Antrodia cinnamomea and its compound dehydroeburicoic acid attenuate nonalcoholic fatty liver disease by upregulating ALDH2 activity.

ETHNOPHARMACOLOGICAL RELEVANCE: Nonalcoholic fatty liver disease (NAFLD) is a prevalent liver disease, but currently has no specific medication in clinic. Antrodia cinnamomea (AC) is a medicinal fungus and it has been shown that AC can inhibit high fat diet (HFD)-induced lipid deposition in mouse livers, but the effective monomer in AC and mechanism against NAFLD remain unclear. It has been reported that aldehyde dehydrogenase 2 (ALDH2) activation shows protective effects on NAFLD. Our previous study demonstrates that AC and its monomer dehydroeburicoic acid (DEA) can upregulate the ALDH2 activity on alcoholic fatty liver disease mouse model, but it is not clear whether the anti-NAFLD effects of AC and DEA are mediated by ALDH2. AIM TO STUDY: To elucidate the active compound in AC against NAFLD, study whether ALDH2 mediates the anti-NAFLD effects of AC and its effective monomer. MATERIALS AND METHODS: WT mice, ALDH2-/- mice and ALDH2-/- mice re-expressed ALDH2 by lentivirus were fed with a methionine-choline deficient (MCD) diet or high fat diet (HFD) to induce NAFLD, and AC at the different doses (200 and/or 500 mg/kg body weight per day) was administrated by gavage at the same time. Primary hepatocytes derived from WT and ALDH2-/-mice were stimulated by oleic acid (OA) to induce lipid deposition, and the cells were treated with AC or DEA in the meantime. Lentivirus-mediated ALDH2-KD or ALDH2-OE were used to knock down or overexpress ALDH2 expression in HepG2 cells, respectively. Finally, the effects of DEA against NAFLD as well as its effects on upregulating liver ALDH2 and removing the harmful aldehyde 4-hydroxynonenal (4-HNE) were studied in the MCD diet-induced NAFLD mouse model. RESULTS: In WT mice fed with a MCD diet or HFD, AC administration reduced hepatic lipid accumulation, upregulated ALDH2 activity in mouse livers, decreased 4-HNE contents both in mouse livers and serum, inhibited lipogenesis, inflammation and oxidative stress and promoted fatty acid ß-oxidation. These effects were abolished in ALDH2 KO mice but could be restored by re-expression of ALDH2 by lentivirus. In primary hepatocytes of WT mice, AC and DEA inhibited OA-induced lipid accumulation and triglyceride (TG) synthesis, promoting the ß-oxidation of fatty acid in the meantime. However, these effects were lost in primary hepatocytes of ALDH2 KO mice. Moreover, the expression level of ALDH2 significantly affected the inhibitory effects of AC and DEA on OA-induced lipid deposition in HepG2 cells. The effects of AC and DEA on suppressing lipid deposition, inhibiting mitochondrial ROS levels, reducing TG synthesis, and promoting ß-oxidation of fatty acid were all enhanced with the overexpression of ALDH2 and reduced with the knockdown of ALDH2 expression. DEA showed dose-dependent effects on inhibiting liver lipid deposition, elevating ALDH2 activity and reducing 4-HNE levels in the livers of MCD diet-induced NAFLD mice. CONCLUSION: DEA is the effective compound in AC against NAFLD. The related anti-NAFLD mechanisms of AC and DEA were through upregulating ALDH2 expression and activity, thus enhancing the elimination of 4-HNE in the livers, and sequentially alleviating oxidative stress and inflammation, promoting fatty acid ß-oxidation and decreasing lipogenesis.

Grape Seed Polyphenols Ameliorated Dextran Sulfate Sodium-Induced Colitis via Suppression of Inflammation and Apoptosis.

