Jae-Hoon Sa

Anti-angiogenic, antioxidant and xanthine oxidase inhibition activities of the mushroom Phellinus linteus.

Fruiting bodies of Phellinus linteus were extracted with 70% ethanol at room temperature. The Phellinus linteus extract (PL) showed strong anti-angiogenic activity, which was detected using the chick embryo chorioallantoic membrane (CAM) assay. The in vitro antioxidant activities of PL were evaluated using two different bioassays. PL was comparable to Vitamin C in scavenging the stable free radical 1,1-diphenyl-2-picrylhyrazyl (DPPH). It also inhibited lipid peroxidation (LPO) in a concentration-dependent manner. These results suggest that antioxidant and anti-angiogenic activities of Phellinus linteus would be partly responsible for its anti-tumor effect.

Identification of a third thioredoxin gene from Corynebacterium nephridii

We identified and sequenced a gene encoding a third thioredoxin (C3) from Corynebacterium nephridii. The determined nucleotide sequence encodes a thioredoxin of 145 amino acid residues, which is larger than most thioredoxins found in microbial cells and contains 6 cysteine residues. C. nephridii thioredoxin C3 is able to serve as a subunit of T7 DNA polymerase. C. nephridii is the first nonphotosynthetic procaryotic organism known to carry three different thioredoxins.

Anti-inflammatory, anti-angiogenic, and anti-nociceptive activities of the chloroform fraction of a methanol extract from Rosa davurica Pall. leaves in experimental animal models

Rosa davurica Pall. has been traditionally used to treat inflammatory diseases and tumors. Its dried leaves were extracted with absolute methanol, and the methanol extract was successively fractionated into n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous fractions. Anti-angiogenic and anti-nociceptive activities were determined using the chick embryo chorioallantoic membrane (CAM) assay and acetic acid-induced writhing response, respectively. Anti-inflammatory activity was evaluated using two in vivo mouse models, acetic acid-induced vascular permeability and carrageenan-induced inflammation in the air-pouch. The methanol extract gave rise to significant inhibition in the CAM angiogenesis, and showed marked 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Among the fractions prepared from the methanol extract, the chloroform fraction exhibited highest inhibitory effect in the CAM angiogenesis. The chloroform fraction displayed anti-inflammatory activities in vascular permeability and air-pouch models. In the air-pouch model, it was able to diminish exudate volume, number of polymorphonulcear leukocytes, and nitrite content. It also showed anti-nociceptive activity in the writhing response model in mice. The leaves of R. davurica possess anti-angiogenic and related anti-inflammatory and anti-nociceptive activities, which would provide some therapeutic support on its traditional use.