Reproductive effects of prepubertal exposure to 35 % carbamide peroxide in female Wistar rats

Abstract

Carbamide peroxide is a tooth-whitening agent present in home-based products or carefully applied by dental health professionals. It has been shown to cause several adverse reactions however, its effects on the development of reproductive organs and functions have not been fully elucidated. This study was designed to investigate prepubertal exposure of 35 % carbamide peroxide on ovary and uterine development in female Wistar rats. Twenty (20) rats were randomly divided into 4 groups ( n = 5/group) as follow; group 1 served as control, groups 2, 3 and 4 received 100, 250 and 500 mg/kg of 35 % carbamide peroxide respectively. Treatments were orally administered for 21 days. Body, ovary and uterus weights were determined using weighing scale. Anti-Mullerian hormone (AMH), Follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol and progesterone were determined using ELISA method. Malondialdehyde (MDA) level was assessed using spectrophotometry procedure. Estrous cycle was monitored using microscopic examination of vaginal smear. Histological assessment of the ovary and uterus were done using hematoxylin-eosin stain. Data were analyzed using ANOVA, expressed as Mean ± S.E.M., at p < 0.05. Results showed significant decrease in ovary and uterus weights and estradiol in 500 mg/kg carbamide peroxide group compared to control. Malondialdehyde, AMH, LH, FSH, progesterone, decreased significantly in 100, 250 and 500 mg/kg carbamide peroxide compared to control. There was significant decrease in frequencies of proestrous, estrous and diestrous phases in 100, 250 and 500 mg/kg carbamide peroxide compared to their pre-exposure values. The ovary showed decrease in primordial follicles while the uterus showed uterine perforations in 100, 250 and 500 mg/kg compared to control. Oral administration of carbamide peroxide decreases ovary and uterus weights, luteinizing hormones, follicle stimulating hormone, estradiol, primordial follicles, proestrous, estrous and diestrous phases of estrous cycle. These indicate that 35 % carbamide peroxide induce toxicity and decrease the potentials of the reproductive organs for fertilization. • Prepubertal exposure to 35% carbamide peroxide significantly decreased ovary and uterus weights, primordial follicles, and induced uterine perforations in female Wistar rats, indicating toxicity. • Carbamide peroxide reduced levels of reproductive hormones, including AMH, FSH, LH, estradiol, and progesterone, alongside increased malondialdehyde (MDA), highlighting oxidative stress and disrupted hormonal regulation. • Significant reductions in all phases of the estrous cycle (proestrous, estrous, metestrous, and diestrous) were observed, suggesting impaired fertility potential and reproductive dysfunction.