Applied Biological Research 26(1): 26-32; (2024) DOI: 10.48165/abr.2024.26.01.3 SULPHUR DIOXIDE INDUCED OXIDATIVE AND HISTOPATHOLOGICAL DAMAGE TO THE OVARIES OF FEMALE RATS (Rattus rattus) Prerna Sood* and Neena Singla Department of Zoology, College of Basic Sciences and Humanities, Punjab Agricultural University, Ludhiana - 140 000, Punjab (India) *e-mail: prernasood@pau.edu (Received 19 August, 2023; accepted 11 December, 2023) ABSTRACT The aim of the study was to examine the toxic effect of sulphur dioxide on the ovaries of female rats. The effect of different concentrations of SO2 (0, 5, 10 and 15 ppm) on antioxidant enzymes and histopathological changes were investigated in ovaries of female rats under natural and experimental conditions. Naturally exposed, house rats, Rattus rattus (Group I) were collected from agricultural fields alongside the road in Ludhiana, India and acclimatized for 1 month in laboratory. Laboratory-bred house rats were divided into four groups. Group II (control rats), III, IV and V were first exposed to the filtered air in 1 m 3 exposure chamber for 5 h day -1 for 28 days and then treated with 0, 5, 10 and 15 ppm of SO2, respectively. SO2 treatment showed significant increase in lipid peroxidation (LPO) levels, followed by significant decrease in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione-S-transferase (GST) and GSH-PX in ovaries of female rats. The results revealed that SO2 can cause oxidative damage to the ovaries of female rats. The increase in LPO and decrease in other enzymes was more prominent at higher SO2 concentration as compared to the other tested concentrations. Keywords: Body weight, histopathology, oxidative damage, ovaries, rats, sulphur dioxide INTRODUCTION One of the largest problems in the majority of developing countries is the air pollution, mainly caused by industrial activity and the usage of fossil fuels. The air pollutants include particulate particles, sulphur dioxide (SO2) and nitrous oxide (NO2) (Ghorani et al., 2016). SO2 pollution is more prominent in the areas surrounding coal-fired power plants, smelters and sulfuric acid industries as well as in densely populated areas. The respiratory tract may easily hydrate the inhaled SO2 to form sulphuric acid, which then dissociates to form derivatives (bisulfite and sulfite) and enter into human body through blood (Shapiro, 1977). Substantial SO2 exposures cause toxic symptoms such as thickening of mucous membrane lining the respiratory system, pneumonia, nasopharyngitis, fatiguability, gastritis and modifications in taste and smell. Numerous studies have reported the toxic effect of SO2 on nervous system and reproductive system of mammals (Meng et al., 2002a.b, Meng 2003). Very little information is available on how air pollutants including SO2, NO2 and particulate matters affect both male and female reproductive systems (Hansen et al., 2010). Inhaled pollutants or particles reportedly interfere in female reproductive system through the mechanisms of inducing oxidative stress in gonads, and by interrupting the maturation of germ cells by changing the expression of gene regulating differentiation or apoptosis in mice germ cells (Zhang et al., 2016; Wei et al.,