Bioactives in Commonly Consumed Cereal Grains: Implications for Oxidative Stress and Inflammation.

Oxidative stress and inflammation are closely linked to various chronic diseases. Thus, targeting this axis of oxidative stress and inflammation is a particularly interesting area of study for reducing the risk of chronic diseases, including, but not limited to, metabolic disorders, cancer, cardiovascular disease, and Alzheimer's disease. It is well known that antioxidants play a pivotal role in tuning this axis. In this review, we introduce five different cereal grains, which are the most commonly consumed throughout the world and are functionally reported to have antioxidant activity: oat (Avena spp.), barley (Hordeum spp.), rice (Oryza spp.), wheat (Triticum spp.), and rye (Secale spp.). Bioactive components of these grains, partial grains or whole grains, have demonstrated antioxidant and anti-inflammatory activities in cells and animals. Although further study is required to establish their efficacy for treating patients with chronic diseases, we suggest that grains, which are a great source of antioxidants, have potential in the prevention of oxidative stress and inflammation-related chronic diseases.

Epigallocatechin gallate stimulates glucose uptake through the phosphatidylinositol 3-kinase-mediated pathway in L6 rat skeletal muscle cells.

The effect of epigallocatechin gallate (EGCG) on glucose uptake was studied in L6 rat skeletal muscle cells. Glucose uptake assay revealed that EGCG increased glucose uptake >70% compared to control. EGCG-stimulated glucose uptake was blocked by LY294002, an inhibitor of phosphatidylinositol (PI) 3-kinase, which is a major regulatory molecule in glucose uptake pathways. However, AMP-activated protein kinase (AMPK), which is another crucial mediator in independent glucose uptake pathways, did not inhibit EGCG-stimulated glucose uptake by SB203585, a specific inhibitor of the AMPK downstream mediator, p38 mitogen-activated protein kinase (MAPK). We also found that EGCG increased the phosphorylation level of protein kinase B and PI 3-kinase activity, when assessed by PI 3-kinase assay, whereas no increase in the phosphorylation level of AMPK and p38 MAPK was observed. Taken together, these results suggest that EGCG might stimulate glucose uptake, not AMPK-mediated but PI 3-kinase-mediated, in skeletal muscle cells, thereby contributing to glucose homeostasis.