CARDIOPROTECTIVE EFFECT OF FLAVONOIDS RICH FRACTION OF Premna mucronata ON ISOPROTERENOL–INDUCED MYOCARDIAL INFARCTION IN WISTAR RATS 

ABSTRACT

Premna mucronata Roxb. is a herbal medicine that has been traditionally used as a natural remedy for myocardial infarction (MI) in india and a previous study revealed that Premna mucronata was proven to be cardioprotective in MI. Moreover, very little is known about the molecular mechanisms underlying cardioprotective activities of Premna mucronata. Flavonoid fraction is considered as the major active components in Premna mucronata. An endeavor has been made to evaluate the cardioprotective effect of flavonoids rich fraction of Premna mucronata (FPM) on isoproterenol-induced myocardial infarction in rats. FPM was isolated from Premna mucronata. It was identified by various chemical tests and detected by HPTLC. FPM at three dose level, viz 170 µg/kg, 300 µg/kg, 500 µg/kg were selected by dose fixation study and administered once a day p.o. for 28 days in Male Wistar Albino rats (200 ± 30 gm). Nebivolol (5 mg/kg) were used as standard drugs. On the 27^th day MI was induced in rats by administration of the first dose of ISO (85 mg/kg, S.C) followed by second dose of ISO after 24 hours. At the end of experiment i.e 12 hour after second dose of ISO alteration of ECG pattern and hemodynamic changes measured. Both serum and heart was collected and used for the estimation of various biochemical parameters like CK-MB, LDH, α-HBDH, assay of Na⁺/K⁺ATPase, Ca⁺⁺ATPase, Mg⁺⁺ATPase, Estimation of Na⁺, K⁺ and Ca⁺⁺, MDA content, GSH, SOD and Catalase activity. Our result recommend that pretreatment with FPM decreased cardiac marker enzyme level, restoration of antioxidant status and maintained ECG pattern and hemodynamic changes at near normal values. Pretreatment with FPM propound the cardioprotective effect against ISO induced myocardial injury in rat as evidenced by comparing with normal control rats. These salubrious effect observed in the attempts might be due to antioxidant activity.

Key words: Isoproterenol, Myocardial Infarction, Premna mucronata, Flavonoids rich fraction.