Salidroside alleviates oxidative stress in the liver with non- alcoholic steatohepatitis in rats

Screening impacts of Tilmicosin-induced hepatic and renal toxicity in rats: protection by Rhodiola rosea extract through the involvement of oxidative stress, antioxidants, and inflammatory cytokines biomarkers

Tilmicosin (TIL) is a semisynthetic macrolide antibiotic with a broad spectrum of activity derived from tylosin. TIL is effective in the treatment of bovine and ovine respiratory diseases caused by different microbes. In parallel, Rhodiola rosea (RHO) is a popular herbal remedy because of its anti-inflammatory and antioxidant qualities. The experiment lasted for 12 days. Depending on the experimental group, the animals received either distilled water or RHO root extract dissolved in distilled water for 12 days through a stomach tube, and the single subcutaneous injection on day 6 of the experiment of either 500 μL of 0.9% NaCl or TIL dissolved in 500 μL 0.9% NaCl. Samples and blood were collected for serum analysis, gene expression, and immunohistochemistry screening at liver and kidney levels. TIL injection increased serum levels of hepatic and renal markers (ALP, ALT, AST, TC, TG, creatinine, and urea) with decreased total proteins. In parallel, TIL induced hepatic and renal oxidative stress as there was an increase in malondialdehyde levels, with a decrease in catalase and reduced glutathione activities. Of interest, pre-administration of RHO inhibited TIL-induced increase in hepato-renal markers, decreased oxidative stress, and increased liver and kidney antioxidant activities. Quantitative RT-PCR showed that TIL increased the liver's HSP70 (heat shock protein), NFkB, and TNF-α mRNA expression. Moreover, TIL upregulated the expression of desmin, nestin, and vimentin expression in the kidney. The upregulated genes were decreased significantly in the protective group that received RHO. Serum inflammatory cytokines and genes of inflammatory markers were affected in liver tissues (HSP70, NFkB, and TNF-α) and kidney tissues (desmin, nestin, and vimentin)-TIL-induced hepatic vacuolation and congestion together with glomerular atrophy. The immunoreactivity of PCNA and HMGB1 was examined immunohistochemically. At cellular levels, PCNA was decreased while HMGB1 immunoreactivity was increased in TIL-injected rats, which was improved by pre-administration of RHO. RHO administration protected the altered changes in liver and renal histology. Current findings support the possible use of RHO to shield the liver and kidney from the negative effects of tilmicosin.

Salidroside prevents cadmium chloride-induced DNA damage in human fetal lung fibroblasts

BACKGROUND

Cadmium (Cd) is an environmental pollutant and a heavy metal known for its genotoxic effects, which can lead to cancer and other related diseases. Preventing Cd-induced genotoxicity is crucial; however, there is limited research on this topic. Salidroside (SAL), a phenylpropanoid glycoside isolated from Rhodiola rosea L., is a popular medicinal compound with several health benefits. Nevertheless, its therapeutic effect on Cd-induced genotoxicity remains unexplored.

METHODS

Human fetal lung fibroblasts were treated with 20 μM Cd2+ (CdCl2) for 12 h and 5-20 μM SAL was used to test the anti-DNA damage effect. DNA damage was evaluated using γH2AX expression and the alkaline comet assay. Intracellular reactive oxygen species (ROS) levels were measured using flow cytometry.

RESULTS

Exposure to 20 μM Cd2+ for 12 h induced significant DNA damage in human fetal lung fibroblasts, and this effect was notably attenuated by SAL treatment. SAL treatment did not decrease ROS levels in cells treated with Cd2+.

CONCLUSION

SAL effectively prevented Cd2+-induced DNA damage in human fetal lung fibroblasts. However, the underlying mechanism requires further investigation.

Salidroside inhibits insulin resistance and hepatic steatosis by downregulating miR-21 and subsequent activation of AMPK and upregulation of PPARα in the liver and muscles of high fat diet-fed rats

This study evaluated if salidroside (SAL) alleviates high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) by downregulating miR-21. Rats (n = 8/group) were treated for 12 weeks as normal diet (control/ND), ND + agmoir negative control (NC) (150 µg/kg), ND + SAL (300 mg/kg), HFD, HFD + SAL, HFD + compound C (an AMPK inhibitor) (200 ng/kg), HFD + SAL + NXT629 (a PPAR-α antagonist) (30 mg/kg), and HFD + SAL + miR-21 agomir (150 µg/kg). SAL improved glucose and insulin tolerance and preserved livers in HFD-fed rats. In ND and HFD-fed rats, SAL reduced levels of serum and hepatic lipids and the hepatic expression of SREBP1, SREBP2, fatty acid (FA) synthase, and HMGCOAR. It also activated hepatic Nrf2 and increased hepatic/muscular activity of AMPK and levels of PPARα. All effects afforded by SAL were prevented by CC, NXT629, and miR-21 agmoir. In conclusion, activation of AMPK and upregulation of PPARα mediate the anti-steatotic effect of SAL.

Salidroside alleviates cholestasis-induced liver fibrosis by inhibiting hepatic stellate cells via activation of the PI3K/AKT/GSK-3β signaling pathway and regulating intestinal flora distribution

Salidroside (SAL), a phenylpropanoid bioactive compound, has various pharmacological properties, including antioxidant, anti-inflammatory, and hepatoprotective effects. However, the pharmacological effects and mechanisms of action of SAL on cholestatic liver injury are unclear. This study investigated the mechanism and effects of salidroside (SAL) on intestinal flora distribution and hepatic stellate cell (HSC) activation in cholestatic hepatic fibrosis. Bile duct ligation was used to cause cholestasis BALB/c mice. The therapeutic efficacy of SAL in liver fibrosis was assessed via serum/tissue biochemical analyses and liver tissue hematoxylin and eosin and Masson staining. Inflammation and oxidative stress were analyzed using enzyme-linked immunosorbent assay and western blotting. HSC were activated in vitro using lipopolysaccharide, and the effects of SAL on HSC migration and inflammatory factor expression were detected via scratch, transwell, and western blotting assays. The effects of SAL on the PI3K/AKT/GSK-3β pathway in vivo and in vitro were detected using western blotting. 16sRNA sequencing was used to detect the effect of SAL on the diversity of the intestinal flora. Ileal histopathology and western blotting were used to detect the protective effect of SAL on the intestinal mucosal barrier. SAL reduces liver inflammation and oxidative stress and protects against liver fibrosis with cholestasis. It inhibits HSC activation and activates the PI3K/AKT/GSK-3β pathway in vitro and in vivo. Additionally, SAL restores the abundance of intestinal flora, which contributes to the repair of the intestinal mucosal barrier, inhibits endotoxin translocation, and indirectly inhibits HSC activation, reversing the course of cholestatic liver fibrosis. SAL inhibits HSC activation through the PI3K/AKT/GSK-3β pathway and improves intestinal flora distribution, thereby protecting and reversing the progression of hepatic fibrosis.

