Cinnamic oil is an aromatic stomachic and carminative. It stimulates the gastrointestinal tract, promotes salivary and gastric secretion and strengthens the digestive action. It relieves spasm of the smooth muscle of internal organs and relieves pain due to intestinal spasm.

The extract of C. cassia strongly inhibited gastric ulcers induced by a subcutaneous injection of seratonin. Pharmacological studies have shown that this extract not only inhibits gastric secretion, but also promotes gastric mucosal blood flow, indicating that the antiulcerogenic effect of C. cassia is due to both the inhibition of aggressive factors and the potentiation of defensive factors.

Experiments have shown that cinnamic oil and, particularly cinnamic aldehyde, inhibited gastric motility,thereby decreasing gastric contractility, and like papaverine, they antagonized acetylcholine or histamine induced spasm of the the isolated intestinal tract.

Cinnamaldehyde at a concentration of 4.8mg/ml inhbited the growth of L1210 leukemia cells in culture by 50%. The aldehyde group of cinnamaldehyde was responsible for the inhibition. Incorporation of (3H)uridine, (3H)thymadine,and (3H)leucine by the cells was suppressed by the presence of cinnamaldehyde. Direct reactions between aldehyde groups of cinnamaldehyde and thiol groups of cell components was demonstrated, indicating that the inhibitory effect of cinnamaldehyde on the growth of L1210 cells might have been ascribed to such reactions.

Cinnamaldehyde exhibited bactericidal activity against some bacteria species using the agar-diffusion method. The cinnamon oil was found to have fungicidal activity against Trichophyton mentagrophytes. The active component of the oil was cinnamaldehyde. Cinnamaldehyde wasalso active against Microsporum audouini The minimal fungicidalconcentration of cinnamaldehyde against these two dermatophytes was less than 0.09mg/ml. A study on the antifungal activity of cinnamaldehyde against a number of fungi showed that cinnamaldehyde, at a concentration of 0.33 mM, has inhibitory effects on Aspergullus nidurans, Cryptococcus neoformans, Penicillum rugolosum, Sporothrix schenckii, Tricophyton rubrum, T. mentagrophytes, T.violaceum, Microsporum gypseum, Histoplasma capsulatum and Blastomyces dermatidis.

A significant hypotensive action was exhibited by the compound prescription of C.cassia and the lateral root tuber of Aconitum carmichaeli in cases of adrenalcortical hypertension in rats. Experiments on the incorporation of 14C1-sodium acetate, performed four weeks after medication proved that the compound prescription markedly affected the adrenal cholesterol metabolism in rats with adrenocortical hypertension, thereby intensifying the activity of the damaged adrenal gland. The hypotensive action is thought to be through the promotion and normalisation of the activity of the depressed adrenal gland.

The decoction of the herb increased coronary flow in the isolated heart of guinea pigs and partially antagonized pituitrin in reducing the coronary flow. Definite improvement of acute myocardial ischaemia due to pituitrin was achieved with the oral decoction of the herb at the daily dose of 1.2g (crude drug)/kg for 6 days. Intra-arterial injection of this preparation markedly decreased periperal vascular resistance suggesting a direct dilatory action on peripheral blood vessels.

C. cassia is one of the herbs shown to be effective in clinical and experimental research in the treatment of weakened intelligence as caused or accompanied by an ischemic cerebrovascular mechanism. The therapeutic principle of promoting blood circulation to remove stasis is very effective for this condition.

Cinnamon is effective in causing perspiration, resolving the body onload="highlight();" 's surface, warming and unblocking Meridians and vessels, moving Yang and generating Qi. It is the most important herb in cimmanom containing herbal formulas. Its major constituent, cinnamaldehyde is capable of dilating blood vessels in the skin, promoting blood circulation beneath the body onload="highlight();" 's surface, inducing perspiration and resolving fever.

The drug is contraindicated in asthma complicated with progressive pulmonary tuberculosis or cardiac decompensation and in extremely weak patients.

Oral administration of rou gui powder, 5g, bid, for 3 weeks was used to treat 102 cases of lumbago of Kidney-yang deficiency type, 47 cases were cued, 39 improved, 14 effective, 2 ineffective.

Chronic renal failure of yang deficiency of Spleen and Kidney was treated with fu zi, gan jiang, rou gui, xian mao, xian ling pi, ba ji tian. Intravenous injection of Dan Shen Injection was also applied, after 5~31 months' treatment, the effect of delaying renal failure was found.

Except those noted, all references come from Weng Weiliang, et al., Clinical Chinese materia medica, Henan Science & Technology Press, 1998