• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.523-532
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• 2014

This study was done to evaluate the antioxidant effect of oak hot water extracts on the oxidative stress induced by reactive oxygen species (ROS). The cytotoxicity of $H_2O_2$-induced oxidative stress was performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for the cell viability according to the dose-dependent treatment. Oak extracts demonstrated a dose-dependent ability to inhibit $H_2O_2$-induced apoptosis in cultured tenofibroblasts, as assessed by MTT assay and FACS analysis. $H_2O_2$ increased the phosphorylation of extracellular regulated kinase1/2 (ERK1/2) and of c-Jun N-terminal kinase (JNK) and the production of reactive oxygen species (ROS). In contrast, treatment with oak extracts was decreased this activation of ERK1/2 and JNK, as confirmed by western blot analysis, and reduced the production of ROS, as verified by fluorescent microscopic and flow cytometry (FACS) analyses. These findings suggest that oak extracts, by suppressing JNK, ERK1/2, and intracellular ROS production, have a concentration-dependent antiapoptotic effect on achilles tenofibroblasts exposed to an oxidative stressor, and may have therapeutic potential.

• Journal of the Korean Wood Science and Technology
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• v.43 no.2
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• pp.224-237
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• 2015

We hypothesized that the extract from steam exploded Q. variabilis might be cytoprotective for tenofibroblasts cells during oxidative stress. In the present study, the extracts obtained from steam exploded (severity log Ro 4.68) Q. variabilis contained high quantities of phenolics and flavonoids contents. Also, the extracts appear to have, on these tenofibroblasts, a protective effect against oxidative stress. Tenofibroblasts cells incubated with the extracts and stressed with $H_2O_2$ showed an increase in cell viability by MTT assay. The extracts is found to inhibit $H_2O_2$-induced apoptosis in tenofibroblasts cells, as shown by Annexin V/PI double staining analysis. Western blot data showed that in the extracts/$H_2O_2$-treated cells, the extracts inhibited the $H_2O_2$-dependent phosphorylation of ERK and p38. From these results, it is suggested that the extracts showed the protective effect on $H_2O_2$-mediated oxidative stress. The main chemical compounds of the extract was identified as 1,8-cineole by GC-MS analysis. The anti-apoptosis activity is accordingly believed to be attributable to the 1,8-cineole.