Antitumor effect and mechanism of total alkaloids of Gelsemium elegans and sempervirine in vitro / 中国药房

OBJECTIVE To explore the antitumor effect and mechanism of total alkaloids of Gelsemium elegans （TA） and sempervirine （SPV） in vitro. METHODS The effects of low， medium and high concentrations of TA （50， 100， 200 μg/mL） and SPV （10， 30， 50 μmol/L） on the morphology of human hepatoma cells （HepG2， Bel-7402）， human lung cancer cells （A549） and human colon cancer cells （HCT-8） were observed， and the toxicity of TA and SPV to four tumor cells was monitored. The effects of TA and SPV on the contents of caspase-3 and caspase-9 in the supernatant of HCT-8 cells， the protein expressions of phosphorylated protein kinase B （p-Akt） （Thr308， Ser473）， B-cell lymphoma 2 （Bcl-2）， Bcl-2-related X protein （Bax）， survivin， C/EBP-homologous protein （CHOP）， immunoglobulin binding protein （Bip） and microtubule-associated protein 1 light chain 3Ⅱ （LC3Ⅱ） in HCT-8 cells were detected. RESULTS After the intervention of TA and SPV， the volume reduction and nuclear shrinkage were founded in four tumor cells； the cell activity decreased to varying degrees， among which TA and SPV had the best inhibitory effect on HCT-8 cells. After the intervention of TA and SPV， the contents of caspase-3 and caspase-9 in the supernatant of HCT-8 cells， the protein expressions of Bax， CHOP， Bip and LC3Ⅱ all increased to different degrees， while the protein expressions of p-Akt （Thr308， Ser473）， Bcl-2 and survivin in HCT-8 cells all decreased to different degrees. CONCLUSIONS TA and SPV have inhibitory effects on the above four tumor cells， and the inhibitory effect on HCT-8 cells is the best. The mechanism of their action on HCT-8 cells may be related to promoting apoptosis， activating endoplasmic reticulum stress and autophagy.

Sempervirine Mediates Autophagy and Apoptosis via the Akt/mTOR Signaling Pathways in Glioma Cells.

The potential antitumor effects of sempervirine (SPV), an alkaloid compound derived from the traditional Chinese medicine Gelsemium elegans Benth., on different malignant tumors were described in detail. The impact of SPV on glioma cells and the basic atomic components remain uncertain. This study aimed to investigate the activity of SPV in vitro and in vivo. The effect of SPV on the growth of human glioma cells was determined to explore three aspects, namely, cell cycle, cell apoptosis, and autophagy. In this study, glioma cells, U251 and U87 cells, and one animal model were used. Cells were treated with SPV (0, 1, 4, and 8 µM) for 48 h. The cell viability, cell cycle, apoptosis rate and autophagic flux were examined. Cell cycle, apoptotic, autophagy, and Akt/mTOR signal pathway-related proteins, such as CDK1, Cyclin B1, Beclin-1, p62, LC3, AKT, and mTOR were investigated by Western blot approach. As a result, cells induced by SPV led to G2/M phase arrest and apoptosis. SPV also promoted the effect of autophagic flux and accumulation of LC3B. SPV reduced the expression of p62 protein and induced the autophagic death of glioma cells. Furthermore, SPV downregulated the expressions of AKT and mTOR phosphorylated proteins in the mTOR signaling pathway, thereby affecting the onset of apoptosis and autophagy in U251 cells. In conclusion, SPV induced cellular G2/M phase arrest and blockade of the Akt/mTOR signaling pathway, thereby triggering apoptosis and cellular autophagy. The in vivo and in vitro studies confirmed that SPV inhibits the growth of glioma cancer.

Sempervirine Inhibits Proliferation and Promotes Apoptosis by Regulating Wnt/ß-Catenin Pathway in Human Hepatocellular Carcinoma.

Gelsemium elegans (G. elegans) Benth., recognized as a toxic plant, has been used as traditional Chinese medicine for the treatment of neuropathic pain and cancer for many years. In the present study, we aim to obtain the anti-tumor effects of alkaloids of G. elegans and their active components in hepatocellular carcinoma (HCC) and the potential mechanism was also further investigated. We demonstrated that sempervirine induced HCC cells apoptosis and the apoptosis was associated with cell cycle arrest during the G1 phase, up-regulation of p53 and down-regulation of cyclin D1, cyclin B1 and CDK2. Furthermore, sempervirine inhibited HCC tumor growth and enhances the anti-tumor effect of sorafenib in vivo. In addition, inactivation of Wnt/ß-catenin pathway was found to be involved in sempervirine-induced HCC proliferation. The present study demonstrated that alkaloids of G. elegans were a valuable source of active compounds with anti-tumor activity. Our findings justified that the active compound sempervirine inhibited proliferation and induced apoptosis in HCC by regulating Wnt/ß-catenin pathway.

Sempervirine inhibits proliferation of human glioma U251 cells in vitro and in vivo / 药学学报

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.

Fingerprint analysis of Gelsemium elegans by HPLC followed by the targeted identification of chemical constituents using HPLC coupled with quadrupole-time-of-flight mass spectrometry.

Gelsemium elegans, which is a genus of the family Loganiaease, is commonly used as a traditional medicine for promoting animal growth and treating rheumatoid arthritis pain and neuropathic pain, among others. In this study, we first established a valid high-performance liquid chromatography (HPLC) method for the fingerprint analysis of Gelsemium elegans samples. Then, the comprehensive detection of chemical constituents from the samples was performed using HPLC coupled with quadrupole-time-of-flight mass spectrometry. The similarity evaluation results showed that location and area differences influenced the quality of the samples. An efficient strategy for the rapid targeted identification of chemical components was matching with a developed Gelsemium database. As a result, the accurate elemental compositions and known structures of compounds are found as hits. This process facilitated the structural identification of compounds combined with the accurate mass measurement of product ions and fragmentation behaviors. Consequently, 41 components including six alkaloids and non-alkaloids were systematically identified from Gelsemium elegans. The results showed that at least seven relatively major components existing in Gelsemium elegans may be useful for its quality control. The present analytical method combined with the developed Gelsemium database was shown to be a useful tool for investigating the chemical components of Gelsemium products.