Rou Gui

Cinnamomi Cortex, Cinnamon Bark

Dosage

Decoction: 2-5g.

Toxicity

LD50 (mice/water decoction/abdominal injection): 46 ( 4.3g/kg). (1)

Chemical Composition

Cinnamaldehyde; Cinnamyl acetate; Ethyl cinnamate; Benzyl benzoate; Benzaldehyde; Coumarin; (-cadinene; Calamenene; (-elemene; Protocatechuic acid; Trans-cinnamic acid; Cinnzeylanine; Cinnzeylanol; Syringaresinol; Cassioside; Cinnamoside; Cinnaman AX; 4'-O-methyl-(+)-catechin; Cinnamtannin A2, A3, A4; 3'-O-methyl-(-)-epicatechin; Procyanidin C1, B1, B2, B5, B7, A2; Lyoniresinol-3(-O--(-D-glucopyranoside; Cinncassiols A, B, C1, C2, C3, D1, D2, D3, D4, E; ( 5,7-dimethyl-3',4'-di-O-methylene-(()-epicatechin; ( Cinnamic aldehyde-cyclicglycerol-1,3-acetal, 9, 2'-trans; ( 3,4,5-trimethoxyphenol-(-D-apiofuranosyl (1→6)- (-D-glucopyranoside.

Pharmacology

Effects on gastrointestinal movement

A fragrant stomachic tonic and a carminative, Gui Pi oil has a slight stimulatory effect on the gastrointestinal tract. It promotes saliva and gastric juice secretion, enhances digestion, ameliorates gastrointestinal smooth muscle spasm, and lessens pain caused by gastrointestinal spasms. (2) , (3)

Anti-ulceration effect

Administered orally or by abdominal injection at 50-300mg/kg, the water-based extract of Rou Gui has a strong inhibitory effect on cold- or immersion-induced stress ulcers, an effect similar to that of cimetidine. This effect of Rou Gui is also observed on ulcers induced by 5-hydroxytryptamine, on which cimetidine does not have a similar effect. (4)

Counteracting platelet aggregation

In-vitro experiments show that both methanol-based extract of Rou Gui and cinnamaldehyde can inhibit platelet aggregation and counteract thrombin. Cinnamic acid can also counteract thrombin. In-vivo experiments show that methanol-based extract of Rou Gui has an inhibitory effect on endotoxin-induced thrombosis in rats. (5)

Effects on the cardiovascular system

Administered at 50-500(g, Cinnamaldehyde can increase myocardial contraction and the heartbeat rate in isolated hamster hearts, an effect that can be checked by a pretreatment of propranolol. (6) Rou Gui can increase coronary blood flow in isolated hamster hearts and in dogs under anesthesia, and dilate periphery blood vessels. (7)

Effects on the immune system

A single abdominal injection of Rou Gui extract (Rou Gui W2) at 200mg/kg can significantly lower the nonspecific immune function and the production of antibody in mice. Injected at the same dosage for five consecutive days, it can decrease the weight of the spleen in juvenile mice, but it affects neither the weight of the mice' thymus, or rats' passive anaphylactic reaction. (8) Cinnaman polysaccharide AX can significantly increase mice's reticuloendothelial system's phagocytic function against carbon granules. (9)

Effects on the central nervous system

Rou Gui oil, sodium cinnamic acid, and cinnamaldehyde all have sedative, analgesic, antipyretic, and anticonvulsive effects. (10) Abdominal injection of cinnamaldehyde at a dosage higher than 30mg/kg can decrease spontaneous activity in mice. When the dosage is higher than 100mg/kg, a temporary and short-lived excitatory effect or running fit is observed before the inhibitory effect kicks in. At 125 mg/kg and 250mg/kg, cinnamaldehyde can inhibit anhydromorphine- or deoxyephedrine-induced motor excitation. (11)

Anti-inflammatory effects

Rou Gui has an inhibitory effect on both acute and chronic inflammation. It also inhibits carrageenin-induced foot swelling and capillary permeability increase. It can prevent adjuvant-induced arthritis, and its general secondary symptoms (e.g., ear hyperemia, dropsy, and flatulence). (12)

Antibacterial effects

In-vitro experiments show that cinnamaldehyde has a strong antibacterial effect, with the effect being especially pronounced on skin fungi (MIC: 0.02-0.07(l/ml). The MIC on deep pathogenic fungi is 0.1-0.3(l/ml). (13)

Antineoplastic effects

Administered to mice by injection, cinnamaldehyde can completely inhibit SV40-virus induced tumor. (14) Both methanol-based extract of Rou Gui and cinnamaldehyde have a significant inhibitory effect on tyrosynase, a substance extracted from melanoma. (15)

Other effects

The volatile oil and water-based extract of Rou Gui both can significantly lower icy water-induced elevated triglycerides in mice. (16) Ether-based extract of Rou Gui at 0.8ml/kg can lengthen the survival time of mice suffering from sodium nitrite poisoning. (17)

References

  1. Zhu Zhao Yi, et al. Journal of Chinese Herbs. 1985;16(7):316.
  2. Editorial Board of Application of Traditional Chinese Medicine. Application of Traditional Chinese Medicine. Guangzhou: Guangdong People's Publishing House; 1975.
  3. Xi-Ye-Shi-Lang. Journal of Clinical Application of Traditional Chinese Medicine. 1976;23(9):515.
  4. Toshiaki Akira, et al. Journal of Foreign Medicine, vol. of Traditional Chinese Medicine. 1987;9(6):348.
  5. Jiu-Bao-Dao-De, et al. Journal of Foreign Medicine, vol. of Traditional Chinese Medicine. 1982;4(6):366.
  6. Yuan-Tian-Zheng-Min. Journal of Foreign Medicine, vol. of Traditional Chinese Medicine. 1981;3(4):227.
  7. Chen Yi, et al. Chinese Materia Medica Bulletin. 1981;6(5):32.
  8. Zeng Xue Yu, et al. Guangxi Journal of Madicine. 1984;6(2):62.
  9. You-Tian-Zheng-Si, et al. Journal of Foreign Medicine, vol. of Traditional Chinese Medicine. 1990;12(6):373.
  10. Luo He Sheng, et al. Advances in Pharmacological and Clinical Research of Traditional Chinese Medicine Formulas. Changsha: Hunan Science and Technology Press; 1982.
  11. Du-Bian-Yu-Si, et al. Journal of Foreign Medicine, vol. of Traditional Chinese Medicine. 1986;8(1):25.
  12. Li Jing De. Journal of Foreign Medicine, vol. of Traditional Chinese Medicine. 1989;11(1):1.
  13. Bai Yi Jie. Journal of Chinese Dermatology. 1988;21(6):380.
  14. Higashikaze M, et al. C A. 1981;94:16805k.
  15. Higashikaze M, et al. C A. 1981;94:16805k.
  16. Xu Qing Huan, et al. Journal of Pharmacology and Clinical Application of Traditional Chinese Medicine. 1989;5(1):34.
  17. Zhang Ming Fa, et al. Journal of Chinese Medicinal Matericals. 1990;13(8):34.