Therapeutic strategies of small molecules in the microbiota-gut-brain axis for alcohol use disorder.

The microbiota-gut-brain axis (MGBA) is important in maintaining the structure and function of the central nervous system (CNS) and is regulated by the CNS environment and signals from the peripheral tissues. However, the mechanism and function of the MGBA in alcohol use disorder (AUD) are still not completely understood. In this review, we investigate the underlying mechanisms involved in the onset of AUD and/or associated neuronal deficits and create a foundation for better treatment (and prevention) strategies. We summarize recent reports focusing on the alteration of the MGBA in AUD. Importantly, we highlight the properties of small-molecule short-chain fatty acids (SCFAs), neurotransmitters, hormones, and peptides in the MGBA and discusses their usage as therapeutic agents against AUD.

Characterization of Key Aroma Compounds in Tartary Buckwheat (Fagopyrum tataricum Gaertn.) by Means of Sensory-Directed Flavor Analysis.

The key odorants of tartary buckwheat (TB) were researched by a sensory-directed flavor analysis approach for the first time. After the volatiles of TB were isolated by solvent-assisted flavor evaporation (SAFE), 49 aroma-active components with flavor dilution (FD) factors in the range of 1-2187 were identified using gas chromatography-olfactometry-mass spectrometry (GC-O-MS) combined with aroma extract dilution analysis (AEDA). Geranylacetone, phenethyl alcohol, and ß-damascone showed the highest FD factors of 2187. All 49 odorants were further quantitated by the internal standard curve method, and their odor activity values (OAVs) were obtained. The overall aroma of TB was successfully simulated (similarity > 98.16%) by mixing 16 odorants (OAV ≥ 1) with their natural concentrations. The omission tests revealed that geosmin, α-isomethylionone, α-methylionone, ß-ionone, linalool, ß-damascone, geranylacetone, guaiacol, ethyl hexanoate, geraniol, vanillin, tetrahydrolinalool, and 2,5-dimethyl-4-hydroxy-3-(2H)-furanone were the key odorants of TB. Chiral analysis showed that tetrahydrolinalool and linalool existed as racemics in the commercial TB. The relative content of R-enantiomers of α-isomethylionone and α-methylionone was slightly higher than that of their S-enantiomers. The odor thresholds of R- and S-enantiomer of tetrahydrolinalool were first detected as 0.029 and 3.8 µg/L in air, respectively.

Quercetin in Tartary Buckwheat Induces Autophagy against Protein Aggregations.

Tartary buckwheat is used as an ingredient in flour and tea, as well as in traditional Chinese medicine for its antioxidant effects. Here, we found that an ethanol extract of tartary buckwheat (TBE) potently induced autophagy flux in HeLa cells by suppressing mTORC1 activity, as revealed by dephosphorylation of the mTORC1 substrates Ulk1, S6K, and 4EBP, as well as by the nuclear translocation of transcriptional factor EB. In addition to non-selective bulk autophagy, TBE also induced aggrephagy, which is defined as autophagy against aggregated proteins. Quercetin is a flavonol found at high levels in TBE. We showed that quercetin induced both non-selective bulk autophagy and aggrephagy. These effects were also observed in Huh-7 cells derived from hepatocytes. Thus, aggrephagy induction by TBE and quercetin may relieve alcoholic hepatitis, which is closely linked to the accumulation of protein aggregations called Mallory-Denk bodies.

A Traditional Chinese Medicine Plant Extract Prevents Alcohol-Induced Osteopenia.

