Leucine accelerates blood ethanol oxidation by enhancing the activity of ethanol metabolic enzymes in the livers of SHRSP rats

Valorization of broiler edible byproducts: a chicken-liver hydrolysate with hepatoprotection against binge drinking

Over 10,000 metric-ton broiler livers are produced annually in Taiwan. Concerning unpleasant odor and healthy issue, broiler livers are not attractive to consumers. Although the patented chicken-liver hydrolysates (CLHs) through pepsin digestion possess several biofunctionalities, there is no study on hepatoprotection of CLH-based formula capsule (GBHP01) against binge drinking (Whiskey, 50% Alc./Vol.). GBHP01 led to an accelerated blood-alcohol clearance in rats, as evidenced by lowering blood-alcohol increment within 0 to 4 h, increasing blood-alcohol decrement within 4 to 8 h, and smaller blood alcohol concentration areas under the curve (BAC AUC) in the 8-h period (p < 0.05). The ameliorative effects of GBHP01 against binge drinking in rats over 6 wk were attributed to accelerated alcohol metabolism by further increasing alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activities while downregulating cytochrome P450 2E1 (CYP2E1) protein expression, elevating antioxidant capacity, decreasing zonula occludens-1 (ZO-1) protein decrement and serum endotoxin, and reducing inflammation related protein levels, that is, toll-like receptor 4 (TLR4) and mitogen-activated protein kinase (MAPK), and proinflammatory cytokines. The development of CLH supplements could not only enhance the added value of broiler livers through nutraceutical development but also offer a strategy to maximize the utilization of poultry processing residues, as shown in this study.

Effects of Mactra chinenesis Peptides on Alcohol-Induced Acute Liver Injury and Intestinal Flora in Mice

Food-borne bioactive peptides have shown promise in preventing and mitigating alcohol-induced liver injury. This study was the first to assess the novel properties of Mactra chinenesis peptides (MCPs) in mitigating acute alcoholic liver injury in mice, and further elucidated the underlying mechanisms associated with this effect. The results showed that MCPs can improve lipid metabolism by modulating the AMPK signaling pathway, decreasing fatty acid synthase activity, and increasing carnitine palmitoyltransferase 1a activity. Meanwhile, MCPs ameliorate inflammation by inhibiting the NF-κB activation, leading to reduced levels of pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-1β). Additionally, a 16S rDNA sequencing analysis revealed that MCPs can restore the balance of gut microbiota and increase the relative abundance of beneficial bacteria. These findings suggest that supplementation of MCPs could attenuate alcohol intake-induced acute liver injury, and, thus, may be utilized as a functional dietary supplement for the successful treatment and prevention of acute liver injury.

Fermented Protaetia brevitarsis Larvae Ameliorates Chronic Ethanol-Induced Hepatotoxicity in Mice via AMPK and TLR-4/TGF-β1 Pathways

This study evaluated the hepatoprotective effect of fermented Protaetia brevitarsis larvae (FPB) in ethanol-induced liver injury mice. As a result of amino acids in FPB, 18 types of amino acids including essential amino acids were identified. In the results of in vitro tests, FPB increased alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activities. In addition, FPB treatment increased cell viability on ethanol- and H2O2-induced HepG2 cells. FPB ameliorated serum biomarkers related to hepatoxicity including glutamic oxaloacetic transaminase, glutamine pyruvic transaminase, total bilirubin, and lactate dehydrogenase and lipid metabolism including triglyceride, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol. Also, FPB controlled ethanol metabolism enzymes by regulating the protein expression levels of ADH, ALDH, and cytochrome P450 2E1 in liver tissue. FPB protected hepatic oxidative stress by improving malondialdehyde content, reduced glutathione, and superoxide dismutase levels. In addition, FPB reversed mitochondrial dysfunction by regulating reactive oxygen species production, mitochondrial membrane potential, and ATP levels. FPB protected ethanol-induced apoptosis, fatty liver, and hepatic inflammation through p-AMP-activated protein kinase and TLR-4/NF-κB signaling pathways. Furthermore, FPB prevented hepatic fibrosis by decreasing TGF-β1/Smad pathway. In summary, these results suggest that FPB might be a potential prophylactic agent for the treatment of alcoholic liver disease via preventing liver injury such as fatty liver, hepatic inflammation due to chronic ethanol-induced oxidative stress.

