Acetaminophen, also known as N-acetyl-p-aminophenol (APAP), is commonly used as an antipyretic and analgesic agent. APAP overdose can induce hepatic toxicity, known as acetaminophen-induced liver injury (AILI). However, therapeutic doses of APAP can also induce AILI in patients with excessive alcohol intake or who are fasting. Hence, there is a need to understand the potential pathological mechanisms underlying AILI. In this review, we summarize three main mechanisms involved in the pathogenesis of AILI: hepatocyte necrosis, sterile inflammation, and hepatocyte regeneration. The relevant factors are elucidated and discussed. For instance, N-acetyl-p-benzoquinone imine (NAPQI) protein adducts trigger mitochondrial oxidative/nitrosative stress during hepatocyte necrosis, danger-associated molecular patterns (DAMPs) are released to elicit sterile inflammation, and certain growth factors contribute to liver regeneration. Finally, we describe the current potential treatment options for AILI patients and promising novel strategies available to researchers and pharmacists. This review provides a clearer understanding of AILI-related mechanisms to guide drug screening and selection for the clinical treatment of AILI patients in the future.
Acetaminophen/toxicity* ; Analgesics, Non-Narcotic/toxicity* ; Animals ; Chemical and Drug Induced Liver Injury/pathology* ; Chemical and Drug Induced Liver Injury, Chronic/pathology* ; Humans ; Inflammation/metabolism* ; Liver/pathology* ; Mice ; Mice, Inbred C57BL ; Necrosis/pathology*

Excess acetaminophen(APAP) can be converted by the cytochrome P450 system to the toxic metabolite N-acetyl-p-benzoquinoneimine(NAPQI), which consumes glutathione(GSH). When GSH is depleted, NAPQI covalently binds with proteins, inducing mitochondrial dysfunction and oxidative stress and thereby leading to hepatotoxicity. Schisandrin C(SinC) is a dibenzocyclooctadiene derivative isolated from Schisandra chinensis. Although there is some evidence showing that SinC has hepatoprotective activity, its protective effect and mechanism on APAP-induced liver injury remain unclear. In this paper, an acute liver injury mouse model was established by intraperitoneal injection of APAP at a dose of 400 mg·kg~(-1) to evaluate the effect of SinC administration on the APAP-induced liver injury and its mechanism through an animal experiment. At the same time, a potential candidate drug was provi-ded for traditional Chinese medicine(TCM) prevention and treatment of overdose APAP-induced liver injury. In the APAP-induced liver injury mouse model, we found that SinC can relieve hepatic histopathological lesions and significantly reduce the activities of alanine aminotransferase(ALT), aspartate aminotransferase(AST) and alkaline phosphatase(ALP). It was also capable of increasing the content of GSH and superoxide dismutase(SOD) and decreasing the levels of total bilirubin(TBIL), direct bilirubin(DBIL), malondialdehyde(MDA), interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α). Further analysis showed that SinC decreased the content of CYP2 E1 in liver tissues at protein and mRNA levels and increased nuclear factor erythroid 2-related factor 2(Nrf2) and the expression of its downstream targets(including HO-1, NQO1 and GCLC). Taken together, the above results indicate that SinC can alleviate APAP-induced liver injury by reducing the expression of CYP2 E1, suppressing apoptosis, improving inflammatory response and activating the Nrf2 signaling pathway to inhibit oxidative stress.
Mice ; Animals ; Acetaminophen/toxicity* ; NF-E2-Related Factor 2/metabolism* ; Chemical and Drug Induced Liver Injury/pathology* ; Chemical and Drug Induced Liver Injury, Chronic/pathology* ; Liver ; Signal Transduction ; Oxidative Stress ; Bilirubin/metabolism*

OBJECTIVETo analyze the development of liver damage and reactivation of hepatitis B virus (HBV) during the treatment of extremely severe burn injury in HBsAg positive patients, in order to provide reference for prevention and treatment of liver damage in patients with HBV infection after extremely severe burn.

METHODSMedical records of 54 HBsAg positive patients after extremely severe burn injury admitted from January 2004 to December 2014 were retrospectively analyzed. Development of liver damage and HBV reactivation of these patients during the treatment were analyzed according to the classification of their gender, results of hepatitis B e antigen (HBeAg) and HBV DNA examinations on admission, and development of sepsis in the process of treatment. Data were processed with chi-square test.

RESULTS(1) The incidence of liver damage in the process of treatment of these patients was 85.2% (46/54). Among all the patients, the proportion of liver damage was 35/38 in male, which was significantly higher than that in female (11/16, χ² = 4.867, P<0.05). Liver damage was found in all of 26 patients who were HBeAg positive on admission, 34 patients who were HBV DNA positive on admission, and 36 patients who developed sepsis in the process of treatment; the proportions were significantly higher than those in patients who were HBeAg negative on admission (20/28), patients who were HBV DNA negative on admission (12/20), and patients who did not develop sepsis in the process of treatment (10/18), with χ² values respectively 11.801, 18.384, and 20.574, P values below 0.01. (2) The incidence of HBV reactivation in these patients was 29.6% (16/54). Among all the patients, the proportion of HBV reactivation was 13/38 in male and 3/16 in female, with no statistically significant difference between them (χ² = 0.656, P>0.05). The proportions of HBV reactivation in patients who were HBeAg positive on admission, patients who were HBV DNA positive on admission, and patients who developed sepsis in the process of treatment were respectively 13/26, 16/34, and 15/36, and they were significantly higher than those in patients who were HBeAg negative on admission (3/28), patients who were HBV DNA negative on admission (0/20), and patients who did not develop sepsis in the process of treatment (1/18), with χ² values respectively 9.979, 18.615, and 5.873, P<0.05 or P<0.01.

CONCLUSIONSPatients who are HBsAg positive, HBeAg positive, HBV DNA positive on admission, and develop sepsis in the process of treatment of extremely severe burn injury are more likely to develop liver damage and HBV reactivation. It is necessary to dynamically monitor the changes in HBV DNA and liver function, in order to identity the reactivation of virus.

Alanine Transaminase ; blood ; Burns ; complications ; drug therapy ; Chemical and Drug Induced Liver Injury ; DNA, Viral ; Female ; Hepatitis Antibodies ; blood ; Hepatitis B ; drug therapy ; epidemiology ; virology ; Hepatitis B Surface Antigens ; blood ; immunology ; Hepatitis B virus ; drug effects ; immunology ; isolation & purification ; Hepatitis B, Chronic ; blood ; pathology ; virology ; Humans ; Incidence ; Liver ; pathology ; Male ; Retrospective Studies