Hepatoprotective effect of the natural flavonoid Dihydromyricetin

The liver, as an important metabolic and detoxifying organ in the human body, is susceptible to damage from various factors such as alcohol, drugs, and high-fat diets, which can lead to diseases like liver injury and fatty liver. Dihydromyricetin is a flavonoid compound extracted from natural plants such as Ampelopsis grossedentata. In recent years, studies have shown that it exhibits significant activity in protecting the liver. This article reviews the source and physicochemical properties of dihydromyricetin, systematically elaborates on its protective effects and related mechanisms on various common liver diseases, summarizes its research status and application potential, and looks forward to future research directions, aiming to provide a reference for the in-depth research and application of dihydromyricetin in the prevention and auxiliary treatment of liver diseases.

Keywords: Dihydromyricetin; hepatoprotection; liver injury; fatty liver; liver fibrosis

1. Introduction

The liver is a core organ for maintaining human metabolic homeostasis, with multiple functions such as substance synthesis, detoxification, and bile secretion. However, it is also vulnerable due to long-term exposure to metabolic toxins, pathogens, and other factors. Currently, commonly used clinical hepatoprotective drugs have problems such as single action and questionable safety with long-term use. Therefore, exploring efficient and low-toxic hepatoprotective active ingredients from natural products has become a research hotspot. Dihydromyricetin is the main active ingredient of Ampelopsis grossedentata (a plant of the Vitaceae family). Its chemical structure contains multiple phenolic hydroxyl groups, with various biological activities such as antioxidant and anti-inflammatory properties. A large number of studies in recent years have confirmed that dihydromyricetin has a protective effect on liver injury induced by various factors, with low toxicity and side effects, showing good development prospects.

2. Natural Source and Physicochemical Properties of Dihydromyricetin

Dihydromyricetin is a flavonoid compound existing in nature. Due to the special groups in its molecular structure, it has strong physiological activity. In the plant kingdom, its distribution has obvious preference, mainly concentrated in plants of the genus Ampelopsis in the Vitaceae family. Among them, the leaves and young stems of Ampelopsis grossedentata (commonly known as vine tea among folks) are its most important natural storage sites, with a content much higher than that in other plants. In addition, small amounts can also be detected in the peel of some grape varieties, but the concentration is low, which does not have the value of large-scale extraction. The physical and chemical properties of this component provide convenience for its application: it has good water solubility, so no complex solvent system is needed in the extraction process; it has strong thermal stability, and most of its activity can be retained after processing. These characteristics make dihydromyricetin have advantages in the development of natural products and lay a material foundation for its research in the field of hepatoprotection.

3. Analysis of Multiple Etiologies of Liver Function Damage

As the core organ of human metabolism, the liver is often exposed to various damage risks in daily operation. If these damages accumulate for a long time, they will gradually damage liver function. Alcoholic liver injury is one of the most common types. When drinking for a long time or excessively, the toxic substances produced during the metabolism of alcohol in the liver will directly damage liver cells. Initially, it manifests as fatty degeneration of liver cells, which then triggers inflammation, and can develop into cirrhosis in severe cases. Non-alcoholic fatty liver is closely related to modern lifestyles. Factors such as high-fat and high-sugar diets and lack of exercise can lead to abnormal accumulation of fat in the liver, interfering with the normal metabolism of the liver, gradually making liver cells lose their function. If not intervened in time, it may progress to liver fibrosis. Drug-induced liver injury cannot be ignored. Many drugs need to be metabolized by the liver after entering the human body. The metabolites of some drugs will directly damage liver cells, especially when taking multiple drugs for a long time, the detoxification burden of the liver will increase, which is prone to inflammatory reactions. In addition, viral infections can also attack liver cells, damage the structural integrity of the liver, affect the synthesis and detoxification functions of the liver, and long-term infection may lead to chronic liver disease.

4. Fourfold Protection Mechanism of Dihydromyricetin against Liver Injury

4.1 Antioxidation and Reduction of Oxidative Damage

A large amount of reactive oxygen species will be produced during the metabolism and detoxification process of the liver. When reactive oxygen species accumulate excessively, they will trigger oxidative stress reactions, damaging the membrane structure and organelles of liver cells. Dihydromyricetin has strong antioxidant activity, which can scavenge excess reactive oxygen species in the body and reduce the damage of oxidative stress to liver cells. At the same time, it can also increase the activity of antioxidant enzymes in the liver, enhance the liver's own antioxidant capacity, thereby protecting liver cells from oxidative damage and maintaining the normal structure and function of the liver.

4.2 Inhibition of Inflammatory Response

Liver injury is often accompanied by inflammatory reactions, and the excessive release of inflammatory factors will further aggravate the damage of liver cells. Dihydromyricetin can inhibit the transmission of inflammatory signals, reduce the production and release of inflammatory factors, thereby alleviating the inflammatory response of the liver. In disease models such as alcoholic liver disease and non-alcoholic fatty liver, dihydromyricetin can reduce the level of inflammatory factors in liver tissue, alleviate the inflammatory infiltration of liver cells, and delay the progression of liver injury.

4.3 Regulation of Lipid Metabolism

Lipid metabolism disorder is an important cause of non-alcoholic fatty liver. Excessive fat accumulation in the liver will affect liver function. Dihydromyricetin can regulate the synthesis and decomposition process of lipids in the liver, reducing the deposition of fat in liver cells. It can inhibit the activity of enzymes related to fat synthesis and promote the oxidative decomposition of fat, thereby reducing the fat content in the liver and improving the pathological state of fatty liver.

