Mu Dan Pi

Moutan Radicis Cortex, Moutan

Dosage

6~9g for oral decoction, or for pill and powder.

Toxicity

LD50 (mice/peritoneal injection): 735mg/kg (paeonol oil); 6.9mg/kg (paeonol sodium sulfonate). (1)

Chemical Composition

Paeoniflorin; Oxypaeoniflorin; Benzoylpaeoniflorin; Benzoyloxy-paeoniflorin; Paeonol; Paeonoside; Paeonolide; Aplopaeonoside; 2£-3-di-hydroxy-4-methoxyacetophenone; 3-hydroxy-4-methoxyacetophenone; 1£-2£-3£-4£-6-pentagalloylglucose. (2)

Precautions

Patients with the following conditions should avoid using this herb: blood deficiency syndromes, cold of the deficiency type, hypermenorrhea, or pregnancy. There has been one report of side-effects: when 5% Mu Dan Pi cream was used to treat acute localized eczema, local red spots, itch, and burning sensation were experienced by some patients. (3)

Pharmacology

Analgesic effect

Experiments show that paeonol has a significant analgesic effect on mice. Paeonol was administered to mice via subcutaneous injection for 7 days. Hot plate test was used to measure the pain threshold. The results suggested that paeonol induced analgesia causes no drug resistance. Both tail-erection reaction test and jumping reaction test showed negative results, when mice were given paeonol via subcutaneous injection. Hot plate test showed that the analgesic effect of paeonol can not be reversed by naloxone. (4)

Anti-inflammatory effects

In mice, dimethylbenzene-induced auricle inflammation can be inhibited effectively by gastrolavaging Mu Dan Pi decoction at dosages 10g/kg, 20g/kg, or 40g/kg. Also, feet swelling that is caused by carrageenin, formaldehyde, or egg white can be significantly inhibited by intraperitoneal injection of Mu Dan Pi at 15g/kg or 30g/kg. The effects are dosage-dependent. (5)

Effects on the blood system

Total glycoside of Mudanpi (TGM) can protect RBC, inhibit platelet aggregation, increase the cAMP level in blood platelets, counteract atheroscleorsis, and promote local microcirculation. (6) , (7) , (8) , (9) It can inhibit H202-induced hemolysis. Low concentrations of TGM inhibits osmotic hemolysis, while in higher concentration (100mg.L-1), it promotes osmotic hemolysis. TGM inhibits H202-induced consumption of reduced glutathione in RBC and the production of lipide peroxide. Experiments show that paeonol can inhibit platelet aggregation both in vivo and in vitro.

Liver-protective effect

Experiments show that in mice with carbon tetrachloride or ethanol-induced liver damages, TGM (20mg/kg-1) can significantly inhibit the increase in serum SGPT and the generation of lipide peroxid. (10)

Effect on immunological functions

Paeonol, given by i.g. 200mg/kg for 5 consecutive days, can reduce the weight of immune organs in mice, increase carbon clearance, relieve delayed hypersensitivity, and decrease the hemolysin antibody level in the spleen. In mice, it can significantly inhibit lymphocyte proliferation in the spleen that is induced by LPS and by Con A in sub-suitable concentrations. Paeonol (50¦Ìg/ml) can also, in vitro, significantly inhibit the proliferation of mice's experimental spleen lymphocytes. (11) In low concentrations (10-15mg/kg), paeonol functions to increase the percentage of lymphocyte with positive (-ANAE and promotes the release of leukocyte migration inhibitory factor in peripheral circulation, thereby improving the cellular immunity. Furthermore, it could promote the phagocytosis of peripheral neutrophil on Staphylococcus aureus, thereby enhancing nonspecific immunity. (12)

Effects on the cardiovascular system

Paeonol has a significant and immediate inhibitory effect on delayed I K, I Na, I Ca T, and I Ca L. The effect can be observed within 1 minute of administration, and it shows a dose-effect correlation and a good reversibility. (13) When paeonol was given by intraperitoneal in a dose of 160.80mg/kg for 7 days to rats with myocardial reperfusion injury, it showed significant anti-arrhythmic effect on the animals. Its mechanism is probably related to anti-oxidation free radicals. (14)

Other actions

Experiments show that paeonol can slow down the gaining of body weight in animals. The body temperature of normal mice was decreased by 2.9¡æ within 30 minutes after the peritoneal injection of paeonol (200mg/kg). It has an antipyretic effect on the fever induced by choler-typhoid-paratyphoid vaccine. (15)

References

  1. Wang Qi Bao, et al. Journal of Chinese Materia Medica. 1983;(10):26.
  2. Editorial Committee of Chinese Materia Medica. State Drug Administration of China. Chinese Materia Medica. Shanghai: Science and Techonology Press; 1998.
  3. Tang Hong Shan. Journal of Chinese Materia Medica. 1983;24(10):19.
  4. Liu Xue Jun, et al. Chinese Pharmacology Bulletin. 1993;9(6):464-467.
  5. Wu Guan Zhong,et al. Journal of University of Pharmacology of China. 1990;21(4).
  6. Gao Ben Po, et al. China Journal of Pharmacology. 1992;8(3):202-205.
  7. Dai Ming, et al. China Journal of Chinese Medicine, 1999;24(8):488-490.
  8. Shi Ling, et al. China Journal of Pharmacology. 1988;9(6):555.
  9. Ye Zhi Yi, et al. China Journal of Blood Rheology. 1999;9(3):137-138.
  10. Dai Li Ming, et al. China Journal of Pharmacology. 1994;10(1):58-59.
  11. Wang Xing Wang, et al. Journal of Pharmacology and Clinical Application of TCM. 1992;8(2):29-30.
  12. Li Feng Chun, et al. China Journal of Integrated Medicine. 1994;14(1):37-38.
  13. Hu Qian, et al. Journal of Physiology. 1994;46(6):575-580.
  14. Zhang Guang Qin, et al. Journal of University of Pharmacology of China. 1997;28(4):225-227.
  15. Wang Qi Bao, et al. Journal of Chinese Materia Medica. 1983;(10):26.