[Effect of methanol-ethyl acetate partitioned fractions from Descurainia sophia on proliferation and apoptosis of human non-small cell lung cancer H1975 cells]

Abstract

Objective: To investigate the effects of methanol-ethyl acetate partitioned fractions from Descurainia sophia (MEDS) on the proliferation and apoptosis of human non-small cell lung cancer H1975 cells.

Methods: The systemic solvent extraction method was used to preliminary separation of the effective fractions in the methanol extract of Descurainia sophia. The cytotoxicity of each extract (5, 10, 20, 40, and 80 μg/mL) was tested using MTT assay. Colony cloning method was used to assess the effect of different concentrations of methanol-ethyl acetate partitioned fractions from MEDS (5, 10, 20, 40, and 80 μg/ mL) on the proliferation of H1975 cells. Flow cytometric analysis with Annexin V-FITC/PI staining was performed to detect the apoptosis of the cells after treatment with different concentrations of MEDS fractions (10, 20, and 40 μg/mL). Western blotting was used to evaluate the effects of MEDS fractions on the expressions of apoptosis-related proteins Akt, Bax, and Bcl-2. The anti-tumor activity of 100 mg/kg MEDS fractions was tested in a nude mouse model bearing H1975 cell xenografts.

Results: MTT assay and colony forming experiment showed that MEDS fractions significantly inhibited the proliferation of H1975 cells in a dose-and time-dependent manner (P < 0.05). The results of flow cytometry showed that MEDS fractions induced obvious apoptosis of H1975 cells in a concentration-dependent manner (P < 0.05). MEDS fractions also significantly decreased the expressions of Bcl-2 and Akt protein and increased the protein expression of Bax (P < 0.05). In the tumor-bearing nude mouse model, MEDS fractions showed potent anti-tumor effects with a low toxicity to affect the body weight and organs of the mice.

Conclusions: The methanol-ethyl acetate partitioned fractions from MEDS show potent anti-tumor activity both in vivo and in vitro, suggesting their value as promising therapeutic agents against lung cancer.

Keywords: Descurainia sophia; apoptosis; cytotoxicity; human non-small cell lung cancer.

1

MEDS对人肺癌H1975细胞增殖的影响 Anti-proliferation effects of MEDS in human non-small cell lung cancer H1975 cell line. A:Dose-and time-response curve of the effect of MEDS on cell viability in H1975 cells; B: Representative images of H1975 cell colonies treated with MEDS for 7 days; C:Quantitifaction of the clone counts demonstrated that treatment with MEDS had a significantly inhibitory effect on colony formation in the H1975 cells. ^*P < 0.05 vs control group.

2

MEDS的体内抗肿瘤活性 Anti-tumor effects of MEDS on H1975 cell tumor xenograft growth in nude mice. A:Representative images of tumors from control group, MEDS, and 17-DMAG; B:Tumor volume of the mice; C:Body weight of the mice; D:The GOT and GPT activities (U/L); E:HE staining of the tumor, lung, liver, and kidney tissues form the mice (Original magnification:× 200). ^*P < 0.05 vs control groups.

3

南葶苈子乙酸乙酯浸膏对H1975细胞凋亡的影响 MDES induces apoptosis in the human lung cancer H1975 cell line. A:Cell apoptosis measured by the Annexin VFITC/PI analysis using flow cytometry; B:Expression of Akt, Bcl-2, and Bax proteins detected by Western blotting; C: Quantitative analysis of Bax/Bcl-2 ratio in H1975 cells relative to that in the control cells. ^*P < 0.05 vs control group.