What are the pharmacological effects of Bupleurum?

Bupleurum is a common Chinese medicine. You often see it in the ingredients of cold medicines. It has the effects of clearing away heat, removing fire and detoxifying. Bupleurum is relatively bitter and is available in major pharmacies. Only after understanding the function of Bupleurum chinense can we use it reasonably and maximize its medicinal value without wasting it. So, what are the pharmacological effects of Bupleurum? Now let me give you a detailed introduction.

① Antipyretic effect

It was demonstrated in the early years that large doses of Bupleurum decoction (5 g crude drug/kg) or alcohol extract (2.5 g crude drug/kg) had an antipyretic effect on artificially feverish rabbits. For rabbits with fever caused by typhoid mixed vaccine, oral decoction or infusion (2 g/kg) also has a mild cooling effect. Later, it was reported that the antipyretic effect of Bupleurum decoction was not obvious, while oral administration of 200-800 mg/kg of Bupleurum glycoside had a definite effect of lowering normal body temperature and relieving fever in mice.

②Sedative and analgesic effects

Oral administration of saikoside has a sedative effect on mice (pole climbing test) and can prolong the sleep of cyclobarbital; it has good analgesic effect and strong antitussive effect, but no anticonvulsant effect, and does not reduce the tension of skeletal muscle. Some people believe that saikoside can be classified as a central nervous system depressant.

③ Anti-inflammatory effect

Oral administration of saikoside (600 mg/kg) can significantly reduce dextran and 5-hydroxytryptamine edema in the ankles of rats. In the subcutaneous granuloma cyst experiment on rats (croton oil and cotton ball method), it was determined that saikoside has the effect of anti-exudation and inhibiting granuloma growth. Bupleurum is effective when used alone or in combination. Its effect in inhibiting granuloma growth is stronger than its anti-exudative effect. The intensity of action of the prescriptions for removing blood stasis and promoting blood circulation (Danggui Shaoyao San, Taoren Chengqi Tang, Dahuang Mudanpi Tang, etc.) is opposite to that of Bupleurum, so it is recommended to use the two together. Bupleurum glycosides can inhibit the increase in vascular permeability caused by histamine and 5-hydroxytryptamine, and slightly inhibit pleural effusion; however, it is ineffective against carrageenan and acetic acid edema, and has no protective effect against histamine shock in guinea pigs and anaphylactic shock in mice.

④Anti-pathogen effect

It has been reported that Northern Bupleurum injection has a strong inhibitory effect on influenza virus; the oily unknown component distilled from this injection also has a strong inhibitory effect on the virus. It is said to be effective against a certain strain of Mycobacterium tuberculosis. Some people have speculated that Bupleurum chinense can prevent the development of malarial parasites, but experimental studies have not been able to confirm this.

⑤Effects on the liver

For mice with liver dysfunction caused by feeding moldy rice, the increase of alanine and aspartate aminotransferase levels was much milder when they were fed with Bupleurum chinense at the same time, compared with the control group not given Bupleurum chinense; the effect of bupleurum glycosides seemed to be inferior to that of Bupleurum chinense powder. Oral administration of Bupleurum chinense decoction (0.5-1.0 g crude drug/kg) has a significant improvement effect on rabbit liver dysfunction caused by typhoid vaccine (positive reaction of urobilinogen). It is also somewhat effective for liver dysfunction caused by alcohol, but not as good as licorice. It is very ineffective for liver dysfunction caused by organophosphorus, and is ineffective for liver dysfunction caused by carbon tetrachloride. It also has no protective effect on experimental "liver fibrosis" in rats caused by injection of fresh egg yolk solution. Plants of the same genus, Bupleurum chinense and Bupleurum rotundum, are said to have choleretic effects.

⑥ Effects on cardiovascular system

The alcohol extract of Bupleurum chinense can slightly reduce the blood pressure of anesthetized rabbits and has an inhibitory effect on the isolated frog heart. Atropine cannot block this inhibition. The injection of Bupleurum chinense has no effect on the heart and blood pressure of in situ cats even at a larger dose. Bupleurum glycosides can cause a transient hypotensive response in dogs and slow down the heart rate. They also have a hypotensive effect on rabbits, and can inhibit isolated frog hearts and isolated guinea pig atria, and contract isolated rabbit ear blood vessels.

Bupleurum is light and has a thin aroma. If taken in large quantities and for a long time, it will lower blood pressure. Therefore, patients with low blood pressure should not take it in large quantities and for a long time. Bupleurum can also raise blood sugar, so it is best not to be used by people with diabetes. Infants, young children and the elderly should use it under the guidance of a doctor. People with oral and tongue erosions should not take Bupleurum in large quantities for a long time.