Sanguisorba officinalis L. Ameliorates Hepatic Steatosis and Fibrosis by Modulating Oxidative Stress, Fatty Acid Oxidation, and Gut Microbiota in CDAHFD-Induced Mice

Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver diseases and encompasses non-alcoholic steatosis, steatohepatitis, and fibrosis. Sanguisorba officinalis L. (SO) roots have traditionally been used for their antioxidant properties and have beneficial effects on metabolic disorders, including diabetes and obesity. However, its effects on hepatic steatosis and fibrosis remain unclear. In this study, we explored the effects of a 95% ethanolic SO extract (SOEE) on NAFLD and fibrosis in vivo and in vitro. The SOEE was orally administered to C57BL/6J mice fed a choline-deficient, L-amino-acid-defined, high-fat diet for 10 weeks. The SOEE inhibited hepatic steatosis by modulating hepatic malondialdehyde levels and the expression of oxidative stress-associated genes, regulating fatty-acid-oxidation-related genes, and inhibiting the expression of genes that are responsible for fibrosis. The SOEE suppressed the deposition of extracellular matrix hydroxyproline and mRNA expression of fibrosis-associated genes. The SOEE decreased the expression of fibrosis-related genes in vitro by inhibiting SMAD2/3 phosphorylation. Furthermore, the SOEE restored the gut microbial diversity and modulated specific bacterial genera associated with NAFLD and fibrosis. This study suggests that SOEE might be the potential candidate for inhibiting hepatic steatosis and fibrosis by modulating oxidative stress, fatty acid oxidation, and gut microbiota composition.

Salidroside protects against intestinal barrier dysfunction in septic mice by regulating IL‑17 to block the NF‑κB and p38 MAPK signaling pathways

Sepsis is a systemic inflammatory response syndrome, mainly caused by infection or suspected infectious factors. The intestine is not only one of the most easily involved organs in the course of sepsis, but also the dynamic organ for the course of sepsis. The present study investigated the protective effect and mechanism of salidroside on intestinal barrier dysfunction of septic mice. Briefly, C57BL/6 mice were used to establish a septic model and then administered with salidroside. The ileum tissues of mice were examined by histopathological examination. Fluorescein isothiocyanate-dextran concentration was measured. IL-17, IL-6, IL-13 and TNF-α levels in ileum tissues and NF-κB and p38 MAPK activations were detected by ELISA and the expressions of NF-κB p65 and p38 MAPK protein with their phosphorylation and intestinal tight junction proteins were gauged by western blotting. The above assays were performed again to investigate the effect of anti-IL-17A and salidroside (160 mg/kg) alone or in combination. The septic model induced the ileum tissue injury, increased intestinal permeability and TNF-α, IL-17 and IL-6 levels, activated NF-κB and p38 MAPK pathways, promoted the expressions of NF-κB p65 and p38 MAPK and their phosphorylation, while suppressing the levels of IL-13 and intestinal tight junction proteins. Salidroside and anti-IL-17A partially reversed the above effects of septic model, which in combination further strengthened the reversing effect. Collectively, salidroside protected against intestinal barrier dysfunction in septic mice by downregulating IL-17 level to inhibit NF-κB and p38 MAPK signaling pathways, thus providing a new treatment direction.

Salidroside in the Treatment of NAFLD/NASH

Non-alcoholic fatty liver disease (NAFLD) is the commonest reason for chronic liver diseases in the world and is commonly related to the hepatic manifestation of the metabolic syndrome. Non-alcoholic steatohepatitis (NASH) is a deteriorating form of NAFLD, which can eventually develop into fibrosis, cirrhosis, and liver cancer. The reason for NAFLD/NASH development is complicated, such as liver lipid metabolism, oxidative stress, inflammatory response, apoptosis and autophagy, liver fibrosis and gut microbiota. Apart from bariatric surgery and lifestyle changes, officially approved drug therapy for NAFLD/NASH treatment is lacking. Salidroside (SDS) is a phenolic compound extensively distributed in the tubers of Rhodiola plants, which possesses many significant biological activities. This review summarized the related targets regulated by SDS in treating NAFLD/NASH. It is indicated that SDS could improve the status of NAFLD/NASH by ameliorating abnormal lipid metabolism, inhibiting oxidative stress, regulating apoptosis and autophagy, reducing inflammatory response, alleviating fibrosis and regulating gut microbiota. In conclusion, although the multiple bioactivities of SDS have been confirmed, the clinical data are inadequate and need to become the focus of attention in the later study.

Dietary Supplementation of Salidroside Alleviates Liver Lipid Metabolism Disorder and Inflammatory Response to Promote Hepatocyte Regeneration via PI3K/AKT/Gsk3-β Pathway

Fatty liver hemorrhagic syndrome (FLHS) is a chronic hepatic disease which occurs when there is a disorder in lipid metabolism. FLHS is often observed in caged laying hens and characterized by a decrease in egg production and dramatic increase of mortality. Salidroside (SDS) is an herbal drug which has shown numerous pharmacological activities, such as protecting mitochondrial function, attenuating cell apoptosis and inflammation, and promoting antioxidant defense system. We aimed to determine the therapeutic effects of SDS on FLHS in laying hens and investigate the underlying mechanisms through which SDS operates these functions. We constructed oleic acid (OA)-induced fatty liver model in vitro and high-fat diet-induced FLHS of laying hens in vivo. The results indicated that SDS inhibited OA-induced lipid accumulation in chicken primary hepatocytes, increased hepatocyte activity, elevated the mRNA expression of proliferation related genes PCNA, CDK2, and cyclinD1 and increased the protein levels of PCNA and CDK2 (P < 0.05), as well as decreased the cleavage levels of Caspase-9, Caspase-8, and Caspase-3 and apoptosis in hepatocytes (P < 0.05). Moreover, SDS promoted the phosphorylation levels of PDK1, AKT, and Gsk3-β, while inhibited the PI3K inhibitor (P < 0.05). Additionally, we found that high-fat diet-induced FLHS hens had heavier body weight, liver weight, and abdominal fat weight, and severe steatosis in histology, compared with the control group (Con). However, hens fed with SDS maintained lighter body weight, liver weight, and abdominal fat weight, as well as normal liver without hepatic steatosis. In addition, high-fat diet-induced FLHS hens had high levels of serum total cholesterol (TC), triglyceride (TG), alanine transaminase (ALT), and aspartate aminotransferase (AST) compared to the Con group, however, in the Model+SDS group, the levels of TC, TG, ALT, and AST decreased significantly, whereas the level of superoxide dismutase (SOD) increased significantly (P < 0.05). We also found that SDS significantly decreased the mRNA expression abundance of PPARγ, SCD, and FAS in the liver, as well as increased levels of PPARα and MTTP, and decreased the mRNA expression of TNF-α, IL-1β, IL-6, and IL-8 in the Model+SDS group (P < 0.05). In summary, this study showed that 0.3 mg/mL SDS attenuated ROS generation, inhibited lipid accumulation and hepatocyte apoptosis, and promoted hepatocyte proliferation by targeting the PI3K/AKT/Gsk3-β pathway in OA-induced fatty liver model in vitro, and 20 mg/kg SDS alleviated high-fat-diet-induced hepatic steatosis, oxidative stress, and inflammatory response in laying hens in vivo.