Traditional Chinese medicine (TCM) has been practiced in the treatment of bone diseases and alcoholism. Chronic excessive alcohol use results in alcohol-induced bone diseases, including osteopenia and osteoporosis, which increases fracture risk, deficient bone repair, and osteonecrosis. This preclinical study investigated the therapeutic effects of TCM herbal extracts in animal models of chronic excessive alcohol consumption-induced osteopenia. TCM herbal extracts (Jing extracts) were prepared from nine Chinese herbal medicines, a combinative herbal formula for antifatigue and immune regulation, including Astragalus, Cistanche deserticola, Dioscorea polystachya, Lycium barbarum, Epimedium, Cinnamomum cassia, Syzygium aromaticum, Angelica sinensis, and Curculigo orchioides. In this study, Balb/c male mice were orally administrated alcohol (3.2 g/kg/day) with/without TCM herbal extracts (0.125 g/kg, 0.25 g/kg, or 0.5 g/kg) by gavage. Our results showed that after 50 days of oral administration, TCM herbal extracts prevented alcohol-induced osteopenia demonstrated by µ-CT bone morphological analysis in young adults and middle-aged/old Balb/c male mice. Biochemical analysis demonstrated that chronic alcohol consumption inhibits bone formation and has a neutral impact on bone resorption, suggesting that TCM herbal extracts (Jing extracts) mitigate the alcohol-induced abnormal bone metabolism in middle-aged/old male mice. Protocatechuic acid, a natural phenolic acid in Jing extracts, mitigates in vivo alcohol-induced decline of alkaline phosphatase (ALP) gene expression in the bone marrow of Balb/c male mice and in vitro ALP activity in pre-osteoblast MC3T3-E1 cells. Our study suggests that TCM herbal extracts prevent chronic excessive alcohol consumption-induced osteopenia in male mice, implying that traditional medicinal plants have the therapeutic potential of preventing alcohol-induced bone diseases.

Tartary buckwheat extract alleviates alcohol-induced acute and chronic liver injuries through the inhibition of oxidative stress and mitochondrial cell death pathway.

Alcohol use disorder (AUD) is an enormous public health problem that poses significant social, medical, and economic burdens. Under AUD, the liver is one of the most adversely affected organs. As current therapies and protective drugs for AUD-mediated liver injury are very limited, the prevention and therapy of alcoholic liver disease are urgently needed. The present study aims to investigate the beneficial effects of tartary buckwheat extract (TBE), the important component of Maopu tartary buckwheat liquor, on both alcoholic-induced acute and chronic liver injuries. We show that the TBE administration, similar to curcumin, significantly reduces the elevated serum aspartate aminotransferase and alanine aminotransferase levels, improves liver index, alleviates the elevated contents of hepatic malondialdehye, and restores the decreased contents of hepatic glutathione both in acute and chronic liver injuries in alcohol-exposed rats. Furthermore, histopathological analyses show that a medium dose of TBE (16.70 ml/kg body weight) alleviates hepatocyte morphology changes in both acute and chronic alcohol exposure models. We also show the protective effects of TBE on the cell death rates of alcohol-exposed primary cultured hepatocytes, HepG2 hepatoma, and Huh 7 hepatoma cells. Furthermore, we demonstrate that TBE exerts hepatoprotection partly through inhibiting the mitochondrial cell death pathway by reducing cytochrome c release, caspase-9 and -3 activities, and the number of TUNEL-positive cells. These effects of TBE were accompanied by enhanced levels of Bcl-2 and Bcl-xL and autophagic cell death pathway by reducing Beclin-1 expression, as well as through promoting its anti-oxidant capacity by suppressing reactive oxygen species production. This study demonstrates, for the first time, the protective effect of TBE against alcohol-induced acute and chronic liver injury in vivo and in vitro. Given the dietary nature of tartary buckwheat, pueraria, lycium barbarum, and hawthorn, the oral intake of TBE or liquor contained TBE, e.g., Maopu Tartary buckwheat liquor, compared with pure liquor consumption alone, may have the potential to alleviate alcoholic-induced liver injuries.

IP3R and RyR channels are involved in traffic-related PM2.5-induced disorders of calcium homeostasis.