4.4 Promotion of Hepatocyte Repair and Regeneration

Hepatocytes have a regenerative capacity. When the liver is slightly damaged, the liver function can be restored through the regeneration of hepatocytes. Dihydromyricetin can promote the proliferation of hepatocytes and accelerate the repair and regeneration process of damaged hepatocytes. Studies have found that in liver injury models, dihydromyricetin can increase the number of regenerated hepatocytes, improve the repair ability of the liver, and help the recovery of liver function.

5. Research on Multi-Target Hepatoprotective Effects of Dihydromyricetin

5.1 Effect against Alcoholic Liver Injury

The harmful substances produced by alcohol metabolism are the main inducement of alcoholic liver injury. Dihydromyricetin can reduce the attack of these harmful substances on liver cells and alleviate the oxidative damage of liver cells. At the same time, it can reduce the degree of inflammatory response in liver tissue, alleviate the swelling and necrosis of liver cells caused by alcohol, and so on. In related experiments, the indicators related to alcohol damage in the liver of the experimental subjects taking dihydromyricetin were significantly improved, and the pathological changes of liver cells were milder than those in the control group.

5.2 Effect on Improving Non-Alcoholic Fatty Liver

The core problem of non-alcoholic fatty liver is the disorder of liver fat metabolism. Dihydromyricetin can play a role by regulating the processes related to fat metabolism. It can reduce the synthesis of fat in the liver, promote the decomposition and utilization of existing fat, and reduce the fat content in the liver. For fatty liver models caused by obesity, after supplementing dihydromyricetin, the degree of steatosis in the liver is significantly reduced, and liver function indicators gradually return to the normal range.

5.3 Effect on Alleviating Drug-Induced Liver Injury

The toxic effects of drugs and their metabolites on liver cells will lead to abnormal increase of liver function indicators. Dihydromyricetin can enhance the detoxification ability of the liver, reduce the accumulation of toxic substances in liver cells, and protect the integrity of the membrane structure of liver cells, reducing the damage of drugs to liver cells. In the drug-induced liver injury model, it can significantly reduce the levels of transaminases and other indicators in the serum, and alleviate the necrosis and inflammatory infiltration of liver cells.

6. Research Evidence of Hepatoprotective Effects of Dihydromyricetin

6.1 Preclinical Pharmacodynamic Research

In animal experiments, researchers systematically observed the effect of dihydromyricetin by constructing different types of liver injury models. For the alcoholic liver injury model, after intervention with dihydromyricetin, the liver weight and fat content of the experimental animals were lower than those of the control group, and the level of inflammatory factors in liver tissue decreased significantly. In the non-alcoholic fatty liver model, it can reduce the content of triglycerides and other lipid components in the liver and improve the steatosis of liver cells. Cellular studies also provide strong support. In vitro cultured liver cells, after adding dihydromyricetin, the survival rate of liver cells exposed to harmful substances such as alcohol and drugs is significantly increased, and the level of oxidative stress in cells is reduced, indicating that it has a direct protective effect on liver cells.

6.2 Preliminary Clinical Observation and Analysis

At present, although there are few human studies on dihydromyricetin, preliminary results have shown its potential. In a small-scale trial involving patients with mild fatty liver, subjects took an extract containing dihydromyricetin daily. After 3 months, liver function indicators (such as alanine transaminase and aspartate transaminase) were significantly improved compared with before taking, and liver ultrasound showed that the degree of fat infiltration was reduced. Another study on people who drink for a long time found that supplementing dihydromyricetin can reduce the level of markers related to liver injury in serum. However, the current research sample size is small, and larger-scale clinical trials are needed for verification.

7. Application Value and Development Direction of Dihydromyricetin

7.1 Application Potential in the Health Field

Based on existing research evidence, dihydromyricetin has clear potential in the development of hepatoprotective health products. For people who drink for a long time, liver-protecting drinks with it as the main component can be developed to help reduce the damage of alcohol to the liver; for high-risk groups of fatty liver, it can be made into dietary supplements to assist in regulating liver fat metabolism. Its natural source characteristics make the product highly safe and suitable for long-term use, which is also its advantage compared with synthesized liver-protecting ingredients.

7.2 Research Bottlenecks to be Broken Through

There are still some problems to be solved in current research. Firstly, the absorption process of dihydromyricetin in the body has not been fully clarified, and its bioavailability needs to be improved. How to enhance its effective concentration in the body through preparation technology is a key direction. Secondly, different populations may have different reactions to it, and it is necessary to further clarify the applicable dose and population characteristics. In addition, there are few studies on its synergistic effect with other liver-protecting ingredients, and exploring the effect of combined application may expand its application range.

8. Summary and Outlook

As a natural active ingredient, dihydromyricetin has shown various protective effects in dealing with common liver problems such as alcoholic liver injury, non-alcoholic fatty liver, and drug-induced liver injury. Basic experiments and preliminary clinical studies have provided support for its efficacy. Its unique physicochemical properties and natural source advantages make it have broad prospects in the development of hepatoprotective health products. Future research should focus on improving bioavailability and clarifying clinical application standards. Through more in-depth mechanism research and large-scale clinical trials, more solid scientific basis will be provided for its application in the field of liver health. With the advancement of research, dihydromyricetin is expected to become an important component of natural liver-protecting products, providing a new choice for maintaining liver health.

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