Effects of Rauwolfia serpentina L. Benth. ex Kurz (Serpentina) and Costus igneus Nak. (Insulin plant) leaves crude extracts on the blood glucose levels of alloxan induced albino rats

Abstract

The prevalence of treatment failures from dietary patterns and oral medications associated with diabetes have generated adverse effects and are oftentimes expensive. Recently, food-based therapies such as Rauwolfia serpentina (serpentina) and Costus igneus (insulin plant) have been received much attention due to the urge for an alternative and safe solution against diabetes. Thus, the hypoglycemic effects of serpentina and insulin plant leaf crude extracts were determined on the blood glucose level of test rats. Twenty-four alloxan-induced male albino rats were subjected to this experimental study distributed into six groups in a completely randomized design. The negative control (NEG) comprised of diabetic rats receiving no treatment; while the positive control (MET) comprised of diabetic rats treated with metformin; experimental groups include IN1X and IN2X for the diabetic rats treated with extracts of insulin plant leaves administered once and twice daily and SER1X and SER2X for the diabetic rats treated with extracts of serpentina leaves administered once and twice daily. Results of the study revealed that both serpentina and insulin plant leaves crude extract demonstrated hypoglycemic effects due to the presence of zinc that potentiated insulin action. Further, the insulin plant improved glucose and insulin levels due to quercetin which reduced oxidative stress and protects DNA damage, β-amyrin and β-L-arabinose methyl glucoside which builds-up insulin for glucose metabolism. The presence of significant phytochemical contents in the insulin plant has been attributed to the stimulation of β cells. In conclusion, insulin plant leaf crude extract elucidated better hypoglycemic activity than the serpentina plant leaf crude extract in the blood glucose levels of alloxan-induced diabetic rats.