Effects of Different Green Tea Extracts on Chronic Alcohol Induced-Fatty Liver Disease by Ameliorating Oxidative Stress and Inflammation in Mice

Composition of Higher Alcohols in Different Alcoholic Beverages and Their Metabolic Dynamics in Bama Pigs

The unique flavour contribution of higher alcohols in alcoholic beverages has received growing attention; however, there is a dearth of information on their in vivo metabolic kinetics. In this study, the composition and content of higher alcohols in different alcoholic beverages from Chinese Baijiu and Lujiu were studied via in vivo analysis using Bama pigs to elucidate the mechanisms for intoxication of alcohol in vitro and in drinkers. Direct injection combined with gas chromatography-mass spectrometry (GC-MS) were used to accurately quantify a total of 14 higher alcohols in five alcoholic beverages. Based on the external standard method, a total content of 289.37-938.33 mg/L was detected, mainly 1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-methyl-1-propanol and 2-butanol. Then, headspace solid-phase microextraction (HS-SPME) and solid-phase extraction (SPE) combined with GC-MS analysis strategy, respectively, were adopted to continuously monitor the changes in the concentrations of ethanol and 11 higher alcohols in the blood within 24 h after gavage of different alcoholic beverages, and the key pharmacokinetic parameters were analysed. The peak concentration (Cmax) and area under curve (AUC) of blood higher alcohols were significantly lower than those of ethanol (p < 0.05), accompanied by a later peak time (Tmax) and a larger apparent clearance rate (CL_F), and there were certain differences between the same higher alcohols in different alcoholic beverages and between different higher alcohols in the same alcoholic beverage. This work provides valuable insights into the metabolism of alcoholic beverages.

Natural resourced polysaccharides: Preparation, purification, structural elucidation, structure-activity relationships and regulating intestinal flora, a system review

Natural resourced polysaccharides (NRPs), as metabolites synthesized during activity of organisms, widely present in animal cell membranes or plant and microbial cell walls. NRPs have garnered extensive attention in the fields of medicine, foods, and farming owing to their distinct bioactivities and structural diversity. Despite the burgeoning growth in NRPs research, the available literature focuses primarily on a review of specific polysaccharides, necessitating an urgent need for a comprehensive summary of NRPs to offer readers a whole landscape of current advancements in NRPs research. Based on this, this article comprehensively reviews the latest research progress regarding preparation, purification, structure elucidation, structure-activity relationships and regulation of intestinal flora of NRPs in electronic databases, such as PubMed, Wiley, ScienceDirect and Web of Science from last 5 years. This review analyzes the effects of various extraction techniques on NRPs and also delves into the intrinsic correlation between the biological activity and structure of NRPs, highlighting that chemical modification can enhance their structural diversity and confer novel or improved biological functions. Moreover, this article extensively explores the application of NRP in promoting intestinal microecology balance, underscoring its significant potential as a probiotic initiator. This review lays a solid theoretical foundation for the future research and development of NRPs.

Dietary supplementation of poly-dihydromyricetin-fused zinc nanoparticles alleviates fatty liver hemorrhagic syndrome by improving antioxidant capacity, intestinal health and lipid metabolism of laying hens

Fatty liver hemorrhagic syndrome is the main cause of noninfectious death of laying hens and results in substantial economic losses to the poultry industry. This study focused on evaluating the effects of Poly-dihydromyricetin-fused zinc nanoparticles (PDMY-Zn NPs) on antioxidant capacity, liver lipid metabolism, and intestinal health in laying hens. A total of 288 Jingfen laying hens (52 wk old) with similar body weights were randomly divided into 4 dietary groups with 6 replicates in each group for 8 wk. The control group received a basal diet, while the treatment groups were supplemented with PDMY-Zn NPs at levels of 200, 400, and 600 mg/kg, respectively. The results indicate that PDMY-Zn NPs supplementation can enhance antioxidant parameters (P < 0.05) in the blood and liver of laying hens. Simultaneously, it can mitigate vacuolar degeneration and inflammatory necrosis in hepatocytes, improve the relative expression level of related parameters associated with liver lipid metabolism and key regulatory genes (P < 0.05). Furthermore, it has been observed to reshape the composition and diversity of cecum microbes by increasing beneficial probiotics such as Lactobacillus and Prevotella, while also enhancing villi height and villi/crypt ratio in the duodenum and ileum (P < 0.05). Additionally, it elevates liver bile acid content along with the relative expression of key genes involved in liver synthesis (P < 0.05). In summary, PDMY-Zn NPs showed potential to alleviate fatty liver hemorrhagic syndrome by enhancing antioxidant capacity, regulating liver lipid metabolism, and maintaining intestinal health.

