Emerging science on whole grain intake and inflammation.

Although the biological mechanisms surrounding the widely reported association between whole grain (WG) consumption and reduced risk of several diseases are not fully understood, there is growing evidence suggesting that inflammation may be an essential mediator in this multifaceted process. It also appears that several mechanisms influence the modulatory actions of WGs on inflammation, including the effect of fiber, phytochemicals, and their microbial-derived metabolites. While some of these effects are direct, others involve gut microbiota, which transform important bioactive substances into more useful metabolites that moderate inflammatory signaling pathways. This review evaluates emerging evidence of the relationship between WGs and their effects on markers of subclinical inflammation, and highlights the role of fiber, unique WG phytochemicals, and gut microbiota on the anti-inflammatory effects of WG intake.

Avenanthramide Aglycones and Glucosides in Oat Bran: Chemical Profile, Levels in Commercial Oat Products, and Cytotoxicity to Human Colon Cancer Cells.

Avenanthramides (AVAs), unique phytochemicals in oat, have attracted an increasing amount of attention due to their outstanding health benefits. However, the chemical profile and the levels of AVAs in commercial oat products as well as their health benefits have not been examined in detail. In the present study, a total of 29 AVA aglycones and AVA glucosides were identified and characterized from oat bran using NMR (1D and 2D NMR) and LC-MS techniques. Among them, 17 novel AVA glucosides were reported in oat bran for the first time. The most abundant AVA glucoside, 2c-3'- O-glc, had a similar growth inhibitory activity with the major AVA, 2c, against HCT-116 and HT-29 human colon cancer cells, indicating glucosylation does not affect the growth inhibitory effects of AVAs. Furthermore, the levels of all individual AVAs in 13 commercial oat products were analyzed using HPLC-MS/MS. The total AVAs contents in various oat products ranged from 9.22 to 61.77 mg/kg (fresh weight).

Bioactive phytochemicals in barley.

Epidemiological studies have consistently shown that regular consumption of whole grain barley reduces the risk of developing chronic diseases. The presence of barley fiber, especially ß-glucan in whole grain barley, has been largely credited for these health benefits. However, it is now widely believed that the actions of the fiber component alone do not explain the observed health benefits associated with the consumption of whole grain barley. Whole grain barley also contains phytochemicals including phenolic acids, flavonoids, lignans, tocols, phytosterols, and folate. These phytochemicals exhibit strong antioxidant, antiproliferative, and cholesterol lowering abilities, which are potentially useful in lowering the risk of certain diseases. Therefore, the high concentration of phytochemicals in barley may be largely responsible for its health benefits. This paper reviews available information regarding barley phytochemicals and their potential to combat common nutrition-related diseases including cancer, cardiovascular disease, diabetes, and obesity.

Steroidal Saponins in Oat Bran.

Saponins are one type of widespread defense compound in the plant kingdom and have been exploited for the production of lead compounds with diverse pharmacological properties in drug discovery. Oats contain two unique steroidal saponins, avenacoside A, 1, and avenacoside B, 2. However, the chemical composition, the levels of these saponins in commercial oat products, and their health effects are still largely unknown. In this study, we directly purified 5 steroidal saponins (1-5) from a methanol extract of oat bran, characterized their structures by analyzing their MS and NMR spectra, and also tentatively identified 11 steroidal saponins (6-16) on the basis of their tandem mass spectra (MS(n), n = 2-3). Among the five purified saponins, 5 is a new compound and 4 is purified from oats for the first time. Using HPLC-MS techniques, a complete profile of oat steroidal saponins was determined, and the contents of the two primary steroidal saponins, 1 and 2, were quantitated in 15 different commercial oat products. The total levels of these two saponins vary from 49.6 to 443.0 mg/kg, and oat bran or oatmeal has higher levels of these two saponins than cold oat cereal. Furthermore, our results on the inhibitory effects of 1 and 2 against the growth of human colon cancer cells HCT-116 and HT-29 showed that both had weak activity, with 2 being more active than 1.