Chemical characterization and immunostimulatory activity of phenolic acid bound arabinoxylans derived from foxtail and barnyard millets

Abstract

The chemical characterization and evaluation of immunostimulating effect of phenolic acid bound arabinoxylan (PA-AXs) isolated from barnyard (PA-AX-B) and foxtail (PA-AX-F) millets were performed. The sugar composition analysis and bound phenolic acids' (caffeic acid, p-coumaric acid, and ferulic acid) content of PA-AXs were examined by gas chromatography and mass spectroscopy (GC-MS) and high performance liquid chromatography (HPLC), respectively. The immunostimulatory activity of PA-AXs was evaluated by studying the effect of PA-AXs on the release of nitric oxide (NO), ROS, and cytokine (TNF-α, IL-1β, and IL-6) in RAW 264.7 murine macrophage cells. The GC-MS results revealed the xylose: arabinose ratio of PA-AX-F and PA-AX-B as 1.96:1.0 and 1.64:1.0, respectively. In HPLC analysis, PA-AX-B showed higher phenolic acid content than PA-AX-F. In RAW 264.7 cells, immunostimulatory activity was established by its increased release of NO, ROS, and cytokine (TNF-α, IL-1β, and IL-6) in a dose-dependent manner. Both PA-AX-B and PA-AX-F exhibited significant immunostimulation in in vitro studies. Practical applicationsMillets are known for the higher content of phenolic acid bound arabinoxylans (PA-AX). The composition of PA-AX varies with different types of millets. In general, rice bran and wheat arabinoxylans are well reported to have significant immunostimulatory and antitumor properties. The bound ferulic acid with arabinoxylan isolated from finger millet bran also possesses immunostimulatory property. As the millets grains, foxtail and barnyard are also rich in PA-AXs, the present study was focused to evaluate the immunostimulatory property of PA-AX derived from two different millets. The study results indicated the immune stimulatory action of millet PA-AX's and thus the purified PA-AX can be explored further to identify the mechanism of action with respect to its immune stimulation property. K E Y W O R D S barnyard millet, foxtail millet, immunostimulatory activity, phenolic acid bound arabinoxylans (PA-AXs), RAW 264.7 cells From the above study, PA-AXs isolated from barnyard and foxtail millets were chemically characterized and unveiled no toxicity with better immunostimulation in in vitro studies by increasing the NO, ROS, and cytokine production in RAW 264.7 murine macrophage cells with increasing doses. Further, in vivo studies are requisite to confirm its immunostimulating activity and its mechanism of action. How to cite this article: Srinivasan A, Ekambaram SP, Perumal SS, Aruldhas J, Erusappan T. Chemical characterization and immunostimulatory activity of phenolic acid bound arabinoxylans derived from foxtail and barnyard millets. J Food Biochem. 2020;44:e13116. https ://doi.

Antioxidant, Immunostimulatory, and Anticancer Properties of Hydrolyzed Wheat Bran Mediated through Macrophages Stimulation

“…Among soluble polysaccharides, WB arabinoxylans can induce the production of nitric oxide (NO) in a dose-dependent manner, as well as the production of MCP-1, TNF-α, and IL-6 on RAW264.7 macrophages via the NF-κB signalling pathway [ 13 ]. Similar results were reported when RAW264.7 cells were treated with phenolic acid bound arabinoxylans isolated from two different varieties of millets [ 28 ]. Smaller molecules, such as xylooligosaccharides, also induce the release of TNF-α, IL-1β, IL-6, and NO production in unstimulated RAW264.7 cells [ 29 ].…”

Phenolic acid bound arabinoxylans extracted from Little and Kodo millets modulate immune system mediators and pathways in RAW 264.7 cells

“…The present study is a continuation of our previous study from our laboratory on the evaluation of immunostimulating effect of phenolic acid bound arabinoxylan derived from barnyard (PA‐AX‐B) and foxtail (PA‐AX‐F) millets (Srinivasan et al., 2020). On comparing the results of the previous study, among the four millets the release of NO, ROS, and cytokines from PCA‐AX‐L–treated cells was significantly higher when compared to other PCA‐AXs like PCA‐AX‐K, barnyard (PA‐AX‐B) and foxtail (PA‐AX‐F) millets.…”

“…Further stimulation followed by binding with pattern recognition receptors (PRRs) on the surface of the activated macrophage (Toll‐like receptors (TLRs), Dectin‐1, and complement receptor type 3 (CR3)) includes initiation of signal transduction pathways (phosphoinositide‐3‐kinase (PI3K)/ protein kinase‐B (Akt) & mitogen‐activated protein kinases (MAPKs)) and activation of transcription factors (nuclear factor (NF)‐κB & activator protein (AP)‐1) (Lee & Hing, 2011; Ren et al., 2012). Earlier, we reported the immunostimulant effect of foxtail and barnyard millet in RAW 264.7 cells by in vitro assays (Srinivasan et al., 2020). The aim of the present study is to explore the phenolics bound arabinoxylan of little and kodo millet varieties for its immunomodulating effects.…”

Nutritional Properties, Nutraceutical Potential of Different Millets, and Their Value-Added Food Products

“…Barnyard millet is useful in the treatment of biliousness and constipation [25,26] and allergic diseases such as atopic dermatitis [27]. It is best in lowering blood glucose and lipid levels therefore can be potentially recommended for patients with cardiovascular disease and diabetes mellitus [22].…”