Emodin is an orange-yellow long needle-like crystal. It crystallizes in orange in acetone. It crystallizes in methanol and has a melting point of 256 ° C to 257 ° C. It has a special reaction of hydrazine, is almost insoluble in water, and is soluble in ethanol and alkali solution. . [1]
Emodin is the dried rhizome and root of Polygonum cuspidatum. The rhizome of palm rhubarb is a plant-type agent.
The physiological activity of emodin determines that it can be used not only in medical treatment, but also in health care and household chemicals. If it is used in hair care and skin care products, it is also incorporated into natural pigments. Abroad, people use it as a laxative

Antitumor activity
Emodin on mouse solid sarcoma S-180, mouse liver cancer, breast cancer, Ehrlich ascites carcinoma, lymphosarcoma,
Polygonaceae palm leaf rhubarb
Polygonaceae palm leaf rhubarb
Melanoma and rat Wacker tumors and lung cancer A-549 have inhibitory effects, and the inhibition rate is above 30%. The inhibition rate of mouse melanoma growth was 73% at a dose of 50 mg/kg day-1; the inhibition rate of mouse breast cancer at a dose of 75 mg/kg day-1 was 45%. Emodin can prolong the survival of P388 leukemia mice with a prolongation rate of more than 40%. One of its mechanisms of action is to inhibit the biosynthesis of DNA, RNA and proteins of cancer cells and inhibit the oxidative dehydrogenation of cancer cells. [1]
Antimicrobial growth
Emodin inhibits Staphylococcus aureus 209P, Streptococcus, Diphtheria, Bacillus subtilis, Paratyphoid bacillus, Shigella, Escherichia coli, Influenza, Pneumococci, and catarrhalis; It has a strong inhibitory effect; its MIC is slightly higher than metronidazole, and the concentration of anaerobic bacteria can be inhibited by 76%~91% at 8μg/ml. The antibacterial mechanism of emodin is related to inhibition of mitochondrial respiratory chain electron transport, inhibition of respiration and oxidation and dehydrogenation of amino acid, sugar and protein metabolism intermediates. The final result of inhibiting the synthesis of nucleic acids and proteins inhibits bacterial growth. [1]
Immunosuppressive effect
Intraperitoneal injection of emodin at a dose of 70 mg/kg can inhibit the production of rat antibodies, inhibit the clearance of carbon particles, reduce the weight of immune organs, reduce the number of white blood cells, and reduce the phagocytic function of peritoneal macrophages. In vitro, the concentration of [3H]-TdR and [3H]-Urd in lymphocytes at 10 mg/ml was significantly inhibited.
Antispasmodic and antitussive effects
Emodin has a strong inhibitory effect on sputum induced by acetylcholine in isolated rat intestinal tract, which is about 4 times that of papaverine. Emodin also has a significant antitussive effect.
Role in the cardiovascular system
Emodin has an excitatory effect on isolated sputum hearts at low doses, while large doses have an inhibitory effect. Emodin also has a hypotensive effect.
Diuretic effect
Emodin can increase the content of sodium and potassium in the urine, promote ureteral motility, and increase urine output. [1]
Effect on histamine
Administration of emodin to rats with experimental intestinal obstruction at a dose of 10 μg/kg can restore histamine content in rat intestinal mucosa
Emodin
Emodin
To normal levels, but no effect on histamine content in the blood. [1]
Synthesis of LTB4
Emodin is an inhibitor of 5-lipoxygenase, which inhibits the synthesis of LTB4 in human polynuclear leukocytes and LTB4 in whole blood, and has no inhibitory effect on the synthesis of PGE2.
Laxative effect
Emodin can inhibit the transport of sodium and potassium ions from the intestinal lumen to the cells, so that the water stays in the intestinal lumen, stimulates the large intestine, promotes its peristalsis, and thus acts as a diarrhea, but the effect is weak.