Japanese herbal medicines shosaikoto, inchinkoto, and juzentaihoto inhibit high-fat diet-induced nonalcoholic steatohepatitis in db/db mice

Natural Compounds as Integrative Therapy for Liver Protection against Inflammatory and Carcinogenic Mechanisms: From Induction to Molecular Biology Advancement

The liver is exposed to several harmful substances that bear the potential to cause excessive liver damage ranging from hepatitis and non-alcoholic fatty liver disease to extreme cases of liver cirrhosis and hepatocellular carcinoma. Liver ailments have been effectively treated from very old times with Chinese medicinal herbal formulations and later also applied by controlled trials in Japan. However, these traditional practices have been hardly well characterized in the past till in the last decades when more qualified studies have been carried out. Modern advances have given rise to specific molecular targets which are specifically good candidates for affecting the intricate mechanisms that play a role at the molecular level. These therapeutic regimens that mainly affect the progression of the disease by inhibiting the gene expression levels or by blocking essential molecular pathways or releasing cytokines may prove to play a vital role in minimizing the tissue damage. This review, therefore, tries to throw light upon the variation in the therapies for the treatment of benign and malignant liver disease from ancient times to the current date. Nonetheless, clinical research exploring the effectiveness of herbal medicines in the treatment of benign chronic liver diseases as well as prevention and treatment of HCC is still warranted.

Juzentaihoto improves adenine-induced chronic renal failure in BALB/c mice via suppression of renal fibrosis and inflammation

Renal inflammation and fibrosis are observed in underlying diseases associated with the pathological progression of chronic kidney disease (CKD). The inhibition of renal inflammation and fibrosis is one method to suppress the progression of CKD. Juzentaihoto (TJ-48), a Kampo medicine, effectively relieves chronic wasting diseases and fatigue and has been reported to decrease inflammation. In this study, we investigated whether TJ-48 has a renal protective effect and its underlying mechanism in mice with adenine-induced CKD. BALB/c mice were divided into four groups for examination: (1) control, (2) dietary restriction, (3) adenine, and (4) adenine + TJ-48. Biochemical and histological analyses, gene expression analysis, and complete blood counts were performed. TJ-48 treatment decreased tubular damage and fibrosis. TJ-48 also decreased creatinine levels exacerbated by adenine, suppressed the mRNA expression of tumor necrosis factor-α, chemokine ligand 2, transforming growth factor-β, and kidney injury molecule-1, and decreased the neutrophil/lymphocyte ratio increased by adenine. TJ-48 exerts a renoprotective effect possibly via the suppression of fibrosis and inflammation.

Exploring the protective effect of Modified Xiaochaihu Decoction against hepatic steatosis and inflammation by network pharmacology and validation in ageing rats

Background

Based on therapy with syndrome differentiation and clinical studies on Xiaochaihu decoction (XCHD), we hypothesize that Modified Xiaochaihu Decoction (MXD) has an ability to ameliorate non-alcoholic fatty liver disease (NAFLD). This study aims to elucidate the pharmacological efficacy of MXD and its mechanism in the treatment of NAFLD by network pharmacology and experimental validation.

Methods

The active ingredients in MXD and their potential targets were identified using network analysis followed by experimental validation. First, we used data on the ingredients and targets obtained from professional database and related literature to do PPI network analysis, GO functional analysis, and KEGG pathway enrichment analysis. Core targets identified by network pharmacology were then tested in natural ageing female rats model. Indexes of lipid and glucose homeostasis were determined enzymatically and/or histologically. Gene expression was analyzed by real-time PCR and/or Western blot (WB).

Results

In total, 4009 NAFLD-related targets and 1953 chemical ingredients of MXD were obtained. In-depth network analysis of 140 common targets indicated that MXD played a critical role in anti-NAFLD via multiple targets and pathways. Based on the data of PPI analysis, GO functional enrichment analysis, KEGG pathway enrichment analysis, and literatures on the mechanism of NAFLD, we chose the core targets related to lipid metabolism (SREBP-1c, ChREBP, FASN, PPARα, and ACACA) and inflammation (IL-6 and NF-κB) to do further study. Significantly, in further animal verification experiment we using naturally ageing rats with NAFLD as a model, we found that MXD administration ameliorated age-related NAFLD and mechanistically down-regulated the mRNA/protein expression of core targets in lipid metabolism and inflammation related pathways such as FASN, ACACA, IL-6, and NF-κB. In addition, 12 of 24 potential ingredients acting on verified targets came from BC, and 11 of 24 potential ingredients acting on verified targets were derived from SM, implying that both BC and SM served as the key role in MXD against NAFLD.

