Ruisheng Li

Rhein protects against acetaminophen-induced hepatic and renal toxicity

This study investigated the possible protective effects and mechanism of rhein on Acetaminophen (APAP)-induced hepatotoxicity and nephrotoxicity in rats. Treatment of rats with APAP resulted in severe liver and kidney injuries, as demonstrated by drastic elevation of serum glutamate-pyruvate transaminase (GPT), glutamate-oxaloacetic transaminase (GOT), total bilirubin (TBIL), creatinine (CREA), urea nitrogen (UREA) levels and typical histopathological changes including necrosis, phlogocyte infiltration and fatty degeneration in liver, tubules epithelium swelling and severe vacuolar degeneration in kidney. APAP caused oxidative stress, as evidenced by increased reactive oxygen species (ROS) production, nitric oxide (NO) and malondiadehyde (MDA) levels, together with depleted glutathione (GSH) concentration in the liver and kidney of rats. However, rhein can attenuate APAP-induced hepatotoxicity and nephrotoxicity in a dose-dependent manner. Our results showed that GPT, GOT, UREA and CREA levels and ROS production were reduced dramatically, NO, MDA, GSH contents were restored remarkedly by rhein administration, as compared to the APAP alone treated rats. Moreover, the histopathological damage of liver and kidney were also significantly ameliorated by rhein treatment. These findings suggested that the protective effects of rhein against APAP-induced liver and kidney injuries might result from the amelioration of APAP-induced oxidative stress.

Paeoniflorin protects against ANIT-induced cholestasis by ameliorating oxidative stress in rats

Paeoniflorin, one of the primary bioactive components in Chi shao, are widely used in traditional Chinese medicine. A lot of evidences suggest that Paeoniflorin has potential anti-oxidant effects. However, whether Paeoniflorin plays roles in cholestasis is unclear. In this study, we examined the protective effect of Paeoniforin against alpha-naphthylisothicaynate (ANIT)-induced cholestasis in rats. Our data demonstrated that the high (0.2 g/kg body weight) and medium (0.1 g/kg body weight) doses of Paeoniflorin significantly prevented ANIT-induced changes in bile flow and the serum levels of total bilirubin, direct bilirubin, total bile acid, γ-glutamyltranspeptidase, glutamate-pyruvate transaminase, glutamate-oxaloacetic transaminase and alkaline phosphatase. Moreover, we also found that Paeoniflorin significantly inhibited nitric oxide and malondialdehyde production, and restored glutathione decrease induced by ANIT. EPR data further indicated that Paeoniflorin inhibited ANIT-mediated reactive oxygen species (ROS) production. The overexpression of NADPH oxidase 4 induced by ANIT were significantly reversed when treated with Paeoniflorin, suggesting that Paeoniflorin could scavenge ROS via inhibiting NADPH oxidase 4 expression. Paeoniflorin treatment could also relieve ANIT-induced liver pathological injuries as indicated by histological assay. These findings indicate that Paeoniflorin exerts a dose-dependent protective effect on ANIT-induced cholestatic liver injury in rats, and the mechanism of this activity is related to its attenuation of oxidative stress in liver tissue.

Comparative pharmacokinetic study of paeoniflorin and albiflorin after oral administration of Radix Paeoniae Rubra in normal rats and the acute cholestasis hepatitis rats.

A comparative study was designed and conducted to compare the pharmacokinetic difference of paeoniflorin and albiflorin after oral administration of Radix Paeoniae Rubra to normal rats and the acute cholestasis hepatitis rats induced by alpha-naphthylisothiocyanate (ANIT). UPLC-ESI-MS/MS method was employed to determine the level of paeoniflorin and albiflorin in rat plasma using geniposide as the internal standard (IS). Unpaired Students t-test was used for the statistical comparison. The investigation showed that there were significant differences between the normal rats and the acute cholestasis hepatitis rat groups in calculated parameters, such as AUC(0-t), AUC(0-∞), T(max) and CLz/F. The results indicated that acute liver injury in rats could alter the pharmacokinetics of drug. Since patients are the final users of the drug, it is essential to investigate the pharmacokinetics of the drug in disease status. Therefore, we used normal rats and the acute cholestasis hepatitis rats to study pharmacokinetics of Radix Paeoniae Rubra with the purpose of examining the influence of disease on the metabolic course.

Curcumin Protects against CCl4-Induced Liver Fibrosis in Rats by Inhibiting HIF-1α Through an ERK-Dependent Pathway

The ERK/HIF-1α signaling pathway is believed to play an important role in the genesis of progressive fibrosis. An increasing expression of HIF-1α and ERK accompanies CCl4-induced liver fibrosis in rats. Curcumin is verified to have antifibrotic effects in several kinds of liver fibrosis models. There is no specific evidence illustrating a connection between curcumin and the HIF-1α/ERK pathway in rat liver fibrosis induced by CCl4. In this study, liver fibrosis was induced by CCl4 in treated rats. The data demonstrated that curcumin was able to attenuate liver fibrosis and inhibit the proliferation of HSC. Moreover, curcumin could remarkably elevate the hepatic function by decreasing serum levels of ALT, AST and ALP, and increasing levels of ALB, TP and α-SMA, Col III mRNA expression. Meanwhile, ECM status could also be reflected by curcumin treatment. The alleviation with curcumin treatment was associated with inhibition of HIF-1α and phosphor-ERK. This study indicates that curcumin alleviates fibrosis by reducing the expression of HIF-1α partly through the ERK pathway.

