Cardioprotective activity of alcoholic extract of Tinospora cordifolia (Willd.) Miers in calcium chloride-induced cardiac arrhythmia in rats

Abstract

The present study investigated the antiarrhythmic activity of alcoholic extract of Tinospora cordifolia (T. cordifolia) in CaCl2 induced arrhythmia. CaCl2 (25 mg/kg) was administered by intravenous infusion (iv) to produce arrhythmia in rats. The animals were then treated with T. cordifolia extract (150, 250, and 450 mg/kg) and verapamil (5 mg/kg,iv). Lead II electrocardiogram was monitored. Plasma calcium, sodium and potassium levels were measured. In CaCl2 induced arrhythmia, heart rate was decreased by 41.10%, T. cordifolia at 150, 300, and 450 mg/kg decreased the heart rate by 26.30%, 29.16%, and 38.29%, respectively, and verapamil reduced the heart rate by 9.70% compared to the normal group. The PQRST waves were normalized and atrial and ventricular fibrillation was controlled in rats treated with verapamil and T. cordifolia. CaCl2 increased calcium and sodium levels and decreased potassium levels in blood. T. cordifolia dose-dependently decreased calcium and sodium levels and increased potassium levels. Hence, T. cordifolia can be used in antiarrhythmic clinical settings and beneficial in atrial and ventricular fibrillation and flutter and may be indicated in ventricular tachyarrhythmia.

Keywords: Tinospora cordifolia; arrhythmia; cardioprotection..

Fig. 1. Representative electrocardiogram of Group II (10% CaCl₂) at different time intervals.

The ECGs were detected in Group II [Arrhythmia control group 1, 10% CaCl₂ (50 mg/kg) (n = 6)]. with Dose 10% of CaCl₂ (at different time intervals after intravenous administration). Arrhythmia, cardiodepression and mortality were observed at 20 min after 10% of CaCl₂ administration. A: Normal reading (Control); B: Dose 10% of CaCl₂ (at 0 min after administration) induced arrhythmic, C: Dose 10% of CaCl₂ (at 5 min after administration) induced arrhythmic; D: Dose 10% of CaCl₂ (at 10 min after administration) induced arrhythmic; E: Dose 10% of CaCl₂ (at 15 min after administration) induced complete cardiodepression; F: Dose 10% of CaCl₂ (at 20 min after administration) caused complete cardiodepression and mortality.

Fig. 2. Representative electrocardiogram of different groups (Group I to Group VIII, n = 6)

A: Normal reading (Control); B: Group III: Arrhythmia control [5% CaCl₂ (25 mg/kg)]; C: Group IV CaCl₂ (5%)-induced arrhythmia+alcohol (95%, 0.5ml, iv); D: Group V: CaCl₂ (5%)-induced arrhythmia+verapamil (5 mg/kg, iv); E: Group VI CaCl₂ (5%)-induced arrhythmia+Tinospora cordifolia dried ethanolic extract dissolved in saline.(150 mg/kg, iv); F: Group VII CaCl₂ (5%)-induced arrhythmia+Tinospora cordifolia extract dissolved in saline (250 mg/kg, iv); G: Group VIII CaCl₂ (5%)-induced arrhythmia+Tinospora cordifolia dried ethanolic extract dissolved in saline (450 mg/kg, iv) (n = 6)

Fig. 3. Comparison between the effects of Tinospora cordifolia extract and Verapamil on heart rate.

*P < 0.05 for statistically significant vs control (Group I). (n = 6). Group I: Control; Group II: 10%CaCl₂; Group III: 5%CaCl₂; GroupIV: Alcohol 95%+5% CaCl₂; Group V: Standard: CaCl₂ (5%)+verapamil (5 mg/kg, iv); GroupVI: CaCl₂(5%) + Tinospora cordifolia (150 mg/kg, iv); GroupVII: CaCl₂(5%)+Tinospora cordifolia (250 mg/kg, iv); GroupVIII: CaCl₂(5%)+Tinospora cordifolia (450 mg/kg, iv)