ORIGINAL PAPER The potential benefits of a garlic and hydrochlorothiazide combination as antihypertensive and cardioprotective in rats Syed Mohammed Basheeruddin Asdaq • Mohammed Naseeruddin Inamdar Received: 7 April 2010 / Accepted: 2 August 2010 / Published online: 7 September 2010 Ó The Japanese Society of Pharmacognosy and Springer 2010 Abstract The purpose of the present study was to investigate the protective effects of combined therapy of garlic homogenate and hydrochlorothiazide (HCTZ) in animals with hypertension and myocardial damage. Three weeks of high fructose (10% w/v) in fluid to albino rats resulted in hypertension. They were subsequently admin- istered garlic (125, 250 and 500 mg/kg, 3 weeks in sepa- rate groups) and HCTZ (10 mg/kg, 6th week) once daily in their respective groups. At the end of 6 weeks, myocardial damage was induced by subcutaneous administration of isoproterenol (175 mg/kg) for 2 consecutive days. The results showed that garlic and HCTZ increase the lactate dehydrogenase, creatinine phosphokinase, superoxide dis- mutase and catalase activities in heart homogenate when used concurrently or separately. Further, restoration of normal values in fluid/food intake, body weight, systolic blood pressure, cholesterol, triglycerides, glucose and his- topathological scores were observed in all treated groups. Furthermore, histological disturbances and hypertension were significantly ameliorated in treated animals. More- over, moderate dose of garlic was more effective than low dose, while a high dose of garlic was least effective in correcting electrocardiographic changes. Thus it is con- cluded that garlic in moderate dose (250 mg/kg) with added HCTZ possesses synergistic cardioprotective and antihypertensive properties against fructose- and isoprote- renol-induced toxicities. Keywords Hydrochlorothiazide Á Fructose Á Garlic Á Interaction Á Isoproterenol Introduction Hydrochlorothiazide (HCTZ) is a potent diuretic of low toxicity and is widely used in combination with cardio- vascular drugs for the treatment of hypertension. HCTZ causes increased elimination of water, which lowers blood volume and reduces blood pressure. It affect renal tubular mechanisms of electrolyte reabsorption, directly increasing excretion of sodium and chloride in approximately equiv- alent amounts [1, 2]. In patients with cardiac ischemia, heart failure or left ventricular hypertrophy, even mild-to- moderate hypokalemia increases the likelihood of cardiac arrhythmias [3–5]. Indeed, it has been proved that HCTZ produces undesirable metabolic consequences that have been suspected of contributing to increased cardiovascular morbidity and mortality. Hence the search for concurrently administered safe therapeutic medicaments that can ame- liorate hypokalemia in patients with ischemic heart dis- eases continues. Our earlier study demonstrated the prevention of HCTZ- induced hypokalaemia in animals upon simultaneous administration of moderate doses of garlic [6]. We also reported recently the advantages of adding HCTZ to pro- longed garlic therapy in ischemia reperfusion-induced myocardial damage using isolated rat heart [7]. However, the effect of combined garlic and HCTZ therapy in hypertensive cases with myocardial dysfunction is still not scientifically proven. Thus the current study was designed S. M. B. Asdaq (&) Department of Pharmacology, Krupanidhi College of Pharmacy, Varthur Hobli, Chikkabellandur Village, Carmalaram Post, Bangalore 560 035, India e-mail: basheer_1@rediffmail.com; sasdaq@gmail.com M. N. Inamdar Department of Pharmacology, Al-Ameen College of Pharmacy, Bangalore 560 027, India 123 J Nat Med (2011) 65:81–88 DOI 10.1007/s11418-010-0467-9