Therapeutic Effect of Acer tegmentosum Maxim Twig Extract in Bile Duct Ligation-Induced Acute Cholestasis in Mice

Cholestatic liver disease, or cholestasis, is a condition characterized by liver inflammation and fibrosis following a bile duct obstruction and an intrahepatic accumulation of bile acids. Inhibiting inflammation is a promising therapeutic strategy for cholestatic liver diseases. Acer tegmentosum Maxim extract (ATE) is best known for its anti-inflammatory and antioxidative properties. In this study, we investigated the effects of ATE on liver injury and fibrosis in mice with bile duct ligation (BDL)-induced cholestasis through analysis of gene expression, cytokines, and histological examination. Oral administration of ATE (20 or 50 mg/kg) for 14 days significantly attenuated hepatocellular necrosis compared to vehicle-treated BDL mice, which was accompanied by the reduced level of serum bile acids and bilirubin. We determined that ATE treatment reduced liver inflammation, oxidative stress, and fibrosis. These beneficial effects of ATE were concurrent with the decreased expression of genes involved in the NF-κB pathway, suggesting that the anti-inflammatory effect of ATE could be a possible mechanism against cholestasis-associated liver injury. Our findings substantiate ATE's role as an alternative therapeutic agent for cholestasis-induced liver injury and fibrosis.

Potential Natural Compounds for the Prevention and Treatment of Nonalcoholic Fatty Liver Disease: A Review on Molecular Mechanisms

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a kind of metabolic stress-induced liver injury closely related to insulin resistance and genetic susceptibility, and there is no specific drug for its clinical treatment currently. In recent years, a large amount of literature has reported that many natural compounds extracted from traditional Chinese medicine (TCM) can improve NAFLD through various mechanisms. According to the latest reports, some emerging natural compounds have shown great potential to improve NAFLD but are seldom used clinically due to the lacking special research.

PURPOSE

This paper aims to summarize the molecular mechanisms of the potential natural compounds on improving NAFLD, thus providing a direction and basis for further research on the pathogenesis of NAFLD and the development of effective drugs for the prevention and treatment of NAFLD.

METHODS

By searching various online databases, such as Web of Science, SciFinder, PubMed, and CNKI, NAFLD and these natural compounds were used as the keywords for detailed literature retrieval.

RESULTS

The pathogenesis of NAFLD and the molecular mechanisms of the potential natural compounds on improving NAFLD have been reviewed.

CONCLUSION

Many natural compounds from traditional Chinese medicine have a good prospect in the treatment of NAFLD, which can serve as a direction for the development of anti-NAFLD drugs in the future.

Lack of salidroside impact on selected cytochromes encoding genes transcription in the liver of ethanol induced rats

Introduction: The molecular basis of in vivo metabolism of selected representatives of phenylethanoids in the presence of ethanol has not been fully elucidated.

Objective: The aim was to estimate a salidroside (Sal) metabolism in the liver tissue in rats with induced alcohol tolerance by assessing changes in the transcription of genes encoding cytochromes: CYP1A2, 2D2, 3A1, 2C23.

Methods: cDNA was synthesized from total RNA isolated from rat liver samples. mRNA level changes were evaluated using real-time PCR (qRT-PCR) technique.

Results: Ethanol caused a significant induction of the CYP1A2 and CYP2C23 genes transcription, and a decrease in the CYP3A1 mRNA level, predominantly without statistical significance. A statistically significant increase of the CYP1A2 mRNA level was observed in the group receiving only Sal (4.5 mg/kg b.w.; p.o.) (p<0.01).

Conclusions: There was no unequivocal effect of salidroside on the transcription of investigated cytochrome genes in the liver of rats with induced alcohol tolerance.

Protective effect of Salidroside on hypoxia-related liver oxidative stress and inflammation via Nrf2 and JAK2/STAT3 signaling pathways

High-altitude hypoxia-induced oxidative stress and inflammation played an essential role in the incidence and development of liver injury. Salidroside (Sal), a phenylpropanoid glycoside extracted from the plant Rhodiola rosea, has recently demonstrated antioxidant, anti-inflammatory, and antihypoxia properties. Herein, we hypothesized that salidroside may alleviate hypoxia-induced liver injury via antioxidant and antiinflammatory-related pathways. A high-altitude hypoxia animal model was established using hypobaric chamber. Male SD rats were randomly divided into the control group, hypoxia group, control +Sal group, and hypoxia +Sal group. Salidroside treatment significantly inhibited hypoxia-induced increases of serum and hepatic pro-inflammatory cytokines release, hepatic ROS production and MDA contents; attenuated hypoxia-induced decrease of hepatic SOD, CAT, and GSH-Px activities. Furthermore, salidroside treatment also potentiated the activation of Nrf2-mediated anti-oxidant pathway, as indicated by upregulation of n-Nrf2 and its downstream HO-1 and NQO-1. In vitro study found that blocking the Nrf2 pathway using specific inhibitor ML385 significantly reversed the protective effect of salidroside on hypoxia-induced liver oxidative stress. In addition, salidroside treatment significantly inhibited hepatic pro-inflammatory cytokines release via JAK2/STAT3-mediated pathway. Taken together, our findings suggested that salidroside protected against hypoxia-induced hepatic oxidative stress and inflammation via Nrf2 and JAK2/STAT3 signaling pathways.

Plant-Based Foods and Their Bioactive Compounds on Fatty Liver Disease: Effects, Mechanisms, and Clinical Application

Fatty liver disease (FLD), including nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD), is a serious chronic metabolic disease that affects a wide range of people. Lipid accumulation accompanied by oxidative stress and inflammation in the liver is the most important pathogenesis of FLD. The plant-based, high-fiber, and low-fat diet has been recommended to manage FLD for a long time. This review discusses the current state of the art into the effects, mechanisms, and clinical application of plant-based foods in NAFLD and AFLD, with highlighting related molecular mechanisms. Epidemiological evidence revealed that the consumption of several plant-based foods was beneficial to alleviating FLD. Further experimental studies found out that fruits, spices, teas, coffee, and other plants, as well as their bioactive compounds, such as resveratrol, anthocyanin, curcumin, and tea polyphenols, could alleviate FLD by ameliorating hepatic steatosis, oxidative stress, inflammation, gut dysbiosis, and apoptosis, as well as regulating autophagy and ethanol metabolism. More importantly, clinical trials confirmed the beneficial effects of plant-based foods on patients with fatty liver. However, several issues need to be further studied especially the safety and effective doses of plant-based foods and their bioactive compounds. Overall, certain plant-based foods are promising natural sources of bioactive compounds to prevent and alleviate fatty liver disease.

