Protective effect of ethyl acetate extract from Bidens bipinnata on hepatocyte damage induced by endoplasmic reticulum stress / 中国中药杂志

To explore the protective effect and mechanism of ethyl acetate extract from Bidens bipinnata on hepatocyte damage induced by endoplasmic reticulum stress. Tunicamycin was used to establish the damage model in L02 cells. Methyl thiazolyl tetrazolium(MTT) colorimetric assay was used to investigate the survival rate of ethyl acetate extract from B. bipinnata in L02 cells injury induced by endoplasmic reticulum stress; the protein expressions of endoplasmic reticulum stress-related molecule glucose regulated protein 78(GRP78), PKR-like ER kinase(PERK), eukaryotic initiation factor-2(eIF2α), activating transcription factor 4(ATF4), C/EBP homologous protein(CHOP), B-cell CLL/lymphoma 2(Bcl-2), Bal-2 associated X apoptosis regulator(Bax) were examined by Wes-tern blot. The expressions of the above proteins were also detected after endoplasmic reticulum stress inhibitor(4-phenyl butyric acid) and CHOP shRNA-mediated knockdowns were added. The expressions of GRP78, PERK, CHOP in L02 cells were observed by immunofluorescence method. The results showed that ethyl acetate extract from B. bipinnata could significantly increase the survival rate of L02 cell injury caused by endoplasmic reticulum stress in a dose and time-dependent manner(P<0.05 or P<0.01). The expression levels of GRP78, PERK, eIF2α, ATF4, CHOP and Bax in the drug treatment groups were significantly down-regulated(P<0.05 or P<0.01), while Bcl-2 was significantly up-regulated(P<0.01). After endoplasmic reticulum stress inhibitor and CHOP shRNA-mediated knockdowns were added, the expression levels of GRP78, PERK, eIF2α, ATF4, CHOP, Bax in the drug treatment groups were significantly down-regulated(P<0.01), whereas Bcl-2 was significantly up-regulated(P<0.01). Immunofluorescence results showed that the expressions of GRP78, PERK, CHOP were consistent with the Western blot method. In conclusion, ethyl acetate extract from B. bipinnata has a significant protective effect on the damage of L02 cells caused by endoplasmic reticulum stress. The mechanism may be related to the inhibition of endoplasmic reticulum stress and the down-regulation of apoptosis in cells through the PERK/eIF2α/ATF4/CHOP signaling pathway.

Effect and mechanism of Bidens pilosa decoction on non-alcoholic fatty liver induced by high fat and high glucose in mice / 中国中药杂志

This study aimed to investigate the effect and possible mechanism of Bidens pilosa decoction on non-alcoholic fatty liver disease(NAFLD) induced by high fat and high glucose in mice. Bald/c mice were randomly divided into normal group, model group, metformin(200 mg·kg~(-1)) treatment group, Bidens pilosa decoction(10 g·kg~(-1)) treatment group, metformin and B. pilosa decoction(100 mg·kg~(-1)+5 g·kg~(-1)) treatment group. Except for the normal group, mice in the other four groups were fed with high-fat and high-glucose diet for 8 weeks to establish the non-alcoholic fatty liver model. After 4 weeks of treatment, blood was collected from the eyeballs, the mice were sacrificed, and relevant indicators were detected. The results showed that compared with the model group, blood lipid and blood glucose levels of each treatment group were significantly lower(P<0.05); HE staining results showed that liver pathological damage in each treatment group was significantly improved; oil red O staining results showed fat distribution in each treatment group significantly reduced(P<0.01); immunohistochemical staining showed that glucose regulated the protein expression of protein 78(GRP78) in liver tissues of each treatment group was also significantly reduced(P<0.01); Western blot results showed that endoplasmic reticulum stress signal pathway-related factors GRP78, phosphorylated-protein kinase R-like ER kinase(p-PERK), eukaryotic translation-initiation factor 2α(eIF2α), activating transcription factor 4(ATF4), C/EBP homologous protein(Chop), inositol requiring 1α(IRE1α), and cleaved-cysteinyl aspartate specific proteinase 12(cleaved-caspase-12) were significantly reduced(P<0.01). The results of the combined drug treatment group were better than those of the single drug treatment group. These results showed that B. pilosa decoction had the effect in improving non-alcoholic fatty liver, and its mechanism may be related to the down-regulation of the expression of endoplasmic reticulum stress(ERS)-related factors, and the reduction of the apoptosis of hepatocytes caused by ERS and the down-regulation of blood lipid and blood glucose levels.

