[Effects of the mixture of Swertia pseudochinensis Hara and Silybum marianum Gaertn extracts on CCl(4)-induced liver injury in rats with non-alcoholic fatty liver disease]

Sweroside Protects Against Myocardial Ischemia-Reperfusion Injury by Inhibiting Oxidative Stress and Pyroptosis Partially via Modulation of the Keap1/Nrf2 Axis

Aims: Sweroside, a secoiridoid glucoside extracted from Swertia pseudochinensis Hara, is reported to possess antioxidant and anti-inflammatory activities. However, whether sweroside has a protective effect on myocardial ischemia-reperfusion (IR) injury is yet to be elucidated. The present study aimed to confirm the cardioprotective effect of sweroside and to identify its underlying mechanism. Methods and Results: H9c2 cells were pretreated with sweroside and then underwent hypoxia-reoxygenation. Cell Counting Kit-8, creatine kinase-myocardial band (CK-MB) and lactate dehydrogenase (LDH) assays were conducted to detect cell viability and myocardial injury, respectively. The Langendorff method was used to induce myocardial IR injury ex vivo. Triphenyltetrazolium chloride staining was performed to detect myocardial infarct size, while protein expression was analyzed using western blotting. Overall, the results indicated that sweroside pretreatment dose-dependently led to a significant enhancement in cell viability, a decrease in release of CK-MB and LDH, a reduction in infarct size, and an improvement in cardiac function. Additionally, sweroside pretreatment caused a marked suppression of oxidative stress, as evidenced by the fact that sweroside decreased the accumulation of reactive oxygen species and malondialdehyde, while enhancing the activities of superoxide dismutase and glutathione peroxidase. Moreover, sweroside was found to notably repress pyroptosis, as sweroside blocked pore formation in the cell membrane, inhibited caspase-1 and interleukin (IL)-1β activity, and decreased the expression levels of NLR family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD, cleaved caspase-1, and IL-1β. Mechanistically, it was found that sweroside inhibited Kelch-like ECH-associated protein 1 (Keap1) and induced nuclear factor E2-associated factor 2 (Nrf2) nuclear translocation. Furthermore, the inhibition of oxidative stress and pyroptosis by sweroside could be abrogated via the inhibition of Nrf2 expression, which suggested that the protective effect induced by sweroside was Nrf2-dependent. Conclusions: The present study demonstrated that sweroside pretreatment could protect against myocardial IR injury by inhibiting of oxidative stress and NLRP3 inflammasome-mediated pyroptosis partially via modulation of the Keap1/Nrf2 axis.

Sweroside ameliorates NAFLD in high-fat diet induced obese mice through the regulation of lipid metabolism and inflammatory response

ETHNOPHARMACOLOGICAL RELEVANCE

Sweroside, an iridoid derived from Traditional Chinese Medicine, is an active component in Swertia pseudochinensis Hara. Swertia pseudochinensis Hara is first recorded in "Inner Mongolia Chinese Herb Medicine"and is considered as a folk medicine for treating hepatitis in northern China.

AIM OF THE STUDY

This study sought to elucidate the role of sweroside in high fat diet induced obesity and fatty liver by using mouse model and investigated the primary molecular mechanism via transcriptomics analysis.

MATERIALS AND METHODS

C57BL/6 mice were fed high-fat diet (HFD) for 14 weeks to induce obesity, hyperglycemia, and fatty liver. These mice were subsequently treated with HFD alone or mixed with sweroside (at a daily dosage of 60 mg per kg of BW, 120 mg per kg of BW and 240 mg per kg of BW) for 6 weeks. BW and food intake was monitored weekly. Biochemical and pathological analysis were conducted to investigate the effect of sweroside on NAFLD. RNA-sequence and RT-qPCR analysis were performed to analyze the potential mechanism.

RESULTS

The mice treated with sweroside were resistant to HFD-induced body weight gain, insulin resistance and hepatic steatosis. Ingenuity pathway analysis (IPA) demonstrated that hepatic gene networks related to lipid metabolism and inflammatory response were down-regulated in the HFD + sweroside group. PPAR-ɑ was located in the center of the hepatic gene network, and the significantly altered genes were CD36 and FGF21, which are related to hepatic inflammation and lipid metabolism. Consistently, upstream-regulators analysis revealed that the main enriched upstream-regulator was PPAR-ɑ.

CONCLUSION

Our results indicate that sweroside may ameliorate obesity with fatty liver via the regulation of lipid metabolism and inflammatory responses. The beneficial effects of sweroside might be closely associated with the regulation of PPAR-α.

High-fat diet plus carbon tetrachloride-induced liver fibrosis is alleviated by betaine treatment in rats

Steatosis, the first lesion in non-alcoholic fatty liver disease (NAFLD), may progress to fibrosis, cirrhosis, and hepatocellular carcinoma. Steatosis predisposes the liver to oxidative stress, inflammation, and cytokines. Betaine (BET) has antioxidant, antiinflammatory and hepatoprotective effects. However, the effects of BET on liver fibrosis development are unknown. Rats were treated with high-fat diet (60% of total calories from fat) for 14weeks. Carbon tetrachloride (0.2mL/kg; two times per week; i.p.) was administered to rats in the last 6weeks with/without commercial food containing BET (2%; w/w). Serum liver function tests and tumor necrosis factor-α, insulin resistance, hepatic triglyceride (TG) and hydroxyproline (HYP) levels and oxidative stress parameters were determined along with histopathologic observations. Alpha-smooth muscle-actin (α-SMA), transforming growth factor-β1 (TGF-β1) and type I collagen (COL1A1) protein expressions and mRNA expressions of matrix metalloproteinase-2 (MMP-2) and its inhibitors (TIMP-1 and TIMP-2) were evaluated. BET decreased TG and HYP levels, prooxidant status and fibrotic changes in the liver. α-SMA, COL1A1 and TGF-β1 protein expressions, MMP-2, TIMP-1, and TIMP-2 mRNA expressions diminished due to BET treatment. BET has an antifibrotic effect and this effect may be related to its antioxidant and antiinflammatory actions together with suppression on HSC activation.