BACKGROUND: Ulcerative colitis (UC) is an inflammatory bowel disease. Its onset is typically gradual, usually followed by periods of spontaneous remission and subsequent relapses. Grape seed polyphenols (GSP), a natural product extracted from grape seeds, have strong anti-inflammatory functions. OBJECTIVES: In this study, we investigated whether GSP has an inhibitory effect on UC and its related mechanism or not. METHODS: We induced UC by 2.5% dextran sulfate sodium (DSS) and GSP at different doses (500 and 750 mg/kg body weight per day) was administrated to the mice by gavage. Body weight, diarrhea, and bloody stool were recorded every day to evaluate disease activity index. Hemotoxylin-eosin staining and immunohistochemical staining were used to identify the histological damages and inflammatory infiltration in colon tissues. Real-time polymerase chain reaction was used to evaluate mRNA expression of interleukin (IL)-6, IL-1ß, and tumor necrosis factor (TNF)-α and the expression of phosphorylated-signal transducer and activator of transcription 3 (STAT3) and STAT3 were assessed by western blot. The immunofluorescent assay was used to evaluate the apoptosis of intestinal epithelial cells (IECs). RESULTS: GSP could alleviate the loss of body weight, diarrhea, bloody stool, the mucosal damage, and inflammatory infiltration. GSP could also downregulate the mRNA expression of inflammatory cytokines IL-6, IL-1ß, and TNF-α as well as the phosphorylation of STAT3 and ameliorate the apoptosis of IECs. CONCLUSIONS: Our study suggests that GSP has protective effects against DSS-induced UC, which may through suppression of inflammation and apoptosis.

Inhibitory effects of cycloastragenol on abdominal aortic aneurysm and its related mechanisms.

BACKGROUND AND PURPOSE: Abdominal aortic aneurysm (AAA) is a degenerative disease affecting human health, but there are no safe and effective medications for AAA therapy. Cycloastragenol (CAG), derived from Astragali Radix, has various pharmacological effects. However, whether CAG can protect against AAA remains elusive. In this study, we investigated whether CAG has an inhibitory effect on AAA and its related mechanism. EXPERIMENTAL APPROACH: The AAA mouse model was induced by incubating the abdominal aorta with elastase. CAG was administered by gavage at different doses beginning on the same day or 14 days after inducing AAA to explore its preventive or therapeutic effects respectively. The preventive effects of CAG on AAA were verified in another AAA mouse model induced by angiotensin II in ApoE-/- mouse. In vitro experiments were implemented on rat vascular smooth muscle cells (VSMCs) stimulated by TNF-α. KEY RESULTS: Compared to the control AAA model group, CAG (125 mg·kg-1 body weight day-1 ) reduced the incidence of AAA, the dilatation of aorta and elastin degradation in media in both mouse models of AAA. CAG suppressed the inflammation, oxidation, phenotype switch and apoptosis in TNF-α-stimulated VSMCs, ameliorated the expression and activity of MMPs and decreased the activation of the ERK/JNK signalling pathway. CAG also inhibited the degradation of elastin in TNF-α-stimulated VSMCs. CONCLUSION AND IMPLICATIONS: CAG presents protective effects against AAA through down-regulation of the MAPK signalling pathways and thus attenuates inflammation, oxidation, VSMC phenotype switch and apoptosis and the expression of MMPs as well as increasing elastin biosynthesis.

Grape-seed Polyphenols Play a Protective Role in Elastase-induced Abdominal Aortic Aneurysm in Mice.

Abdominal aortic aneurysm (AAA) is a kind of disease characterized by aortic dilation, whose pathogenesis is linked to inflammation. This study aimed to determine whether grape-seed polyphenols (GSP) has anti-AAA effects and what mechanism is involved, thus to find a way to prevent occurrence and inhibit expansion of small AAA. In our study, AAA was induced by incubating the abdominal aorta of the mice with elastase, and GSP was administrated to the mice by gavage at different doses beginning on the day of the AAA inducement. In in vivo experiments, 800 mg/kg GSP could significantly reduce the incidence of AAA, the dilatation of aorta and elastin degradation in media, and dramatically decrease macrophage infiltration and activation and expression of matrix metalloproteinase (MMP) -2 and MMP-9 in the aorta, compared to the AAA model group. Meanwhile, 400 mg/kg GSP could also but not completely inhibit the occurrence and development of AAA. In in vitro experiments, GSP dose-dependently inhibited mRNA expression of interleukin (IL)-1ß, IL-6 and monocyte chemoattractant protein-1 (MCP-1), and significantly inhibited expression and activity of MMP-2 and MMP-9, thus prevented elastin from degradation. In conclusion, GSP showed great anti-AAA effects and its mechanisms were related to inhibition of inflammation.