Background: Tamoxifen is a commonly used anticancer drug acting as a selective estrogen receptor blocker so, used primarily for prophylaxis of breast cancer in high risk women and the treatment of breast malignancies in both males and females. N-acetylcysteine is a well-known drug with strong antimicrobial, antioxidant, mucolytic anti-inflammatory properties hence; it's used as an effective drug for protection against numerous toxic substances. The current study aimed to evaluate the protective effects of N-acetylcysteine against tamoxifen-induced hepatotoxicity in the adult female albino rats.

Methods: Sixty adult female albino rats were used in the current study. The rats were randomly divided into 4 groups with 15 rats in each group; group 1 received only the standard food and distilled water, group 2 received N-acetylcysteine in a daily dose of 150 mg/kg, group 3 received tamoxifen in a daily dose of 45 mg/kg and group 4 received tamoxifen and N-acetylcysteine daily for 6 successive weeks. At the end of the experiment, blood samples and livers were collected for biochemical and histological evaluation.

Results: Tamoxifen administration resulted in obvious hepatotoxic effects in the form of marked elevation of the serum liver enzymes, disturbance of the antioxidant liver tissue capacity and distortion of the liver architecture with congestion, portal fibrosis and disarrangement and increased apoptosis affecting the hepatocytes. N-acetylcysteine co-treatment ameliorated all the biochemical and histological hepatotoxic effects of tamoxifen.

Conclusion: N-acetylcysteine has effective properties against the hepatotoxic effects induced by tamoxifen so, it is useful to be given to the high risk women.