RESUMO
ObjectiveTo explore the effect of Gelsemium elegans combined with Mussaenda pubescens on efflux transporter breast cancer resistance protein （BCRP） and cytochrome P450 3A11 （CYP3A11） and their attenuation mechanism， and to investigate whether the nuclear receptors were involved in such regulation by intervening it with nuclear receptor activators. MethodC57BL/6 mice were divided into the blank group， G. elegans （GE， 0.25 g·kg-1）group， GE + M. pubescens （MP） （0.25 g·kg-1+10 g·kg-1） group， GE + pregnane X receptor （PXR） activator （rifampicin）（GE + Rif，0.25 g·kg-1+50 mg·kg-1） group， GE + MP + Rif （0.25 g·kg-1+10 g·kg-1+50 mg·kg-1） group， GE + constitutive androstane receptor （CAR） activator （1，4-Bis ［2-（3，5-Dichloropyridyloxy）］ benzene， TCPOBOP）（GE + TCP， 0.25 g·kg-1+0.5 mg·kg-1） group， and GE + MP + TCP （0.25 g·kg-1+10 g·kg-1+0.5 mg·kg-1） group. The medication lasted for 14 successive days. One hour after the last administration， the mice were sacrificed by cervical dislocation and the liver tissue was harvested. The left liver tissue was stained with hematoxylin- eosin （HE） for observing the pathological changes. The right liver tissue was used for BCRP and CYP3A11 mRNA and protein expression detection by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultThe survival rates of mice in the GE + Rif group， GE group， and GE + MP group were 25% （the lowest）， 40%， and 80%， respectively， and no death was observed in the other groups. Compared with the obvious lesions in the liver cells of the GE group， the pathological changes in liver cells of the GE + MP group were alleviated， while those in the GE + Rif group were worsened. Compared with the GE + Rif group， the GE + MP + Rif group exhibited relieved pathological changes in liver cells. Both the GE + TCP group and the GE + MP + TCP group showed mild liver lesions. The comparison with the GE + MP group revealed that the pathological changes in the GE + MP + TCP group were slightly relieved. Compared with the blank group， the expression of BCRP protein and mRNA in GE group were significantly decreased （P<0.05，P<0.01）.The expression of CYP3A11 protein in GE group were significantly decreased （P<0.01）. Compared with the GE group， the GE + MP group displayed remarkably up-regulated BCRP protein and mRNA expression （P<0.05，P<0.01） and CYP3A11 protein expression （P<0.05）， but slightly up-regulated CYP3A11 mRNA expression. Compared with the GE group， the GE + Rif group exhibited down-regulated BCRP protein expression （P < 0.05）. The protein and mRNA expression levels of BCRP were lower in the GE + MP + Rif group than in the GE + MP group （P<0.05，P<0.01）. The PXR activator rifampicin regulated BCRP before and after the combination of G. elegans with M. pubescens. The CYP3A11 protein and mRNA expression levels in the GE + TCP group were higher than those in the GE group （P<0.05，P<0.01）. Compared with the GE + MP group， the GE + MP + TCP group showed up-regulated CYP3A11 protein and mRNA expression （P<0.05，P<0.01）. CAR activator TCPOBOP also had a regulatory effect on CYP3A11 before and after the compatibility of G. elegans with M. pubescens. ConclusionThe attenuated toxin after the combination of G. elegans with M. pubescens is closely related to the efflux transporter BCRP and the drug-metabolizing enzyme CYP3A11.
RESUMO
Objective::On the basis of previous research, to detect the changes of six main alkaloids in Gelsemium elegans rhizomes before and after being processed, so as to reveal its internal mechanism of processing. Method::The contents of gelsemine, humantenidine, koumine, gelsenicine, gelsevirine and humantenine in G. elegans rhizomes was determined simultaneously by HPLC, the content changes of these components before and after processing and its reasons were analyzed by cluster analysis and principal component analysis. The mobile phase was methanol (A)-0.1%formic acid aqueous solution (B) for gradient elution (0-10 min, 22%A; 10-20 min, 22%-30%A; 20-30 min, 30%-40%A). The flow rate was 1.0 mL·min-1. The detection wavelength was set at 254 nm, the injection volume was 10 μL, and the column temperature was 30 ℃. Result::Before processing, contents of the above six components in raw products were 1.444, 1.129, 3.590, 1.603, 2.376, 1.631 mg·g-1, after processing, the contents of these six components were 2.258, 0.343, 1.176, 0.115, 0.459, 0.281 mg·g-1, respectively. Gelsenicine, the most toxic ingredient of G. elegans rhizomes, decreased most significantly with a decreasing rate of 92.83%, while the less toxic ingredient, gelsemine, increased by 56.37%after processing. The contents of other four components in G. elegans rhizomes decreased to varying degrees after processing. The results of cluster analysis indicated that G. elegans rhizomes were clearly divided into two categories before and after processing. Principal component analysis showed that the first principal component before and after processing was changed from koumine to gelsemine. Conclusion::The degradation of toxic components and content changes of other components may be one of the intrinsic mechanism of toxicity attenuation and efficacy reservation of G. elegans rhizomes being processed.