Effects of Several Tea-like Plants on Liver Injury Induced by Alcohol via Their Antioxidation, Anti-Inflammation, and Regulation of Gut Microbiota

Liver injury induced by alcohol is a serious global health problem. Several tea-like plants are widely used as beverages, which are drunk like tea. In this study, the hepatoprotective effects of eight tea-like plant extracts with the intake of 200 mg/kg.bw/day were investigated and compared using a C57BL/6J mouse model of acute alcohol exposure, including sweet tea, vine tea, Rabdosia serra kudo, broadleaf holly leaf, mulberry leaf, bamboo leaf, Camellia nitidissima, and Akebia trifoliata peels. The results showed that the eight tea-like plants had hepatoprotective effects to different degrees against acute alcohol exposure via enhancing the activities of alcoholic metabolism enzymes, ameliorating oxidative stress and inflammation in the liver, as well as regulating gut microbiota. In particular, sweet tea, bamboo leaf, mulberry leaf, and Camellia nitidissima increased the activities of alcohol dehydrogenase or aldehyde dehydrogenase. Among these tea-like plants, sweet tea and Camellia nitidissima had the greatest hepatoprotective effects, and their bioactive compounds were determined by high-performance liquid chromatography. Chlorogenic acid, rutin, and ellagic acid were identified in sweet tea, and epicatechin, rutin, and ellagic acid were identified in Camellia nitidissima, which could contribute to their hepatoprotective action. These tea-like plants could be drunk or developed into functional food against alcoholic liver injury, especially sweet tea and Camellia nitidissima. In the future, the effects of sweet tea and Camellia nitidissima on chronic alcoholic liver diseases should be further investigated.

Hepatoprotective effects of fruits pulp, seed, and peel against chemical-induced toxicity: Insights from in vivo studies

The liver is a vital organ in human physiology positioned in the upper right quadrant of the peritoneal cavity, which plats a critical role in metabolic processes, detoxification of various substances and overall homeostasis. Along with these critical functions, hepatic diseases impose as significant global health threat. Liver illness is the cause of two million fatalities every year, or 4% of all deaths. Traditionally, healthcare providers have prescribed antibacterial and antiviral medications to address liver illness. Nephrotoxicity is a frequently observed negative reaction to drugs, with the majority of such events happening in individuals who have advanced cirrhosis. Thus, recognizing this gap, there is a dire need of exploration of pharmaceutical alterative for hepatic diseases, with special focus on their efficacy and reduced toxicity. Fruits have long been known to therapeutic impact on human health, thus exploration of fruits components namely pulp, seeds and peels containing phytochemicals have emerged as a promising avenue for hepatoprotective interventions. Thus, review comprehends the information about worldwide burden of chemical induced toxicity and injuries as well as highlight the on-going challenges in hepatic disease management. It also shed light on the valuable contributions fruit parts and their phytocompounds obtained from different components of fruits. Fruit pulp, especially when rich in flavonoids, has demonstrated significant potential in animal model studies. It has been observed to enhance the activity of antioxidant enzymes and reduce the expression of pro-inflammatory markers. The methanolic and ethanolic extracts have demonstrated the most favorable outcomes. Further, this review also discusses about the safety assessments of fruits extracts for their utilization as hepatoprotective agents.

Liquid Chromatography/Tandem Mass Spectrometry Analysis of Sophora flavescens Aiton and Protective Effects against Alcohol-Induced Liver Injury and Oxidative Stress in Mice

