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.

Protective Effects of Antrodia cinnamomea and Its Constituent Compound Dehydroeburicoic Acid 32 Against Alcoholic Fatty Liver Disease.

BACKGROUND: Alcoholic fatty liver disease (AFLD), a leading chronic hepatic disease, affects an increasing number of people, and no effective drugs for the treatment of AFLD are available. Antrodia cinnamomea (AC) can inhibit AFLD, but its mechanisms and the effective compound in AC are unknown. OBJECTIVE: We aimed to explore the anti-AFLD mechanism of AC and the active compound within AC. METHODS: Wild-type (WT) C57BL/6J mice underwent 4 weeks of daily ethanol (EtOH) feeding to induce AFLD. AC or dehydroeburicoic acid 32 (DEA32), a compound in AC, was given to the mice. Parallel experiments to assess the effect of AC were conducted in aldehyde dehydrogenase 2 (ALDH2)-knockout (KO) mice. Primary mouse hepatocytes were incubated with ethanol and Alda- 1 (an ALDH2 agonist), AC or DEA32. RESULTS: In WT mice with AFLD, AC reduced lipid deposition, increased the expression and activity of ALDH2, reduced the acetaldehyde content, and downregulated the expression of lipogenic and inflammatory genes in the liver. These effects of AC disappeared in ALDH2 KO mice. DEA32 was identified as an active compound in AC, as its effects on EtOH-treated WT hepatocytes were similar to those of AC, which were comparable to the effects of Alda-1. These effects of DEA32 disappeared in EtOH-treated ALDH2 KO hepatocytes. Furthermore, in WT mice with AFLD, DEA32 reduced lipid deposition, increased the activity of ALDH2, and reduced the accumulation of acetaldehyde in the liver. DEA32 also downregulated the mRNA expression of genes related to lipogenesis and inflammation. CONCLUSION: AC and its constituent compound DEA32 inhibit AFLD by upregulating ALDH2 activity, accelerating acetaldehyde metabolism, and suppressing lipogenesis and inflammation in the liver.

[Identification of C(2)M interacting proteins by yeast two-hybrid screening].

The synaptonemal complex (SC) is a huge structure which assembles between the homologous chromosomes during meiotic prophase I. Drosophila germ cell-specific nucleoprotein C(2)M clustering at chromosomes can induce SC formation. To further study the molecular function and mechanism of C(2)M in meiosis, we constructed a bait vector for C(2)M and used the yeast two-hybrid system to identify C(2)M interacting proteins. Forty interacting proteins were obtained, including many DNA and histone binding proteins, ATP synthases and transcription factors. Gene silencing assays in Drosophila showed that two genes, wech and Psf1, may delay the disappearance of SC. These results indicate that Wech and Psf1 may form a complex with C(2)M to participate in the formation or stabilization of the SC complex.