Salidroside: A review of its recent advances in synthetic pathways and pharmacological properties

Salidroside has been identified as one of the most potent compounds isolated from various Rhodiola plants, which have been used for a long time as adaptogens in traditional Chinese medicine. However, due to the severe growing environment of herbal medicine and large-scale excavation, the content of natural salidroside is extremely small. Most of the previous studies focused on herbal medicine, and there were few reviews on the synthesis of its main active ingredient salidroside. This paper presents different synthetic routes of salidroside to resolve the contradiction between supply and demand and lays the foundation for new drug research and development. Furthermore, emerging evidence indicates that salidroside, a promising environmentally-adapted drug with low toxicity and few side effects, possesses a wide spectrum of pharmacological properties, including activities on the cardiovascular system and central nervous system, anti-hypoxia, anti-fatigue and anti-aging activities, anticancer activity, anti-inflammatory activity, antioxidant activity, antivirus and immune stimulation activities, antidiabetic activity, anti-osteoporotic activity, and so on. Although the former researches have summarized the pharmacological effects of salidroside, focusing on the central nervous system, diabetes, and cancer, the overall pharmacological aspects of it have not been analyzed. This review highlights biological characteristics and mechanisms of action from 2009 to now as well as toxicological and pharmacokinetic data of the analyzed compound reported so far, with a view to providing a reference for further development and utilization of salidroside.

Effects of late-onset dietary intake of salidroside on insulin/insulin-like growth factor-1 (IGF-1) signaling pathway of the annual fish Nothobranchius guentheri

Salidroside (SDS) is the main active ingredient of Rhodiola which has many biological functions including anti-fatigue, anti-tumor, and immune regulation activities. Our last paper demonstrated that SDS prolonged longevity of the annual fish Nothobranchius guentheri, a promising vertebrate model for anti-aging research. However, little is known about its effect on insulin/insulin-like growth factor-1 (IGF-1) signaling pathway (IIS pathway). In this study, we show that SDS is able to decrease accumulation of SA-β-Gal. We also show that SDS administraton could reduce the expression levels of Igf-1 and Igf-1R, downregulate the expressions of p-PI3K and p-Akt and upregulate the expression levels of Sirt1 and Foxo3a, both of which are the downstream regulators of the IIS pathway. We also find that SDS could alleviate DNA damage, which could result in increased expression of transcription factor Foxo3a. Collectively, these data indicate that SDS may take part in the IIS pathway.

Modulation of hepatic lipidome by rhodioloside in high-fat diet fed apolipoprotein E knockout mice

BACKGROUND

Rhodioloside is a glucoside of tyrosol isolated from Rhodiola rosea. However, its regulating effect on hepatic dyslipidemia of atherogenic mice has rarely been studied.

PURPOSE

The specific aims of current study included to clarify lipidomic perturbation in liver tissues of apolipoprotein E deficient (apoE^-/-) mice fed with high-fat diet, and to examine the effects of rhodioloside against atherosclerosis and dyslipidemia.

STUDY DESIGN

The comparisons of hepatic lipidome were executed between wide type (WT) mice fed with normal diet (NDC) and apoE^-/- mice fed with high-fat diet (Model), WT mice fed with high-fat diet (HFDC) versus the model mice, as well as the model mice versus rhodioloside-treated atherosclerotic mice.

METHODS

Ultra high performance liquid chromatography coupled with a Q exactive hybrid quadrupole-orbitrap mass spectrometry (UPLC-MS/MS) was employed to provide an unbiased and simultaneous measurement of individual lipid species in liver tissues.

RESULTS

Multivariate statistical analysis derived from LC-MS spectra revealed that high-fat diet and apoE deficiency caused a series of disturbances on glyerolipid metabolism, glycerophospholipid metabolism and sphingolipid metabolism. Rhodioloside administration showed atheroprotective effects on the apoE^-/- mice with regulating the levels of 1 phosphatidylcholine, 2 phosphatidylserines, 5 alkyldiacylglycerols and 3 alkenyldiacylglycerols back to normal. In particular, PC (4:0/15:0) was positively associated with high-density lipoprotein cholesterol in blood, both of which could be ameliorated by rhodioloside.

CONCLUSION

Our results identified the abnormal hepatic lipids in atherosclerosis progression that could efficiently improved by rhodioloside. These lipids contributed to biological understanding of atherogenic dyslipidemia in liver and could also served as sensitive indicators for drug target screening.

Bioinformatics analysis reveals novel core genes associated with nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the most frequent liver disease and associated with a wide spectrum of hepatic disorders ranging from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma (HCC). NASH is projected to become the most common indication for liver transplantation, and the annual incidence rate of NASH-related HCC is 5.29 cases per 1000 person-years. Owing to the epidemics of NAFLD and the unclear mechanism of NAFLD progression, it is important to elucidate the underlying NAFLD mechanisms in detail. NASH is mainly caused by the development of NAFL Therefore, it is also of great significance to understand the mechanism of progression from NAFL to NASH. Gene expression chip data for NAFLD and NASH were downloaded from the Gene Expression Omnibus database to identify differentially expressed genes (DEGs) between NAFLD and normal controls (called DEGs for NAFLD), as well as between NASH and normal tissue (called DEGs for NASH-Normal), and between NASH and NAFL tissue (called DEGs for NASH-NAFL). For DEGs for the NAFLD group, key genes were identified by studying the form of intersection. Potential functions of DEGs for NASH were then analyzed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. A protein-protein interaction network (PPI) was constructed using the STRING database. A total of 249 DEGs and one key gene for NAFLD were identified. For NASH-Normal, 514 DEGs and 11 hub genes were identified, three of which were closely related to the survival analysis of HCC, and potentially closely related to progression from NASH to HCC. One key gene for NASH-NAFL (AKR1B10) was identified. These genes appear to mediate the molecular mechanism underlying NAFLD and may be promising biomarkers for the presence of NASH.

