Cis-stilbene glucoside in Polygonum multiflorum induces immunological idiosyncratic hepatotoxicity in LPS-treated rats by suppressing PPAR-γ.

The root of Polygonum multiflorum Thunb (PM) has been used in China to treat a variety of diseases, such as constipation, early graying of the hair and hyperlipemia. Recent evidence shows that PM causes idiosyncratic drug-induced liver injury (IDILI) in humans. In this study, we investigated the molecular basis of PM-induced liver injury in a rat model of IDILI based on a non-hepatotoxic dose of LPS. SD rats were orally administered 3 potentially hepatotoxic compounds of PM: cis-stilbene glucoside (cis-SG, 50 mg/kg), trans-SG (50 mg/kg) or emodin (5 mg/kg), followed by injection of LPS (2.8 mg/kg, iv). Serum and liver histology were evaluated 7 h after LPS injection. Among the 3 compounds tested, cis-SG, but not emodin or trans-SG, induced severe liver injury in rats when combined with LPS. The levels of AST and ALT in plasma and inflammatory cytokines in both plasma and liver tissues were markedly elevated. The liver tissues showed increased injury, hepatocyte apoptosis, and macrophage infiltration, and decreased cell proliferation. Microarray analysis revealed a negative correlation between peroxisome proliferator-activated receptor-γ (PPAR-γ) and LPS/cis-SG-induced liver injury. Immunohistochemical staining and RT-PCR results further confirmed that cis-SG significantly inhibited activation of the PPAR-γ pathway in the liver tissues of LPS/cis-SG-treated rats. Pre-treatment with a PPAR-γ agonist pioglitazone (500 g/kg, ig) reversed LPS/cis-SG-induced liver injury, which was associated with inhibiting the nuclear factor kappa B (NF-κB) pathway. These data demonstrate that cis-stilbene glucoside induces immunological idiosyncratic hepatotoxicity through suppressing PPAR-γ in a rat model of IDILI.

[Protective effects of luteolin against acetaminophen-induced damage in L02 liver cells].

This paper was aimed to investigate the protective effects of luteolin (Lut) against acetaminophen（APAP）-induced damage in L02 liver cells. CCK-8 was used to detect the cell activation of L02 cells treated by different Lut. The concentration and time of APAP induced L02 cell damage was screened. The effect of Lut on APAP induced apoptosis of L02 cells was detected by cell morphological observation, CCK-8 assay and flow cytometry. The contents of MDA, GSH and SOD activity in cell supernatant were detected by colorimetric assay. The expression of apoptosis-related genes Bax, Bcl-2 and caspase-3 was detected by RT-PCR. The results showed that Lut in 2.5-40 µmol•L⁻¹ range does not affect the activity of L02 cells; 12 mmol•L⁻¹ APAP incubated with L02 cell 12 h to establish damage model. Compared with the model group, the cell status of Lut group was significantly improved, the cell body was increased, the adherence ability was recovered, and the apoptosis rate was obviously decreased. MDA content decreased significantly (P<0.05, P<0.01), GSH and SOD activity significantly increased (P<0.05, P<0.01), at the same time, it could up-regulate expression of Bcl-2 mRNA and down-regulate the expression of Bax and caspase-3 mRNA. In conclusion,Lut has protective effect on APAP induced L02 cell injury, and its mechanism may be related to the reduction of oxidative stress and inhibition of apoptosis.

[Protective effects of Liuwei Wuling tablet on acute alcoholic-induced liver injury in mice].

The protective action and the relevant mechanism of Liuwei Wuling tablet on acute alcoholic hepatic injury in mice were investigated. All the C57BL/6 mice were divided randomly into 7 groups including blank, model, bifendate (150 mg•kg⁻¹, positive control) and experimental groups consisted of extremely low dose (0.1 g•kg⁻¹), low (0.5 g•kg⁻¹), upper (4 g•kg⁻¹) and high dose (8 g•kg⁻¹) of Liuwei Wuling tablet groups. The acute liver injury model was induced by modified method that the model, positive control and experimental groups were orally administrated 56% alcohol (6 g•kg⁻¹) twice at 12 hour intervals on the fifth day after drugs administration. After 12 hours, the mice were sacrificed to contribute blood and liver for biochemical and histological examinations. Compared with the model, the activities of ALT and AST in serum decreased significantly in different Liuwei Wuling tablet groups. Meanwhile, in liver tissue, the levels of TG, MDA, TNF-α and IL-1ß reduced obviously while the GSH and SOD activities showed markedly increase with a dose-dependent manner. Correspondingly, the microscopically pathological differences of the liver tissue observed by HE and oil red O staining indicated that the liver cell swelling, hydropic degeneration and lipid droplets formation induced by alcohol were significantly improved, which suggested the Liuwei Wuling tablet can reduce the liver injure. In conclusion, the Liuwei Wuling tablet had the protective effect on acute alcoholic hepatic injury which maybe depended on the mechanism of relieving lipid peroxidation, elevating antioxidant enzymes activity, inhibiting oxidative stress and reducing inflammation factors expression.

[Protective effects of oxymatrine against H2O2-induced damage in L02 cells].

To investigate the protective effects of oxymatrine (OMT) against H2O2-induced damage in L02 cells and research the mechanism,L02 cells were used as the research object. The oxidative stress model of L02 was established by hydrogen peroxide (H2O2). CCK-8 was used to detect the cell activation of L02 cells treated by different OMT. FCM (flow cytometry) assay was used to evaluate the cell proliferation of L02 cells treated by OMT. The apoptosis of L02 cells was detected using Annexin-V/7-AAD apoptosis detection kit. The level of ROS was detected by DCFH-DA fluorescence probe. The GSH-PX and SOD were detected by micro plate and colorimetric method. Results showed that when the concentration of OMT is between 6.25 and 100 mg•L⁻¹, it could promote the production of NADPH and strengthen the activity of GSH-PX and SOD to get rid of the ROS to protect the L02 cell from the apoptosis of L02 cell induced by H2O2.

Untargeted Metabolomics Reveals Dose-Response Characteristics for Effect of Rhubarb in a Rat Model of Cholestasis.

Cholestasis is a serious manifestation of liver diseases with limited therapies. Rhubarb, a widely used herbal medicine, has been frequently used at a relatively large dose for treating cholestasis. However, whether large doses are optimal and the therapeutic mechanism remain unclear. To explore these questions, the anti-cholestatic effect of five doses of rhubarb (0.21, 0.66, 2.10, 6.60, and 21.0 g/kg) in an alpha-naphthylisothiocyanate (ANIT)-induced rat model of cholestasis was examined by histopathology and serum biochemistry. A dose-dependent anti-cholestatic effect of rhubarb (0.21-6.6 g/kg) was observed, and an overdose of 21.0 g/kg showed a poor effect. LC-MS-based untargeted metabolomics together with pathway analysis were further applied to characterize the metabolic alterations induced by the different rhubarb doses. Altogether, 13 biomarkers were identified. The dose-response curve based on nine important biomarkers indicated that doses in the 0.42-6.61 g/kg range (EC20-EC80 range, corresponding to 4.00-62.95 g in the clinic) were effective for cholestasis treatment. The pathway analysis showed that bile acid metabolism and excretion, inflammation and amino acid metabolism were altered by rhubarb in a dose-dependent manner and might be involved in the dose-response relationship and therapeutic mechanism of rhubarb for cholestasis treatment.