Effects of Gum Arabic on Metabolic Syndrome Parameters in Postmenopausal Women

Overview

Gum Arabic ingestion has been proved to decrease some of the inflammatory markers in some metabolic diseases that have an inflammatory background. Nevertheless, the mechanism/s by which it does so is uncertain. This study is targeting one of the postulated molecular mechanisms at genetic level that may help to understand how Gum Arabic exerts its effect .The effects of GA on Nuclear Factor Kappa Beta, P38 Mitogen Activated Protein (MAP) Kinase levels, and on the expression of inflammatory cytokines genes are going to be assessed in postmenopausal females with Metabolic Syndrome.

The Metabolic syndrome (MetS) is a collection of several interconnected biochemical, clinical, and metabolic factors that directly increase the risk of atherosclerotic cardiovascular disease and Diabetes Mellitus. Hypertension, Dyslipidemia, insulin resistance, obesity, glucose intolerance, proinflammatory and prothrombotic states are the cornerstone features defining the syndrome. Glycerol, free fatty acids (FFA), tumor necrosis factor alpha (TNFα), interleukin 6 (IL6), interleukin 1(IL-1) and Interferon Gamma (INFγ) are some of the inflammatory substances (cytokines) that are released from different cells (monocytes and adipocytes) in MetS. Gum Arabic is found as a mixture of sodium, calcium and potassium salts of branched polysaccharides. In the colon, GA is fermented by colonic bacteria into short chain fatty acids such as butyrate, which are partially absorbed into blood. Butyrate treatment was found to inhibit expression of cytokine mRNAs in peripheral blood monocytes (PBMC) that are stimulated by bacterial lipopolysaccharide (LPS). In unstimulated (PBMC), a transcription factor (Nuclear Factor kappa β (NF-κB)) controls gene expression of some inflammatory cytokines; Tumor Necrosis Factor Alpha (TNF- α), IL-1 and IL-6. NF-κB was detected mainly in the cytoplasm tightly bound to an Inhibitory protein (IκB). When those cells are stimulated by bacterial lipopolysaccharide (LPS) or by adipokines, NFκB is activated and translocates to the nucleus to start gene expression of the inflammatory cytokines. Moreover; stimulation causes degradation of IκB which releases NFκB and allows its translocation to the nucleus. This nuclear translocation of NFκB was found to be inhibited by butyrate (a byproduct of Gum Arabic fermentation ) providing evidence that butyrate mediated reduction of proinflammatory cytokines was achieved by reducing NFκB activation. Consequently; the postulated mechanisms by which butyrate may regulate gene expression are through inhibition of NFκB activation and IκBα degradation. NFκB and the inflammatory cytokines: Target for therapy in inflammatory diseases, are they? As NFκB is involved in transcriptional regulation of many cytokines genes that contributes to immune and inflammatory responses, it may be a good target for therapy also. At present, treatment of inflammatory diseases depends greatly on aminosalicylates, corticosteroids, and immune-suppressants that decrease cytokines level especially TNF. The anti-inflammatory and immune-modulatory properties of gum Arabic, through butyrate, described previously may offer an interesting alternative therapeutic approach for inflammatory conditions.