Effects of Zinc supplementation on male reproductive function in night shift work model of chronic sleep deprivation

Abstract

Modernization and industrialization have changed human lifestyle with night shift work (NSW) becoming necessary part of regular  working hours. NSW is invariably associated with sleep deprivation (SD). Coincidentally, there is remarkable decline in fertility rates in  these modern societies, which is believed to be due to lifestyle modifications. NSW model of SD, was therefore created to study its effects on male reproductive functions and role of concomitant Zinc supplementation on those effects. Twenty four (24) male Wistar rats (aged  12- 14 weeks) were equally divided into three groups; Control, NSW and NSWZ models. NSW and NSWZ models were subjected to SD for  12 hours (07:00am – 07:00pm) using Modified Multiple Platform Method (MMPM) every day for the 56 days of the study. Each rat received  either distilled water (1ml/animal/day) for Control and NSW models, or Zinc sulphates (5mg/animal/day) for NSWZ model, by  gavage daily respectively. Testicular tissue Malondialdehyde (MDA) and Total Antioxidant Capacity (TAC), male reproductive hormones  (FSH, LH, Testosterone and Estradiol) and Sperm parameters (sperm count, morphology and motility) were evaluated and statistically  compared. Sleep deprivation in NSW model resulted in significant (p<0.05) increase in testicular tissue MDA, serum FSH and significant  (p<0.05) decrease in TAC, serum Testosterone, serum Estradiol, sperm count and percentage of sperm with active progressive motility  (APM) compared to the control. Concomitant Zinc supplementation significantly (p<0.05) increases testicular tissue TAC, serum Estradiol  and significantly (p<0.05) decreases testicular tissue MDA and serum FSH. The NSW model of Sleep deprivation negatively affects male  reproductive functions, while concomitant Zinc supplementation ameliorates some of these negative effects.