ObjectiveThis paper aims to verify the therapeutic effect of Cranial Painkiller pills' extract powder prepared by the new process on the rat's trigeminal neuralgia model caused by infraorbital injection of tal， evaluate its potential clinical application value， and compare the therapeutic effect with that of Cranial Painkiller granules， so as to provide data support for the application of the Cranial Painkiller pills' extract powder and precise treatment.MethodsThe rat's trigeminal neuralgia model was constructed by infraorbital injection of tal， and the rats were randomly divided into the normal group， model group， carbamazepine group （60 mg·kg^-1）， Cranial Painkiller granules group （2.70 g·kg^-1）， and low， medium， and high dosage groups of Cranial Painkiller pills' extract powder （1.35， 2.70， and 5.40 g·kg^-1） according to the basal mechanical pain thresholds， and there were 10 rats in each group. The drug was administered by gavage to each group 2 h after modeling， and distilled water was given by gavage to the normal and model groups under the same conditions once a day for 10 d. Von Frey brushes were used to measure mechanical pain thresholds in rats. Hematoxylin-eosin （HE） staining was used to detect pathological changes in the trigeminal ganglion， and enzyme-linked immunosorbent assay （ELISA） was used to detect the inflammatory factors interleukin-1 （IL-1）， interleukin-6 （IL-6）， interleukin-8 （IL-8）， and tumor necrosis factor-α （TNF-α） levels in rat serum， as well as neuropeptide substance P （SP） and β-endorphin （β-EP） levels in rat brain tissue. Western blot technique was used to detect the levels of NLRP3， ASC， Caspase-1， and OTULIN proteins in rat brain tissue.ResultsCompared with the normal group， the pain threshold of rats in the model group showed a continuous significant decrease （P<0.01）. The pathological damage of brain tissue was significant （P<0.01）， and the inflammatory levels of IL-1， IL-6， IL-8， and TNF-α in serum were significantly elevated （P<0.01）. The level of the SP in the brain tissue was significantly elevated （P<0.01）， and the level of β-EP was significantly reduced （P<0.01）， while the level of OTULIN was significantly reduced， and NLRP3， ASC， and Caspase-1 protein levels were significantly elevated （P<0.01）. After administration of the drug， compared with the model group， the pain threshold of each dose group of the Cranial Painkiller pills' extract powder and the Cranial Painkiller granules group significantly increased （P<0.01）. The inflammatory levels of IL-1， IL-6， IL-8， and TNF-α and SP levels significantly decreased （P<0.01）， and the β-EP levels were significantly elevated （P<0.01）， while the levels of OTULIN protein were significantly elevated （P<0.05， P<0.01）， and the levels of NLRP3， ASC， and Caspase-1 proteins were decreased （P<0.05， P<0.01）. Meanwhile， compared with those in the model group， the trigeminal ganglion lesions of rats in the Cranial Painkiller pills' extract powder and Cranial Painkiller granules groups showed different degrees of improvement （P<0.05， P<0.01）.ConclusionThe Cranial Painkiller pills' extract powder has significant therapeutic effects on the rat model of trigeminal neuralgia induced by infraorbital injection of tal， and its mechanism is related to the improvement of OTULIN-regulated neuroinflammation.

Cranial Painkiller pills' extract powder;trigeminal neuralgia;OTU-deubiquitinating enzyme protein （OTULIN）;neuroinflammation;tal