Gegen Qinlian Decoction abates nonalcoholic steatohepatitis associated liver injuries via anti-oxidative stress and anti-inflammatory response involved inhibition of toll-like receptor 4 signaling pathways

Gegen Qilian Decoction (GGQLD) is a well-established classic Chinese medicine prescription in treating nonalcoholic steatohepatitis (NASH). However, the molecular mechanism of GGQLD action on NASH is still not clear. This study aimed to assess the anti-NASH effect of GGQLD, and to explore its molecular mechanisms in vivo and in vitro. In HFD-fed rats, GGQLD decreased significantly serum triglyceride (TG), cholesterol (CHO), total bile acid (TBA), low-density lipoprotein (LDL), free fatty acid (FFA) and lipopolysaccharide (LPS) levels, increased levels of differentially expressed proteins (DEPs) Ahcy, Gpx1, Mat1a, GNMT, and reduced the expression of ALDOB. In RAW264.7 macrophages, GGQLD reduced the expression levels of inflammatory factors TNF-α and IL-6 mRNA, and diminished NASH by increasing differentially expressed genes (DEGs) CBS, Mat1a, Hnf4α and Pparα to reduce oxidative stress or lipid metabolism. The results of DEGs verification also showed that GGQLD up-regulated expressions of Hnf4α, Pparα and Cbs genes. In HepG2 cells, GGQLD decreased IL-6 levels and intracellular TG content, and inhibited FFA-induced expression of toll-like receptor 4 (TLR4). In summary, GGQLD abates NASH associated liver injuries via anti-oxidative stress and anti-inflammatory response involved inhibition of TLR4 signal pathways. These findings provide new insights into the anti-NASH therapy by GGQLD.

Salidroside improves high-fat diet-induced non-alcoholic steatohepatitis by regulating the gut microbiota-bile acid-farnesoid X receptor axis

BACKGROUND

Our previous studies found that salidroside can effectively treat non-alcoholic steatohepatitis (NASH). Here, we discuss the mechanism of salidroside in the treatment of NASH with a focus on the gut microbiota-bile acid-farnesoid X receptor axis.

METHODS

A NASH mouse model was created by providing mice with a high-fat diet (HFD) for 14 weeks. Mice were randomly divided into the HFD group, HFD + salidroside treatment group, and HFD + obeticholic acid treatment group (n = 8 in each group) and were intragastrically administered corresponding drugs for 4 weeks. Hematoxylin-eosin staining was performed to evaluate the histopathological changes associated with the various treatments. In addition, liver triglyceride (TG) content, serum alanine aminotransferase (ALT) activity, serum inflammatory factors, gut microbiota diversity, and the bile acid profile were evaluated. Western blotting and RT-PCR were performed to detect the expressions of FXR and fibroblast growth factor 15 (FGF15).

RESULTS

The HFD group displayed obvious signs of hepatic steatosis. The liver TG, serum ALT, and IL-1a, IL-12, MCP-1, KC, MIP-1a, and MIP-1β were significantly higher in the HFD group than the control group (P < 0.01). Intestinal bacteria and bile acid profiles changed significantly in the HFD group (P < 0.05). Further, the expressions of FXR and FGF15 decreased significantly in the HFD group (P < 0.05). After treatment with salidroside, liver steatosis, TG content, and serum inflammatory factors significantly improved and HFD-induced intestinal bacteria, bile acid disorder, and FXR deficiency were significantly alleviated (P < 0.05).

CONCLUSION

Salidroside can improve NASH via the gut microbiota-bile acid-FXR axis.

Protective Effects of Salidroside on Lead Acetate-induced Oxidative Stress and Hepatotoxicity in Sprague-Dawley Rats

Lead has heavy metal toxicity which endangers human and animal health. Salidroside (SDS) is a natural antioxidant that has extensive pharmacological usage. However, its protective effects on lead-induced oxidative stress and hepatotoxicity has not been reported. In this study, we established an animal model to evaluate the protective effects of SDS on chronic lead exposure induced oxidative stress and hepatotoxicity. Forty healthy Sprague-Dawley (SD) rats were assigned to control group (control, animals were provided with distilled water, n = 10); lead acetate-exposed group (PbAc, animals received lead acetate solution of 500 ppm for 60 days, n = 10); low dosage of SDS-treated group (PbAc-SDS-L, lead acetate exposed animals were given intragastric SDS 150 mg/kg body weight for 60 days, n = 10); and high dosage of SDS-treated group (PbAc-SDS-H, lead acetate exposed animals were given intragastric SDS 300 mg/kg body weight for 60 days, n = 10). The results showed that lead exposure caused a significant increase in serum ALP, AST, ALT, and TB (P < 0.01), and these were reversed after treatment with salidroside for 60 days. Compared to the control, the liver GSH, SOD, and GSH-Px were decreased significantly after lead acetate exposure (P < 0.01). However, after treatment with SDS for 60 days, those were dose-dependently reversed. Similarly, MDA was significantly increased in the PbAc group (P < 0.01), and it was significantly decreased in SDS treatment group. Moreover, SDS ameliorated lead-induced congestion and necrosis of hepatocytes. In addition, the RT-PCR and immunohistochemistry results revealed that the PbAc group showed a significant increase in the protein and mRNA of cytochrome P450 2E1 (CYP2E1) and NADPH oxidase 2 (NOX2) in rat liver. Treatment with SDS significantly reversed CYP2E1 and NOX2 expressions in the liver of lead-exposed rats. The results above indicated that SDS has obvious antioxidant activity; it can cure liver injury caused by lead acetate by inhibiting oxidative stress and increasing the antioxidant stress activity, thus improving the liver tissue structure.

Diosgenin ameliorates palmitic acid-induced lipid accumulation via AMPK/ACC/CPT-1A and SREBP-1c/FAS signaling pathways in LO2 cells

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and is characterized by excessive hepatic lipid accumulation. Many studies have suggested that lipid overload is the key initial factor that contributes to hepatic steatosis. Our previous study indicated that diosgenin (DSG) has a beneficial effect on energy metabolism, but the underlying mechanism remains unclear.

METHODS

Human normal hepatocytes (LO2 cells) were incubated with palmitic acid to establish the cell model of nonalcoholic fatty liver. The effects of DSG on lipid metabolism, glucose uptake and mitochondrial function were evaluated. Furthermore, the mechanism of DSG on oxidative stress, lipid consumption and lipid synthesis in LO2 cells was investigated.

RESULTS

The results indicated that palmitic acid induced obvious lipid accumulation in LO2 cells and that DSG treatment significantly reduced the intracellular lipid content. DSG treatment upregulated expression of lipolysis proteins, including phospho-AMP activated protein kinase (p-AMPK), phospho-acetyl-coA carboxylase (p-ACC) and carnitine acyl transferase 1A (CPT-1A), and inhibited expression of lipid synthesis-related proteins, including sterol regulatory element-binding protein 1c (SREBP-1c) and fatty acid synthase (FAS). Additionally, DSG-treated cells displayed a marked improvement in mitochondrial function, with less production of reactive oxygen species and a higher mitochondrial membrane potential compared with the model group.

CONCLUSION

This study suggests that DSG can reduce intracellular lipid accumulation in LO2 cells and that the underlying mechanism may be related to the improving oxidative stress, increasing fatty acid β-oxidation and decreasing lipid synthesis. The above changes might be mediated by the activation of the AMPK/ACC/CPT-1A pathway and inhibition of the SREBP-1c/FAS pathway.