Differentially expressed genes of HepG2 cells treated with gecko polypeptide mixture / 中国药理学与毒理学杂志

OBEJECTIVE Gecko has been clinically used in China for many years. It has been proved that the gecko polypeptide mixture(GPM)extracted from gecko could inhibit the growth of multiple types of tumor cells.In order to investigate the possible anti-tumor molecular mechanisms of GPM,we used RNA-seq technology to identify the differentially expressed genes of human hepatocellular carci-noma(HCC)HepG2 cells treated with or without GPM.METHODS The HepG2 cells were treated with different concentration of GPM(0,0.1,0.2,0.3,0.4 mg·mL-1)for 6 h,12 h and 24 h,respectively.MTT assay was used to detect the viability of HepG2 cells. DAPI fluorescence staining was performed to observe nucleus morphological changes of HepG2 cells.Western blot analysis was applied to observe the expres-sion of apoptosis- related proteins and endoplasmic reticulum stress (ERs)-related proteins in HepG2 cells.Flow cytometry was also applied to detect reactive oxygen species(ROS)generation.In this report, we showed that GPM could induce HepG2 cells apoptosis and influence HepG2 cells proliferation in a dose-dependent manner.We applied many analysis methods,including differentially expressed genes analysis,Gene Ontology(GO)enrichment analysis,KEGG pathway enrichment analysis,protein-protein interaction network analysis to screen out possible molecular mechanisms.RESULTS ER-nucleus signaling pathway, cellular response to stress and apoptotic processes were identified the potential anti-cancer molecular biological process of GPM.GPM may also induce apoptosis in HepG2 cells via endoplasmic reticulum stress pathway. The GPM could induce ROS generation and up-regulate ERs-related proteins. CONCLUSION The present study revealed the potential anti-tumor mechanism of GPM.

Protective effect of earthworm active ingredients against endoplasmic reticulum stress induced L-02 hepatocyte apoptosis / 中国中药杂志

This study focused on the protective effect of earthworm active ingredients (EWAs) on hepatocyte apoptosis induced by endoplasmic reticulum stress (ERS) in L-02 cells. The L-02 cells were cultured in vitro. The cell viability was measured with CCK-8, the apoptosis of L-02 cells was detected by flow cytometry, and the relevant protein and mRNA expressions were detected by Western blot and qPCR. According to the findings, tunicamycin (TM) could obviously reduce the survival rate of L-02 cells in a time-dependent and dose-dependent manner. Compared with normal group, the apoptosis rate in model group was significantly increased (<0.05 or <0.01). The protein and mRNA expressions of ERS-related signal molecules, such as GRP78, PERK, eLF2α, ATF4, CHOP and Bax, were significantly up-regulated (<0.05 or <0.01), while Bcl-2 was significantly down-regulated (<0.05 or <0.01). After the administration with different concentrations of EWAs, compared with model group, EWAs could significantly increase the survival rate ofL-02 hepatocyte and decrease the cell apoptosis rates. It could also reduce the protein and mRNA expressions of ERS-related signal molecules, such as GRP78, PERK, eLF2α, ATF4, CHOP and Bax, in a dose-dependent manner (<0.05 or <0.01) and increased the protein and mRNA expressions of Bcl-2(<0.05 or <0.01). These results showed that EWAs had a significantly protective effect on hepatocyte apoptosis induced by ERS in L-02 cells. Its mechanism may be related to the down-regulation of mRNA and protein expressions of GRP78, PERK, ATF4, eLF2α, CHOP and Bax, and the up-regulation, the relief of ERS and the promotion of the proliferation of impaired L-02 cells.

Protective effect of earthworm active ingredients against endoplasmic reticulum stress-induced acute liver injury in mice / 中国中药杂志

To study the protective effect of earthworm active ingredients(EWAs) against endoplasmic reticulum stress(ERS)-induced acute liver injury in mice. The model of liver injury was induced through intraperitoneal injection of 10%CCl4. Serum glutamic-pyruvic transaminase(ALT), glutamic-oxaloacetic transaminase(AST), superoxide dismutase(SOD) and glutathione peroxidase(GSH-PX) activity and malondialdehyde(MDA) concentration were detected by colorimetric method. Histological examination was performed through hematoxylin-eosin staining and light microscopy, and apoptosis was detected using terminal transferase dUTP nick end labeling. The expressions of ERS related proteins, including glucose regulated protein 78(GRP78), protein kinase R-like ER kinase(PERK), eukaryotic transcription initiation factor 2α(eIF2α), active transcription factor-4(ATF4) and CCAAT/enhancer binding homologous protein(CHOP), were measured by immunohistochemistry and Western blot. According to the results, compared with the model group,serological indexes in the high, middle and low doses of EWAs were significantly improved (P<0.05 or P<0.01), the extent of liver lesion was decreased and the degree of injury was significantly reduced, and that the liver index and the spleen index of mice were significantly changed(P<0.05 or P<0.01). In liver tissue, the expressions of GRP78 and CHOP were significantly decreased(P<0.05 or P<0.01). The protein expressions of GRP78, CHOP and its upstream signaling pathway PERK-eIF2-ATF4 were significantly decreased in each dose group(P<0.05 or P<0.01). In summary, EWAs has a significant protective effect on ERS-induced acute liver injury, and its mechanism may be correlated with the inhibition of oxidative stress and ERS, and down-regulation of ERS marker protein CHOP expression, andinhibition of apoptosis.