Novel Use of Silymarin as Delayed Therapy for Acetaminophen-Induced Acute Hepatic Injury

Aim: Recently, we have demonstrated that silymarin has a comparable pharmaceutical activity as Phyllanthus urinaria extract when used to rescue mice from acetaminophen-induced acute liver injury. In the present study, we further compared the therapeutic action of silymarin with N-acetyl cysteine (commonly used in clinical practice for emergency treatments) as a rescuer in mice after administering a lethal dose of acetaminophen for 24 h. Methods: Acute liver injury was induced in the treatment groups by intraperitoneally administered acetaminophen at a dose of 550 mg/kg body weight on day 1. The control group received an equal volume of physiological saline intraperitoneally. From day 2 to 4, the treatment groups received various doses of silymarin or N-acetyl cysteine orally once daily, while the control group and the acetaminophen group received an equal volume of water orally. The mortality rate was recorded in all groups. On day 5, all mice were sacrificed for examination. Results: Silymarin greatly improved the counteracting effects on mortality rate as compared to N-acetyl cysteine. Conclusion: Silymarin should be further considered as an antidote for patients with acetaminophen-induced acute hepatic injury and delayed treatment.