Protective Effects of Salidroside against Carbon Tetrachloride (CCl4)-Induced Liver Injury by Initiating Mitochondria to Resist Oxidative Stress in Mice

The antioxidant effect of salidroside has been proven, but its role in liver injury is poorly understood. In this study, we aimed to evaluate the protective effects and mechanism of salidroside on liver injury induced by carbon tetrachloride (CCl4) in vivo. Mice were pretreated with salidroside (60 mg/kg, intraperitoneally injected, i.p.) once per day for 14 consecutive days and then administered with CCl4 (15.95 g/kg, i.p.) for 24 h to produce a liver injury model. Salidroside attenuated hepatic transaminase elevation in serum and ameliorated liver steatosis and necrosis, thereby suggesting its protective effect on the liver. Salidroside antagonized CCl4-induced toxicity by equilibrating antioxidation system, thereby inhibiting reactive oxygen species accumulation, and restoring mitochondrial structure and function. Salidroside exerts antioxidant and liver-protective effects by selectively inhibiting the activation of genes, including growth arrest and DNA -damage-inducible 45 α (Gadd45a), mitogen-activated protein kinase 7 (Mapk7), and related RAS viral oncogene homolog 2 (Rras2), which induce oxidative stress in the mitogen-activated protein kinase pathway. These results revealed that salidroside can protect the liver from CCl4-induced injury by resisting oxidative stress and protecting mitochondrial function.

2, 3, 4', 5-tetrahydroxystilbene-2-0-β-d Glycoside Attenuates Age- and Diet-Associated Non-Alcoholic Steatohepatitis and Atherosclerosis in LDL Receptor Knockout Mice and Its Possible Mechanisms

The compound, 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside (TSG), a primary bioactive polyphenolic component of Polygonum multiflorum exerts numerous pharmacological activities. However, its protective effect against non-alcoholic steatohepatitis (NASH), in the context of metabolic syndrome, remains poorly understood. The aim of the present study is to evaluate the effects of TSG treatment on middle-aged (12-mo-old) male LDLr^-/- mice, which were fed a high fat diet for 12 weeks to induce metabolic syndrome and NASH. At the end of the experiment, the blood samples of mice were collected for determination of metabolic parameters. Liver and aorta tissues were collected for analysis, such as histology, immunofluorescence, hepatic lipid content, real-time PCR, and western blot. Our data show that TSG treatment improved the different aspects of NASH (steatosis, inflammation, and fibrosis) and atherosclerosis, as well as some of the metabolic basal characteristics. These modulatory effects of TSG are mediated, at least in part, through regulating key regulators of lipid metabolism (SREBP1c, PPARα and their target genes, ABCG5 and CYP7A1), inflammation (CD68, TNF-α, IL-6 and ICAM), fibrosis (α-SMA and TNFβ) and oxidative stress (NADPH-oxidase 2/4, CYP2E1 and antioxidant enzymes). These results suggest that TSG may be a promising candidate for preventing and treating the progression of NASH.

Long-Term Measures of Dyslipidemia, Inflammation, and Oxidative Stress in Rats Fed a High-Fat/High-Fructose Diet

Inflammation and oxidative stress are thought to be involved in, or associated with, the development of obesity, dyslipidemia, hepatic steatosis, and insulin resistance. This work was designed to determine the evolution of inflammation and oxidative stress during onset and progression of hepatic steatosis and glucose intolerance. Seventy-five male Wistar rats were divided to control and high-fat high-fructose (HFHFr) groups. A subgroup of each group was sacrificed at 4, 8, 12, 16, and 20 weeks. HFHFr-fed rats exhibited overweight, glucose intolerance, and hepatic steatosis with increased contents of hepatic diacylglycerols and ceramides. The HFHFr diet increased hepatic interleukin 6 (IL-6) protein and adipose tissue CCL5 gene expression and hepatic nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity but not mitochondrial reactive oxygen species (ROS) production. The HFHFr diet decreased plasma and liver levels of isoprostanoid metabolites as well as plasma thiobarbituric acid-reactive substance (TBARS) levels. Hepatic glutathione content was decreased with a moderate decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPx) with the HFHFr diet. Overall, HFHFr diet led to hepatic lipid accumulation and glucose intolerance, which were accompanied by only moderate inflammation and oxidative stress. Most of these changes occurred at the same time and as early as 8 or 12 weeks of diet treatment. This implies that oxidative stress may be the result, not the cause, of these metabolic alterations, and suggests that marked hepatic oxidative stress should probably occur at the end of the steatotic stage to result in frank insulin resistance and steatohepatitis. These findings need to be further evaluated in other animal species as well as in human studies.

Salidroside protects LPS-induced injury in human thyroid follicular epithelial cells by upregulation of MiR-27a

AIMS

Hypothyroidism is a common endocrine disease without standard treatment. Salidroside (SAL) has various positive biological activities. In this study, experiments were performed to investigate whether SAL had protective effects on LPS-induced cell inflammatory injury.

MAIN METHODS

The human thyroid follicular epithelial cells (Nthy-ori 3-1) stimulated by LPS were treated with SAL and/or transfected with miR-27a inhibitor. Cell viability and cell apoptosis were detect by Cell Counting Kit-8 assay and flow cytometry, respectively. The expression of Cyclin D1 and apoptosis-related proteins, Notch proteins and NF-κB pathways related proteins were all measured by western blot. The expression of miR-27a and inflammatory chemokines MCP-1, IL-6 and TNF-α was examined by qRT-PCR. The protein weight of MCP-1, IL-6 and TNF-α was detected by ELISA.

KEY FINDINGS

LPS treatment induced cell injury by decreasing cell viability, and inducing cell apoptosis and inflammatory chemokines MCP-1, IL-6 and TNF-α. In addition, SAL alleviated LPS-induced cell injury by increasing cell viability, and decreasing cell apoptosis and inflammatory chemokines MCP-1, IL-6 and TNF-α. SAL upregulated miR-27a expression and further study showed that miR-27a downregulation impaired the protective effects of SAL. SAL downregulated the expression of Notch1/2, and phosphorylation of p65 and IκBα.

SIGNIFICANCE

SAL protects against LPS-induced injury in human thyroid follicular epithelial cells by upregulation of miR-27a. This process might be via inactivating Notch and NF-κB pathways.

