The anti-tumor effects of alkaloids from the seeds of Strychnos nux-vomica on HepG2 cells and its possible mechanism.
To screen the anti-tumor effects of the four alkaloids: brucine, strychnine, brucine N-oxide and isostrychnine from the seed of Strychnos nux-vomica, MTT assay was used to examine the growth inhibitory effects of these alkaloids on human hepatoma cell line (HepG2). Brucine, strychnine and isostrychnine revealed significant inhibitory effects against HepG2 cell proliferation, whereas brucine N-oxide didn't have such an effect. In addition, brucine caused HepG2 cell shrinkage, membrane blebbing, apoptotic body formation, all of which are typical characteristics of apoptotic programmed cell death. The results of flow cytometric analysis demonstrated that brucine caused dose-dependent apoptosis of HepG2 cells through cell cycle arrest at G0/G1 phase, thus preventing cells entering S or G2/M phase. Immunoblot results revealed that brucine significantly decreased the protein expression level of cyclooxygenase-2, whereas increased the expression caspase-3 as well as the caspase-3-like protease activity in HepG2 cells, suggesting the involvement of cyclooxygenase-2 and caspase-3 in the pro-apoptotic effects exerted by brucine. Therefore, this paper indicate that the major alkaloids present in the seed of Strychnos nux-vomica are effective against HepG2 cells proliferation, among which brucine proceed HepG2 cells death via apoptosis, probably through the participation of caspase-3 and cyclooxygenase-2.
Deng
Xu-Kun
XK
College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210029, China.
Yin
Wu
W
Li
Wei-Dong
WD
Yin
Fang-Zhou
FZ
Lu
Xiao-Yu
XY
Zhang
Xiao-Chun
XC
Hua
Zi-Chun
ZC
Cai
Bao-Chang
BC
D000470:Alkaloids / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D053148:Caspase 3 / Q000096:biosynthesis; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D003497:Cyclic N-Oxides / Q000302:isolation & purification / Q000494:pharmacology; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D012639:Seeds; D013331:Strychnine / Q000031:analogs & derivatives / Q000302:isolation & purification / Q000494:pharmacology; D031461:Strychnos nux-vomica / Q000737:chemistry*
D000470:Alkaloids; D000970:Antineoplastic Agents; D003497:Cyclic N-Oxides; C083067:brucine N-oxide; C083806:brucine; D051546:Cyclooxygenase 2; D053148:Caspase 3; D013331:Strychnine