Effects of Crude Oil contaminated Water on the reproductive system of Female Wistar Rats

Abstract

The rising level of infertility in the females have been associated with environmental pollutants and one such pollutants is crude oil. Crude oil pollution occurs in the Niger-Delta region of Nigeria and interaction with this toxicant by both humans and animals may adversely the female reproductive system. This study was designed to investigate the effect of crude oil contaminated water on reproductive functions in female Wistar rats. Fifteen (15) female rats weighing between 140g-230g were used for this study and the rats were divided into three (3) groups (1, 2 and 3) and each group had five rats. Group 1 was the control group while group 2 and 3 were the test groups receiving 2.5mls and 5mls of crude oil contaminated water twice daily for four weeks. The stages of Oestrus cycle of the rats were checked daily. The rats were sacrificed after four weeks and the blood collected were used for hormonal assays (Follicle stimulating hormone (FSH), Luteinizing hormone (LH), Testosterone). The uterus and ovaries were used for histology (Haematoxylin and Eosin staining), Superoxide dismutase (SOD) activity and Malondialdehyde (MDA) concentration. The results were analyzed using GraphPad Prism software for windows and data were expressed as mean±standard error of mean. Statistical significance was accepted at p<0.05.

There was no significant changes (p>0.05) in the weights and relative reproductive organ weights (uterus and ovary) of among the three groups. FSH and LH in the test group of rats fed with crude oil contaminated water when compared with the control were not statistically significant (p<0.05). Oestradiol was significantly lower (p<0.05) in the test group whereas progesterone and progesterone-oestradiol ratio was significantly elevated (p<0.05) in the test groups when compared with the control. There were degenerative changes in the ovaries and uterus of rats fed with crude oil contaminated water when compared with the control. SOD was significantly reduced (p<0.05) in the test group while MDA was elevated in the ovaries and uterus of the test group. The oestrus cycle was irregular in the test groups.  

Crude oil contaminated water has endocrine disrupting effects on the female reproductive system as well as inducing oxidative stress and this may adversely affect female reproductive functions and fertility.

KEY WORDS: Crude oil contaminated water, Endocrine disruptor, Female reproductive functions, Oxidative stress

DOI: 10.7176/JMPB/72-05

Publication date: June 30^th 2022