银杏叶类黄酮对人胃癌细胞 BGC823 体外的增殖抑制作用

EGb761 enhances cisplatin- and etoposide-induced apoptosis of human gastric cancer SGC-7901 cells

AIM: To assess the effect of Ginkgo biloba extract (EGb761) combined with cisplatin or etoposide on cell proliferation and apoptosis in human gastric cancer cell line SGC-7901 and to explore the possible mechanisms involved.

METHODS: SGC-7901 cells were treated with EGb761, cisplatin, etoposide, or EGb761 combined with cisplatin or etoposide. Cell viability was measured by MTT assay, and apoptosis was measured by flow cytometry. The colorimetric method was used to detect the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and the content of malondialdehyde (MDA) in cells. The protein expression of extracellular signal-regulated kinase1/2 (ERK1/2), p-ERK1/2 and nuclear transcription factor-kappa B (NF-κB) p65 was determined by Western blot.

RESULTS: Monotherapy with each of EGb761, cisplatin and etoposide significantly inhibited the growth of SGC-790l cells in a dose- and time-dependent manner. EGb761 significantly enhanced the inhibitory effect of cisplatin and etoposide on cell growth. Cells treated with EGb761 combined either cisplatin or EGb761 showed a significantly higher level of apoptosis than those treated with cisplatin or etoposide alone. Compared to the control group, the activities of SOD, GSH-Px and CAT were notably elevated (SOD: 16.57 U/mg prot ± 3.20 U/mg prot vs 25.96 U/mg prot ± 3.57 U/mg prot; CAT: 2.51 U/mg prot ± 0.32 U/mg prot vs 3.79 U/mg prot ± 0.55 U/mg prot; GSH-Px: 22.18 µmol/(min•mg) prot ± 4.36 µmol/(min•mg) prot vs 33.49 µmol/(min•mg) prot ± 5.64 µmol/(min•mg) prot; all P < 0.05) and the content of MDA was significantly decreased (2.46 nmol/mg prot ± 0.38 nmol/mg prot vs 1.42 nmol/mg prot ± 0.26 nmol/mg prot, P < 0.05) in cells treated with EGb761. The expression of ERK1/2, p-ERK1/2 and NF-κBp65 was significantly induced by cisplatin or etoposide, while EGb761 suppressed the expression of ERK1/2, p-ERK1/2 and NF-κBp65 induced by cisplatin or etoposide. The expression levels of ERK1/2, p-ERK1/2 and NF-κBp65 in the control group, cisplatin group, EGB761 + cisplatin group, etoposide group and EGB761 + etoposide group were as follows: ERK1/2: 0.496 ± 0.078, 0.831 ± 0.091, 0.521 ± 0.082, 0.816 ± 0.101, 0.489 ± 0.072; p-ERK1/2: 0.289 ± 0.032, 0.521 ± 0.068, 0.276 ± 0.049, 0.486 ± 0.087, 0.298 ± 0.053; NF-κBp65: 0.268 ± 0.038, 0.456 ± 0.08, 0.276 ± 0.052, 0.446 ± 0.076, 0.229 ± 0.056).

CONCLUSION: EGb761 enhances cisplatin- and etoposide-induced apoptosis of SGC-7901 cells possibly by enhancing cellular antioxidant capacity and suppressing the up-regulation of ERK, p-ERK and NF-κBp65 protein expression.