Antioxidant activity of extracts from Alpinia katsumadai seed

Abstract

Alpinia katsumadai (Zingiberaceae) has been widely used in traditional Chinese medicine to treat a variety of conditions such as emesis and gastric disorders. However, very little is known about the cellular actions by which this plant mediates its therapeutic effects. Various aspects of antioxidant activity were evaluated in a total extract derived from Alpinia katsumadai seed in this study. Relatively high levels of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity were detected in the total extract (IC(50) 1.6 microgram/mL). Other known compounds such as (-)-epigallocatechine-3-gallate (EGCG) and resveratrol showed IC(50) values of <0.8 and 4.8 microgram/mL, respectively. The total extract also enhanced the viability of Chinese hamster lung fibroblast (V79-4) cells and inhibited H(2)O(2)-induced apoptosis. The total extract of Alpinia katsumadai also dose-dependently enhanced the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in V79-4 cells, and these effects were comparable to other antioxidant compounds such as EGCG and resveratrol. Taken together, our findings show that Alpinia katsumadai contains significant antioxidant activity.

Evaluation of anti–apoptotic activity of different dietary antioxidants in renal cell carcinoma against hydrogen peroxide

“…In the presence of only H 2 O 2 (control), cell death ratio reached up to 70% after 45 min of the treatment ( Figure 3). As compared with the control, the reduction of cell death was observed after the treatment of each antioxidant at 20 and 50 毺 g/mL concentration. We estimated enrichment factor to detect nucleosomal damage, a quantitative measurement of apoptosis (cell death detection), which was carried out by ELISA.…”

“…Thereafter, cells become resistant to oxidant and oxidant-induced apoptosis [24] . Results (Figure 7,8) indicated that antioxidants (SA, AA, CA and 毩-TA) treated at both concentrations 20 and 50 毺 g/mL to cell lines for 18 h significantly protected the bcl-2 levels. Additionally, only H 2 O 2 treatment (vegative control) for 2 h significantly reduced the bcl-2 levels as compared with positive control RCC-26 cell lines.…”

“…Cell lines were cultured and seeded on sterilized cover glasses and treated with different antioxidants, at both concentrations as mentioned earlier, in different methods for 24 h followed by the PI staining (10 毺 g/mL). Morphology of cell nucleus was observed by fluorescence microscope at the magnitude of 200× consisting of the sample of 2×10 6 cells [20] . Nucleosomal damage studies have been further carried out for more precision.…”

“…These viable cells (2×10 6 /mL) were dispersed in 96-well micro plates for 24 h at 37 曟 with 5% CO 2 . The medium was removed and cells were washed subsequently three times by PBS for the complete removal of medium, then different antioxidants were added and the microplates were incubated for 2 h. Thereafter, 20 毺 m 2', 7'-dichlorofluorescin diacetate (DCFH-DA) was loaded after another 45 min. The cells were washed with PBS for removing the DCFH-DA.…”

“…In this study, we have evaluated radical (generated by H 2 O 2 ) scavenging activity of selected antioxidants by spectrophotometer. H 2 O 2 scavenging (Hs) ability of the different antioxidants (at 20 and 50 毺 g/mL) against H 2 O 2 was depicted in Figure 1 …”