What Is Rou Gui
Rou Gui commonly known as Cinnamomi Cortex, Cinnamon Bark, or Cassia Bark is the dried bark of Cinnamomum cassia Presl, which is an evergreen tree belonging to the Lauraceae family. It is a relatively practical and common Chinese herbal medicine, which first appeared in <Shennong Ben Cao Jing> in the late Western Han Dynasty (around 100 BCE).
There are about 250 species of Camphoraceae, which are mainly distributed in tropical and subtropical areas of eastern Asia, Australia, and the Pacific islands. Most of them are economic plants, and a small number of species can be used medicinally and for food.
Cinnamomum cassia Presl commonly known as Chinese cassia or Chinese cinnamon is an important aromatic medicinal plant. This plant prefers warm and humid environments. They are often grown in subtropical frost-free areas and tropical regions.
They grow well in loose, well-drained, slightly acidic, or acidic soils with good permeability. They are mainly distributed in China, India, Laos, Vietnam, and Indonesia.
This plant is also a common garden tree in East Asia. Their twigs can be made into Chinese herbal medicines, their trunks into furniture, and their bark into spices, food preservatives, fungicides, and insecticides.
In autumn, people peel the bark of Cinnamomum cassia Presl, remove impurities and rough bark, dry them in the shade, and make them into Chinese herbal medicines.
Rou Gui contains cinnamaldehyde, cinnamic acid, cinnamic alcohol, 2-methoxycinnamaldehyde, 2-methoxycinnamic acid, 2′-hydroxycinnamaldehyde, phenylpropyl acetate, cinnamyl acetate, methyl cinnamate, ethyl 2-methoxycinnamate, eugenol, paeonol, linalool, α-humulene, α-cadinol, β-elemene, α-cadinol, β-elemene, α-pinene, α-curcumene, α-muurolene, α-cubebene, β-bisabolene, γ-cadinene, calamenene, copaene, α-terpineol, α-caryophyllene, coumarones, fatty acids, flavonoids, polyphenols, polysaccharides, and some trace elements.
Generally, the thick and oily Rou Gui with a strong aroma is preferred.
According to the Chinese Pharmacopoeia, the medicinal nature of Rou Gui is relatively hot, with a pungent and sweet taste. It has a certain therapeutic effect on the pathological changes of the kidney, spleen, heart, and liver meridians.
In traditional Chinese medicine, it is often used to replenish fire to invigorate yang, dispel cold to stop pain, warm and activate meridians, guide fire to the origin, and treat impotence, uterine cold, cold pain in waist and knees, spermatorrhoea, enuresis, frequent night urination, thoracic obstruction, cardiodynia, cold pain of stomach and abdomen, vomiting, diarrhea, periumbilical colic, hernia, swelling pain of the testicles, amenorrhea, dysmenorrhea, dorsal furuncles, frostbite, neurodermatitis, insomnia, infantile diarrhea, senile chronic bronchitis, and stenosing tenovaginitis.
There are more than 500 kinds of classic traditional Chinese medicine prescriptions containing it, such as Shen Qi Wan, You Gui Yin, and Gui Fu Li Zhong Tang.
- Anti-inflammation, inhibiting the rise in vascular permeability induced by acetic acid and paw edema induced by carrageenin in mice .
- Anti-oxidation, scavenging DPPH free radicals and NO, and inhibiting LPS-induced expression of iNOS and COX-II .
- Replenishing fire to invigorating yang, treating impotence, uterine cold, cold pain in waist and knees, spermatorrhoea, enuresis, frequent night urination caused by insufficiency of the kidney yang, and decline of vital gate fire.
- Dispelling cold, treating thoracic obstruction and cardiodynia, cold pain of stomach and abdomen, vomiting, and diarrhea caused by pathogenic cold invading the interior, and periumbilical colic due to cold.
- Warming and activating meridians, treating amenorrhea and dysmenorrhea caused by deficiency and cold in the Chong and Ren Meridians, and congealing cold with blood stasis.
- Treating wind-cold-dampness arthralgia, dorsal furuncles, and deep multiple abscesses caused by cold stagnation due to yang deficiency and blood stasis due to phlegm obstruction.
- Guiding fire to the origin, treating vertigo, red eyes, reddish complexion, deficient dyspnea, sweating, palpitation, insomnia, and weak pulse caused by consumption of kidney-yang, and deficient yang with upper manifestation.
- Its essential oil have antibacterial effects on Staphylococcus cremoris , Bacillus subtilis , Escherichia coli , Aspergillus Aspergillum niger, Penicillium sp and Saccharomyces cerevisiae, Staphylococcus aureus, and Candida albicans in vitro . In addition, Its essential oil have antibacterial effects on Listeria monocytogenes, Listeria innocua, Listeria welshimeri, Listeria ivanovii, Listeria grayi, and Vibrio parahaemolyticus .
