Administration of chai hu decoction to rabbits through gastrogavage at the dosage of 2g/kg had obvious antifebrile effect on the fever caused by vaccine or warm stimulation. The main antifebrile ingredient is saikosaponins. chai hu at medium dosage could allay fever, chai hu at large dosage (50g decoction every day) could restore elevated body onload="highlight();" temperature to normal rapidly. The herb also had antimalaria effect.

Crude saikosaponins and sailogenin A had obvious sedative effect. Crude saikosides at the dosage of 200mg/kg~800mg/kg could have sedative effect on mice.

Oral administration of crude saikosides had analgesic effect. Intraperitoneal injection of Saikogenin A at the dosage of 50mg/kg or 100mg/kg to mice could inhibit the writhe reaction in mice caused by intraperitoneal injection of acetic acid.

Crude saikosides had quite strong anti-tussive effect. ED50 of intraperitoneal injection to Guinea pigs was 9.5mg/kg, and it effect was equal to that of intraperitoneal injection of 7.5mg/kg codeine phosphate.

In vitro tests proved that chai hu had inhibitory effect on tubercle bacillus, leptospira and smallpox virus. Saikosaponins had inhibitory effect on influenza virus and poliomyelitis virus. chai hu decoction is often used in the treatment of marilia and blackwater fever. Oral administration of saikosaponin (600mg/kg) could significantly lower edema caused by dextran and 5-HT. Intramuscular injection or oral administration (10mg) of saikosaponin a or d, or consecutive 7 days of oral administration of crude saikosides at the dosage of 100mg/kg had anti-effusive and anti-granuloma effects. Experiment results showed that the anti-inflammatory effect of saikosaponins was equal to that of hydroprednisone.

Quercetin contained in chai hu had good expectorant effect, and could promote the secretions of phlegm and bronchial cilia movement. It could also dilate trachea.

Experiments proved that chai hu had cholagogue effect. chai hu could also promote the secretions of bile and loosen the sphincter of oddi. chai hu preparations had obvious anti-injury effect on experimental liver injury caused by bacteria (typhoid vaccine), CCl4 and penicillin.

Saikosaponins at the concentration of 1¡Á10-4 ~ 2¡Á10-4 could excite isolated intestinal smooth muscle, and wouldn't be antagonized by atropine. Saikosaponins could obviously inhibit the secretions of gastric juice, lower the activity of pepsin, and tended to reduce ulcer index.

Saikosaponins at the concentration of 1¡Á10-4 ~ 2¡Á10-4 could inhibit isolated frog heart and cardiac muscle of Guinea pigs, and atropine couldn't block this inhibition. Crude saikosides below the dosage of 1/5 LD50 could lower the blood pressure and slow the heart rate of rats.

Intramuscular injection of saikosaponin a and d could promote the formation of liver fat and cholesterol caused by glucose-C14 , lower the increased level of plasma cholesterol, triglyceride and phospholipid caused by cholesterol diet in rats. It could also promote the clearance of cholesterol-C14 injected peritoneally from plasma.

Intramuscular injection of mixture of saikosaponin a, c, d (3:2:2) at the dosage of 2mg/kg for consecutive 4 days could obviously increase the protein biosynthesis in the liver.

chai hu could promote humeral and cellular immunity.

Crude saikosides had obvious hemolysis effect.

Chai Huang Mixture (chai hu 1000g, da huang 1000g, chlofenamic acid 15g and sugar q.s. were made into 1000ml water decoction), 1ml/kg~2ml/kg, three to four times every day. It had good effect on excess Heat in wei system (mostly viral infection), especially good for excess Heat syndrome accompanied with high fever, vexation and constipation.

Tiao Zhi Tang: chai hu, gan cao, 15g each; gou qi 25g, ze xie 25g, shan zha 15g, dan shen 30g, hong hua 10g. The formula could lower blood sugar by regulating and improving lipoprotein and apolipoprotein. 37 cases of hyperlipemia were treated by Da Chai Hu Tang, after 12 ~ 20 weeks' treatment, triglyceride was obviously lowered (P<0.01).

Damp-Heat pattern of multiple sclerosis was treated by modified Da Chai Hu Tang combining Gan Lu Xiao Du Tang (chai hu, huang qin, yin chen, hua shi, bai shao, zhu ru, mu tong, fu ling, zhi shi, fa ban xia, 9g each; da huang 8g, da zao 12 pieces), Blood-stasis pattern was treated by modified Xiao Chai Hu Tang combining Bu Yang Huan Wu Tang (huang qi, dang shen, dan shen, 15g each; sheng di, bai shao 12g each; chai hu, dang gui, chi shao, huang qin 10g each; chuan xiong, ban xia, 9g each; zhi gan cao 4g). After average 24 doses, 2 cases were basically cured, 15 markedly effective, 15 improved and 3 ineffective.

Xiao Chai Hu Tang and Gui Zhi Fu Ling Wan, 2.5g, tid, taken before meals or during meals. 8 subjects were studied. In the 12th week's treatment, 1 cases were effective, 2 were slightly effective, 5 cases couldn't be judged. In the 24th week, 1 cases were very effective, 4 effective, 3 couldn't be judged.

Chai Ling Tang extract, 3g/d, taken in three times and before meals for consecutive 4 weeks, together with carbamazepine. The method was used to treat 26 cases of primary trigeminal neuralgia, 6 cases were markedly improved, 6 improved, 10 slightly improved, 2 ineffective. In addition, the method could reduce he the dosage of carbamazepine.

Modified Chai Hu Shu Gan San was used to treat 30 cases of angina pectoris of coronary heart diseases, 6 were markedly effective, 20 effective, 4 ineffective. 3 cases had markedly improved ECG, 17 had improved ECG, and 10 had no changes.

12 cases suffering from snore were treated. Among them, 10 cases were accompanied with other diseases which included 7 cases of cerebral stroke, 2 were healthy. Chai Hu Gui Zhi Tang extract was used, and the dosage for adult was 7.5g/d, taken in three times. After 2 weeks, 2 cases were markedly effective, 4 effective, 5 slightly effective, 1 ineffective (healthy one). All the effective cases were patients of cerebral stroke. The snore would restore to its original volume 2~4 days after suspension of the drug, repeated application of Chai Hu Gui Zhi Tang was effective, but the snore wouldn't disappear completely.

Supplemented Xiao Chai Hu Tang, Da Chai Hu Tang or Chi Hu Gui Zhi Tang (supplemented herbs included yin chen, zhi zi, dan shen, du zhong, yu jin, etc., powder of wu wei zi was also added frequently for direct intake) were used to treat 9 cases of hepatitis B, 11 Hepatitis C for more than 1 year. Result: Among patients of hepatitis B, GPT of 7 (4 cases of positive e antigen, 3 cases of positive e antibody onload="highlight();" ) cases restored to normal, DNA polymerase was lowered too, the other two cases were aggravated. The method had no significant effect on hepatitis C.

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