Abstract
Pien Tze Huang Gan Bao (PZH‑GB), a traditional Chinese medicine, has been used for thousands of years as a protective remedy effective against liver injury induced by excessive alcohol and smoking. The present study aimed to evaluate the protective effects and potential mechanisms of PZH‑GB against carbon tetrachloride (CCl4)‑induced hepatic injury. Rats were pre‑treated with silymarin (50 mg/kg) or different doses of PZH‑GB (150, 300 or 600 mg/kg) orally administered for 7 days. At the end of treatment, the rats were intraperitoneally injected with CCl4, or control rats received a corn oil injection. The lactate dehydrogenase (LDH) levels in serum were evaluated. Apoptosis was assessed via terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. p53, B‑cell lymphoma 2 (Bcl‑2), B cell‑lymphoma 2‑associated X protein (Bax), cyclooxygenase‑2 (COX‑2), inducible nitric oxide synthase (iNOS) and cytochrome P450 family 2 subfamily E member 1 (CYP2E1) were measured by reverse transcription‑quantitative polymerase chain reaction and western blotting. The activity of caspase‑9 and caspase‑3 were measured by a colorimetric assay. The results indicated that silymarin and PZH‑GB prevented CCl4‑induced serum LDH elevations, and CCl4 induced high levels of LDH. Compared with the CCl4 group, silymarin and PZH‑GB treatment significantly decreased LDH levels. Histopathological results revealed that silymarin and PZH‑GB ameliorated the CCl4‑induced liver histological alterations. The TUNEL results showed that compared with the control group, CCl4 induced liver cell apoptosis, while silymarin and PZH‑GB treatment inhibited apoptosis and the TUNEL‑positive cells. The elevated expression of Bax, p53, iNOS, COX‑2 and CYP2E1 were reduced by silymarin or PZH‑GB pretreatment, whereas reduced Bcl‑2 expression levels were increased. CCl4 increased the activity of caspase‑9 and ‑3 by 6.86‑ and 7.42‑fold, respectively; however, silymarin and PZH‑GB ameliorated this effect. In conclusion, silymarin and PZH‑GB treatment prevented the deleterious effects on liver functions by attenuation of oxidative stress, inflammation and mitochondrial apoptosis via the p53 signaling pathway.