ABSTRACT
Sempervirine, a yohimbane-type alkaloid isolated from Gelsemium elegans, was found to significantly inhibit the cellular proliferation of U251 cells in vitro and in vivo in a dose-dependent manner. U251 cells were treated with 0-16 μmol·L-1 of sempervirine for 24, 48 or 72 h. An MTT assay and clone formation assay were used to investigate cell survival and clone formation. Hoechst staining and Annexin V-FITC/PI staining were used to measure cell apoptosis. The expression of PI3K, AKT, p-AKT, Bax, Bcl-2, caspase-3 and cleaved caspase-3 was determined by Western blot analysis. The antitumor effect of sempervirine in vivo was investigated by inoculating nude mice with U251 cells. All animal experiments were in strict accordance with the regulations of the Biomedical Ethics Committee of Fujian Medical University (Fujian, China). The results show that sempervirine significantly inhibits the proliferation and induces the apoptosis of U251 cells, promotes cleavage of caspase-3, down-regulates the protein expression of PI3K and Bcl-2/Bax, and inhibits phosphorylation of AKT in vitro. Intraperitoneal injection of 4 or 8 mg·kg-1·day-1 of sempervirine inhibits U251 cells tumor growth in the xenograft nude mice, and tumor weight decreased by 44.76% and 61.26%, respectively. Our study shows that sempervirine significantly inhibits the proliferation of U251 cells in vitro and in vivo, laying a foundation for further research and development of its anti-glioma effect.
ABSTRACT
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.