Cross-species analysis of differential transcript usage in humans and chickens with fatty liver disease

Background and Aim

Fatty liver disease is a common condition, characterized by excess fat accumulation in the liver. It can contribute to more severe liver-related health issues, making it a critical concern in avian and human medicine. Apart from modifying the gene expression of liver cells, the disease also alters the expression of specific transcript isoforms, which might serve as new biological markers for both species. This study aimed to identify cross-species genes displaying differential expressions in their transcript isoforms in humans and chickens with fatty liver disease.

Materials and Methods

We performed differential gene expression and differential transcript usage (DTU) analyses on messenger RNA datasets from the livers of both chickens and humans with fatty liver disease. Using appropriate cross-species gene identification methods, we reviewed the acquired candidate genes and their transcript isoforms to determine their potential role in fatty liver disease's pathogenesis.

Results

We identified seven genes - ALG5, BRD7, DIABLO, RSU1, SFXN5, STIMATE, TJP3, and VDAC2 - and their corresponding transcript isoforms as potential candidates (false discovery rate ≤0.05). Our findings showed that these genes most likely contribute to fatty disease development and progression.

Conclusion

This study successfully identified novel human-chicken DTU genes in fatty liver disease. Further research is encouraged to verify the functions and regulations of these transcript isoforms as potential diagnostic markers for fatty liver disease in humans and chickens.

Natural saponin and cholesterol assembled nanostructures as the promising delivery method for saponin

The application of saponins has been restricted by problems such as hemolysis, low bioavailability, and poor solubility. So it is imperative to find a strategy to deliver saponins safely and efficiently. Here, through bottom-up technique, we design and prepare two saponin-cholesterol (Cho) nano-complex: dioscin (Dio, steroid saponin)-Cho nanofibers (NFs) and escin Ia (EIa, triterpene saponin)-Cho nanoparticles (NPs). It is found that the hydrophobic force and hydrogen bonding drive the two pairs of molecules to bind in different directions (the 3β-OH of Cho face the sugar chain of EIa and the 22α-O of Dio, respectively) and finally show spherical NPs (EIa-Cho) and fibrous NFs (Dio-Cho). The equimolar saponin-Cho complex, Dio NFs and EIa NPs, reveal potent cytotoxicities against mouse breast cancer cells (4T1) in vitro. In vivo results confirm the antitumor (4T1 mice model) efficacy of PEGylation Dio NFs (10 mg/kg, i.v.) with a tumor inhibition rate of 61%, meanwhile, it does not cause extreme irritation and pain as free Dio does to mice. Moreover, compared with the free drug, the prepared nano-complex can significantly reduce hemolysis and organ toxicity. Our research reduces the toxicity of saponins while retaining their antitumor activity, providing a new strategy for the delivery of saponins.

Effect and possible mechanisms of dioscin on ameliorating metabolic glycolipid metabolic disorder in type-2-diabetes

BACKGROUND

Our previous study revealed that microRNA-125a-5p plays a crucial role in regulating hepatic glycolipid metabolism by targeting STAT3 in type 2 diabetes mellitus (T2DM). Dioscin, a major active ingredient in Dioscoreae nipponicae rhizomes, displays various pharmacological activities, but its role in T2DM has not been reported.

PURPOSE

The aim of this study was to investigate the effect of dioscin on T2DM and elucidate its potential mechanism.

METHODS

The effect of dioscin on glycolipid metabolic disorder in insulin-induced HepG2 cells, palmitic acid-induced AML12 cells, high-fat diet- and streptozotocin- induced T2DM rats, and spontaneous T2DM KK-Ay mice were evaluated. Then, the possible mechanisms of dioscin were comprehensively evaluated.

RESULTS

Dioscin markedly alleviated the dysregulation of glycolipid metabolism in T2DM by reducing hyperglycemia and hyperlipidemia, improving insulin resistance, increasing hepatic glycogen content, and attenuating lipid accumulation. When the mechanism was investigated, dioscin was found to markedly elevate miR-125a-5p level and decrease STAT3 expression. Consequently, dioscin increased phosphorylation levels of STAT3, PI3K, AKT, GSK-3β, and FoxO1 and decreased gene levels of PEPCK, G6Pase, SREBP-1c, FAS, ACC, and SCD1, leading to an increase in glycogen synthesis and a decrease in gluconeogenesis and lipogenesis. The effects of dioscin on regulating miR-125a-5p/STAT3 pathway were verified by miR-125a-5p overexpression and STAT3 overexpression.

