• The Korea Journal of Herbology
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• v.30 no.6
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• pp.7-15
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• 2015

Objectives : Rosa laevigata Michx. has been used for the treatment of renal disease in traditional Korean medicine. In this study, we investigated cytoprotective effect of R. laevigata water extract (RLE) against oxidative stress induced by arachidonic acid (AA) + iron.Methods : To evaluate the protective effects of RLE against AA + iron-induced oxidative stress in HepG2 cell, cell viability and changes on apoptosis-related proteins were assessed by MTT and immunoblot analyses. The effects of RLE on reduced glutathione level, production of reactive oxygen species and mitochondrial membrane potential were also monitored. Furthermore, to verify underlying molecular mechanism, NF-E2-related factor 2 (Nrf2) was examined by immunoblot analysis. Additionally, Nrf2 transactivation and its downstream target genes expression were also determined by reporter gene and realtime RT-PCR analyses.Results : RLE pretreatment (30-300 μg/ml) prevented cells from AA + iron-mediated cell death in a concentration dependent manner. In addition, 100 μg/ml RLE inhibited AA + iron-induced glutathione depletion, reactive oxygen species production and mitochondrial dysfunction. RLE accumulated nuclear Nrf2 and also transactivated Nrf2, which was evidenced by antioxidant response element- and glutathione S-transferase A2-driven luciferase activities and mRNA level of glutamate-cysteine ligase catalytic subunit, NAD(P)H:quinone oxidoreductase 1 and sestrin 2. Moreover, protective effect of RLE against AA + iron was abolished in Nrf2 knockout cells.Conclusions : These results indicate that RLE has the ability to protect hepatocyte against oxidative stress through Nrf2 activation.

• Journal of The Korean Society of Clinical Toxicology
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• v.17 no.2
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• pp.58-65
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• 2019

Purpose: Alpha-amanitin induces potent oxidative stress and apoptosis, and may play a significant role in the pathogenesis of hepatotoxicity. This study examined the mechanisms of α-amanitin-induced apoptosis in vitro, and whether green tea extract (GTE) offers protection against hepatic damage caused by α-amanitin (AMA) induced apoptosis in vivo. Methods: The effects of GTE and SIL on the cell viability of cultured murine hepatocytes induced by AMA were evaluated using an MTT assay. Apoptosis was assessed by an analysis of DNA fragmentation and caspase-3. In the in vivo protocol, mice were divided into the following four groups: control group (0.9% saline injection), AMA group (α-amanitin 0.6 mg/kg), AMA+SIL group (α-amanitin and silibinin 50 mg/kg), and AMA+GTE group (α-amanitin and green tea extract 25 mg/kg). After 48 hours of treatment, the hepatic aminotransferase and the extent of hepatonecrosis of each subject was evaluated. Results: In the hepatocytes exposed to AMA and the tested antidotes, the cell viability was significantly lower than the AMA only group. An analysis of DNA fragmentation showed distinctive cleavage of hepatocyte nuclear DNA in the cells exposed to AMA. In addition, the AMA and GTE or SIL groups showed more relief of the cleavage of the nuclear DNA ladder. Similarly, values of caspase-3 in the AMA+GTE and AMA+SIL groups were significantly lower than in the AMA group. The serum AST and ALT levels were significantly higher in the AMA group than in the control and significantly lower in the AMA+GTE group. In addition, AMA+GTE induced a significant decrease in hepatonecrosis compared to the controls when a histologic grading scale was used. Conclusion: GTE is effective against AMA-induced hepatotoxicity with its apoptosis regulatory properties under in vitro and in vivo conditions.

• Journal of Life Science
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• v.27 no.8
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• pp.909-918
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• 2017

Ice plant (Mesembryanthemum crystallinum L.) was fermented in brine in the form of mulkimchi (IPMB), and its contents of organic acid and cyclitols and biological activities were compared with those before fermentation. The pH of the IPMB continuously decreased until the sixth day of fermentation. The lactic acid yield was greatest on the fourth day. D-pinitol in ice plant mulkimchi solids (IPMS) decreased during fermentation. However, myo-inositol and D-chiro-inositol increased. The radical scavenging activities of ABTS and DPPH, in addition to the activity of FRAP, of the IPMS extract were generally higher after fermentation, with the activities highest on the fifth ($79.09{\pm}0.69%$), fourth ($87.55{\pm}1.21%$), and sixth ($78.72{\pm}0.99%$) days of fermentation, respectively, when treated with 1 mg/ml of the extract. As shown by a lipid/MA assay, antioxidant activity was generally higher after fermentation. The viability of BNL CL.2 cells damaged by t-BHP, $H_2O_2$, and ethanol was $14.19{\pm}0.98$, $13.80{\pm}2.25$, and $25.89{\pm}2.90%$, respectively. When treated with $200{\mu}g/ml$ of IPMS extract, the cell viability was $57.06{\pm}4.52%$ on the first day, and $66.06{\pm}1.36%$ on the fourth day, and $50.07{\pm}04.85%$ on the sixth day of fermentation. Hepatocyte protective effects did not increase significantly after fermentation. ${\alpha}-glucosidase$ inhibitory activity was quite high, with a range of $83.52{\pm}2.69$ to $92.79{\pm}2.16%$, and the activity increased gradually in all the groups over the fermentation period. There was no clear correlation between ${\alpha}-amylase$ inhibitory activity and fermentation.