Traffic-related PM2.5 can result in immune system damage and diseases; however, the possible mechanism of its effect remains unclear. Calcium (Ca2+) is a critical signaling molecule in a variety of cells. Indeed, Ca2+ is involved in numerous basic functions, including cell growth and death. In this study, Jurkat T cells were used to explore the possible mechanisms of PM2.5-elicited intracellular Ca2+signal responses. The results indicate that PM2.5 could raise the level of intracellular Ca2+ concentration ([Ca2+]i). The [Ca2+]i in Jurkat T cells significantly decreased after treatment with heparin as an inhibitor of inositol trisphosphate receptors (IP3 R), or procaine as an inhibitor of ryanodine receptors (RyR). The expression of calmodulin (CAM) protein decreased in a time-dependent manner after exposure to PM2.5, whereas the activity of Ca2+-Mg2+-ATPase seemed to show a slight drop trend after exposure to PM2.5. Our findings demonstrate that PM2.5 stimulation to Jurkat T cells would result in an increase in [Ca2+]i, which is modulated by IP3 R and RyR, as well as CAM.

Traffic-related PM2.5 induces cytosolic [Ca²âº] increase regulated by Orai1, alters the CaN-NFAT signaling pathway, and affects IL-2 and TNF-α cytoplasmic levels in Jurkat T-cells.

The atmospheric particulate matter with a diameter less than or equal to 2.5 um (PM2.5) can result in increased immune system damage or diseases, however, the possible mechanism remains unclear. In this study, we used Jurkat T cells to determine the effects of PM2.5 on T cell-mediated adaptive immune response. Our results indicated that PM2.5 exposure increased intracellular calcium ion concentration [Ca(2+)]. In contrast, cytosolic free Ca(2+) concentration [Ca(2+)]i significantly decreased in Jurkat T cells transfected with Orai1siRNA. In addition, we detected the level of interleukin (IL)-2 and tumor-necrosis factor (TNF)-α as well as other signalling molecules, including calcineurin (CaN) and NFATc2, a gene on 20q13.2 that encodes a member of the nuclear factor of activated T cells (NFAT), in the supernatant of cells exposed to PM2.5. The expression of NFATc2 protein increased in a time-dependent manner after exposure to PM2.5, but the activity of CaN decreased. NFATc2 was not consistent with IL-2 accumulation, thus indicating the involvement of other signals in the suppression of IL-2 accumulation. Our findings demonstrate that PM2.5 exposure in immune cells results in locally increased [Ca(2+)]i generated by Orai1 and CaN-NFAT gene expression, TNF-α and IL-2 cytoplasmic concentrations may be altered.

[Traffic-related PM2.5 regulates IL-2 releasing in Jurkat T cells by calcium signaling pathway].

OBJECTIVE: To explore the effects of traffic-related PM2.5 on interleukin-2 (IL-2) in Jurkat T cells and the regulatory action of calcium signaling pathway. METHODS: The cells were exposed to 100 microg/ml of PM2.5 for 3, 6 and 24 h. Normal saline group, blank filter group, calcium chelating agent EGTA group and the calcineurin antagonist cyclosporine A (CSA) group were as parallel control. The level of IL-2 was detected by ELISA kits, the mRNA expression of CaN, NFAT were determined by QRT-PCR. The nuclear distribution of NFAT was observed by immunofluorescence microscopy. RESULTS: The level of IL-2 in Jurkat T cells exposed to 100 microg/ml PM2.5 was significantly lower than parallel groups, but higher than PM2.5 + CSA group and PM2.5 + EGTA group (P < 0.05). With the increase of time, the releasing level of IL-2 appeared reducing trend in 100 microg/ml of PM2.5 group. The mRNA expression level of NFAT and CaN were higher than parallel groups, PM2.5 + CSA group and PM2.5 + EGTA group (P < 0.05). PM2.5 can induce NFAT protein with dephosphorylation and be activated, and NFAT protein can shift into nuclear. The level of IL-2 was negatively associated with the expression level of NFAT and CaN gene (P < 0.05). CONCLUSION: Traffic-related PM2.5 may inhibit the releasing of IL-2, Ca(2+)-CaN-NFAT signal pathway may involve in the regulation of IL-2.