Effect of Isobutylparaben and Phenylmercuric Acetate on Juvenile Female Rats with Special Reference to Development,
Vishwajit B Darekar1, Basawarajeshwari Indur1
1Department of Post Graduate Studies and Research in Zoology, Sharnbasva University, Kalaburagi, Karnataka, India.
Background/Aims:
Isobutylparaben (IBP) and phenylmercuric acetate (PMA) are extensively applied in pharmaceuticals, cosmetics, and industrial chemicals, and are of concern for developmental toxicity. This study was conducted to compare and assess the subchronic effects of IBP and PMA on growth, neurobehavior, reproduction, and organ integrity in juvenile female rats, and establish no-observed-adverse-effect levels (NOAELs).
Methods:
Juvenile female Sprague-Dawley rats (n=10/group) were given IBP (10, 20, 50 mg/kg/day) or PMA (2, 4, 8 mg/kg/day) by gavage for 70 days. Assays encompassed growth assessment, onset of puberty (vaginal opening), estrous cyclicity (vaginal smears), neurobehavioral examination (open-field activity, sensory reflexes, grip strength, motor activity), haematology, serum biochemistry, thyroid hormones (ELISA), organ weights, and histopathology of reproductive, hepatic, and renal tissues.
Results:
IBP and PMA at high doses significantly inhibited terminal body weight, postponed vaginal opening, disrupted motor function, and affected exploratory behavior. Biochemical indicators revealed hepatic and renal stress and histological findings of hepatocellular hypertrophy and renal tubular degeneration. PMA was somewhat more toxic. NOAELs were 20 mg/kg/day (IBP) and 4 mg/kg/day (PMA).
Conclusion:
Both IBP and PMA caused dose-dependent developmental toxicity, calling for more stringent pediatric exposure evaluations and chemical safety regulations.