Preparation, Structural Identification, and Screening of Egg-Derived Peptides with Facilitating Alcohol Metabolism Activity

The aim of this study was to obtain egg-derived peptides with facilitating alcohol metabolism (EPs) by enzymolysis, to identify their structures, and screen small polypeptides with higher activity by molecular docking. The optimum conditions for preparing EPs with facilitating alcohol metabolism were obtained by a single factor experiment, adding 2% Protamex and performing enzymolysis for 3 h with a liquid-material ratio of 35:1. The dose-response relationship experiment showed that 800 mg/kg·bw EPs played a better role in facilitating alcohol metabolism. EPs contained 40% hydrophobic amino acids (HAA), including 9.24% Leu. Eighty-four peptides were identified by HPLC-MS/MS and four peptides with potential activation of alcohol dehydrogenase were further selected by molecular docking. The tetrapeptide Trp-Ile-Val-Asp (WIVD) with the highest binding energy reached -7.16 kcal/mol. These findings suggest that egg is a good source for the preparation of peptides with facilitating alcohol metabolism activity.

Protective Effect of Polyphenols, Protein, Peptides, and Polysaccharides on Alcoholic Liver Disease: A Review of Research Status and Molecular Mechanisms

Alcoholic liver disease (ALD) has emerged as an important public health problem in the world. The polyphenols, protein, peptides, and polysaccharides have attracted attention for prevention or treatment of ALD. Therefore, this paper reviews the pathogenesis of ALD, the relationship between polyphenols, peptides, polysaccharides, and ALD, and expounds the mechanism of gut microbiota on protecting ALD. It is mainly found that the hydroxyl group of polyphenols endows it with antioxidation to protect ALD. The ALD protection of bioactive peptides is related to amino acid composition. The ALD protection of polysaccharides is related to the primary structure. Meanwhile, polyphenols, protein, peptides, and polysaccharides prevent or treat ALD by antioxidation, anti-inflammatory, antiapoptosis, lipid metabolism, and gut microbiota regulation. This contribution provides updated information on polyphenols, protein, peptides, and polysaccharides in response to ALD, which will not only facilitate the development of novel bioactive components but also the future application of functional food raw materials will be promoted.

Extracting myricetin and dihydromyricetin simultaneously from Hovenia acerba seed by Ultrasound-Assisted extraction on a lab and small Pilot-Scale

The flavonoids myricetin and dihydromyricetin are significant components of Hovenia acerba seed. In this work, myricetin and dihydromyricetin were extracted from Hovenia acerba seed using an ultrasound-assisted technique, and the extraction parameters were adjusted using the response surface design approach. HPLC was used to assess the yield of myricetin and dihydromyricetin. According to the data, myricetin and dihydromyricetin yields were 0.53 mg/g and 4.06 mg/g at a 60 % ethanol solution concentration, 180 W of ultrasonic irradiation power, a 20 mL/g ratio of liquid to solid, and a 40 °C optimal extraction temperature. The aforementioned findings are virtually in agreement with the experimental findings suggested by the model. The study mentioned above thus offers a means of separating and developing useful components of natural goods.

Nontargeted metabolomics to characterize the effects of isotretinoin on skin metabolism in rabbit with acne

Background: Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit. This study aimed to explore the pathogenesis of acne and the therapeutic mechanism of isotretinoin from the metabolic perspective in coal tar-induced acne in rabbits.

Methods: Ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-qTOF-MS) based metabolomics was used to identify skin metabolites in groups C (blank control), M (model group) and T (isotretinoin group). Multivariate statistical analysis was used to process the metabolomics data.

Results: 98 differential metabolites in group C and group M were identified. The highest proportion of differential metabolites were organic acids and derivatives, lipid metabolites, organic heterocyclic compounds, and nucleoside metabolites. The most significant metabolic pathways included protein digestion and absorption, central carbon metabolism in cancer, ABC transporters, aminoacyl-tRNA biosynthesis, biosynthesis of amino acids, and sphingolipid signaling pathway. Isotretinoin treatment normalized eight of these metabolites.

Conclusions: Our study will help to further elucidate the pathogenesis of acne, the mechanism of isotretinoin at the metabolite level, and identify new therapeutic targets for treating acne.

