Du Zhong

Eucommiae Cortex, Eucommia

Dosage

6-9g.

Toxicity

No death or changes in physical conditions resulted from administering alcohol-based extract of Du Zhong to mice at 40g/kg for three consecutive days. (1) Neither does death result from a one-time gastrolavage of water-based extract of Du Zhong at the dosage of 120g/kg. (2)

Chemical Composition

Gutta-Percha (Balata); Lignans; Lignon glycosides; Syringaresinols; Olivils; Medioresinols; Coniferol alcohol; Ridoids; Eucommiol; Eucommioside; Genipin; Deoxyeucommiol; Geniposide; Geniposidic acid; Aucubin; Ajugoside; Reptoside; Eucommioside; Asperuloside; Epieucommiol; Phenols; Catechol; Vanillic acid; Caffeic acid; Chlorogenic acid; Methyl chlorogenate; Eugenoside; Coniferin; Ulmoprenol; Kaempferol; Tartaric acid; Galactitol; Triacontanol Nonacosane; Geniposidic acid; b-sitosterol; Daucosterol; Straight Betulin; Betulinic acid; Ursolic acid; Lysine; Tryptophane; Methionine; Threonine; Valine; Leucine; Isoleucine; Glutamic acid; Cystisine; Histidine; Arginine; Chaintriterpenoid ethanol; 3-hydroxyphenylalanine; 3,4-dihydroxyphenylalanine. (3) , (4) , (5) , (6) , (7) , (8) , (9)

Inorganic Chemicals

Cu, Zn, Ge, Se.

Precautions

Patients with hyperactive fire and yin deficiency should use this herb with caution.

Pharmacology

Effects on the heart

Experiments show that administered to guinea pigs, the leaves of Du Zhong (0.2g/guinea pig) can significantly increase the subjects' coronary blood flow. Du Zhong also has a preventive effect on experimental myocardial ischemia in rabbits: the bark and leaves of Du Zhong were administered to rabbits via intravenous injection for four consecutive days, and the pathological results showed that there were no significant hemorrhage, necrosis, or cicatrix formation in the rabbits' endocardium and epicardium; there were dilation and congestion in the capillaries and some larger vessels and there were varying degrees of inflammatory cell infiltration in the endocardium, epicardium, and myocardium. (10)

Lowering blood pressure

The zinc/copper ratio in the erythrocyte of hypertension patients fluctuates around 15.04- 2.50, which is significantly higher than that in healthy people. Du Zhong can lower the zinc/copper ratio, and the blood pressure. (11) The blood pressure of anaesthetized canine can be lowered significantly by intravenous injection of Du Zhong decoction. At the dosage of 0.4 g/kg, the lowered blood pressure began rising again after five minutes. When the dosage is increased to over 1 g/kg, however, the blood pressure-lowering effect of Du Zhong can be sustained for a relatively long period of time. (12)

Anti-inflammatory and anti-viral effects

Chlorogenic acid, an active component of Du Zhong, has a pronounced anti-bacterial effect. (13) Aucubin is a significant protector of the liver; it can inhibit the duplication of the DNA of hepatitis B. Although aucubin in and of itself does not have an anti-viral effect, its being cultivated with glucosiduronidase produces an anti-viral effect. (14)

Effects on immunity

Alcohol-based extract of Du Zhong can promote ConA-induced proliferation of splenic cells, and enhance the phagocytic function of the peritoneal macrophage phagocytosis. But it does not seem to affect splenic antibody formation cells. (15) Du Zhong decoction has a bi-directional regulatory effect on the cellular immune system. It can inhibit DNCB-induced delayed hypersensitivity, counteract hydrocortisone-induced decrease in T-lymphocyte percentage. It can also increase the percentage of T-lymphocytes in the peripheral blood of S180 mice, and strengthen the phagocytic function of the peritoneal macrophage. (16) Various parts of Du Zhong (cortex, leaves, twigs, and regenerated peel, etc.) can elevate the cAMP content in the plasma, indicating a regulatory effect on cyclo-nucleotide metabolism. (17)

Tranquilizing and analgesic effects

Experiments show that Du Zhong can enhance mice's endurance against exogenous stimulation, and has central tranquilizing effects. (18) Du Zhong also has a significant analgesic effect (P

Anti-aging effects

Experiments show that water-based extract of Du Zhong can protect mice from superoxidation injuries due to D-galactose-induced aging. (19) Du Zhong is also shown to increase the activity of GSH-Px in aged mice, (20) increase the activity of SOD and the weight of the adrenal gland in mice of suffering from experimental yang-deficiency. (21)

References

  1. Zhu Li Qing, et al. Journal of Chinese Materia Medica. 1986;17(12):15.
  2. Li Xian Ping, et al. Journal of Chinese Patented Medicine Research. 1988;(1):15-16.
  3. Hu Jia Ling. Journal of Chinese Materia Medica. 1999;30(5):394-396.
  4. Zang You Wei. Journal of Chinese Materia Medica. 1989;20(4):186.
  5. Zhou Ying Xin, et al. Journal of Chinese Materia Medica. 1988;19(9):419-423, 430.
  6. Liu Ya Ming, et al. Shanxi Journal of TCM. 1988;4(3):42,41.
  7. Zang You Wei. China Journal of Chinese Medicine. 1990;15(1):43-44.
  8. Wang Cai Lan, et al. Journal of Trace Elements and Health Research. 1997;14(4):33-34.
  9. Wang Jun Li, et al. Journal of Chinese Materia Medica. 1993;24(12):655-656.
  10. Zhu Li Qing, et al. Journal of Chinese Materia Medica. 1986;17(12):15.
  11. Wang Cai Lan, et al. Journal of Trace Elements and Health Research. 1997;14(4):33-34.
  12. Fan Wei Heng. Pharmacy Bulletin. 1979;14(9):404.
  13. Wang Jun Li, et al. Journal of Chinese Materia Medica. 1993;24(12):655-656.
  14. Hu Jia Ling. Journal of Chinese Materia Medica. 1999;30(5):394-396.
  15. Liu Hui. Journal of Wannan Medical College. 1998;17(3):238-240.
  16. Xu Shi Lun, et al. Journal of Chinese Materia Medica. 1985;16(9):15.
  17. Xu Shi Lun, et al. Journal of Chinese Materia Medica. 1986;17(5):12.
  18. Hu Wen Shu, et al. Journal of Tongji Medical University. 1989;18(3):198-200.
  19. Zhou Hua Zhu, et al. Journal of Xuzhou Medical College. 1998;18(6):463-464.
  20. Su Kun, et al. Heilongjian Journal of Medicine and Pharmacology. 1999;22(4):6-7.
  21. Li Xian Ping, et al. Journal of Chinese Patented Medicine Research. 1988;(1):15-16.