Estrogens in plants and emerging risks to human health.

Steroid estrogens (SEs) accumulate in agro-food systems through wastewater treatment and dairy manure, but very little is known about their potential impact on plants and dietary risk to human health. We conducted a meta-analysis to address key questions including, how plants respond to SEs under different environmental conditions, what is the accumulation potential of SEs in distinct plant families, and associated daily dietary intake risks to humans. Based on 517 endpoints, we revealed that various crop species show a heterogeneous response to SEs types (n = 140), SEs concentrations (n = 141), and exposure medium (n = 166). A subsidy-stress response was observed in terms of SEs accumulation for plant growth. The bioaccumulation of SE in plants was shown to be greatest in sand, followed by soil, and hydroponic media. Plants exposed to SEs exhibit considerable changes in physiological and biochemical characteristics. Surprisingly, food crops such as carrot and potato were found as major source of SEs daily intake in food chain but their consequences remains largely unknown. Further field-oriented research is needed to unveil the threshold levels for SEs in soil-plant systems as it may pose a global threat to human health. The state of knowledge presented here may guide towards urgently needed future investigations in this field for reducing the risk in SEs in agro-food systems.

Composition and safety analysis of Chinese traditional fermented soybean paste made by transgenic soybean.

The traditional Chinese soybean paste was produced by cooked transgenic soybean fermentation with the composition of moisture 53%, amino acid 0.84% (calculated by nitrogen), votive sugar 6.21% and total acid 1.66%. A number of microorganism species were isolated and identified, including fungi and bacteria, and the bacterium species Rhizopus oryzae Went and Prinsen Geerligs were dominant in transgenic soybean paste. The results showed that the transgenic soybean paste contain abundant amino acids and vitamins (vitamin A, 42.87 IU; vitamin B, 10.31 mg; vitamin B, 20.64 mg; nicotinamide, 2.54 mg; pantothenic acid, 0.63 mg; vitamin B, 6,847 microg; folic acid, 105 microg; vitamin B, 123.85 microg; and biotin, 56.34 microg). Pathogenic microorganisms were not be detected in the transgenic fermented soybean paste.

Effects of protein-bound polysaccharide isolated from pumpkin on insulin in diabetic rats.

To investigate hypoglycemic substances from pumpkin, protein-bound polysaccharide was isolated by activity-guided isolation from water soluble substances of the fruits. The protein-bound polysaccharide from pumpkin fruits (PBPP) was identified to consist mainly of polysaccharide (approximately 41.21%) and protein (approximately 10.13%) by anthrone test and Lowry-Folin test. Different doses of PBPP were evaluated for hypoglycemic activity and the effect on serum insulin levels in alloxan diabetic rats. The results indicated that PBPP can obviously increase the levels of serum insulin, reduce the blood glucose levels and improve tolerance of glucose. The hypoglycemic effect of big dose PBPP group (1000 mg/kg body weight) excelled that of small dose PBPP group (500 mg/kg body weight) and antidiabetic agent group. The results suggest that the hypoglycemic effect of PBPP depends on the dose and PBPP possesses the possibility of being developed from a new antidiabetic agent.