CONCLUSIONS

Dioscin showed potent anti-T2DM activity by improving the inhibitory effect of miR-125a-5p on STAT3 signaling to alleviate glycolipid metabolic disorder of T2DM.

Flavone glycosides from Sicyos angulatus and their inhibitory effects on hepatic lipid accumulation

A library of extracted natural materials (Korea Bioactive Natural Material Bank) have been screened to discover candidates for the treatment of non-alcoholic liver disease (NAFLD), and the 70% ethanol extract of Sicyos angulatus was found to inhibit hepatic lipid accumulation. Bioassay-guided fractionation of this bioactive extract yielded five previously undescribed flavonoid glycosides and one previously undescribed flavonolignan glycoside along with seven known flavonoid glycosides. The chemical structures of these compounds were elucidated by a combination of extensive spectroscopic analysis, including MS, NMR and UV techniques. Eight compounds of all isolated compounds showed inhibitory effects on the lipid accumulation induced by high concentrations of palmitic acid and glucose in HepG2 cells. Four selected compounds were tested for lipid content in a dose-dependent manner (10, 20 and 40 μM), and among those compounds, kaempferol 3-O-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside showed the strongest inhibition of hepatic lipid production in HepG2 cells. In an oil-red O staining assay, five compounds were shown to reduce hepatic lipid accumulation better than what was observed in the vehicle control group. The present study suggests a new class of chemical entities for developing bioactive agents for the treatment of diseases caused by fat accumulation in the liver.

Isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomics for the investigation of the effect of Hugan Qingzhi on non-alcoholic fatty liver disease in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Hugan Qingzhi tablet (HQT), a traditional Chinese medicine formula has been adopted for preventing and treating nonalcoholic fatty liver disease (NAFLD).

AIM

In order to explore the anti-NAFLD mechanisms of HQT, iTRAQ-based proteomic was employed to investigate the expression profiles of proteins in NAFLD rats induced by high-fat diet after HQT treatment.

MATERIALS AND METHODS

The NAFLD rat model was administrated with high-fat diet (HFD) for 12weeks. HQT was administrated in a daily basis to the HFD groups. Biochemical markers, liver histology, pro-inflammatory cytokines, and oxidative stress/antioxidant biomarkers were assayed to evaluate HQT effects in HFD-induced NAFLD rats. Furthermore, the combined strategy of iTRAQ labeling with strong cation exchange-non-liquid chromatography-tandem mass spectrometry (SCX-non-LC-MS/MS) analysis were employed to explore the mechanisms of HQT's protective effect against NAFLD in rats. Western blotting was performed to verify the proteomic results.

RESULTS

The histopathologic characteristics and biochemical data showed that HQT exhibited protective effects on HFD-induced NAFLD rats. After being analyzed by the combined strategy of iTRAQ with LC-MS/MS and subsequent investigation, we identified 275 differentially expressed proteins in the HFD group, compared to the control; 207 altered proteins in the HQT high dose + HFD group, compared to the HFD group; and 316 altered proteins in the HQT high dose + HFD group, compared to the control. Based on the Kyoto Encyclopedia of Gene and Genomes (KEGG) pathway mapping, the conclusion has reached that several pathways including microbial metabolism in diverse environments, fatty acid metabolism, inflammatory response, oxidative stress, bile secretion, and peroxisome proliferator activated receptor (PPAR) signaling pathway were closely related to the effects of HQT in HFD-induced NAFLD in rats. Furthermore, several differentially expressed proteins, including phytanoyl-CoA 2-hydroxylase (PHYH), acyl-CoA synthetase 1 long chain (ACSL1), hemopexin, Alpha-1-acid glycoprotein (ORM1), fatty acid binding protein 4 (FABP4), soluble sulphotransferase 2a1 (Sult2a1), and argininosuccinate synthase 1 (ASS1) were verified by the western blotting analysis and these results were consistent with the data obtained from the proteomics analysis.

