An experimental study on wistar rats to see the effect of Gymnema sylvestre on blood pressure

Abstract

Background: Hypertension is a leading cause of morbidity and mortality globally. It is a well-known risk factor for an array of adverse cardiovascular outcomes. Obesity is considered as one of the major contributing factors to essential hypertension in humans. Obesity in itself is a risk factor for conditions like insulin resistance, hypertension, stroke, ischemic heart diseases, CHF etc. Undoubtedly in recent times we have achieved great advances in terms of management of hypertension but still we have miles to cover to have dominance over it. Gymnema sylvestre is a valuable indigenous herb. A number of animal and human studies have shown the potential role of Gymnema sylvestre (GS) as an anti-diabetic and anti-obesity agent. Methods: Adult Female Wistar rats, weighing between 150-200 gm, were included in the study. They were randomly divided into five groups with six rats in each group. High Fat Diet (HFD) was given for 4 weeks to induce hypertension in all the groups except group I which was fed with normal chow. Drugs along with respective diets were given to the rats for next 4 weeks by oral feeding cannula. Systolic blood pressure was measured by NIBP controller machine. Results: On feeding rats with HFD for 4 weeks the mean systolic blood pressure increased significantly. After giving drugs GS (100mg/kg), GS (200mg/kg) and Amlodipine (10mg/kg) to groups III, IV, V respectively for next 4 weeks, mean systolic blood pressure fell significantly (p <0.05) as compared to group II (HFD control group). At final evaluation at week 8 (as compared to Group 2) SBP got maximally reduced in Group 5 (35.1%) followed by Group 4 (26.4%), Group 3 (20.1%). On comparing Amlodipine standard (group 5) with other groups, a significant difference was found. This showed that Gymnema sylvestre reduced the elevated systolic blood pressure significantly but this anti-hypertensive effect was inferior to Amlodipine. Conclusions: The present study concludes that Gymnema sylvestre has a potent dose- dependent antihypertensive action but the effect is inferior to Amlodipine. Hence it can be used as an add-on to standard drugs for hypertension.