ASSOCIATION BETWEEN OXIDATIVE STRESS MARKERS AND REPRODUCTIVE HORMONES IN ADULT MALE WISTAR RATS EXPOSED TO PYRETHROID INSECTICIDES

Introduction: The adverse effects of pesticides as a result of their indiscriminate use have been a concerned issue in many developing countries. Frequently the use of insecticides during the lifetime of human cannot be avoided and it may result in oxidative damage effects. The pyrethroid insecticides are highly toxic which can cause an array of adverse damaging effects including infertility and birth defects in both humans and animals due to generation of free radicals.  

Aim: This study is aimed to investigate the effect(s) of pyrethroid pesticides on oxidative stress biomarkers and reproductive hormones in exposed adult Wistar rats.

Materials and Methods: A total number of healthy thirty one (31) male Wistar rats were randomly selected for this study and divided into two groups. Nineteen (19) were exposed to 1.2% w/v pyrethroid based insecticides while the remaining twelve (12) were grouped as non-exposed/control. The animals in each group were anesthetized and blood sample was collected from the inferior vena cava after 7, 21 and 41 days of exposure. Plasma levels of total antioxidant status (TAS), malondialdehyde (MDA), reduced glutathione (GSH) and hydrogen peroxide (H₂O₂) were determined using standard spectrophotometric techniques. Plasma activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were determined using standard spectrophotometric techniques. ELISA was used to determine levels of reproductive hormones (Luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone (TEST)). Semen fluid analysis was done immediately after the animal was sacrificed appropriately. One way analysis of variance (ANOVA) was used for comparison within the groups. Spearman correlation was used to test the association between variables and P<0.05 was considered significant.

Results: The plasma mean levels of SOD, GPx, CAT, GSH and TAS were significantly decreased while plasma mean levels of MDA and H2O2 were significantly increased from 7 days through 41 days exposure in exposed groups. Similarly, the mean levels of FSH, LH and TEST were significantly decreased from 7 days through 41 days.

Conclusion: Pyrethroid by inhalational route causes oxidative stress on Wistar rats exposed and reduction in antioxidant defenses. Inhaled pyrethroids affect sex hormone levels and motility of semen cells, which might lead to infertility.