EVALUATION OF CARDIOPROTECTIVE EFFECTS OF CAMELLIA SINENSIS ON ISOPROTERENOL INDUCED MYOCARDIAL INFARCTION

Background: Black tea is rich in polyphenols which are antioxidants. The most abundant polyphenolic compounds are flavonols and catechins. Black tea antioxidants showed protective actions against chronic diseases like cardiovascular diseases due to their antioxidant action.

Objective: The present study was conducted to evaluate the cardioprotective effects of Camellia sinensis on isoproterenol induced myocardial infarction in Wistar albino rats. Myocardial infarction (MI) is a condition in which a part of the heart muscle suddenly loses its blood supply, so the myocardium gets destructed and becomes ischemic. Camellia sinensis is a species of plant from which leaves and leaf buds are taken to produce tea. Myocardial infarction was induced by subcutaneous administration of Isoproterenol. Isoproterenol shows positive inotropic and chronotropic effects on heart. Oxidative products of drug cause cytotoxicity and myocardial damage.

Methods: Wistar albino rats were divided into 8 groups, each group containing 8 rats. The following treatment was given for 21 days. Group 1: NS 1mg/kg (orally). Group 2: NS+ISO (85 mg/kg, s.c.). Group 3: BTE 1 (4mg/kg, orally) +ISO. Group 4: BTE2 (8mg/kg) +ISO. Group 5: BTE3 (12mg/kg) +ISO. Group 6: BTE3 per se. Group 7: STD (10mg/kg) +ISO. Group 8: BTE3+STD+ISO. On 20th and 21st day, ISO (85mg/kg) was given. After 24 hrs of last treatment, blood was collected, soon after animals were sacrificed and heart tissues were collected for biochemical and histopathological evaluations.

Result: Administration of BTE reduced the levels of GSH, TBARs, SOD, Catalase, LDH and SGOT. Standard drug treatment alone and in combination with BTE3 protected the heart by reduction in the infarct size.

Conclusion: Isoproterenol induced myocardial infarction in rat heart, which was significantly prevented by Camellia sinensis and carvedilol treatment alone and in combination.
INTRODUCTION: Myocardial infarction (MI) is a condition in which a part of the heart muscle suddenly loses its blood supply, so the myocardium gets destructed and becomes ischemic ^{12, 23, 30}. The most common cause of MI is the formation of blood clot (thrombosis)