CONCLUSIONS

Our results not only confirm that Hugan Qingzhi exhibits a significant protective effect in HFD-induced NAFLD rats but also provide a better understanding for the treatments of NAFLD.

Effect of dioscin on promoting liver regeneration via activating Notch1/Jagged1 signal pathway

BACKGROUND

Development of novel candidates to promote liver regeneration is critical important after partial hepatectomy (PH). Dioscin, a natural product, shows potent effect on liver protection in our previous works.

PURPOSE

This work aimed to investigate the effect and underlying mechanisms of dioscin on liver regeneration.

METHODS

The promoting proliferation effects of dioscin on mouse hepatocytem AML12 cells, rat primary hepatocytes, rats and mice after 70% PH were evaluated.

RESULTS

Dioscin significantly promoted proliferation of rat primary hepatocytes and AML12 cells through MTT, BrdU and PCNA staining assays. Meanwhile, dioscin rapidly recovered the liver to body weight ratios, declined ALT and AST levels, and relieved hepatocytes necrosis compared with 70% PH operation groups in rats and mice. Mechanistic test showed that dioscin significantly increased Notch1 and Jagged1 levels, and accelerated γ-secretase activity by up-regulating PS1 expression, leading to nuclear translocation of Notch1 intracellular domain (NICD1). Subsequently, the significant activation of Notch-dependent target genes (Hey1, Hes1, EGFR, VEGF), and cell-cycle regulatory proteins (CyclinD1, CyclinE1, CDK4 and CDK2) were all recognized. In addition, these results were further confirmed by Notch1 siRNA silencing and inhibition of γ-secretase by DAPT (a well-characterized γ-secretase inhibitor) in vitro.

CONCLUSIONS

Dioscin, as a novel efficient γ-secretase activator, NICD1 nucleus translocation promoter and cell cycle regulator, markedly activated Notch1/Jagged1 pathway to promote hepato-proliferation. Our findings provide novel insights into dioscin as a natural product with facilitating liver regeneration after PH.

Protective effects of dioscin against cisplatin-induced nephrotoxicity via the microRNA-34a/sirtuin 1 signalling pathway

BACKGROUND AND PURPOSE

Dioscin exhibits a range of pharmacological actions but little is known of its effects on cisplatin (CDDP)-induced nephrotoxicity. Here, we have assessed the effects and the possible mechanisms of dioscin against CDDP-induced nephrotoxicity.

EXPERIMENTAL APPROACH

We used an in vivo model of CDDP-induced nephrotoxicity in rats and mice and, in vitro, cultures of NRK-52E and HK-2 cells. The dual luciferase reporter assay was used to demonstrate modulation, by dioscin, of the targeting of sirtuin 1 (Sirt1) by microRNA (miR)-34a. Molecular docking assays were used to analyse the effects of dioscin with Sirt1, Keap1 and NF-κB.

KEY RESULTS

Dioscin attenuated cell damage in vitro and decreased renal injury in rats and mice, treated with CDDP. In terms of mechanisms, dioscin reversed CDDP-induced up-regulation of miR-34a and thus up-regulated Sirt1 levels. In addition, dioscin altered levels of haem oxygenase 1, glutathione-cysteine ligase subunits (GCLC, GCLM) and Keap1, along with increased nuclear translocation of Nrf2, thus decreasing oxidative stress. Also, dioscin affected levels of AP-1, COX-2, HMGB1, IκB-α, IL-1β, IL-6 and TNF-α and decreased the ratio of acetylated NF-κB and normal NF-κB, to suppress inflammation. From molecular docking assays, dioscin directly bound to Sirt1, Keap1 and NF-κBp65 by hydrogen bonding and/or hydrophobic interactions.

CONCLUSIONS AND IMPLICATIONS

Our results have linked CDDP-induced nephrotoxicity and the miR-34a/Sirt1 signalling pathway, which was modulated by dioscin. This natural product could be developed as a new candidate to alleviate CDDP-induced renal injury.