Salidroside Attenuates High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease via AMPK-Dependent TXNIP/NLRP3 Pathway

Our previous studies suggested that salidroside could alleviate hepatic steatosis in type 2 diabetic C57BLKS/Lepr^db (db/db) mice. The aim of the present study was to evaluate the therapeutic effect of salidroside on high-fat diet- (HFD-) induced nonalcoholic fatty liver disease (NAFLD) by investigating underlying mechanisms. Mice were fed with HFD or regular diet, randomly divided into two groups, and treated with salidroside or vehicle for 8 weeks. Then, biochemical analyses and histopathological examinations were conducted in vivo and in vitro. Salidroside administration attenuated HFD-induced obesity, blood glucose variability, and hepatic lipid deposition, markedly increasing insulin sensitivity in HFD mice. In addition, salidroside suppressed oxidative stress, thioredoxin-interacting protein (TXNIP) expression, and NLRP3 inflammasome activation in the liver. In cultured hepatocytes, salidroside dose dependently regulated lipid accumulation, reactive oxygen species (ROS) generation, and NLRP3 inflammasome activation as well as improved AMP-activated protein kinase (AMPK) activity and insulin sensitivity. The inhibition of AMPK activation by inhibitor or short interfering RNA (siRNA) resulted in the suppression of the beneficial effects of salidroside in hepatocytes. Our findings demonstrated that salidroside protects against NAFLD by improving hepatic lipid metabolism and NLRP3 inflammasome activation, and these actions are related to the regulation of the oxidative stress and AMPK-dependent TXNIP/NLRP3 pathways.

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and liver fibrosis: A review

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) are key producer of reactive oxygen species in liver cells. Hepatic stellate cells (HSCs) and Kupffer cells (KCs) are the two key cells for expression of NOX in liver. KCs produce only NOX2, while HSCs produce NOX1, 2, and 4, all of which play essential roles in the process of fibrogenesis within liver. These NOX subtypes are contributed to induction of liver fibrosis by acting through multiple pathways including induction of HSC activation, proliferation, survival and migration, stimulation of hepatocyte apoptosis, enhancement of fibrogenic mediators, and mediation of an inflammatory cascade in both KCs and HSCs.

SIGNIFICANCE

KCs and HSCs are two key cells for production of NOX in liver in relation to the pathology of liver fibrosis. NOX subtypes 1, 2, and 4 are inducers of fibrogenesis in liver. NOX activation favors hepatocyte apoptosis, HSC activation, and KC-mediated inflammatory cascade in liver, all of which are responsible for generation of liver fibrosis.

Salidroside mediates apoptosis and autophagy inhibition in concanavalin A-induced liver injury

Salidroside (Sal) is a glycoside extract from Rhodiola rosea L. with anti-inflammatory, antioxidant, anticancer and cardioprotective properties. The present study explored the protective effects and the possible mechanisms of Sal on concanavalin A (ConA)-induced liver injury in mice. Balb/C mice were divided into five groups: Normal control (injected with normal saline), ConA (25 mg/kg), Sal (10 mg/kg) +ConA, Sal (20 mg/kg) + ConA (Sal injected 2 h prior to ConA injection) and Sal (20 mg/kg) only. The serum levels of liver enzymes, pro-inflammatory cytokines, and apoptosis- and autophagy-associated marker proteins were determined at 2, 8 and 24 h after ConA injection. LY294002 was further used to verify whether the phosphoinositide 3-kinase (PI3K)/Akt pathway was activated. Primary hepatocytes were isolated to verify the effect of Sal in vitro. The results indicated that Sal was a safe agent to reduce pathological damage and serum liver enzymes in ConA-induced liver injury. Sal suppressed inflammatory reactions in serum and liver tissues, and activated the PI3K/Akt signaling pathway to inhibit apoptosis and autophagy in vivo and in vitro, which could be reversed by LY294002. In conclusion, Sal attenuated ConA-induced liver injury by modulating PI3K/Akt pathway-mediated apoptosis and autophagy in mice.

Salidroside induces apoptosis in human ovarian cancer SKOV3 and A2780 cells through the p53 signaling pathway

Salidroside is one of the most potent compounds extracted from the plant Rhodiola rosea, and its cardiovascular protective effects have been studied extensively. However, the role of salidroside in human ovarian carcinoma remains unknown. The aim of the current study was to investigate the effects of salidroside on the proliferation and apoptosis of SKOV3 and A2780 cells using MTT assay and acridine orange/ethidium bromide staining. Salidroside activated caspase-3 and upregulated the levels of apoptosis-inducing factor, Bcl-2-associated X and Bcl-2-associated death promoter (Bad) proteins. Furthermore, salidroside downregulated the levels of Bcl-2, p-Bad and X-linked inhibitor of apoptosis proteins. Salidroside activated the caspase-dependent pathway in SKOV3 and A2780 cells, upregulating p53, p21^Cip1/Waf1 and p16^INK4a. These results suggest that the p53/p21^Cip1/Waf1/p16^INK4a pathway may serve a key function in salidroside-mediated effects on SKOV3 and A2780 cells. The current findings indicate that salidroside may be a promising novel drug candidate for ovarian cancer therapy.

Time-dependent effects of late-onset dietary intake of salidroside on lifespan and age-related biomarkers of the annual fish Nothobranchius guentheri

One of the most studied and widely accepted conjectures of aging process is the oxidative stress theory. Previous studies have shown that salidroside can protect D-galactose-induced mouse model against aging and a formulation of Rhodiola rosea extracts (SHR-5) containing salidroside increases lifespan of fruit fly. However, direct evidence linking salidroside itself with the observed anti-aging effect in vivo and relevant molecular mechanisms are poorly defined. In this study, we first demonstrated that salidroside exhibited a time-dependent effect, and late-onset long-term salidroside dietary intake extended the lifespan in the annual fish Nothobranchius guentheri. We then showed that salidroside reduced the accumulation of lipofuscin in the gills as well as the levels of protein oxidation, lipid peroxidation and reactive oxygen species in the muscles; enhanced the activities of catalase, glutathione peroxidase, and superoxide dismutase in the fish; and decelerated the increase of P66shc, a critical factor for regulation of intracellular reactive oxygen species contents. Collectively, these data indicate that salidroside can prolong the lifespan and retard the onset of age-related biomarkers via the antioxidant system in aging fish. It also suggests that salidroside may have a potential usefulness in prolonging the lifespan of the elderly.

Salidroside ameliorates autophagy and activation of hepatic stellate cells in mice via NF-κB and TGF-β1/Smad3 pathways

PURPOSE

Liver fibrosis is commonly seen and a necessary stage in chronic liver disease. The aim of this study was to explore the effect of salidroside on liver fibrosis in mice and its potential mechanisms.

MATERIALS AND METHODS

Two mouse liver fibrosis models were established by intraperitoneal injection of carbon tetrachloride (CCl₄) for 8 weeks and bile duct ligation for 14 days. Salidroside was injected intraperitoneally at doses of 10 and 20 mg/kg once a day. Gene and protein expression levels were determined by quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, Western blot, immunohistochemistry, and immunofluorescence.

RESULTS

Salidroside inhibited the production of extracellular matrix (ECM) and regulated the balance between MMP2 and TIMP1 and, therefore, alleviated liver fibrosis in the two fibrosis models. Salidroside reduced the production of transforming growth factor (TGF)-β1 in Kupffer cells and hepatic stellate cells (HSCs) via the nuclear factor-κB signaling pathway and, therefore, inhibited the activation of HSCs and autophagy by downregulation of the TGF-β1/Smad3 signaling pathway.