Conclusion

The bioinformatics data and in vivo experimental results suggest that the MXD-induced amelioration of NAFLD may be predominantly related to modulation of lipid metabolism and inflammation. Both BC and SM serve as the key role in MXD against NAFLD. These results may provide novel evidence for clinical implication of MXD.

Effects of low ethanol consumption on nonalcoholic steatohepatitis in mice

Several recent clinical and epidemiological studies have suggested inhibitory effects of light-to-moderate alcohol consumption on nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH); however, these effects have not been confirmed in experimental studies. Therefore, in this study, we examined the effects of small amounts of ethanol consumption on a mouse model of NASH. Nine-week-old male obese mice (db/db mice) were divided into the following groups: control, high-fat, and low-ethanol groups. The control group was provided ad libitum access to a control liquid diet, the high-fat group was provided access to a high-fat liquid diet, and the low-ethanol group was provided access to the high-fat liquid diet supplemented with 0.1% (w/w) ethanol. Eight weeks later, the mice were sacrificed and serum biochemical, histopathological, and molecular analyses were performed. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were significantly lower in the low-ethanol group than in the high-fat group (p = 0.033 and 0.037, respectively). Liver histopathological analysis showed that intralobular and portal inflammation was significantly milder in the low-ethanol group than in the high-fat group (p = 0.018 and 0.041, respectively). However, no significant differences were observed among the groups in serum insulin and adiponectin levels, hepatic 4-hydroxynonenal (oxidative injury marker) levels, and hepatic cytokine and receptor gene expression levels. In conclusion, the serum transaminase levels and hepatic inflammation in NASH model mice improved after administration of small amounts of ethanol. This study directly demonstrated inhibitory effects of small amounts of ethanol on NASH in mice. The mechanisms underlying these inhibitory effects remain to be elucidated.

Herbal drug discovery for the treatment of nonalcoholic fatty liver disease

Few medications are available for meeting the increasing disease burden of nonalcoholic fatty liver disease (NAFLD) and its progressive stage, nonalcoholic steatohepatitis (NASH). Traditional herbal medicines (THM) have been used for centuries to treat indigenous people with various symptoms but without clarified modern-defined disease types and mechanisms. In modern times, NAFLD was defined as a common chronic disease leading to more studies to understand NAFLD/NASH pathology and progression. THM have garnered increased attention for providing therapeutic candidates for treating NAFLD. In this review, a new model called “multiple organs-multiple hits” is proposed to explain mechanisms of NASH progression. Against this proposed model, the effects and mechanisms of the frequently-studied THM-yielded single anti-NAFLD drug candidates and multiple herb medicines are reviewed, among which silymarin and berberine are already under U.S. FDA-sanctioned phase 4 clinical studies. Furthermore, experimental designs for anti-NAFLD drug discovery from THM in treating NAFLD are discussed. The opportunities and challenges of reverse pharmacology and reverse pharmacokinetic concepts-guided strategies for THM modernization and its global recognition to treat NAFLD are highlighted. Increasing mechanistic evidence is being generated to support the beneficial role of THM in treating NAFLD and anti-NAFLD drug discovery.

Lycopus lucidus Turcz. ex Benth. Attenuates free fatty acid-induced steatosis in HepG2 cells and non-alcoholic fatty liver disease in high-fat diet-induced obese mice

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is closely related to metabolic diseases such as obesity and insulin resistance.

PURPOSE

We studied whether an ethanol extract of Lycopus lucidus Turcz. ex Benth (LLE) exhibited effects on lipid metabolism in NAFLD.

STUDY DESIGN

An in vitro modelwas established by treatment of HepG2 cells with a 1 mM free fatty acid (FFA) mixture (oleic acid/palmitic acid, 2:1). C57BL/6 mice were fed a high-fat diet (HFD; 60 kcal% fat) for 14 weeks to induce obesity and were treated with or without LLE (100 or 200  mg/kg daily by oral gavage).

METHODS

HepG2 cells were exposed to 1 mM FFA, with or without LLE (250 - 1000  mg/ml). Intracellular lipid contents were measured by Oil Red O staining and a Nile Red assay. The body weight, relative liver weight, hepatic lipids, triglycerides (TGs), and total cholesterol (TC) were measured in the mice. Serum alanine aminotransferase (ALT), TG, TC, glucose, insulin, leptin, and tumor necrosis factor-alpha (TNF-α) levels were determined by biochemical or enzyme-linked immunosorbent assays. Histologic analysis was performed in the liver. Western blotting and quantitative real-time polymerase chain reaction were used to analyze the expression of key enzymes of hepatic lipid metabolism.

