Eucommia is a perennial deciduous tree of the family Eucommia. Its medicinal material is the dried bark of the tree.

Eucommia has the effect of tonifying liver and kidney, strengthening muscles and bones, and placenta. It is used for liver and kidney insufficiency, waist and knee pain, weak muscles and bones, dizziness, bleeding during pregnancy, and restless fetal movement.

Pharmacological studies have found that Eucommia chemical components have pharmacological activity on hypertension, hyperglycemia, diabetes, obesity, osteoporosis, Alzheimer's disease, aging and sexual dysfunction. The chemical constituents and pharmacological effects of Eucommia eucommia are summarized as follows.

1 Chemical composition of Eucommia

According to its structure, it can be divided into lignans, iridoids, flavonoids, phenylpropanoids, sterols and triterpenoids, polysaccharides, antifungal proteins and mineral elements.

1.1 Lignans

Lignans are the most abundant active substances in Eucommia ulmoides. According to its structure, it can be divided into double epoxide lignans, single epoxide lignans, cyclolignans, neolignans and sesquisilans, among which rosin glycol diglucoside is an important index for quality control of Eumoides.

1.2 iridoid terpenes

29 iridoid terpenoids have been isolated from Eucommia ulmoides. The most studied are geniposide, geniposide and peach leaf coral.

1.3 Flavonoids

The content of flavonoids is an important index to judge the quality of Fructus Duzhong and its products. Eighteen kinds of flavonoid compounds have been isolated and identified from Eucommia Eucommia.

1.4 Phenylpropanes

Phenylpropanoids are precursors to lignans. It is widely present in the leaves and skins of Eucommia ulmoides. A total of 14 kinds of eucommia phenylpropanoids have been reported. In 2005, the chlorogenic acid content of phenylpropanoid compounds was regarded as the main active component and quality control standard of Eucommia leaves in Chinese Pharmacopoeia.

1.5 phenols

Phenolic substances have rich anti-inflammatory, antioxidant, anti-tumor activities. There are 10 kinds of phenolic substances isolated and purified from Eucommia eucommia.

2 Pharmacological effects of Eucommia eucommia

2.1 Effect of lowering blood lipids

Eucommia can reduce plasma triglycerides, cholesterol, free fatty acids and low density lipoprotein. Its mechanism includes :(1) inhibiting the activities of HMG-CoA reductase and cholesterol acyltransferase, and blocking the synthesis of fatty acids and cholesterol in the liver. (2) Increase the level of Apo I; (3) The oxidation of fatty acids, especially β-oxidation, is regulated by PPAR signaling pathway; (4) Promote the secretion of apolipoprotein B and enhance lysosomal activity. At present, chlorogenic acid, quercetin, peach chlorophyllin and geniposide are thought to be related to lipid lowering.

2.2 Hypoglycemic effect

Eucommia has great potential in the field of diabetes treatment, and its main hypoglycemic mechanism is :(1) inhibiting the activity of α-glucosidase and amylase, inhibiting the decomposition of carbohydrates; (2) Increased the activity of glycolytic enzyme, decreased the activity of gluconeogenic enzyme glucose-6-phosphatase, phosphoenolpyruvate carboxykinase (PEPCK); (3) Inhibit glycosylation, hinder the generation of end-stage glycosylation products, and reduce the occurrence of diabetes complications; (4) Increase the plasma insulin level, enhance the activity of islet beta cells and improve insulin resistance. Quercetin, astragalus, isoquercetin, quercetin-3-0-α-L-arabopyranoside -(1→2) -glucoside are known important material bases.

2.3 Anti-tumor effect

The antitumor effects of Eucommia ulmoides were mainly related to enhancing host immunity and promoting tumor cell apoptosis. Studies have shown that the A549 cell cycle can be stagnated in the GO/G phase, promote cell apoptosis, and have the potential to inhibit non-small cell lung cancer. Kaempferol contained in Eucommia ulmoides can up-regulate p53, inhibit the cell cycle of MDA-MB-453 in G2/M phase, and inhibit the development of breast cancer. Polysaccharides from Eucommia ulmoides can inhibit the growth of Sarcomal180 cells in rats, and its mechanism is related to scavenging oxygen free radicals, enhancing the activities of antioxidant enzymes SOD and GSH, and improving the body immunity. In addition, syringin diglucoside has a better anti-lymphocytic leukemia effect l. Genipin, Genipin and Genipin acid also have good antitumor activity.

2.4 Antibacterial and antiviral effects

Eucommia has inhibitory effect on many kinds of bacteria and viruses. The chlorogenic acid contained in it can effectively inhibit Escherichia coli, stenotrophomonas maltophilia and Staphylococcus aureus, as well as Coxarchie B group 3, adenovirus 7, hepatitis B virus and so on. Peach phylloside (AU) can inhibit the growth of Escherichia coli and Staphylococcus aureus. The combination of AU and glucosidase can inhibit gram-negative and positive bacteria, and inhibit HBV DNA replication. Caffeic acid can reduce the secretion of HBV surface antigen (HBsAg) and HBeAg. EAFP has a good inhibitory effect on trichoderma, aspergillus flavus and other plant pathogens. In addition, Eucommia extract can also inhibit the formation of HIVgp41 six-helix structure, which is a potential HIV inhibitor.

2.5 Anti-inflammatory effect

At present, it is believed that the main active component of Eucommia eucommia's anti-inflammatory effect is peophyllin (AU). The mechanism is related to the inhibition of NF-KB activity. NF-kB regulates the expression of pro-inflammatory factors TNF-a and IL-6. AU can inhibit the degradation of IkB, reduce the activity of NF-KB, cause the expression of TNF-a and IL-6 to be down-regulated, and inhibit the inflammatory response. Some studies believe that the real anti-inflammatory effect is the hydrolyzed product of AU.

2.6 Antioxidant effect

Eucommia has strong antioxidant activity, which can reduce the damage of oxidative stress on the body. Its mechanisms include:

(1) Remove reactive oxygen species and prevent their damage to DNA;

(2) Enhance SOD, CAT, GSH-Px activities, reduce the generation of peroxide products, inhibit lipid peroxidation;

(3) Chelate metal ions to reduce the damage of biological macromolecules caused by oxidative stress;

(4) Decreased the production of matrix metalloproteinase-1 and the activity of β-galactosidase; (5) Inhibit the expression of apoptotic proteases caspases3, 6, 7 and 9, and inhibit H, O2-induced cell death. Coumaric acid, protocatechuic acid, chlorogenic acid, pyrogallic acid, peophylloside, rutin, ferulic acid and caffeic acid contained in Eucommia ulmoides were thought to be related to these effects.

Eucommia ulmoides is our unique tree species, rich resources, in recent years, domestic and foreign scholars of research and development, make eucommia ulmoides not only has medicinal value, at the same time in health food, cosmetics and animal husbandry and breeding industry also appeared a lot of products about eucommia ulmoides, some also has become a series of products, broad application prospect.