CONCLUSION

Salidroside can effectively attenuate liver fibrosis by inhibiting the activation of HSCs in mice.

Salidroside slows the progression of EA.hy926 cell senescence by regulating the cell cycle in an atherosclerosis model

Aging is the major risk factor for diseases of the cardiovascular system, such as coronary atherosclerotic heart disease, but little is known about the relationship between atherosclerosis (AS) and age-related declines in vascular structure and function. Here, we used histological analyses in combination with molecular biology techniques to show that lipid deposition in endothelial cell was accompanied by aging and growth arrest. Endothelial cell senescence is sufficient to cause AS; however, we found that salidroside reduced intracellular lipid deposition, slowed the progression of endothelial cell senescence and inhibited the expression of the senescence-related molecules and phosphorylated the retinoblastoma (Rb) protein. Further study confirmed that salidroside increased the percent of S phase cells in oxidized low-density lipoprotein (ox-LDL)-treated endothelial cells. Collectively, vascular endothelial cell function declined with age and AS, and our data suggested that salidroside prevented ox-LDL-treated endothelial cell senescence by promoting cell cycle progression from G0/G1 phase to S phase via Rb phosphorylation. We demonstrated for the first time the complex interactions between AS and endothelial cell senescence, and we believe that salidroside represents a promising therapy for senescence-related AS.

The effect of β-caryophyllene on nonalcoholic steatohepatitis

The pathogenesis of nonalcoholic steatohepatitis (NASH) is not fully understood, but many studies have suggested that oxidative stress plays a key role. The methionine- and choline-deficient diet (MCD) administration model can reproduce histopathological features of human NASH and is widely used for investigating NASH. C57BL/6J mice have been used in many studies, but strain differences in pathogenesis have not been sufficiently investigated. We administred MCD to two mouse strains and then compared difference between strains and investigated the effects of β-caryophyllene (BCP), which possesses an antioxidant effect, on development and progression of NASH. ICR and C57BL/6J mice were administred a control diet, MCD, MCD containing 0.02% BCP, or MCD containing 0.2% BCP. After 4 or 8 weeks, mice were sacrificed. In both strains, MCD administration induced hepatic steatosis and inflammation. These lesions were more severe in C57BL/6J mice than ICR mice, and liver fibrosis was observed at 8 weeks in C57BL/6J mice. These changes were attenuated by BCP coadministration. The mRNA expression of monocyte chemotactic and activating factor (MCP)-1 and fibrosis-related factors increased in C57BL/6J mice, and these increases were reduced by BCP coadministration. The mRNA expression of antioxidant-related factors decreased in both strains, and these decreases were attenuated by BCP coadministration. Based on these results, the C57BL/6J mouse was a more suitable model for MCD-induced NASH than the ICR mouse. In addition, it was suggested that antioxidant effect of BCP might suppressed the damage of hepatocytes caused by oxidative stress and following inflammation and fibrosis.

Salidroside protects PC12 cells from Aβ1‑40‑induced cytotoxicity by regulating the nicotinamide phosphoribosyltransferase signaling pathway

Alzheimer's disease (AD) is the most common type of senile dementia, which often develops in elderly or presenile individuals. As one of the pathological features of AD, amyloid β-protein (Aβ) causes energy dysmetabolism, thereby inducing cellular damage and apoptosis. Salidroside is the main active component of the traditional Chinese medicine Rhodiola. Previous studies have demonstrated that salidroside exerts a regulatory role in energy metabolism. However, the role and the mechanism of action of salidroside in AD remain unclear. Therefore, the present study used Aβ1–40 to induce damage in PC12 cells, thereby establishing a cell model of AD. In addition, salidroside treatment was performed to investigate the protective effect of salidroside and the underlying mechanisms. Aβ1-40-induced neuronal toxicity reduced cell viability and caused cellular damage. As a result, the expression level of nicotinamide phosphoribosyltransferase (NAMPT) decreased, the synthesis of nicotinamide adenine dinucleotide (NAD⁺; an energy metabolism-associated coenzyme) became insufficient, and the NAD⁺/nicotinamide adenine dinucleotide hydride ratio was reduced. Administration of salidroside alleviated Aβ-induced cell damage and increased the expression level of the key protein NAMPT and the synthesis of NAD⁺. The results of the present study demonstrate that salidroside exerts a protective effect on Aβ1-40-damaged PC12 cells. The underlying mechanism may be associated with the regulation of energy metabolism that relies predominantly on the NAMPT signaling pathway.

Mitotherapy for Fatty Liver by Intravenous Administration of Exogenous Mitochondria in Male Mice

Mitochondrial dysfunction is a major and common mechanism in developing non-alcoholic fatty liver disease (NAFLD). Replacement of dysfunctional mitochondria by functional exogenous mitochondria may attenuate intrahepatic excessive lipid and recover hepatocyte function. However, no data shows that mitochondria can be systemically administrated to animals to date. Here we suggest that mitochondria isolated from hepatoma cells are used as a mitotherapy agent to treat mouse fatty liver induced by high-fat diets. When the mitochondria were intravenously injected into the mice, serum aminotransferase activity and cholesterol level decreased in a dose-dependent manner. Also, the mitotherapy reduced lipid accumulation and oxidation injury of the fatty liver mice, improved energy production, and consequently restored hepatocyte function. The mitotherapy strategy offers a new potential therapeutic approach for treating NAFLD.

Salidroside Modulates Insulin Signaling in a Rat Model of Nonalcoholic Steatohepatitis

A growing body of evidence has shown the beneficial effects of salidroside in cardiovascular and metabolic diseases. This study aimed to evaluate the therapeutic effects of salidroside on nonalcoholic steatohepatitis (NASH) in rats and explore the underlying mechanisms related to insulin signaling. A rat model of NASH was developed by high-fat diet for 14 weeks. From week 9 onward, the treatment group received oral salidroside (4.33 mg/kg) daily for 6 weeks. Salidroside effectively attenuated steatosis and vacuolation of hepatic tissue, with a dramatic decrease in liver triglycerides and free fatty acid levels (P < 0.01). Dysregulation of FINS, FBG, HOMA-IR, ALT, and AST in serum was ameliorated with salidroside treatment (P < 0.01). In the liver, salidroside induced significant increases in key molecules in the insulin signaling pathway, such as phosphorylated insulin receptor substrate 1 (IRS1), phosphoinositide 3-kinase (PI3K), and protein kinase B (PKB), with a significant decrease in SREBP-1c levels (P < 0.01). Therefore, salidroside effectively protected rats from high-fat-diet-induced NASH, which may be partially attributed to its effects on the hepatic insulin signaling pathway.