Taub Leaves on Oral Glucose Tolerance in Normal, Glucose‐induced and Normotensive Female Wistar Rats

Abstract

Traditional Medicine is reported the oldest, widely practiced healthcare system in Africa. This practice has further gained momentum in recent years due to its accessibility, affordability and extensive scientific validation. Leaves of Tetrapleura tetraptera are being used in treatment of diabetes, oxidative stress, hyperlipidemia and managing dysfunctional lipid metabolism (a side effect of the use of sulphonylureas as antidiabetics). However, there has been paucity of information on therapeutic synergy. The present study aimed to evaluate the hypoglycemic effect of Tetrapleura tetraptera ethanol leaf extract on blood glucose levels (BGL) in glucose‐induced hyperglycemic and normotensive rats. Mature female Wistar rats with average weight of 120 g were fasted for 12 h then placed into six groups of five rats each. The following treatment schedules were applied accordingly: no treatment (vehicle); glucose (2 g/kg, control); three groups of glucose‐induced hyperglycemia treated with 100 (TT100GLU), 200 (TT200GLU) and 400 (TT400GLU) mg/kg ethanol extract doses of Tetrapleura tetraptera leaves (EtTT) respectively; and 400 mg/kg extract dose of EtTT (TT400, normotensive). Blood glucose concentration through femoral vein was evaluated at 0, 30, 60, 90, 120 and 150 minutes after oral treatment in all cases. Average fasting blood glucose level in all groups at 0 min was 90± 3.71 mg/dL. All treatment groups showed an elevation in BGL at 30 min with values ranging from 86.20 ± 2.22 in vehicle to 107.4 mg/dL in TT400GLU before a progressive decrease in BGL with increase in time. The decline in BGL of treatment groups was generally not significantly different at p<0.05 from control, however, the extract significantly (p< 0.05) reduced blood glucose in normotensive group (TT400GLU) such that at 150 min, BGL dropped to 59.8 mg/dL and animals were showing symptoms of hypoglycemia. Ethanol extract of T. tetraptera leaves possesses the capacity to lower blood glucose levels thus reducing the tendency for hyperglycemic complications. These results further validate its traditional use and it can be proposed that the leaf extract dose should not be administered singly in fasting conditions as it could lead to hypoglycemia.Support or Funding InformationI am a member of American Society for Pharmacology and Experimental Therapeutics (ASPET) with membership ID 0057705Comparison of fasting blood glucose level of various groups. Data are expressed mean ± SEM for 6 groups of 5 rats each with significant difference tested at p<0.05Figure 1