RESULTS

LLE significantly decreased the intracellular lipid accumulation in FFA-treated HepG2 cells. LLE not only remarkably decreased the expression of lipogenesis genes but also increased β-oxidation in FFA-induced HepG2 cells. In the in vivo study, LLE treatment significantly decreased the body weight, relative liver weight, serum ALT, TC, and low-density lipoprotein cholesterol, as well as the serum glucose, insulin, leptin, and TNF-α levels in HFD-fed mice. The hepatic TG and TC contents were significantly reduced in the LLE-treated groups. Western blot analysis showed that the expression of sterol-regulatory element-binding protein 1 decreased, while that of phosphorylated AMP-activated protein kinase and peroxisome proliferator-activated receptor α increased in the LLE-treated mice.

CONCLUSION

These results suggest that LLE may exert protective effects against NAFLD-related obesity and metabolic disease.

A systematic review of herbal medicines for the treatment of cancer cachexia in animal models

OBJECTIVE

The aim of this study is to summarize preclinical studies on herbal medicines used to treat cancer cachexia and its underlying mechanisms.

METHODS

We searched four representing databases, including PubMed, EMBASE, the Allied and Complementary Medicine Database, and the Web of Science up to December 2016. Randomized animal studies were included if the effects of any herbal medicine were tested on cancer cachexia. The methodological quality was evaluated by the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies (CAMARADE) checklist.

RESULTS

A total of fourteen herbal medicines and their compounds were identified, including Coptidis Rhizoma, berberine, Bing De Ling, curcumin, Qing-Shu-Yi-Qi-Tang, Scutellaria baicalensis, Hochuekkito, Rikkunshito, hesperidin, atractylodin, Sipjeondaebo-tang, Sosiho-tang, Anemarrhena Rhizoma, and Phellodendri Cortex. All the herbal medicines, except curcumin, have been shown to ameliorate the symptoms of cancer cachexia through anti-inflammation, regulation of the neuroendocrine pathway, and modulation of the ubiquitin proteasome system or protein synthesis.

CONCLUSIONS

This study showed that herbal medicines might be a useful approach for treating cancer cachexia. However, more detailed experimental studies on the molecular mechanisms and active compounds are needed.

Sipjeondaebo-tang Alleviates Oxidative Stress-Mediated Liver Injury through Activation of the CaMKK2-AMPK Signaling Pathway

Sipjeondaebo-tang (SDT) is used frequently as a herbal prescription to treat deficiency syndromes in traditional Korean medicine. We investigated the hepatoprotective effects of SDT against oxidative stress and attempted to clarify the underlying molecular mechanisms. SDT pretreatment reduced arachidonic acid (AA) plus iron-mediated cytotoxicity in a concentration-dependent manner and prevented changes in apoptosis-related protein expression. In addition, SDT pretreatment significantly reduced glutathione depletion, hydrogen peroxide production, and mitochondrial dysfunction via treatment with AA plus iron. SDT increased the phosphorylation of AMP-activated protein kinase (AMPK) in accordance with the phosphorylation of Ca²⁺/calmodulin-dependent protein kinase kinase 2 (CaMKK2). Experiments using an AMPK chemical inhibitor (Compound C) or CaMKK2 chemical inhibitor (STO-609) suggested that the CaMKK2-AMPK signaling pathway contributes to SDT-mediated protection of mitochondria and cells. Moreover, administration of SDT for 4 consecutive days to mice significantly reduced the alanine aminotransferase and aspartate aminotransferase activities induced by carbon tetrachloride, and the numbers of degenerated hepatocytes, infiltrated inflammatory cells, nitrotyrosine-positive cells, and 4-hydroxynonenal-positive cells in liver tissue. Therefore, SDT protects hepatocytes from oxidative stress via CaMKK2-dependent AMPK activation and has the therapeutic potential to prevent or treat oxidative stress-related liver injury.

Herbal medicine Yinchenhaotang protects against α-naphthylisothiocyanate-induced cholestasis in rats

Cholestasis is a clinical disorder defined as an impairment of bile flow, and that leads to toxic bile acid (BA) accumulation in hepatocytes. Here, we investigated the hepatoprotective effect of Yinchenhaotang (YCHT), a well-known formulae for the treatment of jaundice and liver disorders, against the cholestasis using the α-naphthylisothiocyanate (ANIT)-induced cholestasis in male Wistar rats. ANIT feeding induced significant cholestasis with substantially increased intrahepatic retention of hydrophobic BAs. The dynamic changes of serum and liver BAs indicated that YCHT was able to attenuate ANIT-induced BA perturbation, which is consistent with the histopathological findings that YCHT significantly decreased the liver damage. YCHT treatment substantially reduced serum alanine aminotransferase (ALT), alkaline phosphatase (AST), total bilirubin (TBIL) and direct bilirubin (DBIL) with minimal bile duct damage in the ANIT treated rats. Elevated mRNA expression of liver IL-6, IL-17A, IL-17F, TGF-β1, α-SMA, TGR5, NTCP, OATP1a1, and ileum ASBT and decreased liver IL-10, FXR, CAR, VDR, BSEP, MRP2, MRP3, MRP4 was also observed in ANIT-induced cholestasis but were attenuated or normalized by YCHT. Our results demonstrated that the BA profiles were significantly altered with ANIT intervention and YCHT possesses the hepatoprotective potential against cholestatic liver injury induced by hepatotoxin such as ANIT.

