Abstract Thymoquinone (TQ), the main constituent of the volatile oil derived from Nigella sativa has shown pharmacological benefits against various diseases while nicotine is an active component in cigarette that is known to be detrimental. This study was conducted to assess the ameliorating effects of TQ on sperm count, membrane, mitochondria and testosterone of nicotine-treated rats.

Rats were randomized into four groups:

control, nicotine, TQ, and nicotine with TQ. Nicotine (5 mg/kg bwt/day) was subcutaneously injected for 30 days to induce damaging effects on sperm and testosterone level. Rats were force-fed with TQ (5 mg/kg bwt/day) for the following 30 days. Sperm count was reduced in the nicotine group (26.72 ± 1.64 106/mL) but showed a significantly higher number in the nicotine+TQ group (30.97 ± 0.88 106/mL; p<0.05). Results of sperm membrane integrity test and number of MitoTracker positive sperm also showed a significantly lower percentage in the nicotine group (47.34 ± 0.69 % and 75.68 ± 0.90 %, respectively) but a notable improvement in the nicotine+TQ group (52.58 ± 1.14 % and 79.08 ± 0.74 %, respectively). Testosterone concentration showed elevation in the nicotine+TQ group (7.61 ± 0.51 ng/mL) compared to the nicotine group (5.71 ± 0.15 ng/mL). TQ demonstrated ameliorative potential against the detrimental effects of nicotine towards sperm count, membrane, mitochondria and testosterone level.