RESUMO
ObjectiveTo investigate the effect of total alkaloids of Corydalis saxicola on a rat model of lipopolysaccharide（LPS）-induced depression， as well as the pharmacokinetic characteristics of 8 of its major components. MethodTwenty-four male SD rats were randomly divided into normal group， model group， fluoxetine group（10 mg·kg-1） and total alkaloids of C. saxicola group（210 mg·kg-1）， with 6 rats in each group. In addition to the normal group， the rats were injected intraperitoneally with LPS to establish the inflammation model of depression， and the drug administration was started 1 week after modeling， and the administration groups were gavaged according to the corresponding dose， and the normal and model groups were intragastric administration with equal volume of distilled water， and the administration was performed along with the modeling. After two weeks of continuous administration， the effect of total alkaloids of C. saxicola on the behavior of depressed rats were tested by sucrose preference， forced swimming and open field experiments， the levels of tumor necrosis factor-α（TNF-α）， interleukin（IL）-1β and IL-6 in serum of rats were determined by enzyme-linked immunosorbent assay（ELISA）， the histopathological changes of rat hippocampus were observed by hematoxylin-eosin（HE） staining. After the last administration， blood was collected from orbit according to the set time， and ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry（UPLC-QqQ-MS） was established to simultaneously detect the concentrations of dehydrocavidine， tetrahydropalmatine， coptisine， palmatine， jatrorrhizine， berberine， berberrubine and epiberberine in plasma， and drug-time curves were drawn. The pharmacokinetic parameters were analyzed by DAS 2.0 software. ResultCompared with the normal group， the model group exhibited a decrease in sucrose preference rate， total distance traveled in the open field， as well as an increase in swimming immobility time and serum inflammatory factor expression（P<0.01）. In contrast， compared with the model group， rats in each administration group showed an increase in sucrose preference rate and total distance traveled in the open field， a decrease in swimming immobility time， and a reduction in serum inflammatory factor expression（P<0.05， P<0.01）. Additionally， HE staining results revealed that neurons in the hippocampus of rats from the model group were characterized by loss， disorganization and residual vacuoles， whereas those from the total alkaloids of C.saxicola group displayed an increase in number with orderly arrangement and clear cytoplasm. Pharmacokinetic results showed that the time to peak（tmax） and half-life（t1/2） of the 8 active ingredients were 0.19-2.06 h and 3.71-8.70 h after continuous administration of total alkaloids of C. saxicola. Among them， the area under the curve（AUC0-∞） of tetrahydropalmatine was the highest and the t1/2 was the shortest， and the AUC0-∞ of coptisine， palmatine， jatrorrhizine， berberine， berberrubine and epiberberine were low. The curves of dehydrocavidine， coptisine， palmatine， berberine and epiberberine showed obvious double peak phenomenon. ConclusionTotal alkaloids of C. saxicola can improve the depression-like behavior of rats， inhibit the expression of inflammatory factors in serum， improve the pathological injury of hippocampus， and has the antidepressant effect. Meanwhile， the effective site is absorbed quickly and eliminated slowly in the depressed model rats， and the efficacy is maintained for a long time.