Melatonin and Vitamin C modulate cassava diet-induced alteration in reproductive and thyroid functions

Abstract

Background: Cyanide, present in cassava, causes adverse effects on the thyroid and male reproductive functions and its poisoning generates free radical and oxidative stress. Melatonin and Vitamin C are antioxidants that improve conditions associated with oxidative stress. Aims and objectives: We evaluated the effects of melatonin and/ or Vitamin C on body weight, thyroid functions, and reproductive parameters in cyanide-enriched cassava-fortified diet (CD)-treated rats and their possible mechanisms of actions. Materials and Methods: Thirty male rats were divided into six groups (n = 5 each): Group I – Control, Group II – Melatonin, Group III – Vitamin C, Group IV – CD, Group V – CD + Melatonin, and Group VI – CD + Melatonin + Vitamin C. The control received normal saline, while melatonin and Vitamin C groups were dosed orally at 15 mg/kg melatonin and 100 mg/kg Vitamin C, respectively, CD group was fed with 40% cassava-fortified diet only, while other groups received the combination of the treatments. Results: In CD-treated rats, the sperm parameters were not affected but sperm count was insignificantly increased by melatonin, while melatonin + Vitamin C significantly increased all semen parameters. Neither CD only nor co-administration with melatonin and/or Vitamin C affected plasma luteinizing hormone and testosterone. The CD increased triiodothyronine (T3), but the increase was abolished by melatonin. Moreover, the CD increased thyroxine (T4), which was neither affected by melatonin alone nor its combination with Vitamin C. The levels of thyroid-stimulating hormone were not different across all treatment groups. The CD increased the thiocyanate, which was ameliorated by melatonin but abolished by combination of melatonin and Vitamin C. The CD also decreased the total antioxidant capacity level, which was abolished by melatonin. The CD increased weight gain, thyroid hormone, and oxidative stress but had no effect on semen parameters and reproductive hormones. Conclusion: Melatonin and Vitamin C attenuate the effects of CD on weight, thyroid hormones, and oxidative stress.