Auricularia auricula Melanin Protects against Alcoholic Liver Injury and Modulates Intestinal Microbiota Composition in Mice Exposed to Alcohol Intake.

Yichen Lin,Weiling Guo,Yuanhui Zhang,Xucong Lv,Penghu Liu,Hua Chen,Pingfan Rao,Yingjia Cao,Li Ni,Wenfeng Li

doi:10.3390/foods10102436

Abstract

The potential effects of Auricularia auricula melanin (AAM) on the intestinal flora and liver metabolome in mice exposed to alcohol intake were investigated for the first time. The results showed that oral administration of AAM significantly reduced the abnormal elevation of serum total triglyceride (TG), cholesterol (TC), low density lipoprotein cholesterol (LDL-C), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and significantly inhibited hepatic lipid accumulation and steatosis in mice exposed to alcohol intake. Besides, the abnormally high levels of bile acids (BAs) and lactate dehydrogenase (LDH) in the liver of mice with alcohol intake were significantly decreased by AAM intervention, while the hepatic levels of glutathione (GSH) and superoxide dismutase (SOD) were appreciably increased. Compared with the model group, AAM supplementation significantly changed the composition of intestinal flora and up-regulated the levels of Akkermansia, Bifidobacterium, Romboutsia, Muribaculaceae, Lachnospiraceae_NK4A136_group, etc. Furthermore, liver metabolomics demonstrated that AAM had a significant regulatory effect on the composition of liver metabolites in mice with alcohol intake, especially the metabolites involved in phosphatidylinositol signaling system, ascorbate and aldarate metabolism, starch and sucrose metabolism, galactose metabolism, alpha-linolenic acid metabolism, glycolysis/gluconeogenesis, and biosynthesis of unsaturated fatty acids. At the gene level, AAM treatment regulated the mRNA levels of lipid metabolism and inflammatory response related genes in liver, including ACC-1, FASn, CPT-1, CD36, IFN-γ, LDLr and TNF-α. Conclusively, these findings suggest that AAM has potential beneficial effects on alleviating alcohol-induced liver injury and is expected to become a new functional food ingredient.

Highlights

Alcohol abuse has harmful impacts on human health by damaging liver metabolism functions [1]
Results of Reverse Transcription-Quantitative Polymerase Chain Reaction (RT-qPCR) of lipid metabolism and inflammatory response related genes in liver showed that alcohol intake promoted the mRNA levels of ACC1, FASn, CD36, IFN-γ and TNF-α in liver, while inhibited the mRNA levels of CPT-1 and low-density lipoprotein receptor (LDLr) in liver
Low dose auricula melanin (AAM) intervention can reverse the expression of these genes and improve the degree of liver injury caused by alcohol intake (Figure 7)

Summary

Introduction

Alcohol abuse has harmful impacts on human health by damaging liver metabolism functions [1]. Alcoholic liver disease (ALD), mainly including fatty liver, hepatitis, cirrhosis, hepatocyte necrosis and even liver failure, is usually caused by long-term excessive alcohol consumption and has become an ever-growing health issue worldwide [2]. Excessive alcohol intake produces large number of destructive endogenous free radicals, and it is difficult for the human body to eliminate these free radicals in a short time, leading to liver damage, hyperglycemia, hyperlipidemia, and even hypertension. How to prevent the pathological process of ALD has become a major global problem [3]. Researchers all over the world are committed to finding effective strategies to intervene in the pathological development of ALD. It is of great significance to excavate natural products with strong antioxidant effect from food resources for the prevention of alcoholic liver injury

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