Silymarin and N-acetylcysteine reduce acetaminophen-induced liver damage in rats by modulating the expression of CYP۲E۱ and Nrf۲ genes

While silymarin and N-acetylcysteine have well-established individual protective properties against acetaminophen (APAP)-induced liver injury, their synergistic effects on key genes, such as CYP۲E۱ and Nrf۲, have not been thoroughly investigated in a combined prophylactic and early post-exposure regimen. In a rat model of APAP-induced acute liver injury, this study examined the hepatoprotective effects of silymarin and NAC, both alone and in combination, with a focus on controlling CYP۲E۱ and Nrf۲ mRNA expression. Thirty male Wistar rats were divided into five groups: the APAP-only group, the APAP+silymarin group, the APAP+NAC group, and the APAP+silymarin+NAC group. Hepatic damage was caused by a single peritoneal administration of ۷۵۰ mg/kg of APAP. Rats were given NAC (۳۰۰ mg/kg) or silymarin (۱۰۰ mg/kg) orally two hours before and four hours after the APAP injection. The activity of antioxidant enzymes (SOD, CAT, and GPx), the levels of ALT, AST, and ALP in the serum, the amounts of MDA and GSH in the liver, and the mRNA levels of Nrf۲ and CYP۲E۱ were all measured using qPCR. Liver slices were examined under a microscope using HandE staining. Statistical comparisons were carried out using one-way ANOVA, followed by Tukey’s post-hoc test. When APAP was administered, blood liver enzymes, MDA levels, and histological necrosis increased significantly, while GSH and antioxidant enzyme activity decreased significantly (p<۰.۰۰۱). The most notable improvements came from the combination of silymarin and NAC treatment: the fastest return to normalcy of liver enzymes, the largest decrease in MDA levels, the strongest recovery of GSH levels, the most obvious downregulation of CYP۲E۱, and the most obvious upregulation of Nrf۲ (all p<۰.۰۰۱ compared to either drug alone). Little protection was provided by monotherapy. Histological necrosis scores were highest in the APAP-only group (۳.۵ ± ۰.۵) and lowest in the combined group (۰.۷۵ ± ۰.۲۵). This suggests a marked decrease in both cellular apoptosis and inflammation. In conclusion, compared to using either agent alone, concurrent administration of silymarin and NAC in a preventive and early post-exposure protocol offers superior hepatoprotection primarily through the beneficial modulation of CYP۲E۱ and Nrf۲ expression. According to these findings, this combination might be used as an additional treatment in preclinical models of acute liver injury caused by APAP.

کلیدواژه ها:

Acetaminophen ، N-acetylcysteine ، Silymarin ، Oxidative stress ، hepatotoxicity ، CYP۲E۱ ، Nrf۲