Hepatoprotective Property of Oral Silymarin is Comparable to N-Acetyl Cysteine in Acetaminophen Poisoning

Background: N-Acetyl Cysteine (NAC) is usually used as antidote for prevention of acetaminophen-induced hepatotoxicity. In present study we have evaluated efficacy of oral silymarin in its prevention in rats intoxicated with lethal dose of acetaminophen. Methods: A total of 50 Male Sprague-Dawley rats were randomly divided into five groups. The first group received only vehicle of acetaminophen and served as control. The second group was given 800 mg/kg acetaminophen by gavage with an orogastric canula. The third, fourth and fifth groups were given 300 mg/kg NAC and 150 and 300 mg/kg silymarin respectively. Analysis of serum AST, ALT, and ALP and liver histopathology were employed for assessment of hepatotoxicity. Results: Mean serum ALT levels were significantly increased in the APAP group rats. The mean serum ALT levels returned to normal in both NAC treated and silymarin treated groups. Silymarin (150 mg/kg) had prevented hepatocytes necrosis similar to NAC. No severe hepatotoxicity were seen in groups 3 and 4; while it is seen in 70% of animals in group 2. Conclusions: We found that a single dose of orally administered silymarin (150 mg/kg) significantly attenuated acetaminopheninduced liver damage in rat. Oral silymarin can be used in these patients instead of NAC.