In this study, we investigated the hepatoprotective effects of an ethanol extract of Sophora flavescens Aiton (ESF) on an alcohol-induced liver disease mouse model. Alcoholic liver disease (ALD) was caused by the administration of ethanol to male C57/BL6 mice who were given a Lieber-DeCarli liquid diet, including ethanol. The alcoholic fatty liver disease mice were orally administered ESF (100 and 200 mg/kg bw/day) or silymarin (50 mg/kg bw/day), which served as a positive control every day for 16 days. The findings suggest that ESF enhances hepatoprotective benefits by significantly decreasing serum levels of aspartate transaminase (AST) and alanine transaminase (ALT), markers for liver injury. Furthermore, ESF alleviated the accumulation of triglyceride (TG) and total cholesterol (TC), increased serum levels of superoxide dismutase (SOD) and glutathione (GSH), and improved serum alcohol dehydrogenase (ADH) activity in the alcoholic fatty liver disease mice model. Cells and organisms rely on the Kelch-like ECH-associated protein 1- Nuclear factor erythroid 2-related factor 2 (Keap1-Nrf2) system as a critical defensive mechanism in response to oxidative stress. Therefore, Nrf2 plays an important role in ALD antioxidant responses, and its level is decreased by increased reactive oxidation stress (ROS) in the liver. ESF increased Nrf2, which was decreased in ethanol-damaged livers. Additionally, four polyphenol compounds were identified through a qualitative analysis of the ESF using LC-MS/MS. This study confirmed ESF's antioxidative and hangover-elimination effects and suggested the possibility of using Sophora flavescens Aiton (SF) to treat ALD.

The Role of Oxidative Stress in Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Preclinical Studies

Alcoholic Fatty Liver Disease (AFLD) is characterized by the accumulation of lipids in liver cells owing to the metabolism of ethanol. This process leads to a decrease in the NAD+/NADH ratio and the generation of reactive oxygen species. A systematic review and meta-analysis were conducted to investigate the role of oxidative stress in AFLD. A total of 201 eligible manuscripts were included, which revealed that animals with AFLD exhibited elevated expression of CYP2E1, decreased enzymatic activity of antioxidant enzymes, and reduced levels of the transcription factor Nrf2, which plays a pivotal role in the synthesis of antioxidant enzymes. Furthermore, animals with AFLD exhibited increased levels of lipid peroxidation markers and carbonylated proteins, collectively contributing to a weakened antioxidant defense and increased oxidative damage. The liver damage in AFLD was supported by significantly higher activity of alanine and aspartate aminotransferase enzymes. Moreover, animals with AFLD had increased levels of triacylglycerol in the serum and liver, likely due to reduced fatty acid metabolism caused by decreased PPAR-α expression, which is responsible for fatty acid oxidation, and increased expression of SREBP-1c, which is involved in fatty acid synthesis. With regard to inflammation, animals with AFLD exhibited elevated levels of pro-inflammatory cytokines, including TNF-a, IL-1β, and IL-6. The heightened oxidative stress, along with inflammation, led to an upregulation of cell death markers, such as caspase-3, and an increased Bax/Bcl-2 ratio. Overall, the findings of the review and meta-analysis indicate that ethanol metabolism reduces important markers of antioxidant defense while increasing inflammatory and apoptotic markers, thereby contributing to the development of AFLD.

Hepatoprotective effects of natural drugs: Current trends, scope, relevance and future perspectives

BACKGROUND

The liver is a well-known player in the metabolism and removal of drugs. Drug metabolizing enzymes in the liver detoxify drugs and xenobiotics, ultimately leading to the acquisition of homeostasis. However, liver toxicity and cell damage are not only related to the nature and dosage of a particular drug but are also influenced by other factors such as aging, immune status, environmental contaminants, microbial metabolites, gender, obesity, and expression of individual genes Furthermore, factors such as drugs, alcohol, and environmental contaminants could induce oxidative stress, thereby impairing the regenerative potential of the liver and causing several diseases. Persons suffering from other ailments and those with comorbidities are found to be more prone to drug-induced toxicities. Moreover, drug composition and drug-drug interactions could further aggravate the risk of drug-induced hepatotoxicity. A plethora of mechanisms are responsible for initiating liver cell damage and further aggravating liver cell injury, followed by impairment of homeostasis, ultimately leading to the generation of reactive oxygen species, immune-suppression, and oxidative stress.

OBJECTIVE

To summarize the potential of phytochemicals and natural bioactive compounds to treat hepatotoxicity and other liver diseases.

STUDY DESIGN

A deductive qualitative content analysis approach was employed to assess the overall outcomes of the research and review articles pertaining to hepatoprotection induced by natural drugs, along with analysis of the interventions.

METHODS

An extensive literature search of bibliographic databases, including Web of Science, PUBMED, SCOPUS, GOOGLE SCHOLAR, etc., was carried out to understand the role of hepatoprotective effects of natural drugs.

