The antioxidant potency and the radical scavenging capacity of superoxide and peroxyl radicals were assessed for 13 hydrophilic knotwood extracts of commercially important wood species, or fractions thereof, as well as for five pure wood-derived lignans and the flavonoid taxifolin. The chemical composition of the knotwood extracts was determined by gas chromatography combined with mass spectrometry. Most of the investigated wood species were rich in hydrophilic extractives (10-20% of the dry wood) with one or a few compounds dominating in each extract. All extracts had a high antioxidative potency and/or radical scavenging capacity as compared to the well-known antioxidants Trolox and butylated hydroxyanisole. The pure wood-derived lignans and taxifolin also had a high antioxidative potency and/or radical scavenging capacity. However, the antioxidant potency and/or radical scavenging capacity of several of the hydrophilic knotwood extracts were higher than that of the dominating compounds in pure form.
Objective-Obesity is associated with endothelial dysfunction that may contribute to the development of atherosclerosis.We studied whether weight reduction improves endothelial function in overweight individuals. Methods and Results-Flow-mediated endothelium-dependent vasodilation of the brachial artery was measured in 67 adults (age: 46Ϯ7 years, body mass index: 35.2Ϯ5.4 kg/m 2 ) before and after a 6-week weight reduction program induced by very-low-calorie diet (daily energy: 580 kcal/2.3 MJ). Caloric restriction reduced body weight from 101Ϯ18 to 90Ϯ17 kg. Flow-mediated vasodilation increased from 5.5%Ϯ3.7 to 8.8%Ϯ3.7% (PϽ0.0001). Nitrate-mediated vasodilation was not significantly affected. The improvement in flow-mediated dilation was associated with the reduction in plasma glucose concentration (Pϭ0.0003). This relationship was independent of changes in weight, serum lipids, oxidized LDL, C-reactive protein, adiponectin, blood pressure, and insulin. Key Words: endothelium Ⅲ obesity Ⅲ risk factors Ⅲ glucose Ⅲ weight reduction T he vascular endothelium plays an important role in the regulation of arterial tone, thrombosis, and inflammation. Endothelial dysfunction may predispose arteries to the development of atherosclerotic lesions and is pathophysiologically linked to acute cardiovascular syndromes. 1 A common condition associated with endothelial dysfunction is obesity. Endothelial-dependent vascular responses to both agoniststimulated 2,3 and flow-mediated vasodilation 4 have been shown to be blunted in obese individuals. The mechanisms of obesity-induced endothelial dysfunction may be multifactorial, because excess adipose tissue induces several metabolic changes that may interfere with normal endothelial function. These may include dyslipidemia, elevated blood pressure, increased inflammation, oxidative stress, and changes in glucose metabolism. 5 Although weight reduction is known to reduce several of these risk factors for endothelial dysfunction, it is inadequately known whether endothelial function can be improved by reducing weight. We hypothesized that weight loss induced by very-low-calorie diet would enhance flow-mediated endothelium-dependent vasodilation in overweight adults. To gain insight for possible mechanisms of weight-loss-mediated changes in flow-mediated dilation, we also measured changes in several potential biochemical determinants of endothelial function. Conclusions-Weight Methods SubjectsWe recruited overweight (body mass index Ͼ27kg/m 2 ) men and women from an occupational health service clinic. The exclusion criteria included diabetes, pregnancy, gout, gall stone disease, alcohol/drug abuse, liver/kidney disorder, psychiatric disorder, and use of cholesterol lowering medication.Of the 74 subjects enrolled, 47 women and 20 men completed the 6-week program (9.5% dropout rate). Sixteen women were postmenopausal (2 using hormone replacement therapy), 19 subjects had treatment for hypertension, and there were 7 smokers and 13 ex-smokers. Most participants (65%) were sedentary, engag...
The potential for the extraction of the plant lignan hydroxymatairesinol (HMR) in large scale from Norway spruce (Picea abies) has given us the opportunity to study the metabolism and biological actions of HMR in animals. HMR, the most abundant single component of spruce lignans, was metabolized to enterolactone (ENL) as the major metabolite in rats after oral administration. The amounts of urinary ENL increased with the dose of HMR (from 3 to 50 mg/kg), and only minor amounts of unmetabolized HMR isomers and other lignans were found in urine. HMR (15 mg/kg body wt po) given for 51 days decreased the number of growing tumors and increased the proportion of regressing and stabilized tumors in the rat dimethylbenz[a]anthracene-induced mammary tumor model. HMR (50 mg/kg body wt) did not exert estrogenic or antiestrogenic activity in the uterine growth test in immature rats. HMR also showed no antiandrogenic responses in the growth of accessory sex glands in adult male rats. Neither ENL nor enterodiol showed estrogenic or antiestrogenic activity via a classical alpha- or beta-type estrogen receptor-mediated pathway in vitro at < 1.0 microM. HMR was an effective antioxidant in vitro.
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