Rutin exhibits hepatoprotective effects in a mouse model of non-alcoholic fatty liver disease by reducing hepatic lipid levels and mitigating lipid-induced oxidative injuries

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive accumulation of hepatic lipids and oxidative injury of hepatocytes. Rutin is a natural flavonoid with significant roles in combating cellular oxidative stress and regulating lipid metabolism. The current study aims to investigate the molecular mechanisms underlying rutin's hypolipidemic and hepatoprotective effects in nonalcoholic fatty liver disease. Rutin treatment was applied to male C57BL/6 mice maintained on a high-fat diet and HepG2 cells challenged with oleic acid. Hepatic lipid accumulation was evaluated by triglyceride assay and Oil Red O staining. Oxidative hepatic injury was assessed by malondialdehyde assay, superoxide dismutase assay and reactive oxygen species assay. The expression levels of various lipogenic and lipolytic genes were determined by quantitative real-time polymerase chain reactions. In addition, liver autophagy was investigated by enzyme-linked immunosorbent assay. In both fat-challenged murine liver tissues and HepG2 cells, rutin treatment was shown to significantly lower triglyceride content and the abundance of lipid droplets. Rutin was also found to reduce cellular malondialdehyde level and restore superoxide dismutase activity in hepatocytes. Among the various lipid-related genes, rutin treatment was able to restore the expression of peroxisome proliferator-activated receptor alpha (PPAR-α) and its downstream targets, carnitine palmitoyltransferase 1 and 2 (CPT-1 and CPT-2), while suppressing those of sterol regulatory element-binding protein 1c (SREBP-1c), diglyceride acyltransfase 1 and 2 (DGAT-1 and 2), as well as acyl-CoA carboxylase (ACC). In addition, rutin was shown to repress the autophagic function of liver tissues by down-regulating key autophagy biomarkers, including tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β). The experimental data demonstrated that rutin could reduce triglyceride content and mitigate oxidative injuries in fat-enriched hepatocytes. The hypolipidemic properties of rutin could be attributed to its ability to simultaneously facilitate fatty acid metabolism and inhibit lipogenesis.

Protective Effects of Dioscin against Lipopolysaccharide-Induced Acute Lung Injury through Inhibition of Oxidative Stress and Inflammation

The protective effects of dioscin, a natural steroidal saponin from some medicinal plants including Dioscorea nipponica Makino, against lipopolysaccharide (LPS)- induced acute liver and renal damages have been reported in our previous works. However, the actions of dioscin against LPS-induced acute lung injury (ALI) is still unknown. In the present study, we investigated the effects and mechanisms of dioscin against LPS-induced ALI in vitro and in vivo. The results showed that dioscin obviously inhibited cell proliferation and markedly decreased reactive oxidative species level in 16HBE cells treated by LPS. In addition, dioscin significantly protected LPS-induced histological changes, inhibited the infiltration of inflammatory cells, as well as decreased the levels of MDA, SOD, NO and iNOS in mice and rats (p < 0.05). Mechanistically, dioscin significantly decreased the protein levels of TLR4, MyD88, TRAF6, TKB1, TRAF3, phosphorylation levels of PI3K, Akt, IκBα, NF-κB, and the mRNA levels of IL-1β, IL-6, and TNF-α against oxidative stress and inflammation (p < 0.05). Dioscin significantly reduced the overexpression of TLR4, and obviously down-regulated the levels of MyD88, TRAF6, TKB1, TRAF3, p-PI3K, p-Akt, p-IκBα, and p-NF-κB. These findings provide new perspectives for the study of ALI. Dioscin has protective effects on LPS-induced ALI via adjusting TLR4/MyD88- mediated oxidative stress and inflammation, which should be a potent drug in the treatment of ALI.

