The influence of stress on female fertility is multifaceted with intricate mechanisms that are not fully elucidated. Nonetheless, it is certain that free radicals play a role.
This study was therefore aimed at investigating the effects of vitamin C supplement and stress on the ovarian functions in Wistar rats.
Twenty female Wistar rats with regular estrus cycle of 4 to 5 days were divided into four groups (n=5). Group A (Control); 10ml/kg BW/day distilled water, group B (VitC); 10mg/kg BW/day vitamin C, group C (Stress); exposed to varying stress models alongside 10ml/kg distilled water, group D (stress/vitC); exposed to varying stress alongside 10ml/kg BW/day vitamin C, Animals were exposed to dark cycles stress models; overnight saturated beddings and strange objects. Light cycles: Multiple cage changes, immobilty and noise. The animals were exposed to varying stress every other day for 3 weeks. Vagina secretion was taken from each rat between 8 and 9am for daily monitoring of estrus cycle. After 3 weeks, each rat was placed in diethylether fume chamber, blood samples were taken from the heart after cervical dislocation. Blood samples were centrifuged to assay estradiol, progesterone, follicle stimulating hormone (FSH), luitenizing hormone (LH) and cortisol using enzyme linked immunosorbent assay (ELISA) (AccuBind, USA). The activities of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) were assayed in the ovaries with randox kit (Sigma Chemicals Ltd, USA). Histology of the ovaries were done. Procedures were done at estrus phase. Graphed pad prism 8.0 was used to analyze data, ANOVA was used to compare the means, Newman keuls was posthoctest and P values ≤ was considered significant.
Results showed a significant decrease (P<0.05) in the number of complete estrus cycle in stress (3.0±0.05 days) compared with vitC (4.87±0.03 days) and control (4.9±0.21 days). Stress (5.80±0.66 days), (3.40±0.40 days) significantly reduced (P<0.05) diestrus and estrus compared with VitC (8.40±0.40 days), (5.00±0.48 days) and control (6.40±0.51 days), (5.20±0.37 days). Occurrence of metestrus was significantly increased (P<0.05) in stress (8.00±0.63 days) compared with VitC (3.80±0.37 days) and control (4.80±0.37 days). Progesterone and estradiol were significantly higher (P<0.05) in Vitamin C (15.8±1.19 ng/dl), (22.24±1.31 ng/dl) than stress (11.58±0.80 ng/dl), (19.38±1.16 ng/dl) and control (13.70±0.66 ng/ml), (20.13±0.74 ng/dl). Progesterone was also higher (P<0.05) in stress/vitC (13.21±0.70 ng/dl) than in stress (11.58±0.80 ng/dl). Cortisol was significantly higher (P<0.05) in Stress (1.14±0.12 µg/dl) than stress/vitC (0.78±0.09 µg/dl), vitC (0.32±0.07 µg/dl) and control (0.34±0.24µg/dl). Serum MDA was higher (P<0.01) in stress (2.30±0.14 mol/ml) than in stress/vitC (1.64±0.25 mol/ml), vitC (1.0±0.24 mol/ml) and control (1.46±0.20 mol/ml). Activities of SOD and CAT were lower (P<0.05) in stress (4.38±0.27 mg/dl), (3.08±0.48 mg/dl) compared with stress/vitC (5.10±0.42 mg/dl), (3.70±0.25 mg/dl), vitC (7.36±0.43 mg/dl), (5.14±0.68 mg/dl) and control (6.48±0.40 mg/dl), (4.2±0.27 mg/dl). Histology of the ovary showed reduced follicular development with degenerating corpus luteum in stress group compared with control and VitC
In conclusion, despite the disruption of the estrus cycle and ovarian follicle distortion induced by stress, the supplementation of vitamin C facilitated follicular development and regulated the cycle.