Blood glutamine synthetase signaling in alcohol use disorder and racial disparity

As of 2018, 14.4 million adults ages 18 and older in the U.S had alcohol use disorder (AUD). However, only about 8% of adults who had AUD in the past year received treatment. Surveys have also shown racial disparities regarding AUD treatments. Thus, it is imperative to identify racial disparities in AUD patients, as it may indicate a specific underlying pathophysiology in an AUD subpopulation. To identify racial disparity in AUD, we enrolled 64 cohorts, including 26 AUD participants and 38 healthy controls, from Northwest Louisiana using community-based enrollment. Then, we used psychometric scales to assess alcohol drinking patterns and measured blood metabolites change using LC-MS/MS. Alcohol-related scales from the questionnaires did not differ between the Caucasian AUD participants and African-American AUD participants. From blood metabolomics analyses, we identified that 6 amino acids were significantly different by AUD status and or race. Interestingly, Caucasian AUD participants had a higher glutamate metabolism mediated by glutamine synthetase (GS). The correlation between blood glutamate/glutamine ratio and GS activity was only significant in the Caucasian AUD group whereas no changes were observed in African-American AUD group or controls. Taken together, our findings from this sample population demonstrate that blood GS is a potential biomarker associated with Caucasian AUD, which is an important step towards the application of a new pharmacological treatment for AUD.

Identification of a novel peptide that activates alcohol dehydrogenase from crucian carp swim bladder and how it protects against acute alcohol-induced liver injury in mice

Alcoholism is a severe threat to public health, and there are no adequate treatments for alcoholic liver disease. The aim of this study was to identify bioactive peptides derived from natural proteins that prevent acute alcohol-induced liver injury. We identified a peptide with the sequence Gly-Leu-hydroxyproline-Gly-Glu-Arg (GLpGER) from the hydrolysate of crucian carp swim bladder using size-exclusion chromatography and reversed-phase chromatography. The in vitro EC₅₀ value of GLpGER to activate alcohol dehydrogenase (ADH) was 137.9 ± 9 µM. Molecular docking experiments indicated that the mechanism by which GLpGER activates ADH may be related to the formation of stable complexes with ADH active pockets through hydrogen bonding, and electrostatic and hydrophobic interactions. Oral administration of GLpGER one hour before acute alcohol ingestion significantly increased alcohol metabolism, manifesting as reduced incidence of the loss of righting reflex, increased alcohol tolerance time, shortened sobering time, and decreased blood alcohol concentration level. GLpGER restored liver ADH activity, maintained the typical morphology of hepatocytes, and reduced serum levels of alanine aminotransferase and aspartate aminotransferase. These findings suggest that GLpGER might reduce acute alcohol-induced liver injury and may have the potential to be developed as an anti-inebriation ingredient.

Chicken breast muscle hydrolysates ameliorate acute alcohol-induced liver injury in mice through alcohol dehydrogenase (ADH) activation and oxidative stress reduction

In this study, the ameliorative effect of chicken breast muscle hydrolysates (CBMHs) against acute alcohol-induced liver injury was investigated and its probable mechanism was further elucidated. In vitro studies clearly showed that CBMHs are able to activate alcohol metabolic enzymes (i.e. alcohol dehydrogenase, ADH) in an exponential manner. Meanwhile, an in vivo experiment on male NIH mice indicated that the oral administration of CBMHs (150, 300 and 600 mg per kg bw) 30 min prior to acute alcohol ingestion could significantly promote alcohol metabolism as revealed by the reduced duration of the loss of righting reflex (LORR) and the enhanced activity of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in the liver, the latter accelerating alcohol oxidation and therefore the decreased blood alcohol concentration (BAC) level. Pretreatment with CBMHs significantly decreased the elevations of serum aspartate transaminase (AST) and alanine transaminase (ALT) after alcohol administration. CBMHs could also retard lipid peroxidation as revealed by the suppressed malondialdehyde (MDA) level and simultaneously enhance the activities of superoxide dismutase (SOD) in liver tissue. Furthermore, increased histological damage and higher (p < 0.05) hepatic triglyceride (TG) contents in acute alcoholic-diet fed mice were also reduced (p < 0.05) by supplementing with CBMHs. These benefits clearly suggested that CBMHs could be a potential nutraceutical to facilitate alcohol metabolism and prevent or ameliorate early liver injury induced by acute alcohol exposure.