Dioscin alleviates dimethylnitrosamine-induced acute liver injury through regulating apoptosis, oxidative stress and inflammation

In our previous study, the effects of dioscin against alcohol-, carbon tetrachloride- and acetaminophen-induced liver damage have been found. However, the activity of it against dimethylnitrosamine (DMN)-induced acute liver injury remained unknown. In the present study, dioscin markedly decreased serum ALT and AST levels, significantly increased the levels of SOD, GSH-Px, GSH, and decreased the levels of MDA, iNOS and NO. Mechanism study showed that dioscin significantly decreased the expression levels of IL-1β, IL-6, TNF-α, IκBα, p50 and p65 through regulating TLR4/MyD88 pathway to rehabilitate inflammation. In addition, dioscin markedly up-regulated the expression levels of SIRT1, HO-1, NQO1, GST and GCLM through increasing nuclear translocation of Nrf2 against oxidative stress. Furthermore, dioscin significantly decreased the expression levels of FasL, Fas, p53, Bak, Caspase-3/9, and upregulated Bcl-2 level through decreasing IRF9 level against apoptosis. In conclusion, dioscin showed protective effect against DMN-induced acute liver injury via ameliorating apoptosis, oxidative stress and inflammation, which should be developed as a new candidate for the treatment of acute liver injury in the future.

Dioscin reduces ovariectomy-induced bone loss by enhancing osteoblastogenesis and inhibiting osteoclastogenesis

Our previous studies showed that dioscin can promote osteoblasts proliferation and differentiation in vitro, but its anti-osteoporosis effect in vivo and the underlying mechanisms remain unclear. In the present work, the results showed that dioscin significantly increased the viability of MC3T3-E1 cells, ALP level and alizarin red S staining area, markedly decreased the numbers of RANKL-induced TRAP-positive multinucleated cells and bone resorption pits formation, enhanced the levels of some osteogenic markers including COL1A2, ALP and OC, which suggested that dioscin clearly promoted osteoblasts proliferation and suppressed osteoclasts formation. In vivo experiments demonstrated that dioscin obviously reduced OVX-induced body weight increase, and improved the biochemical indexes including ALP, StrACP, OC, DPD/Cr, HOP/Cr, BMD, biomechanics and microarchitecture. Moreover, H&E, TB, TRAP staining, and fluorescent double labeling tests indicated that dioscin enhanced osteoblastogenesis and inhibited osteoclastogenesis. Further researches demonstrated that dioscin promoted osteoblastogenesis through up-regulating OPG/RANKL ratio, and inhibited osteoclastogenesis through down-regulating the levels of RANKL induced TRAF6 and the downstream signal molecules including MAPKs, Akt, NF-κB, AP-1, cathepsin K and NFATc1. In addition, dioscin also inhibited TLR4/MyD88 pathway to decrease the levels of TRAF6 and the related proteins. These findings provide new insights to elucidate the effects of dioscin against OVX-induced bone loss, which should be developed as a potential candidate for treating postmenopausal osteoporosis in the future.

Potent effects of dioscin against gastric cancer in vitro and in vivo

BACKGROUND

We previously reported the effect of dioscin on human gastric carcinoma SGC-7901 cells, but its effects on other gastric cancers are still unknown.

PURPOSE

The present paper aimed to demonstrate the activity of dioscin against human gastric carcinoma MGC-803 and MKN-45.

STUDY DESIGN

In our study, MGC-803 and MKN-45 cells were used to examine the effects of dioscin on human gastric carcinoma in vitro. The effects of dioscin against human gastric carcinoma in vivo were accomplished by the xenografts of MGC-803 cells in BALB/c nude mice.

METHODS

AO/EB and DAPI staining, TEM, single cell gel electrophoresis and flow cytometry assays were used in cell experiments. Then, an iTRAQ-based proteomics approach, DNA and siRNA transfection experiments were carried out for mechanism investigation.

RESULTS

In MGC-803 cells, dioscin caused DNA damage and mitochondrial change, induced ROS generation, Ca(2+) release and cell apoptosis, and blocked cell cycle at S phase. In vivo results showed that dioscin significantly suppressed the tumor growth of MGC-803 cell xenografts in nude mice. In addition, dioscin markedly inhibited cell migration, caused Cytochrome c release and adjusted mitochondrial signal pathway. Then, an iTRAQ-based proteomics approach was carried out and 121 differentially expressed proteins were found, in which five biomarkers associated with cell cycle, apoptosis and migration were evaluated. Dioscin significantly up-regulated the levels of GALR-2 and RBM-3, and down-regulated CAP-1, Tribbles-2 and CliC-3. Furthermore, overexpressed DNA transfection of CAP-1 enhanced cell migration and invasion, which was decreased by dioscin. SiRNA to Tribbles-2 affected the protein levels of Bcl-2, Bax and MAPKs, suggesting that dioscin decreased Tribbles-2 level leading to cell apoptosis.