Preclinical Models for Investigation of Herbal Medicines in Liver Diseases: Update and Perspective

Liver disease results from a dynamic pathological process associated with cellular and genetic alterations, which may progress stepwise to liver dysfunction. Commonly, liver disease begins with hepatocyte injury, followed by persistent episodes of cellular regeneration, inflammation, and hepatocyte death that may ultimately lead to nonreversible liver failure. For centuries, herbal remedies have been used for a variety of liver diseases and recent studies have identified the active compounds that may interact with liver disease-associated targets. Further study on the herbal remedies may lead to the formulation of next generation medicines with hepatoprotective, antifibrotic, and anticancer properties. Still, the pharmacological actions of vast majority of herbal remedies remain unknown; thus, extensive preclinical studies are important. In this review, we summarize progress made over the last five years of the most commonly used preclinical models of liver diseases that are used to screen for curative herbal medicines for nonalcoholic fatty liver disease, liver fibrosis/cirrhosis, and liver. We also summarize the proposed mechanisms associated with the observed liver-protective, antifibrotic, and anticancer actions of several promising herbal medicines and discuss the challenges faced in this research field.

[Comparative study on the effects of different therapeutic methods in preventing and treating nonalcoholic fatty liver in rats]

OBJECTIVE

To explore the pathogenesis of nonalcoholic fatty liver (NAFL) in traditional Chinese medicine (TCM) by comparing the therapeutic efficacy of methods for fortifying the spleen and replenishing qi, warming yang and fortifying the spleen and warming yang to move water.

METHODS

Male Wistar rats were randomly divided into normal, model, Sijunzi Tang (SJZ), Lizhong Tang (LZ), Linggui Zhugan Tang (LGZG) and Shenzhuo Tang (SZ) groups. Rats in the normal group were fed with ordinary diet, while the rats in the other groups were fed with high fat diet including 88% ordinary food, 10% lard oil and 2% cholesterol. After four weeks of treatment, the weight of liver and epididymal fat was recorded respectively for calculating the indexes of liver (liver weight/body weight) and epididymal fat (weight of epididymal fat pads/body weight); the pathological changes in liver tissues were observed by hematoxylin and eosin (HE) staining; the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), triacylglycerol (TAG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and very-low-density lipoprotein cholesterol (VLDL-C) and liver TAG concentration were analyzed by biochemical test.

RESULTS

Body weight, liver and epididymal fat indexes and liver TAG level of rats all significantly increased in the model group as compared with the normal group (P<0.05). Hepatic fatty infiltration, TAG concentration and the levels of serum TAG and ALT were significantly decreased in the LGZG and SZ groups when compared to those in the model group (P<0.05). In addition, epididymal fat index and serum TC level also significantly decreased in the LGZG group as compared with the model group (P<0.05). However, there was no significant change in liver TAG concentration in LZ and model groups.

CONCLUSION

Method of warming yang or moving water can promote the lipid metabolism. It may be an effective strategy in preventing and treating NAFL by treating with warming yang and moving water together.

N-acetylcysteine attenuates cardiopulmonary bypass-induced lung injury in dogs

Background

Cardiopulmonary bypass (CPB) is usually associated with inflammatory response that leads to various degrees of organ dysfunction in multiple systems, including lung injury. Our previous study showed that transforming growth factor beta1 (TGFβ1) was involved in CPB-induced lung injury. N-acetylcysteine (NAC) is an antioxidant and is able to prevent CPB-induced pneumocyte apoptosis through scavenging radical. Therefore, we investigated whether NAC may attenuate CPB-induced lung injury by inhibiting TGFβ1 expression.

Methods

Fifty-four 18 to 24-month-old mongrel dogs (15–16 kg) were randomly divided into control group, CPB group and NAC group (n = 18). Six dogs in each group were killed prior to, as well as 30 and 60 minutes after the operation (T0, T1 and T2). Lung injury was evaluated by hematoxylin and eosin (H&E) staining. Respiratory index (RI), oxygenation index (OI), malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the lung were determined at each time point. TGFβ1 expression was determined using real time RT-PCR and immunohistochemistry.

Results

A serious lung injury was observed after CPB in dogs. RI and MDA content were increased significantly after CPB, whereas OI and SOD activity were decreased. H&E staining showed that NAC treatment obviously attenuated CPB-induced lung injury. NAC treatment upregulated OI and SOD activity and downregulated RI and MDA content in the lung tissues of dogs after CPB. Treatment with NAC significantly suppressed the TGFβ1 expression in the lung tissues at both mRNA and protein levels.

Conclusion

Our results suggest that NAC is a potent agent against CPB-induced acute lung injury through inhibiting TGFβ1 expression.