Tetrahydropalmatine (dl-THP, tetrahydropalmatine), also known as TETRAHYDROPALMATINE HYDROCHLORIDE. The analgesic effect is weaker than pethidine and morphine, but less addictive and stronger than general antipyretic analgesics. It has good analgesic effect on chronic persistent dull pain, but poor analgesic effect on pain after trauma or surgery or advanced cancer pain. Fumarine ethyl hydrochloride, the main active substance of fumarine, induces hypotension and bradycardia in rats by antagonizing striatal dopamine D2 receptors. It has a significant effect on the pain caused by the gastrointestinal system and the hepatobiliary system, and can also relieve labor pains, headache, concussion headache, etc. It is also used to eliminate irritability, anxiety and other mental tension and treat neurasthenic insomnia.

1. Analgesic and anesthetic effects The analgesic effect of this product is related to the activity of central dopamine receptors, and L-tetrahydropalmatine can enhance the analgesic intensity and prolong the analgesic effect of electroacupuncture. Tetrahydropalmatine may have analgesic effects by blocking D1 dopamine receptors and increasing the content of leucine enkephalin in striatum. 2. Protective effect on cerebral ischemia-reperfusion injury L-THP has a protective effect on neurons in ischemic brain injury, and some studies have found that L-THP reduces the expression of ICAM-1 in endothelial cells during cerebral ischemia reperfusion. L-THP significantly reduces neuronal apoptosis induced by ischemia reperfusion injury and is related to its inhibition of calcium ion aggregation. L-THP can reduce the content of Glu and the ratio of Glu/GABA in the brain tissue of mice during cerebral ischemia, which may be one of the mechanisms of the protective effect of L-THP in the brain during cerebral ischemia, and provide a certain basis for its clinical use in the treatment of cerebral ischemia. 3. Inhibition of platelet aggregation dl-THP(15, 7.5 mg·kg-1) can significantly inhibit experimental cerebral thrombosis in rats, and dl-THP can inhibit platelet aggregation induced by adenosine diphosphate, arachidonic acid and collagen in a dose-dependent manner. The remaining effects may be produced by antagonizing the action of calcium ions. 4. Anti-ulcer and inhibition of gastric acid secretion containing dehydrofumarine and a small amount of ethyl, the original opioid extract, for gastric and duodenal ulcer effect is obvious, clinical application of fumarine preparation of other traditional Chinese medicine oral, stomach, twelve finger ulcer, stomach pain, stomach acid excess has therapeutic effect, fumarine has anti-pyloric ulcer in rats. Water immersion stress ulcer and histamine ulcer inhibited acetic acid ulcer, but not reserpine ulcer. dl-THP made the dose-effect curve of histamine shift to the right, and the maximum secreting acid response decreased, suggesting non-competitive inhibition. 5. Anti-tumor effect dl-THP has killing effect on tumor cells in vitro at high concentration. 6. Withdrawal effect of addictive drugs L-tetrahydropalmatine alleviates the withdrawal symptoms of opioids such as morphine, heroin, amphetamine, methamphetamine and other drugs, and studies on the influence of L-tetrahydropalmatine on drug psychodependence, providing experimental basis for its application in the treatment of opioid addiction, withdrawal and prevention of relapse.