CONCLUSION

Our works confirmed the activity of dioscin against gastric cancer. In addition, this work also provided that dioscin is a new potent candidate for treating gastric cancer in the future.

iTRAQ-based quantitative proteomic analysis for identification of biomarkers associated with emodin against severe acute pancreatitis in rats

Emodin has potent actions against SAP injury by inhibiting the HTRA1/TGF-β1 signaling pathway and subsequent inflammatory responses.

Potential hepatoprotective effects of fullerenol nanoparticles on alcohol-induced oxidative stress by ROS

The free radical scavenging ability of fullerenols is their most exploited property in biomedical studies.

Dioscin alleviates alcoholic liver fibrosis by attenuating hepatic stellate cell activation via the TLR4/MyD88/NF-κB signaling pathway

The present work aimed to investigate the activities and underlying mechanisms of dioscin against alcoholic liver fibrosis (ALF). In vivo liver fibrosis in mice was induced by an alcoholic liquid diet, and in vitro studies were performed on activated HSC-T6 and LX2 cells treated with lipopolysaccharide. Our results showed that dioscin significantly attenuated hepatic stellate cells (HSCs) activation, improved collagen accumulation, and attenuated inflammation through down-regulating the levels of myeloid differentiation factor 88 (MyD88), nuclear factor κB (NF-κB), interleukin (IL)-1, IL-6 and tumour necrosis factor-α by decreasing Toll-like receptor (TLR)4 expression both in vivo and in vitro. TLR4 overexpression was also decreased by dioscin, leading to the markedly down-regulated levels of MyD88, NF-κB, transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA) and type I collagen (COL1A1) in cultured HSCs. Suppression of cellular MyD88 by ST2825 or abrogation of NF-κB by pyrrolidine dithiocarbamate eliminated the inhibitory effects of dioscin on the levels of TGF-β1, α-SMA and COL1A1. In a word, dioscin exhibited potent effects against ALF via altering TLR4/MyD88/NF-κB signaling pathway, which provided novel insights into the mechanisms of this compound as an antifibrogenic candidate for the treatment of ALF in the future.

Dioscin attenuates renal ischemia/reperfusion injury by inhibiting the TLR4/MyD88 signaling pathway via up-regulation of HSP70

We previously reported the effect of dioscin against hepatic ischemia/reperfusion injury (IRI) in rats. However, little is known concerning the role of dioscin in renal IRI. In the present study, rats were subjected to IRI and dioscin was intragastrically administered for seven consecutive days before surgery. In vitro models of hypoxia/reoxygenation were developed in NRK-52E and HK-2 cells, which were prophylactically treated with or without dioscin. The results showed that dioscin significantly decreased serum BUN and Cr levels, and markedly attenuated cell injury. Mechanistic studies showed that dioscin significantly increased HSP70 levels, decreased the levels of TLR4, MyD88, TRAF6, COX-2, JNK, ERK and p38 MAPK phosphorylation, suppressed the nuclear translocation of NF-κB and HMGB1, and subsequently decreased the mRNA levels of IL-1β, IL-6, TNF-α, ICAM-1 and IFN-γ. Moreover, HSP70 siRNA or TLR4 DNA reversed the nephroprotective effects of dioscin, while dioscin still significantly down-regulated the TLR4 signaling pathway. Furthermore, by inhibiting MyD88 with ST2825 (a MyD88 inhibitor), renal IRI was significantly attenuated, suggesting that the effect of dioscin against renal IRI depended on MyD88. Our results suggested that dioscin had a potent effect against renal IRI through suppressing the TLR4/MyD88 signaling pathway by up-regulating HSP70. These data provide new insights for investigating the natural product with the nephroprotective effect against IRI, which should be developed as a new therapeutic agent for the treatment of acute kidney injury in the future.

