TY - JOUR
T1 - Wogonin and fisetin induction of apoptosis through activation of caspase 3 cascade and alternative expression of p21 protein in hepatocellular carcinoma cells SK-HEP-1
AU - Chen, Yen-Chou
AU - Shen, Shing-Chuan
AU - Lee, Woan-Ruoh
AU - Lin, Hui Yi
AU - Ko, Ching Huai
AU - Shih, Chun-Ming
AU - Yang, Ling-Ling
PY - 2002
Y1 - 2002
N2 - Wogonin and fisetin are flavonoids, which are widely distributed in plants. Our recent study demonstrated that, among seven structurally related flavo-noids, wogonin and fisetin showed the most potent apoptosis-inducing activities in human promyeloleuke-mic cells HL-60. In the present investigation, we performed molecular studies to assess the apoptotic effects of wogonin and fisetin on hepatocellular carcinoma cells SK-HEP-1. Both wogonin and fisetin showed dose-dependent cytotoxic effects on SK-HEP-1 cells, accompanied by DNA fragmentation. Microscopic observation under Giemsa staining showed that wogonin and fisetin, at the dose of 80 μM, induced cellular swelling and the appearance of apoptotic bodies, characteristics of apoptosis, in SK-HEP-1 cells. Furthermore, flow cy-tometry analysis showed an increase of hypodiploid cells in wogonin- and fisetin-treated SK-HEP-1 cells. These data demonstrated that wogonin and fisetin were effective inducers of apoptosis in SK-HEP-1 cells. Treatment with an apoptosis-inducing concentration of wogonin or fisetin caused induction of caspase 3/CPP32 activity, but not of caspase 1 activity. In addition, a caspase 3 inhibitor, Ac-DEVD-CHO, but not the caspase 1 inhibitor Ac-YVAD-CHO, reversed the cytotoxic effects of wogonin and fisetin on SK-HEP-1 cells. Further, cleavage of caspase 3 substrates including poly(ADP-ribose) polymerase (PARP) and D4-GDI protein, and decrease of pro-caspase 3 protein were detected in wogonin- and fisetin-treated SK-HEP-1 cells. Increase of p53 protein was associated with wogonin- and fisetin-induced apoptosis; however, a p53-controlled gene, p21Waf/Cip-1, was only induced in wogonin- (not fisetin-) treated SK-HEP-1 cells. Serum starvation elevated p21Waf/Cip-1 protein expression, and enhanced the apoptotic induction activity of wogonin (not fiseitn) in SK-HEP-1 cells. Our study has provided molecular evidence to demonstrate that wogonin and fisetin had effective cytotoxic effects through apoptosis induction in hepatocellular carcinoma cells SK-HEP-1; activation of caspase 3 cascade, induction of p53 protein and alternative expression of p21Waf/Cip-1 protein were involved.
AB - Wogonin and fisetin are flavonoids, which are widely distributed in plants. Our recent study demonstrated that, among seven structurally related flavo-noids, wogonin and fisetin showed the most potent apoptosis-inducing activities in human promyeloleuke-mic cells HL-60. In the present investigation, we performed molecular studies to assess the apoptotic effects of wogonin and fisetin on hepatocellular carcinoma cells SK-HEP-1. Both wogonin and fisetin showed dose-dependent cytotoxic effects on SK-HEP-1 cells, accompanied by DNA fragmentation. Microscopic observation under Giemsa staining showed that wogonin and fisetin, at the dose of 80 μM, induced cellular swelling and the appearance of apoptotic bodies, characteristics of apoptosis, in SK-HEP-1 cells. Furthermore, flow cy-tometry analysis showed an increase of hypodiploid cells in wogonin- and fisetin-treated SK-HEP-1 cells. These data demonstrated that wogonin and fisetin were effective inducers of apoptosis in SK-HEP-1 cells. Treatment with an apoptosis-inducing concentration of wogonin or fisetin caused induction of caspase 3/CPP32 activity, but not of caspase 1 activity. In addition, a caspase 3 inhibitor, Ac-DEVD-CHO, but not the caspase 1 inhibitor Ac-YVAD-CHO, reversed the cytotoxic effects of wogonin and fisetin on SK-HEP-1 cells. Further, cleavage of caspase 3 substrates including poly(ADP-ribose) polymerase (PARP) and D4-GDI protein, and decrease of pro-caspase 3 protein were detected in wogonin- and fisetin-treated SK-HEP-1 cells. Increase of p53 protein was associated with wogonin- and fisetin-induced apoptosis; however, a p53-controlled gene, p21Waf/Cip-1, was only induced in wogonin- (not fisetin-) treated SK-HEP-1 cells. Serum starvation elevated p21Waf/Cip-1 protein expression, and enhanced the apoptotic induction activity of wogonin (not fiseitn) in SK-HEP-1 cells. Our study has provided molecular evidence to demonstrate that wogonin and fisetin had effective cytotoxic effects through apoptosis induction in hepatocellular carcinoma cells SK-HEP-1; activation of caspase 3 cascade, induction of p53 protein and alternative expression of p21Waf/Cip-1 protein were involved.
KW - Apoptosis
KW - Caspase 3
KW - Fisetin
KW - Protein p21
KW - Protein p53
KW - Wogonin
UR - http://www.scopus.com/inward/record.url?scp=0036016874&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036016874&partnerID=8YFLogxK
U2 - 10.1007/s00204-002-0346-6
DO - 10.1007/s00204-002-0346-6
M3 - Article
C2 - 12107653
AN - SCOPUS:0036016874
SN - 0340-5761
VL - 76
SP - 351
EP - 359
JO - Archives of Toxicology
JF - Archives of Toxicology
IS - 5-6
ER -