Xyloketal B Attenuates Fatty Acid-Induced Lipid Accumulation via the SREBP-1c Pathway in NAFLD Models

The goal of this study was to examine the effects of xyloketal B on nonalcoholic fatty liver disease (NAFLD) and to explore the molecular mechanisms underlying its effects in both in vivo and in vitro models. We discovered an association between xyloketal B and the sterol regulatory element-binding protein-1c (SREBP-1c) signaling pathway, which is related to lipid metabolism. Mice were dosed with xyloketal B (5, 10 and 20 mg/kg/d) and atorvastatin (15 mg/kg/d) via intraperitoneal injection once daily for 40 days after being fed a high fat diet plus 10% high fructose liquid (HFD+HFL) for 8 weeks. Xyloketal B significantly improved HFD+HFL-induced hepatic histological lesions and attenuated lipid and glucose accumulation in the blood as well as lipid accumulation in the liver. Xyloketal B increased the expression of CPT1A, and decreased the expression of SREBP-1c and its downstream targeting enzymes such as ACC1, ACL, and FAS. Xyloketal B also significantly reduced lipid accumulation in HepG2 cells treated with free fatty acids (FFAs). These data suggested that xyloketal B has lipid-lowering effects via the SREBP-1c pathway that regulate lipid metabolism. Thus, targeting SREBP-1c activation with xyloketal B may be a promising novel approach for NAFLD treatment.

Ameliorative Effects of Pomegranate Peel Extract against Dietary-Induced Nonalcoholic Fatty Liver in Rats

Non-alcoholic fatty liver disease (NAFLD) is caused by fat accumulation and is associated with oxidative stress. In this study, we investigated the potential protective effect of pomegranate (Punica granatum L.) peel extract (PPE) against oxidative stress in the liver of rats with NAFLD. Sprague-Dawley rats were fed a high fat diet (HFD), 20% corn oil, or palm oil for 8 weeks in the presence or absence of PPE. The control group was fed a basal diet. The progression of NAFLD was evaluated histologically and by measuring liver enzymes (alanine transaminase and aspartate transaminase), serum lipids (triglycerides and total cholesterol), and oxidative stress markers. The HFD feeding increased the body weight and caused NAFLD, liver steatosis, hyperlipidemia, oxidative stress, and elevated liver enzymes. Administration of PPE ameliorated the hepatic morphology, reduced body weight, improved liver enzymes, and inhibited lipogenesis. Furthermore, PPE enhanced the cellular redox status in the liver tissue of rats with NAFLD. Our findings suggest that PPE could improve HFD-induced NAFLD via abolishment of hepatic oxidative damage and hyperlipidemia. PPE might be considered as a potential lead material in the treatment of NAFLD and obesity through the modulation of lipid metabolism.

Current pharmacological therapies for nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) is considered to be a hepatic manifestation of metabolic syndrome, and its incidence is rapidly increasing worldwide. It is currently the most common chronic liver disease. NASH can progress to liver cirrhosis and hepatocellular carcinoma, and may result in liver-related death. Currently, the principal treatment for NAFLD/NASH is lifestyle modification by diet and exercise. However, pharmacological therapy is indispensable because obese patients with NAFLD often have difficulty maintaining improved lifestyles. The pathogenesis of NAFLD/NASH has not been completely elucidated. However, insulin resistance, inflammatory cytokines, and oxidative stress are thought to be important in the development and/or progression of the disease. Currently, insulin sensitizers (thiazolidinediones) and antioxidants (vitamin E) seem to be the most promising therapeutic agents for NAFLD/NASH, and lipid-lowering drugs, pentoxifylline, angiotensin receptor blockers, and n-3 polyunsaturated fatty acids also have promise. However, there is a lack of consensus regarding the most effective and appropriate pharmacotherapy for NAFLD/NASH. Animal experiments suggest that herbal medicines and natural products may be promising therapeutic agents for NAFLD/NASH, but their efficacy and safety are yet to be investigated in human studies. In this paper, we review the existing and potential pharmacological therapies for NAFLD/NASH.