Hypolipidemic effects of HVC1 in a high cholesterol diet­induced rat model of hyperlipidemia.

HVC1, a novel formation containing four herbs, was developed and its hypolipidemic effects in rats with high cholesterol diet (HCD)­induced hyperlipidemia were investigated. The rats were given a HCD for 8 weeks. The HVC1­treated groups were orally administered HVC1 at doses of 10, 50 or 250 mg/kg, respectively, and the simvastatin group was treated at a dose of 10 mg/kg. The normal diet and HCD control groups were administered with physiological saline. Oral administration of HVC1 (10, 50 or 250 mg/kg) significantly reduced the body weight of rats with hyperlipidemia and regulated the total cholesterol, low­density lipoprotein cholesterol and high­density lipoprotein cholesterol levels in the serum. In addition, tissue analysis revealed that lipid accumulation in the liver and aorta was reduced by HVC1 administration. Furthermore, HVC1 significantly reduced the mRNA expression of peroxisome proliferator­activated receptor­Î³, 3­hydroxy­3­methylglutaryl­CoA reductase and low­density lipoprotein receptor, as well as the protein level of 5' adenosine monophosphate­activated protein kinase in the liver. The results clearly demonstrate that HVC1 has a potent hypolipidemic effect, and suggest that HVC1 should be evaluated as a potential treatment for hyperlipidemia.

Identification of flavonoids and flavonoid rhamnosides from Rhododendron mucronulatum for. albiflorum and their inhibitory activities against aldose reductase.

To investigate the therapeutic potential of compounds from natural sources, Rhododendron mucronulatum for. albiflorum flowers (RMAF) and R. mucronulatum flowers (RMF) were tested for inhibition of aldose reductase (AR). The methanol extracts of RMAF and RMF exhibited AR inhibitory activities (IC(50) values 1.07 and 1.29 µg/mL, respectively). The stepwise polarity fractions of RMAF were tested for in vitro inhibition of AR from rat lenses. Of these, the ethyl acetate (EtOAc) fraction exhibited AR inhibitory activity (IC(50) 0.15 µg/mL). A chromatography of the active EtOAc fraction of RMAF led to the isolation of six flavonoids, which were identified by spectroscopic analysis as kaempferol (1), afzelin (2), quercetin (3), quercitrin (4), myricetin (5) and myricitrin (6). Compounds 1-6 exhibited high AR inhibitory activity, with IC(50) values of 0.79, 0.31, 0.48, 0.13, 11.92 and 2.67 µg/mL, respectively. HPLC/UV analysis revealed that the major flavonoids of RMAF and RMF are quercitrin (4) and myricitrin (6). Our results suggest that RMAF containing these six flavonoids could be a useful natural source in the development of a novel AR inhibitory agent against diabetic complications.

Antioxidant activity of the methanolic extract of the newly generated vegetable, baemuchae (xBrassicoraphanus).

We investigated the radical scavenging activity and protective effects of the methanol extract (ME) and ferulic acid (FA) from baemuchae (xBrassicoraphanus) against oxidative stress in vitro and on a cellular system using LLC-PK1 renal epithelial cells. In vitro, ME and FA showed dose-dependent radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals. LLC-PK1 cells displayed decreased viability in response to nitric oxide-induced oxidative stress. However, ME and FA significantly increased LLC-PK1 cell viability in a dose-dependent manner. Based on HPLC/UV analysis, the FA content was higher in the shoot of baemuchae than in the root. The results of the present study suggest that baemuchae may be a promising source of antioxidants against oxidative stress induced by free radicals.

Isolation and identification of polymethoxyflavones from the hybrid Citrus, hallabong.

Seven polymethoxyflavones (PMFs) were isolated from the dried peels of hallabong, the hybrid Citrus , by a repeated column chromatography. The structures of PMFs were identified as 5,6,7,3',4'-pentamethoxyflavone (1), 6,7,8,3',4'-pentamethoxyflavone (2), 3-hydroxy-5,6,7,4'-tetramethoxyflavone (3), 5,6,7,8,3',4'-hexamethoxyflavone (4), 3,6,7,4'-tetramethoxyflavone (5), 3,5,6,7,8,3',4'-heptamethoxyflavone (6), and 5,6,7,8,4'-pentamethoxyflavone (7) using 1H and 13C NMR in combination with mass spectrometry. Among these compounds, 5 was isolated for the first time from nature. The content of PMFs 1-7 in hallabong was determined by HPLC-UV. The major PMFs of hallabong are 5 in the dried peels (15.4 mg/g) and 7 in the dried leaves (12.2 mg/g).