Kuk-Hyun Shin

An anti-inflammatory principle from cactus

In previous studies, the ethanol extract of cactus (Opuntia ficus-indica) showed potent anti-inflammatory action. In the present study, following fractionation of the methanol extract of cactus stems guided by adjuvant-induced chronic inflammation model in mice, an active anti-inflammatory principle has been isolated and identified as beta-sitosterol.

Osteopenia in men with mild and severe ankylosing spondylitis

We investigated the frequency and distribution of osteopenia according to the clinical severity in ankylosing spondylitis (AS). Bone mass was measured in men with mild (n=45) and severe AS (n=31) with dual-energy X-ray absorptiometry (DEXA). Definition of clinical severity was based on the Schober’s test. Osteopenia was commonly detected (48% in mild AS and 39% severe AS) and, in mild disease, more frequently observed at the lumbar spine than any of the proximal femur sites. In severe AS, however, the frequency of osteopenia at the femoral neck and Ward’s triangle was as high as at the lumbar spine. Both bone mineral density and T-scores in severe disease were lower than in mild disease at the femur neck, Ward’s triangle, and total proximal femur, but not in the lumbar spine. The progression of osteopenia may be reflected more reliably at proximal femur sites than at the lumbar spine.

Degradation of acharan sulfate and heparin byBacteroides stercoris HJ-15, a human intestinal bacterium

When glycosaminoglycan (GAG)-degrading enzymes were measured in normal human stool suspensions, all 5 tested different stools degraded titrable heparin and acharan sulfate. GAG-degrading bacteria were screened from the isolates of human stools. Among them, HJ-15 had the most potent activities of heparinases (GAGs-degrading enzymes). However, HJ-15 produced the enzyme even if in the media without heparin. Acharan sulfate lyase was induced by acharan sulfate and heparin. Heparinase production was also induced by these GAGs. These enzymes, acharan sulfate lyase and heparinase, were produced in exponential and stationary phase of HJ-15 growth, respectively. Optimal pHs of the acharan sulfate lyase and heparinase activities were 7.2 and 7.5, respectively. The biochemical properties of HJ-15 was similar to those ofB. stercoris. However, difference fromB. stercoris was utilization of raffinose. This HJ-15 also degraded chondroitin sulfates A and C.

Identification of new urinary metabolites of byakangelicin, a component ofAngelicae dahuricae Radix, in Rats

Byakangelicin, 9-(2,3-dihydroxy-2-methylbutoxy)-4-methoxy-7H-furo[3,2-g][l]benzopyran-7-one (BKG), a component ofAngelicae dahuricae Radix, is considered to be an inhibitor of aldose reductase for the treatment of diabetic cataract. An analytical method for the isolation of BKG developed by high-performance liquid chromatography has been reported. No literature on the metabolism of BKG, however, has been found. With the purpose of identifying new metabolites of BKG, BKG (100 mg/kg) was orally administered to Sprague-Dawley rats via a gavage. Using a metabolic cage, urine was collected for 24 h, and the urine samples were extracted by liquid-liquid extraction. For structural identification of new urinary metabolites of BKG, various instrumental analyses were conducted by gas-chromatography/mass spectrometry, high-performance liquid chromatography/diode array detector, liquid chromatography/mass spectroscopy with thermospray interface and1H nuclear magnetic resonance spectroscopy. Two metabolites produced from the O-demethylation or O-dealkylation of BKG were newly identified, and another new but unknown metabolite was assumed to be the hydroxylated form of BKG. These results indicate that the major metabolic products of BKG are formed by O-demethylation or O-dealkylation of BKG side chains.

Screening for Aldose Reductase Inhibitory Activity of Extracts of the Marine Plants from Korea

We examined MeOH extracts of the marine plants from Korea for their inhibitory activities on rat lens aldose reductase in vitro. Among the MeOH extracts tested, the extracts of Enteromorpha prolifera, Ecklonia cava, Pelvetia siliquosa and Salicornia herbacea exhibited a rat lens aldose reductase inhibition (IC: 3.04, 8.84, 11.42 and 4.99 g-ml, respectively) in vitro.