Vascular Protective Effect of an Ethanol Extract of Camellia japonica Fruit: Endothelium-Dependent Relaxation of Coronary Artery and Reduction of Smooth Muscle Cell Migration.

Camellia japonica is a popular garden plant in Asia and widely used as cosmetic sources and traditional medicine. However, the possibility that C. japonica affects cardiovascular system remains unclear. The aim of the present study was to evaluate vascular effects of an extract of C. japonica. Vascular reactivity was assessed in organ baths using porcine coronary arteries and inhibition of proliferation and migration were assessed using human vascular smooth muscle cells (VSMCs). All four different parts, leaf, stem, flower, and fruits, caused concentration-dependent relaxations and C. japonica fruit (CJF) extract showed the strongest vasorelaxation and its effect was endothelium dependent. Relaxations to CJF were markedly reduced by inhibitor of endothelial nitric oxide synthase (eNOS) and inhibitor of PI3-kinase, but not affected by inhibitor of cyclooxygenase and endothelium-derived hyperpolarizing factor-mediated response. CJF induced activated a time- and concentration-dependent phosphorylation of eNOS in endothelial cells. Altogether, these studies have demonstrated that CJF is a potent endothelium-dependent vasodilator and this effect was involved in, at least in part, PI3K-eNOS-NO pathway. Moreover, CJF attenuated TNF-α induced proliferation and PDGF-BB induced migration of VSMCs. The present findings indicate that CJF could be a valuable candidate of herbal medicine for cardiovascular diseases associated with endothelial dysfunction and atherosclerosis.

Insulin resistance as a risk factor for gallbladder stone formation in Korean postmenopausal women.

BACKGROUND/AIMS: The objective of this study was to determine whether insulin resistance is associated with gallbladder stone formation in Korean women based on menopausal status. METHODS: The study included 4,125 consecutive Korean subjects (30-79 years of age). Subjects who had a medical history of diabetes, hypertension, dyslipidemia, other cardiovascular disorders, or hormone replacement therapy were excluded. The women were subdivided into two groups according to their menopausal status. RESULTS: Analysis of premenopausal women showed no significant differences in the homeostasis model of assessment-insulin resistance (HOMA-IR) index between the two groups in terms of gallstone disease. The associations between the occurrence of gallbladder stones and age, obesity, abdominal obesity, hyperinsulinemia, and high HOMA-IR index were statistically significant in the analysis with postmenopausal women. In a multiple logistic regression analysis, low high density lipoprotein-cholesterol was an independent predictor of gallbladder stone formation in premenopausal women. However, the multiple logistic regression analysis also showed that age and HOMA-IR were significantly associated with gallbladder stone formation in postmenopausal women. In an additional analysis stratified by obesity, insulin resistance was a significant risk factor for gallbladder stone formation only in the abdominally obese premenopausal group. CONCLUSIONS: Insulin resistance may be associated with gallbladder stone formation in Korean postmenopausal women with abdominal obesity.