Abstract
Exercise training is employed as supplementary therapy to patients with heart failure due to its multiple beneficial cardiac effects including physiological remodeling of the heart. However, precautions might be taken for the concomitant high oxidant release. Nigella sativa (NS) has been found to induce cardiac hypertrophy and enhance cardiac function. Combination of NS supplementation and exercise training might induce a safer model of cardiac hypertrophy. Our aim was to study biomarkers associated with cardiac hypertrophy induced by NS supplementation of exercise-trained rats. Forty-five adult male Wistar rats (body weight 150-220 g) were divided equally into three groups: control, exercise-trained (ET) and NS-treated-exercise-trained (NSET) groups. Daily 800 mg/kg NS was administered orally to NSET group for 8 weeks. Rats of the ET and NSET groups were subjected to treadmill running sessions for 2 h/day for 8 weeks. By the end of the experiment, the following were recorded: body, heart and left ventricular weights (BW, HW, LVW), cardiomyocyte diameter, serum growth hormone, insulin growth factor-I (IGF-I), thyroid hormones, catecholamines, total nitrate, ICAM and antioxidant capacity. A homogenous cardiac hypertrophy was evidenced by increased HW/BW, LVW/BW ratios and cardiomyocyte diameter in the two groups of exercise-trained compared with control rats. Rats of ET group had higher growth hormone. Those of NSET group developed higher IGF-I and total antioxidant capacity, as well as lower serum thyroxin level. Simultaneous NS supplementation to an exercise training program preserves and augments exercise-induced physiological cardiac hypertrophy with step-forward adaptive signs of increased IGF-I and reduced thyroxin level, and with an added advantage of elevation of total serum antioxidant capacity. Thus, the novel model of NSET-induced cardiac hypertrophy might be introduced as a new therapeutic strategy for the treatment of heart failure with superior advantages to exercise training alone.