RESULTS

Bioactive natural products, including curcumin, resveratrol, etc., have been seen as neutralizing agents against the side effects induced by the drugs. Moreover, these natural products are dietary and are readily available; thus, could be supplemented along with drugs to reduce toxicity to cells. Probiotics, prebiotics, and synbiotics have shown promise of improving overall liver functioning, and these should be evaluated more extensively for their hepatoprotective potential. Therefore, selecting an appropriate natural product or a bioactive compound that is free of toxicity and offers a reliable solution for drug-induced liver toxicity is quintessential.

CONCLUSIONS

The current review highlights the role of natural bioactive products in neutralizing drug-induced hepatotoxicity. Efforts have been made to delineate the possible underlying mechanism associated with the neutralization process.

Aqueous extract of Laurus nobilis leaf accelerates the alcohol metabolism and prevents liver damage in single-ethanol binge rats

BACKGROUND/OBJECTIVES

Excessive alcohol consumption has harmful health effects, including alcohol hangovers and alcohol-related liver disease. Therefore, methods to accelerate the alcohol metabolism are needed. Laurus nobilis is a spice, flavoring agent, and traditional herbal medicine against various diseases. This study examined whether the standardized aqueous extract of L. nobilis leaves (LN) accelerates the alcohol metabolism and protects against liver damage in single-ethanol binge Sprague-Dawley (SD) rats.

MATERIALS/METHODS

LN was administered orally to SD rats 1 h before ethanol administration (3 g/kg body weight [BW]) at 100 and 300 mg/kg BW. Blood samples were collected 0.5, 1, 2, and 4 h after ethanol administration. The livers were excised 1 h after ethanol administration to determine the hepatic enzyme activity. The alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities in the liver tissue were measured.

RESULTS

LN decreased the serum ethanol and acetaldehyde levels in ethanol-administered rats. LN increased the hepatic ADH and ALDH activities but decreased the alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase activities in the ethanol-administered rats. In addition, LN inhibited lipid peroxidation and increased the activities of SOD and GPx.

CONCLUSIONS

LN modulates the mediators of various etiological effects of excessive alcohol consumption and enhances the alcohol metabolism and antioxidant activity, making it a potential candidate for hangover treatments.

miR-9 utilizes precursor pathways in adaptation to alcohol in mouse striatal neurons

microRNA-9 (miR-9) is one of the most abundant microRNAs in the mammalian brain, essential for its development and normal function. In neurons, it regulates the expression of several key molecules, ranging from ion channels to enzymes, to transcription factors broadly affecting the expression of many genes. The neuronal effects of alcohol, one of the most abused drugs in the world, seem to be at least partially dependent on regulating the expression of miR-9. We previously observed that molecular mechanisms of the development of alcohol tolerance are miR-9 dependent. Since a critical feature of alcohol action is temporal exposure to the drug, we decided to better understand the time dependence of alcohol regulation of miR-9 biogenesis and expression. We measured the effect of intoxicating concentration of alcohol (20 mM ethanol) on the expression of all major elements of miR-9 biogenesis: three pri-precursors (pri-mir-9-1, pri-mir-9-2, pri-mir-9-3), three pre-precursors (pre-mir-9-1, pre-mir-9-2, pre-mir-9-3), and two mature microRNAs: miR-9-5p and miR-9-3p, using digital PCR and RT-qPCR, and murine primary medium spiny neurons (MSN) cultures. We subjected the neurons to alcohol based on an exposure/withdrawal matrix of different exposure times (from 15 min to 24 h) followed by different withdrawal times (from 0 h to 24 h). We observed that a short exposure increased mature miR-9-5p expression, which was followed by a gradual decrease and subsequent increase of the expression, returning to pre-exposure levels within 24 h. Temporal changes of miR-9-3p expression were complementing miR-9-5p changes. Interestingly, an extended, continuous presence of the drug caused a similar pattern. These results suggest the presence of the adaptive mechanisms of miR-9 expression in the presence and absence of alcohol. Measurement of miR-9 pre- and pri-precursors showed further that the primary effect of alcohol on miR-9 is through the mir-9-2 precursor pathway with a smaller contribution of mir-9-1 and mir-9-3 precursors. Our results provide new insight into the adaptive mechanisms of neurons to alcohol exposure. It would be of interest to determine next which microRNA-based mechanisms are involved in a transition from the acute, intoxicating effects of alcohol to the chronic, addictive effects of the drug.