Comparative Proteomics Analysis Reveals L-Arginine Activates Ethanol Degradation Pathways in HepG2 Cells

L-Arginine (Arg) is a versatile amino acid that plays crucial roles in a wide range of physiological and pathological processes. In this study, to investigate the alteration induced by Arg supplementation in proteome scale, isobaric tags for relative and absolute quantification (iTRAQ) based proteomic approach was employed to comparatively characterize the differentially expressed proteins between Arg deprivation (Ctrl) and Arg supplementation (+Arg) treated human liver hepatocellular carcinoma (HepG2) cells. A total of 21 proteins were identified as differentially expressed proteins and these 21 proteins were all up-regulated by Arg supplementation. Six amino acid metabolism-related proteins, mostly metabolic enzymes, showed differential expressions. Intriguingly, Ingenuity Pathway Analysis (IPA) based pathway analysis suggested that the three ethanol degradation pathways were significantly altered between Ctrl and +Arg. Western blotting and enzymatic activity assays validated that the key enzymes ADH1C, ALDH1A1, and ALDH2, which are mainly involved in ethanol degradation pathways, were highly differentially expressed, and activated between Ctrl and +Arg in HepG2 cells. Furthermore, 10 mM Arg significantly attenuated the cytotoxicity induced by 100 mM ethanol treatment (P < 0.0001). This study is the first time to reveal that Arg activates ethanol degradation pathways in HepG2 cells.

Alanine with the Precipitate of Tomato Juice Administered to Rats Enhances the Reduction in Blood Ethanol Levels

Delay in gastric emptying (GE) lowers the blood ethanol concentration (BEC) after alcohol administration. We previously demonstrated that water-insoluble fractions, mainly comprising dietary fiber derived from many types of botanical foods, possessed the ability to absorb ethanol-containing aqueous solutions. Furthermore, there was a significant correlation between the absorption of ethanol and lowering of BEC because of delay in GE. Here we identified dietary nutrients that synergize with the water-insoluble fraction of tomatoes to lower BEC in rats. Consequently, unlike tomato juice without alanine, tomato juice with 5.0% alanine decreased BEC depending on the delay in GE and mediated the ethanol-induced decrease in the spontaneous motor activity (an indicator of drunkenness). Our findings indicate that the synergism between tomato juice and alanine to reduce the absorption of ethanol was attributable to the effect of alanine on precipitates such as the water-insoluble fraction of tomatoes.

Comparative studies of oral administration of marine collagen peptides from Chum Salmon (Oncorhynchus keta) pre- and post-acute ethanol intoxication in female Sprague-Dawley rats

The present study aimed to evaluate the effect of an oral administration of marine collagen peptides (MCPs) pre- and post-acute ethanol intoxication in female Sprague-Dawley (SD) rats. MCPs were orally administered to rats at doses of 0 g per kg bw, 2.25 g per kg bw, 4.5 g per kg bw and 9.0 g per kg bw, prior to or after the oral administration of ethanol. Thirty minutes after ethanol treatment, the effect of MCPs on motor incoordination and hypnosis induced by ethanol were investigated using a screen test, fixed speed rotarod test (5 g per kg bw ethanol) and loss of righting reflex (7 g per kg bw ethanol). In addition, the blood ethanol concentrations at 30, 60, 90, and 120 minutes after ethanol administration (5 g per kg bw ethanol) were measured. The results of the screen test and fixed speed rotarod test suggested that treatment with MCPs at 4.5 g per kg bw and 9.0 g per kg bw prior to ethanol could attenuate ethanol-induced loss of motor coordination. Moreover, MCP administered both pre- and post-ethanol treatment had significant potency to alleviate the acute ethanol induced hypnotic states in the loss of righting reflex test. At 30, 60, 90 and 120 minutes after ethanol ingestion at 5 g per kg bw, the blood ethanol concentration (BEC) of control rats significantly increased compared with that in the 4.5 g per kg bw and 9.0 g per kg bw MCP pre-treated groups. However, post-treatment with MCPs did not exert a significant inhibitory effect on the BEC of the post-treated groups until 120 minutes after ethanol administration. Therefore, the anti-inebriation effect of MCPs was verified in SD rats with the possible mechanisms related to inhibiting ethanol absorption and facilitating ethanol metabolism. Moreover, the efficiency was better when MCPs were administered prior to ethanol.