The Effects of Vernonia cinerea Less Extracts on Antioxidant Gene Expression in Colorectal Cancer Cells

OBJECTIVES

To investigate the capability of Vernonia cinerea extracts to disrupt the intracellular oxidative-antioxidative status in colorectal cancer cells.

METHODS

All experiments were conducted on two colorectal cancer cell lines (SW620 and HT29) with aqueous and ethanol extracts of Vernonia cinerea (VC). The cytotoxicity of both extracts was evaluated using MTT assay. Cells were treated for 1, 4, and 7 days with different concentrations of aqueous and ethanol extracts ranging from 100-700 and 10-150 μg/ml respectively. The antioxidant capacity of cell lysates was determined by the 2, 2'-azino-bis-(3-ethylbenzothiazolin-6-sulfonic acid) diammonium salt (ABTS), 2, 2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activities, and malondialdehyde (MDA) inhibitory effect. The possible action mechanism was also investigated through gene expression of antioxidant enzymes, i.e. superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase.

RESULTS

Both aqueous and ethanol extracts showed dose/time-dependent manners in all assays. Ethanol extract had a higher potency for cytotoxicity with obviously lower IC50 and a higher antioxidant capability in cytoplasmic content than aqueous extract, especially at 4-day treatment. Low MDA content and gene expression alteration of four enzymes involved in antioxidant status were found in cells treated with ethanol extract compared to aqueous extract.

CONCLUSIONS

Ethanol VC extracts can cause cytotoxicity to human colorectal cancer cells, possibly be involved in oxidative stress, and/or interfere with oxidative-antioxidative balance by radical scavenging in vitro.

Selective Cytotoxicity of Kaempferia parviflora Extracts in Human Cell Lines

OBJECTIVE

Aims of this study were to (1) compare anti-proliferative activity between aqueous and ethanol Kaempferia parviflora (KP) extracts in both cancer (Human urinary bladder cancer cell, T24) and normal cell lines (Human umbilical vein endothelial cell, HUVEC). (2) confirm selective cytotoxicity of ethanol KP extract to normal and different cancer cell lines (3) investigate its cellular mechanism through p53 and SIRT1 gene expression.

METHODS

Phytochemical difference between aqueous and ethanol extract was determined by thin layer chromatography (TLC). Screening for cytotoxic activity in human cell lines was performed by cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reagent. P53 and SIRT1 gene expression were quantified using RT-PCR.

RESULTS

Results from the cell viability assay were shown as follows: (1) ethanol extract possessed higher toxicity to cancerous cells than aqueous extract (2) ethanol extract exhibited higher cytotoxicity to cancerous cells than normal cells (3) ethanol extract also showed cytotoxicity, with different levels, to three prostate cancer cell lines varying in aggressiveness. (4) ethanol KP extract induced cell death in T24 via p53 gene expression and prolonged cell survival in HUVEC through SIRT1 gene expression.

CONCLUSION

These findings implied that ethanol KP extract might possibly be an alternative for cancer adjuvant therapy through the mechanism of selective p53 and SIRT1 gene expression.

Chemical compositions of essential oils of Amomum verum and Cinnamomum parthenoxylon and their in vitro biological properties

Introduction: In eastern Thailand, Amomum verum and Cinnamomum parthenoxylon are native plants used by local communities for their medical and culinary properties. This study determined the chemical composition and biological activities of the essential oils from A. verum shoots (AVSEO) and C. parthenoxylon wood (CPW-EO). Methods: Essential oils were extracted using hydro-distillation and analyzed using gas chromatography-mass spectroscopy (GC-MS). The antimicrobial activity was evaluated using the disc diffusion method and broth microdilution assay. The cytotoxic activity of the essential oils was assessed against the human prostate adenocarcinoma (DU145) cell line using 3-(4,5-dimethylthiazol2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The antioxidant activity of the essential oils was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis-(3-ethylbenzothiazoline6-sulfonic acid) (ABTS) radical scavenging assays. The expression of antioxidant genes in the DU145 cells was evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). Results: 1,8-Cineole was the main component in AVS-EO and CPW-EO with 84.38, and 45.65 %, respectively. AVS-EO had stronger antimicrobial activity than CPW-EO. The lowest minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) values of AVSEO against Candida albicans were 0.3125 and 2.5 mg/mL, respectively. Both essential oils had timedependent and dose-dependent cytotoxic effects on the DU145 human prostate adenocarcinoma cells. CPW-EO had high antioxidant activity toward DPPH and ABTS radicals with IC50 values of 4.528±0.233 and 0.045±0.007 mg/mL, respectively. The two essential oils up-regulated glutathione peroxidase (GPx) and glutathione reductase (GRx) mRNA expression in the oxidative stress response of DU145 cells. Conclusion: AVS-EO and CPW-EO might be added as natural ingredients in food or dietary supplement products for the benefit of microbial and prostate cancer inhibition.