Sechium edule Shoot Extracts and Active Components Improve Obesity and a Fatty Liver That Involved Reducing Hepatic Lipogenesis and Adipogenesis in High-Fat-Diet-Fed Rats

Excess fat accumulation in the liver increases the risk of developing progressive liver injuries ranging from a fatty liver to hepatocarcinoma. In a previous study, we demonstrated that the polyphenol components of Sechium edule shoots attenuated hepatic lipid accumulation in vitro. Therefore, we investigated the effects and mechanisms of the extract of S. edule shoots (SWE) to modulate fat accumulation in a high-fat-diet (HFD)-induced animal model. In this study, we found that the SWE can reduce the body weight, adipose tissue fat, and regulate hepatic lipid contents (e.g., triglyceride and cholesterol). Additionally, treatment of caffeic acid (CA) and hesperetin (HPT), the main ingredients of SWE, also inhibited oleic acid (OA)-induced lipid accumulation in HepG2 cells. SWE enhanced the activation of AMP-activating protein kinase (AMPK) and decreased numerous lipogenic-related enzymes, such as sterol regulator element-binding proteins (SREBPs), e.g., SREBP-1 and SREBP-2, and HMG-CoA reductase (HMGCoR) proteins, which are critical regulators of hepatic lipid metabolism. Taken together, the results demonstrated that SWE can prevent a fatty liver and attenuate adipose tissue fat by inhibiting lipogenic enzymes and stimulating lipolysis via upregulating AMPK. It was also demonstrated that the main activation components of SWE are both CA and HPT.

Potent effects of dioscin against liver fibrosis

We previously reported the promising effects of dioscin against liver injury, but its effect on liver fibrosis remains unknown. The present work investigated the activities of dioscin against liver fibrosis and the underlying molecular mechanisms. Dioscin effectively inhibited the cell viabilities of HSC-T6, LX-2 and primary rat hepatic stellate cells (HSCs), but not hepatocytes. Furthermore, dioscin markedly increased peroxisome proliferator activated receptor-γ (PPAR-γ) expression and significantly reduced a-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1), collagen α1 (I) (COL1A1) and collagen α1 (III) (COL3A1) levels in vitro. Notably, dioscin inhibited HSCs activation and induced apoptosis in activated HSCs. In vivo, dioscin significantly improved body weight and hydroxylproline, laminin, α-SMA, TGF-β1, COL1A1 and COL3A1 levels, which were confirmed by histopathological assays. Dioscin facilitated matrix degradation, and exhibited hepatoprotective effects through the attenuation of oxidative stress and inflammation, in addition to exerting anti-fibrotic effects through the modulation of the TGF-β1/Smad, Wnt/β-catenin, mitogen-activated protein kinase (MAPK) and mitochondrial signaling pathways, which triggered the senescence of activated HSCs. In conclusion, dioscin exhibited potent effects against liver fibrosis through the modulation of multiple targets and signaling pathways and should be developed as a novel candidate for the treatment of liver fibrosis in the future.

Potent effects of dioscin against obesity in mice

The mechanisms of the natural product dioscin against non-alcoholic fatty liver disease (NAFLD) are unclear. Thus, the purpose of the present study was to further confirm its effects of prevention and then to elucidate the potential mechanisms underlying its activity in mice. High-fat diet (HFD)-induced C57BL/6J mice and ob/ob mice were used as the experimental models. Serum and hepatic biochemical parameters were determined, and the mRNA and protein expression levels were detected. The results indicated that dioscin alleviated body weight and liver lipid accumulation symptoms, increased oxygen consumption and energy expenditure, and improved the levels of serum and hepatic biochemical parameters. Further investigations revealed that dioscin significantly attenuated oxidative damage, suppressed inflammation, inhibited triglyceride and cholesterol synthesis, promoted fatty acid β-oxidation, down-regulated MAPK phosphorylation levels, and induced autophagy to alleviate fatty liver conditions. Dioscin prevents diet induced obesity and NAFLD by increasing energy expenditure. This agent should be developed as a new candidate for obesity and NAFLD prevention.

Quantitative chemical proteomics for investigating the biomarkers of dioscin against liver fibrosis caused by CCl4 in rats

2D-DIGE technology was used for screening the biomarkers and drug-targets of dioscin against liver fibrosis in rats caused by CCl₄.