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Changes of constituents and activity to apoptosis and cell cycle during fermentation of tea.

Zhao H, Zhang M, Zhao L, Ge YK, Sheng J, Shi W - Int J Mol Sci (2011)

Bottom Line: In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared.The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism.Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Molecular Enzymology & Engineering, the Ministry of Education, Jilin University, Changchun 130012, China; E-Mails: zhzky@163.com (H.Z.); zhangmin2584652@yahoo.com.cn (M.Z.); zhaolu_1987@126.com (L.Z.); yakunge@126.com (Y.-K.G.).

ABSTRACT
Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher in the fermented black tea and pu-erh tea, while the polyphenol level was higher in the unfermented green tea. Hence, a treatment of tea aqueous extract and the components, which are emerging as promising anticancer agents, were pursued to determine whether this treatment could lead to enhance apoptosis and cell cycle arrest. In the human gastric cancer cell line SGC-7901, the cell viability and flow cytometry analysis for apoptotic cells indicated effects in a dose-dependent inhibition manner for the three tea treatment groups. The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism. Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins. CCC-HEL-1 normal cells were not sensitive to tea extract. These findings suggest that the fermentation process causes changes of the compounds which might be involved in the changes of cell proliferation inhibition, apoptosis induction and cell cycle arrest.

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Proliferation of SGC-7901 and CCC-HEL-1 cells exposed to various drugs for 48 h by MTT assay. The proliferation rates of (A) SGC-7901 and (B) CCC-HEL-1 cells treated with three tea extract at the concentrations of 31.2–1000 μg/mL. The proliferation rates of (C) SGC-7901 and (D) CCC-HEL-1 cells treated with three main compounds present in tea extract at the concentrations of 15.6–500 μg/mL (as indicated concentration). ★ p < 0.05 when compared with that of the positive control group (only treated with DMEM). # p < 0.05 when compared with that of the green tea cell group at the same concentration.
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f2-ijms-12-01862: Proliferation of SGC-7901 and CCC-HEL-1 cells exposed to various drugs for 48 h by MTT assay. The proliferation rates of (A) SGC-7901 and (B) CCC-HEL-1 cells treated with three tea extract at the concentrations of 31.2–1000 μg/mL. The proliferation rates of (C) SGC-7901 and (D) CCC-HEL-1 cells treated with three main compounds present in tea extract at the concentrations of 15.6–500 μg/mL (as indicated concentration). ★ p < 0.05 when compared with that of the positive control group (only treated with DMEM). # p < 0.05 when compared with that of the green tea cell group at the same concentration.

Mentions: The human gastric cancer cells SGC-7901 and CCC-HEL-1 normal cells were treated with various concentrations of tea extract and their main compounds for 48 h, which induced a significant decrease in MTT reduction. The cell viability was expressed as MTT conversion rate. In SGC-7901 cells, green tea, black tea and pu-erh tea extract could inhibit the growth of gastric cancer cells in a dose dependent manner (Figure 2A). There was not much difference depending on the concentration of 31.2, 62.5 and 125 μg/mL. Cell viability was decreased to 66.4%, 36.5% and 15% with green tea extract at 250, 500 and 1000 μg/mL, respectively. In contrast, black and pu-erh tea extract produced a slight increase in cell viability compared with green tea. In the black tea extract treatment group the cell viability was 73.0%, 50.7% and 31%. While with pu-erh tea extract treatment, the result was 75.2%, 54.6% and 35.2%. The 50%-inhibition concentrations (IC50) value of SGC-7901 cells at 48 h was 335.9, 511.5, 658.1 μg/mL, respectively. The cell viability of the two groups that underwent fermentation process was relatively higher than the green tea treatment. It was noted that green tea had more inhibitory effect than black tea and pu-erh tea on cell growth.


Changes of constituents and activity to apoptosis and cell cycle during fermentation of tea.

Zhao H, Zhang M, Zhao L, Ge YK, Sheng J, Shi W - Int J Mol Sci (2011)

Proliferation of SGC-7901 and CCC-HEL-1 cells exposed to various drugs for 48 h by MTT assay. The proliferation rates of (A) SGC-7901 and (B) CCC-HEL-1 cells treated with three tea extract at the concentrations of 31.2–1000 μg/mL. The proliferation rates of (C) SGC-7901 and (D) CCC-HEL-1 cells treated with three main compounds present in tea extract at the concentrations of 15.6–500 μg/mL (as indicated concentration). ★ p < 0.05 when compared with that of the positive control group (only treated with DMEM). # p < 0.05 when compared with that of the green tea cell group at the same concentration.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3111638&req=5

f2-ijms-12-01862: Proliferation of SGC-7901 and CCC-HEL-1 cells exposed to various drugs for 48 h by MTT assay. The proliferation rates of (A) SGC-7901 and (B) CCC-HEL-1 cells treated with three tea extract at the concentrations of 31.2–1000 μg/mL. The proliferation rates of (C) SGC-7901 and (D) CCC-HEL-1 cells treated with three main compounds present in tea extract at the concentrations of 15.6–500 μg/mL (as indicated concentration). ★ p < 0.05 when compared with that of the positive control group (only treated with DMEM). # p < 0.05 when compared with that of the green tea cell group at the same concentration.
Mentions: The human gastric cancer cells SGC-7901 and CCC-HEL-1 normal cells were treated with various concentrations of tea extract and their main compounds for 48 h, which induced a significant decrease in MTT reduction. The cell viability was expressed as MTT conversion rate. In SGC-7901 cells, green tea, black tea and pu-erh tea extract could inhibit the growth of gastric cancer cells in a dose dependent manner (Figure 2A). There was not much difference depending on the concentration of 31.2, 62.5 and 125 μg/mL. Cell viability was decreased to 66.4%, 36.5% and 15% with green tea extract at 250, 500 and 1000 μg/mL, respectively. In contrast, black and pu-erh tea extract produced a slight increase in cell viability compared with green tea. In the black tea extract treatment group the cell viability was 73.0%, 50.7% and 31%. While with pu-erh tea extract treatment, the result was 75.2%, 54.6% and 35.2%. The 50%-inhibition concentrations (IC50) value of SGC-7901 cells at 48 h was 335.9, 511.5, 658.1 μg/mL, respectively. The cell viability of the two groups that underwent fermentation process was relatively higher than the green tea treatment. It was noted that green tea had more inhibitory effect than black tea and pu-erh tea on cell growth.

Bottom Line: In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared.The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism.Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Molecular Enzymology & Engineering, the Ministry of Education, Jilin University, Changchun 130012, China; E-Mails: zhzky@163.com (H.Z.); zhangmin2584652@yahoo.com.cn (M.Z.); zhaolu_1987@126.com (L.Z.); yakunge@126.com (Y.-K.G.).

ABSTRACT
Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher in the fermented black tea and pu-erh tea, while the polyphenol level was higher in the unfermented green tea. Hence, a treatment of tea aqueous extract and the components, which are emerging as promising anticancer agents, were pursued to determine whether this treatment could lead to enhance apoptosis and cell cycle arrest. In the human gastric cancer cell line SGC-7901, the cell viability and flow cytometry analysis for apoptotic cells indicated effects in a dose-dependent inhibition manner for the three tea treatment groups. The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism. Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins. CCC-HEL-1 normal cells were not sensitive to tea extract. These findings suggest that the fermentation process causes changes of the compounds which might be involved in the changes of cell proliferation inhibition, apoptosis induction and cell cycle arrest.

Show MeSH
Related in: MedlinePlus