Biomedical subjects

Chan-Yong Jun

Publications and source records attributed to Chan-Yong Jun.

3 recordsLinked to original sources

PubMed2006

Rhus verniciflua stokes extract: radical scavenging activities and protective effects on H2O2-induced cytotoxicity in macrophage RAW 264.7 cell lines.

The goal of this study was to determine the effects of Rhus verniciflua stokes (RVS) on the radical scavenging activities and H2O2-induced cytotoxicity in macrophage 264.7 cells. An 80% ethanol extract of RVS was purified by ion exchange chromatography (IEC). Purified RVS extract contained a high amount of phenolics (55.5 g/100 g of extract) and flavonoids (5.9 g/100 g of extract) and its antioxidant activities, such as DPPH, superoxide anion and hydroxyl radical scavenging activities, was higher than the unpurified RVS extract. Purified RVS extract significantly reduced intracellular ROS formation caused by H2O2. Purified RVS extract also prevented the cell death of macrophage RAW 264.7 cells induced by H2O2. Interestingly, co-treated purified RVS extract effectively reduced thiobarbituric acid reactive substance (TBARS) formation, and attenuated catalase depletion at concentration of 100 microg/ml (p<0.05). Study using PDA-HPLC analyses have found that the purified RVS extract contains six major low molecular compounds as p-coumaric acid, fustin, kaempferol-3-O-glucoside, sulfuretin, butein and kaempferol. These results indicate that purified RVS extract, tested in this study, could contribute to the antioxidant activities and inhibition of intracellular ROS level.

Analysis of Variance↗

PubMed2005

Bee venom modulates murine Th1/Th2 lineage development.

Administration of bee venom (BV) elicits anti-inflammatory, anti-nociceptive and anti-allergic effects in various animal models. This study was designed to evaluate the direct effects of BV on helper T cell activities and on Th1/Th2 lineage development using both in vitro and in vivo conditions. In the Th1 skewed condition, BV increased the expression of IFN-gamma mRNA and enhanced the expression of T-bet on purified CD4(+) T cells from splenocytes of BALB/c mice. On the other hand, BV treatment did not alter the expression of IL-4 or GATA-3 in a Th2 driven environment. To elucidate the effects of BV on Th1/Th2 lineage development under in vivo conditions, BV was given by intraperitonial injection to BALB/c mice. It significantly increased the CD4(+) T cell population and enhanced IFN-gamma expression, while IL-4 transcripts were not altered upon in vivo activation using an anti-CD3 antibody injection. Taken together, these results imply that BV induces Th1 lineage development from CD4(+) T cells by increasing the expression of a Th1-specific cytokine, IFN-gamma. In addition, this result may be mediated by inducing a Th1-specific transcription factor, T-bet.

Animals↗

PubMed2004

Induction of apoptosis by Saussurea lappa and Pharbitis nil on AGS gastric cancer cells.

We performed this study to understand the molecular basis underlying the antitumor effects of Saussurea lappa, Pharbitis nil, Plantago asiatica and Taraxacum mongolicum, which have been used for herbal medicinal treatments against cancers in East Asia. We analyzed the effects of these medicinal herbs on proliferation and on expression of cell growth/apoptosis related molecules, with using an AGS gastric cancer cell line. The treatments of Saussurea lappa and Pharbitis nil dramatically reduced cell viabilities in a dose and time-dependent manner, but Plantago asiatica and Taraxacum mongolicum didn't. FACS analysis and Annexin V staining assay also showed that both Saussurea lappa and Pharbitis nil induce apoptotic cell death of AGS. Expression analyses via RT-PCR and Western blots revealed that Saussurea lappa, but not Pharbitis nil, increased expression of the p53 and its downstream effector p21Waf1, and that the both increased expression of apoptosis related Bax and cleavage of active caspase-3 protein. We also confirmed the translocation of Bax to mitochondria. Collectively, our data demonstrate that Saussurea lappa and Pharbitis nil induce growth inhibition and apoptosis of human gastric cancer cells, and these effects are correlated with down- and up-regulation of growth-regulating apoptotic and tumor suppressor genes, respectively.

Antineoplastic Agents↗