921 JPP 2004, 56: 921–926 ß 2004 The Authors Received January 15, 2004 Accepted April 08, 2004 DOI 10.1211/0022357023745 ISSN 0022-3573 Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600 025, India R. Jayalakshmi, S. Niranjali Devaraj Correspondence: S. Niranjali Devaraj, Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600 025, India. E-Mail: niranjali@yahoo.com Cardioprotective effect of tincture of Crataegus on isoproterenol-induced myocardial infarction in rats R. Jayalakshmi and S. Niranjali Devaraj Abstract Tincture of Crataegus (TCR), an alcoholic extract of the berries of hawthorn (Crataegus oxycantha), is used in herbal and homeopathic medicine. The present study was done to investigate the protective effect of TCR on experimentally induced myocardial infarction in rats. Pretreatment of TCR, at a dose of 0.5mL/100g bodyweight per day, orally for 30 days, prevented the increase in lipid peroxidation and activity of marker enzymes observed in isoproterenol-induced rats (85 mgkg --1 s.c. for 2 days at an interval of 24h). TCR prevented the isoproterenol-induced decrease in antioxidant enzymes in the heart and increased the rate of ADP-stimulated oxygen uptake and respiratory coupling ratio. TCR protected against pathological changes induced by isoproterenol in rat heart. The results show that pretreatment with TCR may be useful in preventing the damage induced by isoproterenol in rat heart. Introduction Myocardial infarction is the number one cause of death worldwide. It occurs when a coronary artery is severely blocked such that there is a significant reduction in the blood supply, causing damage or death to a portion of the myocardium. Depending on the extent of the heart muscle damage, the patient may experience significant disability or die as a result of myocardial infarction. Isoproterenol (isopropyl norepinephrine) is a potent non-selective -adrenergic agon- ist with very low affinity for -adrenergic receptors. Isoproterenol-induced myocardial infarction in rats has been shown to be accompanied by hyperlipidaemia, increased activity of serum creatine kinase, alanine amino transferase, aspartate amino transferase and lactate dehydrogenase (LDH) (Young et al 1993). Damage to the myocardium could be owing to the induction of free-radical-mediated lipid peroxidation by isoproterenol. The increased level of lipid peroxides is a causative factor in the irreversible damage in isoproterenol-induced myocardial infarction (Golikov et al 1989). Oxidative stress is implicated in the aetiopathogenesis of a variety of human diseases, including cardiovascular diseases (Frei 1994). The antioxidant status has a major influence on the development of coronary artery diseases. Higher plasma con- centrations of the antioxidant vitamins, ascorbic acid and -tocopherol, are correlated to a lower incidence of coronary artery disease (Riemersma et al 1991). Phytopharmaceuticals are gaining importance in allopathic as well as traditional medicine owing to their non-addictive and non-toxic nature. Many of these medicines are a complex mixture of similar or different chemical substances. Tincture of Crataegus (TCR), an alcoholic extract of the berries of hawthorn, Crataegus oxycantha L. Rosaceae, is used in herbal medicine as a heart tonic (Shanthi etal 1994). TCR has a number of pharmacological properties, possibly owing to its major constituents: flavonoids, triterpene saponins and some cardioprotective amines (Willard 1991). Recent epidemiological studies have found an association between dietary flavonoid intake and reduced risk of heart disease, myocardial infarction and stroke (Hertlog et al 1995). The primary cardioprotective activity of this plant is generally attributed to its flavonoid and oligomeric proanthocyanidines (Miller 1998). In the present study, the activity of marker enzymes, levels of antioxidants (enzymic and non-enzymic), Downloaded from https://academic.oup.com/jpp/article/56/7/921/6147319 by guest on 27 January 2022