The hepatoprotective effects of Herbt Tea Essences on phenanthrene-induced liver damage in mice

Phenanthrene (Phe), one of the most frequently occurring pollutants in nature, can cause substantial damage to the human liver. Herbt Tea Essences (HTE), a kind of black tea extract with strong anti-inflammatory activity, can protect humans against disease. Currently, whether HTE can protect the liver from Phe-induced hepatotoxicity remains unclear. Herein, we explore the protective effects of HTE against Phe-induced hepatotoxicity. Our results showed that Phe exposure could significantly induce liver damage and increase serum hepatic enzyme levels in mice. HTE could prevent liver damage and recover the expression levels of inflammatory factors. Furthermore, we found that HTE suppressed the excessive activation of the nuclear transcription factor kappa-B and transforming growth factor-β/SMAD signaling pathways to alleviate Phe-induced liver inflammation and fibrosis. Overall, our data showed that HTE treatment could be a new preventive means for Phe-induced liver disease.

Dietary Phenolic Compounds: Their Health Benefits and Association with the Gut Microbiota

Oxidative stress causes various diseases, such as type II diabetes and dyslipidemia, while antioxidants in foods may prevent a number of diseases and delay aging by exerting their effects in vivo. Phenolic compounds are phytochemicals such as flavonoids which consist of flavonols, flavones, flavanonols, flavanones, anthocyanidins, isoflavones, lignans, stilbenoids, curcuminoids, phenolic acids, and tannins. They have phenolic hydroxyl groups in their molecular structures. These compounds are present in most plants, are abundant in nature, and contribute to the bitterness and color of various foods. Dietary phenolic compounds, such as quercetin in onions and sesamin in sesame, exhibit antioxidant activity and help prevent cell aging and diseases. In addition, other kinds of compounds, such as tannins, have larger molecular weights, and many unexplained aspects still exist. The antioxidant activities of phenolic compounds may be beneficial for human health. On the other hand, metabolism by intestinal bacteria changes the structures of these compounds with antioxidant properties, and the resulting metabolites exert their effects in vivo. In recent years, it has become possible to analyze the composition of the intestinal microbiota. The augmentation of the intestinal microbiota by the intake of phenolic compounds has been implicated in disease prevention and symptom recovery. Furthermore, the “brain–gut axis”, which is a communication system between the gut microbiome and brain, is attracting increasing attention, and research has revealed that the gut microbiota and dietary phenolic compounds affect brain homeostasis. In this review, we discuss the usefulness of dietary phenolic compounds with antioxidant activities against some diseases, their biotransformation by the gut microbiota, the augmentation of the intestinal microflora, and their effects on the brain–gut axis.

Alleviation of Alcoholic Fatty Liver by Dendrobium officinale Flower Extracts due to Regulation of Gut Microbiota and Short-Chain Fatty Acids in Mice Exposed to Chronic Alcohol

Alcoholic fatty liver disease (AFLD) is caused by long-term heavy alcohol consumption; therefore, useful and practical methods for the prevention of AFLD are urgently needed. The edible flower of Dendrobium officinale contains diverse flavonoids, and has shown antioxidant activity as well as antihypertensive and anti-inflammatory effects. In this study, an AFLD model was established, the protective effect of D. officinale flower (DOF) ethanol extract on AFLD was evaluated, and its mechanisms were investigated by analyzing gut microbiota and short-chain fatty acids (SCFAs). DOF extract (DOFE) supplementation promoted alcohol metabolism, restored hepatic antioxidant capacity, alleviated oxidative stress, reduced inflammatory factor levels, and inhibited dyslipidemia induced by alcohol intake in chronic alcohol-exposed mice, especially in the high DOFE group. Moreover, DOFE supplementation increased the diversity, structure, and composition of the gut microbiota in mice, restored some of the abnormal SCFA levels caused by AFLD, and helped restore intestinal function. DOFE supplementation significantly increased the relative abundance of Akkermansia, suggesting that Akkermansia may be a potential target of the protective effect of DOFE. Therefore, DOFE supplementation to improve the composition of the gut microbiota may be an effective therapeutic strategy for the prevention of AFLD.

