Impact of co-administration of red palm oil (Elaeis guineensis Arecaceae) and rooibos (Aspalathus linearis Fabaceae) on glycaemic parameters, liver function and key glycolytic enzymes in diabetic rats

Abstract

Purpose: To investigate the anti-diabetic effects of red palm oil (RPO), rooibos tea extract (RTE) and their combination (RPO + RTE). Methods: Diabetes was induced by a single administration of streptozotocin (50 mg/kg) and the rats were treated for 49 days. The effects of these plant products on plasma glucose, serum insulin, serum fructosamine, glycosylated haemoglobin (HbIAC), liver enzymes in serum and liver glycolytic enzymes were studied using standard techniques. Results: The combined treatment of RPO and RTE significantly (p < 0.05) decreased the glucose (20.98 ± 6.46 mmol/L to 15.60 ± 5.94 mmol/L), HbIAC (16.74 ± 2.73 % to 12.41 ± 2.25 %), fructosamine (98.61 ± 23.35 mmol/L to 62.52 ± 28.41 mmol/L) levels and increased insulin (0.30 ± 0.09 ng/mL to 0.72 ± 0.21 ng/mL) levels in the diabetic rats. Similarly, the combined treatment significantly (p < 0.05) reduced alanine aminotransferase (ALT) in the serum of diabetic rats. RPO + RTE significantly (p < 0.05) increased the activity of pyruvate kinase in the liver when compared with the diabetic control group. Conclusion: Combined treatment with red palm oil and rooibos shows promising beneficial effects in diabetic conditions of rats. Further studies on the mechanism of actions of the plant products are required.