- Inhibiting the growth of A549 lung cancer cells and melanoma cells and the migration and invasion of A375 cells.
- Cinnamaldehyde reduces the atherosclerotic plaque area in high fat diet-fed Atherosclerosis-prone apolipoprotein E-deficient (ApoE−/−) mice .
- Cinnamaldehyde can increase bone mineral density (BMD), trabecular number, trabecular thickness, and trabecular area of osteoporosis rats induced by ovariectomy, and reduce trabecular separation, serum TNF-α, and interleukin-6 (IL-6) levels.
- Its methanolic extract ameliorated nickel nanoparticles (Ni-NPs)-induced liver and kidney injury in male Sprague Dawley rats .
- Its water extract can inhibit the formation of both Aβ toxic oligomer species and amyloid fibrils in both the test tube and in the intact animal and can correct the cognitive impairment in Alzheimer’s Disease animal models .
- Its polyphenol significantly reduces blood sugar levels in insulin-resistant diabetic mice but did not affect weight. Its polysaccharide extract reduces alloxan-induced blood sugar levels in mice.
- Its extract controls weight gain in obese mice by inhibiting lipid accumulation and increasing energy expenditure .
- Studies have shown that intraperitoneal administration of CA can alleviate the cold and mechanical allodynia induced by single oxaliplatin injection in rats .
- Studies have shown that intraperitoneal administration of 2′-Hydroxycinnamaldehyde alleviated imiquimod-induced psoriasis-like dermatitis, epidermal thickening, dermal infiltration of inflammatory cells, and proinflammatory cytokine production .
- It can be used in combination with Fu Zi (Radix Aconiti Lateralis Preparata), Shu Di Huang (Processed Rehmannia Root), Shan Zhu Yu (Fructus Corni), etc. to treat impotence, uterine cold, cold pain in the waist and knees, spermatorrhoea, enuresis, frequent night urination caused by insufficiency of the kidney yang, and decline of vital gate fire.
- It can be used in combination with Fu Zi (Radix Aconiti Lateralis Preparata), Xie Bai (Allii Macrostemonis Bulbus), etc. to treat thoracic obstruction and cardiodynia caused by inactivity of thoracic yang, and pathogenic cold invading the interior.
- It can be used in combination with Gan Jiang (Dried Ginger), Gao Liang Jiang (Rhizoma Alpiniae Officinarum), and Bi Bo (Fructus Piperis Longi), etc. to treat cold pain of stomach and abdomen, vomiting, and diarrhea caused by pathogenic cold invading the interior, and deficiency-cold in the spleen and stomach.
- It can be used in combination with Wu Zhu Yu (Evodiae Fructus) and Xiao Hui Xiang (Fructus Foeniculi), etc to treat periumbilical colic due to cold.
- It can be used in combination with Dang Gui (Radix Angelicae Sinensis), Chuan Xiong (Rhizoma Chuanxiong), Xiao Hui Xiang (Fructus Foeniculi), etc. to treat amenorrhea and dysmenorrhea caused by deficiency and cold in the Chong and Ren Meridians, and congealing cold with blood stasis.
- It can be used in combination with Du Huo (Radix Angelicae Pubescentis), Sang Ji Sheng (Herba Taxilli), Du Zhong (Eucommia Bark), etc. to treat low back pain caused by cold.
- It can be used in combination with Lu Jiao Jiao (Cervi Cornus Colla), Pao Jiang (Zingiberis Rhizoma Praeparatum), Ma Huang (Ephedra), etc. to treat dorsal furuncles and deep multiple abscesses caused by cold stagnation due to yang deficiency and blood stasis due to phlegm obstruction.
- It can be used in combination with Shan Zhu Yu (Fructus Corni), Wu Wei Zi (Fructus Schisandrae), Mu Li (Concha Ostreae), etc. to treat vertigo, red eyes, reddish complexion, deficient dyspnea, sweating, palpitation, insomnia, and weak pulse caused by consumption of kidney-yang, and deficient yang with upper manifestation.
- Animal experiments have shown that small doses of the drug cause a decrease in voluntary activity, and large doses of the drug cause spasms, dyskinesia, and shortness of breath.
- A percentage of patients taking it may cause dizziness, eye swelling, heartburn, dry mouth, cough, sore throat, body heat and itching, epistaxis, bloody urine, or burning pain in the urinary tract.
Precautions and Warnings
- The dosage of Rou Gui should be controlled between 1-5g.
- It can be made into decoctions, pills, powders, or grounds for external use.
- People who are allergic to Rou Gui should not take it.
- It should not be taken at the same time as hematoxylin.
- Patients with hyperactivity of fire due to yin deficiency should not take it.
- Patients with syndromes of excess heat should not take it.
- Patients with bleeding tendencies should not take it.
- Patients with syndromes of excess heat should not take it.
- Pregnant women should not take it.
- Lactating women, children, and the elderly and infirm should be taken under the guidance of a physician.