Possible mechanisms in Ficus exasperata ethanol root fraction amelioration of lead-induced corpus cavernosal contractile impairments in male Wistar rats

Background:Lead exposure is reported to cause impaired male reproductive tract functions often due to elevated oxidative species. F. exasperata leaf extract contains potent phyto-antioxidants with beneficial endothelial functions. Objectives: This study investigates the effect of ethanolic extract of F. exasperata (EEFE) treatment on the corpus cavernosal contractile activity in lead-exposed adult male Wistar rats. Materials & Methods: Corpus cavernosum strips (CS) were excised from control, EEFE only treated (400 mg/kg), lead + EEFE treated and lead only treated (100 mg/kg) male Wistar rats. Cumulative contractile responses of CS to acetylcholine, potassium chloride, and calcium influx were determined. Furthermore, cumulative dose responses to acetylcholine after incubation in L- NAME, indomethacin, nifedipine, and acetovanillone were also determined by measuring isometric contractions using Ugo Basile data capsule acquisition system. Results: Relaxation(%) response to cumulative doses of acetylcholine (10-9–10-5 M) was enhanced in EEFE only treated (59%) compared to lead only (45%). Contractile response to KCl (10-60 M) was restrained in control and EEFE co- treated when compared to lead only treated. Preincubation of the CS with nifedipine (10-4 M) suppressed the relaxation(%) in the lead + EEFE co-treated. Preincubation of the CS in indomethacin improved the relaxant response(%) of the CS in EEFE only and lead + EEFE co-treated (53.53% ±2.80 & 54.65%± 2.95 respectively) compared with the lead only treated (45.40%±1.79). Preincubation with L-NAME significantly reduced relaxation response(%) in EEFE only treated group. Relaxation response(%) of the CS was enhanced in the lead + EEFE group after preincubation with acetovanillone. Conclusion: The study suggests that L-type and voltage-gated calcium channels, NO, and potent antioxidant activity, are important in EEFE amelioration of lead-induced contractile impairments.