Determination And Preliminary Intake Assessment Of Phytoestrogens In Food

Phytoestrogens is a class of aromatic sterols distributing in plants widely. They and their metabolites can bind to estrogen receptors in mammals, and play a similar role of the endogenous estrogen. But at the same time, it can also play an anti-estrogen effect which depends on the concentration of endogenous estrogen. Because of the unique estrogen-like effect, much of reserch about their physiological functions had been done in domestic and foreign countries, such as anti-oxidant, anti-aging, anti-cancer and so on. And markets had started to sell the health care products of them. However, the dose of effective and the negative effects hadn't cleared.In order to assess the effect of the phytoestrogens on the human health for further. First, we established the detection methods of phytoestrogens in food, assessed phytoestrogens content of the daily food, improved the phytoestrogens content database of the food. Second, we established the detection method of the blood and tissue, evaluated the intake of the phytoestrogen in mice, by feeding the diets with different of phytoestrogen content.The main results as follows:1 The detection methodEstablished the extraction conditions and LC-MS detection methods for 6 common phytoestrogens in the daily food and for 10 in the plsma and tissue. A better linear, a better intra-day and inter-day precision, and a higher recovery had been got in the detection conditions for each phytoestrogen, and can be used for detection in food, plsma and tissue.2 The content assessment of the phytoestrogens in foodChose four categories in daily foods:vegetables, fruits, grains, beans and been-products, with a total of more than 100 samples for detection. The result showed that all the samples contained the phytoestrogens, with a total concentration range of 0.1308μg/g～90.0168μg/g. And quercetin had the widest distribution and a higher content value. 3 The intake assessment of the phytoestrogen in miceWhen the proportion of normal feed reched 75% in whole feed, the mice kept in a good physical state. Howere, when the proportion of the normal feed was 0%, any phytoestrogens couldn't been detected in plsma and tissue. At the same time, both the body weight and the anogenital distance of the mice were smaller than the normal mice, and the appearance time of secondary sexual characteristics were delayed.After the metabolism, the phytoestrogens were monitored in the plasma and all the organizations detected in the mice which fed with the diet contained the normal feeds. The main form of the phytoestrogens in the plasma was the combined, and the form was various in organizations. Adrenal had the highest content in the all of the detected tissues.The long-term accumulation in the body was much lower than the long-term intake of the phytoestrogens in mice. There was some sort of automatic adjustment mechanism, which can keep the phytoestrogen in a stable value in body when intake a certain content.