Aging-Accelerated Mouse Prone 8 (SAMP8) Mice Experiment and Network Pharmacological Analysis of Aged Liupao Tea Aqueous Extract in Delaying the Decline Changes of the Body

Aging and metabolic disorders feedback and promote each other and are closely related to the occurrence and development of cardiovascular disease, type 2 diabetes, neurodegeneration and other degenerative diseases. Liupao tea is a geographical indication product of Chinese dark tea, with a “red, concentrated, aged and mellow” flavor quality. In this study, the aqueous extract of aged Liupao tea (ALPT) administered by continuous gavage significantly inhibited the increase of visceral fat and damage to the intestinal–liver–microbial axis in high-fat modeling of SAMP8 (P8+HFD) mice. Its potential mechanism is that ALPT significantly inhibited the inflammation and aggregation formation pathway caused by P8+HFD, increased the abundance of short-chain fatty acid producing bacteria Alistipes, Alloprevotella and Bacteroides, and had a calorie restriction effect. The results of the whole target metabolome network pharmacological analysis showed that there were 139 potential active components in the ALPT aqueous extract, and the core targets of their actions were SRC, TP53, AKT1, MAPK3, VEGFA, EP300, EGFR, HSP90AA1, CASP3, etc. These target genes were mainly enriched in cancer, neurodegenerative diseases, glucose and lipid metabolism and other pathways of degenerative changes. Molecular docking further verified the reliability of network pharmacology. The above results indicate that Liupao tea can effectively delay the body’s degenerative changes through various mechanisms and multi-target effects. This study revealed that dark tea such as Liupao tea has significant drinking value in a modern and aging society.

The therapeutic potential of matcha tea: A critical review on human and animal studies

Matcha is a powdered form of Japanese green tea that has been gaining global popularity recently. Matcha tea has various health benefits, including an enhancing effect on cognitive function, cardio-metabolic health, and anti-tumorogenesis. To date, randomized clinical trials (RCT) showed that matcha decreases stress, slightly enhances attention and memory, and has no effect on mood. Results regarding the effect of matcha on cognitive function are contradictory and more RCTs are warranted. The cardio-metabolic effects of matcha have only been studied in animals, but findings were more homogenous. Consuming matcha with a high-fat diet resulted in decreased weight gain velocity, food intake, improved serum glucose and lipid profile, reduced inflammatory cytokines and ameliorated oxidative stress. Evidence regarding the anti-tumor function of matcha is very limited. Findings showed that matcha can affect proliferation, viability, antioxidant response, and cell cycle regulation of breast cancer cells. Nonetheless, more studies are needed to examine this effect on different types of cancer cells, and there is also a need to verify it using animal models. Overall, the evidence regarding the effect of matcha tea on cognitive function, cardio-metabolic function, and anti-tumor role is still limited, and conclusions cannot be drawn.

Epigallocatechin Gallate Relieved PM2.5-Induced Lung Fibrosis by Inhibiting Oxidative Damage and Epithelial-Mesenchymal Transition through AKT/mTOR Pathway

Oxidative damage and epithelial-mesenchymal transition (EMT) are main pathological processes leading to the development of PM2.5-induced lung fibrosis. Epigallocatechin gallate (EG), a natural polyphenol extracted from green tea, possesses the ability to combat oxidative stress and inflammation. However, the potential roles of EG in PM2.5-induced lung fibrosis have not been reported yet. In the present study, we investigated whether EG could relieve PM2.5-induced lung injury and fibrosis in vivo and in vitro. To mimic PM2.5-induced lung fibrosis, C57/BL6 mice were intranasally instilled with PM2.5 suspension, and MLE-12 lung epithelial cells were stimulated with PM2.5 (100 μg/mL) in vitro. The results showed that intragastric administration of EG (20 mg/kg/d or 80 mg/kg/d for 8 weeks) significantly prevented lung injury, inflammation, and oxidative stress in PM2.5-induced mice, apart from inhibiting collagen deposition. Additionally, EG treatment also suppressed the activation of AKT/mTOR signaling pathway in lung tissues challenged with PM2.5. In vitro experiments further demonstrated that EG treatment could enhance cell viability in a concentration-dependent manner in PM2.5-treated MLE-12 lung epithelial cells. Also, the overexpression of constitutively active AKT could offset the inhibitory effects of EG on EMT and oxidative stress in PM2.5-treated MLE-12 lung epithelial cells. Finally, AKT overexpression also blocked the inhibitory effect of EG on the phosphorylation of mTOR in PM2.5-treated MLE-12 lung epithelial cells. In conclusion, EG could improve PM2.5-induced lung fibrosis by decreasing oxidative damage and EMT through AKT/mTOR pathway, which might be a potential candidate for the treatment of PM2.5-induced lung fibrosis.