Emodin is a trihydroxyanthraquinone that is 9,10-anthraquinone which is substituted by hydroxy groups at positions 1, 3, and 8 and by a methyl group at position 6. It is present in the roots and barks of numerous plants. It is an active ingredient of various Chinese herbs. It has a role as a tyrosine kinase inhibitor, an antineoplastic agent, a laxative and a plant metabolite.

Simple production process in our factory: 

1. crushing rhubarb or Polygonum Cuspidatum material, soaking in water solution of alcohol, thermal refluxing to extract, filtering the extracted liquid and recovering alcohol to obtain extractum 2. hydrolyzing the extractum with water solution of inorganic acid and filtering water solution of acid to eliminate dregs and 3. passing the filtrate through chromatographic polyamide column, eluting with alcohol aqua to eliminate impurity, gradient eluting with mixed alcohol and acetone solution, sectional collecting eluted liquid, recovering solvent, and concentrating to obtain emodin in high purity (about 98%).
 

Overview Information
Common names: 
6-Methyl-1,3,8-trihydroxyanthraquinone.

CAS number：518-82-1

Description: Emodin is a natural anthraquinone derivative that occurs in many widely used Chinese medicinal herbs, such as Rheum palmatum, Polygonum cuspidatum and Polygonum multiflorum. Emodin has been used as a traditional Chinese medicine for over 2000 years and is still present in various herbal preparations. Emerging evidence indicates that emodin possesses a wide spectrum of pharmacological properties, including anticancer, hepatoprotective, antiinflammatory, antioxidant and antimicrobial activities. However, emodin could also lead to hepatotoxicity, kidney toxicity and reproductive toxicity, particularly in high doses and with long-term use. Pharmacokinetic studies have demonstrated that emodin has poor oral bioavailability in rats because of its extensive glucuronidation. This review aims to comprehensively summarize the pharmacology, toxicity and pharmacokinetics of emodin reported to date with an emphasis on its biological properties and mechanisms of action.

Chemical constituents:

Contraindication:

Emodin tablets or ibuprofen childrens suspension should not be used in patients who have previously exhibited hypersensitivity to the drug, or in individuals with the syndrome of nasal polyps, angioedema, and bronchospastic reactivity to aspirin or other nonsteroidal anti-inflammatory agents. Anaphylactoid reactions have occurred in such patients.

Interactions: 

Coumarin-Type Anticoagulants: Several short-term controlled studies failed to wshow that ibuprofen significantly affected prothrombin times or a variety of other clotting factors when administered to individuals on coumarin-type anticoagulants. However, because bleeding has been reported when ibuprofen and other nonsteroidal anti-inflammatory agents have been administered to patients on coumarin-type anticoagulants, the physician should be cautious when administering ibuprofen to patients on anticoagulants.

Aspirin: Animal studies wshow that aspirin given with nonsteroidal anti-inflammatory agents, including ibuprofen, yields a net decrease in anti-inflammatory activity with lowered blood levels of the non-aspirin drug. Single dose bioavailability studies in normal volunteers have failed to wshow an effect of aspirin on ibuprofen blood levels. Correlative clinical studies have not been performed.

Methotrexate: Emodin, as well as other nonsteroidal anti-inflammatory drugs, probably reduces the tubular secretion of methotrexate based on in vitro studies in rabbit kidney slices. This may indicate that ibuprofen could enhance the toxicity of methotrexate. Caution should be used if ibuprofen is administered concomitantly with methotrexate.

H-2 Antagonists: In studies with human volunteers, co-administration of cimetidine or ranitidine with ibuprofen had no substantive effect on ibuprofen serum concentrations.

Furosemide: Clinical studies, as well as random observations, have shown that ibuprofen can reduce the natriuretic effect of furosemide and thiazides in some patients. This response has been attributed to inhibition of renal prostaglandin synthesis. During concomitant therapy with ibuprofen, the patient should be observed closely for signs of renal failure, as well as to assure diuretic efficacy.

Lithium: Emodin produced an elevation of plasma lithium levels and a reduction in renal lithium clearance in a study of eleven normal volunteers. The mean minimum lithium concentration increased 15% and the renal clearance of lithium was decreased by 19% during this period of concomitant drug administration.

This effect has been attributed to inhibition of renal prostaglandin synthesis by ibuprofen. Thus, when ibuprofen and lithium are administered concurrently, subjects should be observed carefully for signs of lithium toxicity. (Read circulars for lithium preparation before use of such concurrent therapy).

PotentialHealth Benefits andApplication of emodin 

Antitumor activity

Emodin has inhibitory effects on mouse solid sarcoma S-180, mouse liver cancer, breast cancer, Ehrlich ascites carcinoma, lymphosarcoma, melanoma, and rat Wacker tumor and lung cancer A-549, and its inhibition rate is 30%. the above. 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.

Antiinflammatory

The exact mechanisms of action of Emodin is unknown. Its antiinflammatory effects are believed to be due to inhibition of both cylooxygenase-1 (COX-1) and cylooxygenase-2 (COX-2) which leads to the inhibition of prostaglandin synthesis, and results in the inhibition of prostaglandin synthesis. Antipyretic effects may be due to action on the hypothalamus, resulting in an increased peripheral blood flow, vasodilation, and subsequent heat dissipation.

Antimicrobial growth

Emodin has inhibitory effects on 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 acids, sugar and protein metabolism intermediates. The final result of inhibiting the synthesis of nucleic acids and proteins inhibits bacterial growth. 

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 was significantly inhibited at a concentration of 10 mg/ml. 

Antispasmodic, antitussive

Emodin has a strong inhibitory effect on sputum in isolated rat intestinal tract caused by acetylcholine, which is about 4 times that of papaverine. Emodin also has a significant antitussive effect. 

Effect on histamine

Administration of emodin to rats with experimental intestinal obstruction at a dose of 10 μg/kg restored the histamine content in the intestinal mucosa of rats to normal levels, but had no effect on the histamine content in the blood. 

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 diarrhea, but the effect is weak.

Cautions:

Emodin is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain and inflammation, reduce fever, and treat osteoarthritis, rheumatoid arthritis, and menstrual cramps. Inform your physician if you are pregnant or nursing. Emodin should not be taken during the last three months of pregnancy. Inform your physician if you use alcohol chronically. Emodin should not be taken with aspirin products. This medication should be taken with food, milk or antacids if stomach upset occurs. Emodin may cause dizziness and drowsiness; use caution while driving or operating hazardous machinery. Emodin may cause increased sensitivity to sunlight. Use sunscreens and wear protective clothing until degree of sensitivity is determined. Notify your physician if you develop stomach pain, bloody vomit, bloody or black tarry stools, cloudy urine, trouble breathing, rash or hives.