Toxic effects caused by rhubarb (Rheum palmatum L.) are reversed on immature and aged rats.

AIM OF THE STUDY Rhubarb is generally used to people of broad age, but diverse responses of people at different age to rhubarb have been little clarified. In this study, an attempt was made to access the safety of rhubarb to both immature and aged rats to provide some references for its clinical usage. MATERIALS AND METHODS The total extract of rhubarb was administered intragastricly to both immature and aged rats once a day and lasted for 5 weeks. Then histopathologic and biochemical examinations were performed. RESULTS No death was observed in immature rat groups, while 23.3% (21/90) subjects in aged rat groups died and most of the death cases were observed in the high-dosage (40 gkg(-1) of body weight per day od, counted on the quantity of crude material) group. The death rate between aged and immature rats was found of significantly statistical difference. Dosage-dependent histopathologic changes in kidney were observed in all the rhubarb-treated rats, principally involving the proximal tubules. Kidney changes in aged rats were severer than those observed in immature ones. Hepatic cells necrosis was occasionally observed in the middle- and high-dosage aged rat groups and minimal biliary hyperplasia was found in all the rhubarb-treated aged rats. Increased incidences of activated Kupffer cells and lymphocytic infiltration were found in all the rhubarb-treated rats. And dosage-dependent increase of interleukin 6 (IL-6) and notable increase of IL-8 was found in aged rat groups. CONCLUSIONS The immature and aged rats showed reversed responses to the toxic potential of rhubarb extract. Elderly subjects were susceptible to the toxicity of high-dosage rhubarb, which drove rigorous consideration on rational use of rhubarb to aged people.

Inflammatory stress potentiates emodin-induced liver injury in rats

Herbal medicines containing emodin, widely used for the treatment of hepatitis in clinic, have been reported with hepatotoxicity in individuals. A modest inflammatory stress potentiating liver injury has been linked to the idiosyncratic drug-induced liver injury (IDILI). In this study, we investigated the hypothesis that lipopolysaccharide (LPS) interacts with emodin could synergize to cause liver injury in rats. Emodin (ranging from 20, 40, to 80 mg/kg), which is in the range of liver protection, was administered to rats, before LPS (2.8 mg/kg) or saline vehicle treatment. The biochemical tests showed that non-toxic dosage of LPS coupled with emodin caused significant increases of plasma ALT and AST activities as compared to emodin alone treated groups (P < 0.05). In addition, with LPS or emodin alone could not induce any changes in ALT and AST activity, as compared with the control group (0.5% CMC-Na treatment). Meanwhile, the plasma proinflammatory cytokines, TNF-α, IL-1β, and IL-6 increased significantly in the emodin/LPS groups compared to either emodin groups or the LPS (P < 0.05). Histological analysis showed that liver damage was only found in emodin/LPS cotreatmented rat livers samples. These results indicate that non-toxic dosage of LPS potentiates the hepatotoxicity of emodin. This discovery raises the possibility that emodin and herbal medicines containing it may induce liver injury in the inflammatory stress even in their therapeutic dosages.

Paeoniflorin alleviates liver fibrosis by inhibiting HIF-1α through mTOR-dependent pathway.

HIF-1α/mTOR signaling pathway is considered to play a crucial role in genesis and progress of tissue fibrosis. The elevation of HIF-1α and mTOR is relevant to CCl4 induced liver fibrotic rats. Paeoniflorin has been consistently shown to exhibit multiple pharmacological effects in liver disease. However, so far, no research demonstrates the relationship between paeoniflorin and HIF-1α/mTOR fibrogenesis pathway in liver fibrosis. In this study, the liver fibrosis was performed by CCl4 rats and HSC-T6 cell line. The data demonstrated that paeoniflorin treatment could attenuate liver fibrosis and inhibit the activation of HSC. Moreover, paeoniflorin significantly enhanced hepatic function by decreasing serum level of ALT, AST and ALP, and increasing level of ALB, TP. Meanwhile, ECM degradation was modulated by paeoniflorin treated rats with a remarkable reduce of α-SMA and collagen III mRNA expression. Moreover, the alleviation effect of liver fibrosis was relevant to inhibiting HIF-1α and phosphor-mTOR. Our data indicate that paeoniflorin alleviates liver fibrosis by inhibiting HIF-1α expression partly through mTOR pathway and paeoniflorin may be a potential therapeutic agent for liver fibrosis.

