Validation of soy isoflavone intake and its health effects: a review of the development of exposure biomarkers

BACKGROUND/OBJECTIVES@#It is difficult to consistently demonstrate the health effects of soy isoflavones owing to the multitude of factors contributing to their bioavailability. To accurately verify these health effects, dietary isoflavone intake should be measured using a biologically active dose rather than an intake dose. This concept has been expanded to the development of new exposure biomarkers in nutrition research. This review aims to provide an overview of the development of exposure biomarkers and suggest a novel research strategy for identifying the health effects of soy isoflavone intake.MATERIALS/METHODS: We cover recent studies on the health effects of soy isoflavones focusing on isoflavone metabolites as exposure biomarkers. @*RESULTS@#Compared to non-fermented soy foods, fermented soy foods cause an increased concentration of isoflavones in the biofluid immediately following ingestion. The correlation between exposure biomarkers in blood and urine and the food frequency questionnaire was slightly lower than that of corresponding 24-h dietary recalls. Urinary and blood isoflavone levels did not show a consistent association with chronic disease and cancer risk. @*CONCLUSION@#It is crucial to understand the variable bioavailabilities of soy isoflavones, which may affect evaluations of soy isoflavone intake in health and disease. Further studies on the development of valid exposure biomarkers are needed to thoroughly investigate the health effects of isoflavone.

Anti-inflammatory effects of Salvia plebeia R. Br extract in vitro and in ovalbumin-induced mouse model

BACKGROUND: Asthma is an increasing global health problem, and novel strategies to prevent or ameliorate the condition are needed. Here, the effects of 80 % ethanol extracts of Salvia plebeia R. Br. (SE) on an induced inflammatory response were investigated RESULTS: Salvia plebeia R. Br. inhibited production of pro-inflammatory cytokines, such as TNF-α and IL-6, as well as nitric oxide (NO) in LPS-stimulated RAW 264.7 cells. NO and pro-inflammatory cytokine production was suppressed more effectively by SE of the aerial parts (SE-A) than of the roots (SE-R) of S. plebeia. In BEAS-2B cells, both SE-A and SE-R inhibited the increase in production of the inflammatory cytokines IL-6 and IL-8. We also investigated the antiasthmatic effects of SE in an ovalbumin (OVA)-induced BALB/c mouse model. SE-A treatment significantly reduced the number of airway eosinophils, IL-4 and IL-13 levels, mucus production, and inflammatory infiltration, as compared with the corresponding levels in the untreated, OVA-induced mice, and had similar effects to dexamethasone CONCLUSIONS: Salvia plebeia ethanol extract ameliorated the induced inflammatory response in RAW 264.7 and BEAS-2B cells, with more effective inhibition noted for SE-A than for SE-R. SE-A treatment was effective in improving the histopathological changes in the lungs of asthma model mice via modulation of eosinophils and Th2 cytokines. These results suggest that SE-A can be considered as a therapeutic agent that can potentially relieve asthma

Effects of Panicum miliaceum L. extract on adipogenic transcription factors and fatty acid accumulation in 3T3-L1 adipocytes

The dietary intake of whole grains is known to reduce the incidence of chronic diseases such as obesity, diabetes, cardiovascular disease, and cancer. To investigate whether there are anti-adipogenic activities in various Korean cereals, we assessed water extracts of nine cereals. The results showed that treatment of 3T3-L1 adipocytes with Sorghum bicolor L. Moench, Setaria italica Beauvois, or Panicum miliaceum L. extract significantly inhibited adipocyte differentiation, as determined by measuring oil red-O staining, triglyceride accumulation, and glycerol 3-phosphate dehydrogenase activity. Among the nine cereals, P. miliaceum L. showed the highest anti-adipogenic activity. The effects of P. miliaceum L. on mRNA expression of peroxisome proliferator-activated receptor-gamma, sterol regulatory element-binding protein 1, and the CCAAT/enhancer binding protein-alpha were evaluated, revealing that the extract significantly decreased the expression of these genes in a dose-dependent manner. Moreover, P. miliaceum L. extract changed the ratio of monounsaturated fatty acids to saturated fatty acids in adipocytes, which is related to biological activity and cell characteristics. These results suggest that some cereals efficiently suppress adipogenesis in 3T3-L1 adipocytes. In particular, the effect of P. miliaceum L. on adipocyte differentiation is associated with the downregulation of adipogenic genes and fatty acid accumulation in adipocytes.

Hog millet (Panicum miliaceum L.)-supplemented diet ameliorates hyperlipidemia and hepatic lipid accumulation in C57BL/6J-ob/ob mice

Dietary intake of whole grains reduces the incidence of chronic diseases such as obesity, diabetes, cardiovascular disease, and cancer. In an earlier study, we showed that Panicum miliaceum L. extract (PME) exhibited the highest anti-lipogenic activity in 3T3-L1 cells among extracts of nine different cereal grains tested. In this study, we hypothesized that PME in the diet would lead to weight loss and augmentation of hyperlipidemia by regulating fatty acid metabolism. PME was fed to ob/ob mice at 0%, 0.5%, or 1% (w/w) for 4 weeks. After the experimental period, body weight changes, blood serum and lipid profiles, hepatic fatty acid metabolism-related gene expression, and white adipose tissue (WAT) fatty acid composition were determined. We found that the 1% PME diet, but not the 0.5%, effectively decreased body weight, liver weight, and blood triglyceride and total cholesterol levels (P < 0.05) compared to obese ob/ob mice on a normal diet. Hepatic lipogenic-related gene (PPARalpha, L-FABP, FAS, and SCD1) expression decreased, whereas lipolysis-related gene (CPT1) expression increased in animals fed the 1% PME diet (P < 0.05). Long chain fatty acid content and the ratio of C18:1/C18:0 fatty acids decreased significantly in adipose tissue of animals fed the 1% PME diet (P < 0.05). Serum inflammatory mediators also decreased significantly in animals fed the 1% PME diet compared to those of the ob/ob control group (P < 0.05). These results suggest that PME is useful in the chemoprevention or treatment of obesity and obesity-related disorders.