The protective and toxic effects of rhubarb tannins and anthraquinones in treating hexavalent chromium-injured rats: the Yin/Yang actions of rhubarb.

Chromium nephrotoxicity (CrNT) is thought to occur through the oxidant lesion mechanism. There is still a lack of specific remedies against CrNT. We primarily screened Chinese herbal medicines with a potential protective effect against CrNT, e.g., rhubarb (Rheum palmatum L.). However, the active constituents in rhubarb and its mechanisms remain unclear. In this study, the total rhubarb extract (TR) was successively separated into three parts: total anthraquinone extract (TA), total tannin extract (TT) and remaining component extract (RC). The effects of each extract on the potassium dichromate (K(2)Cr(2)O(7))-induced nephrotoxicity in rats were comparatively assessed. The results showed that only the administration of TT protected the kidney function in K(2)Cr(2)O(7)-injured rats. Besides, TT showed significant activity to scavenge hydroxyl radicals, which is considered to be the dominant lesion product generated by hexavalent chromium. TT also showed a reduced ability to transform toxic high valence chromium ions into non-toxic low valence ions. And TT was able to further precipitate chromium ions. These results suggested that rhubarb tannins treat CrNT as a free radical scavenger, reductant, and metal precipitant. The multiple protective routes of the plant tannins reveal a superior option for development into a promising natural remedy against CrNT. In addition, the opposite effects of rhubarb anthraquinones in treating CrNT were observed compared to rhubarb tannins, which suggested the duo-directional effects (Yin and Yang) of herbal medicines should be addressed.

Paeoniflorin ameliorates ANIT-induced cholestasis by activating Nrf2 through an PI3K/Akt-dependent pathway in rats.

Cholestasis causes hepatic accumulation of bile acids leading to liver injury, fibrosis and liver failure. Paeoniflorin, the major active compound isolated from the roots of Paeonia lactiflora pall and Paeonia veitchii Lynch, is extensively used for liver diseases treatment in China. However, the mechanism of paeoniflorins hepatoprotective effect on cholestasis has not been investigated yet. In this study, we administered paeoniflorin to rats for 3 days prior to alpha‐naphthylisothiocyanate (ANIT) administration for once, then went on administering paeoniflorin to rats for 3 days. The data demonstrated that paeoniflorin significantly prevented ANIT‐induced change in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphates (ALP), serum total bilirubin (TBIL), direct bilirubin (DBIL), total bile acid (TBA) and gamma‐glutamyl transpeptidase (γ‐GT). Histology examination revealed that paeoniflorin treatment rats relieved more liver injury and bile duct proliferation than ANIT‐administered rats. Moreover, our data indicated that paeoniflorin could restore glutathione (GSH) and its related synthase glutamate‐cysteine ligase catalytic subunit (GCLc) and glutamate‐cysteine ligase modifier subunit (GCLm) in ANIT‐treated group. In addition, the RNA and protein expression of Akt and nuclear factor‐E2‐related factor‐2 (Nrf2) were also activated by paeoniflorin in ANIT‐induced rats. These findings indicated that paeoniflorin protected ANIT‐induced cholestasis and increased GSH synthesis by activating Nrf2 through PI3K/Akt‐dependent pathway. Therefore, paeoniflorin might be a potential therapeutic agent for cholestasis. Copyright

Toxic Constituents Index: A Toxicity-Calibrated Quantitative Evaluation Approach for the Precise Toxicity Prediction of the Hypertoxic Phytomedicine—Aconite

Complex chemical composition is an important reason for restricting herbal quality evaluation. Despite the multi-components determination method significantly promoted the progress of herbal quality evaluation, however, which mainly concerned the total amount of multiple components and ignored the activity variation between each one, and did not accurately reflect the biological activity of botanical medicines. In this manuscript, we proposed a toxicity calibrated contents determination method for hyper toxic aconite, called toxic constituents index (TCI). Initially, we determined the minimum lethal dose value of mesaconitine (MA), aconitine (AC), and hypaconitine (HA), and established the equation TCI = 100 × (0.3387 ×XMA + 0.4778 ×XAC + 0.1835 ×XHA). Then, 10 batches of aconite were selected and their evaluation results of toxic potency (TP), diester diterpenoid alkaloids (DDAs), and TCI were compared. Linear regression analysis result suggested that the relevance between TCI and TP was the highest and the correlation coefficient R was 0.954. Prediction error values study also indicated that the evaluation results of TCI was highly consistent with that of TP. Moreover, TCI and DDAs were both applied to evaluate 14 batches of aconite samples oriented different origins; from the different evaluation results, we found when the proportion of HA was reached 25% in DDAs, the pharmacopeia method could generate false positive results. All these results testified the accuracy and universality of TCI method. We believe that this study method is rather accurate, simple, and easy operation and it will be of great utility in studies of other foods and herbs.