Modified Rice Bran Arabinoxylan by Lentinus edodes Mycelial Enzyme as an Immunoceutical for Health and Aging—A Comprehensive Literature Review

Abstract

Rice bran arabinoxylan compound (RBAC) is derived from defatted rice bran enzymatically treated with Lentinus edodes mycelium. This review explores biologically active compounds and mechanisms of action that support RBAC as an immunomodulating nutraceutical in generally healthy and/or aging individuals. Thirty-seven (n = 37) primary research articles fulfilled the selection criteria for review. Most research is based on Biobran MGN-3, which consists of complex heteropolysaccharides with arabinoxylan as its primary structure while also containing galactan and glucan. RBAC was found to invoke immunological activities through direct absorption via the digestive tract and interaction with immune cells at the Peyer’s patches. RBAC was shown to promote innate defence by upregulating macrophage phagocytosis and enhancing natural killer cell activity while lowering oxidative stress. Through induction of dendritic cell maturation, RBAC also augments adaptive immunity by promoting T and B lymphocyte proliferation. RBAC acts as an immunomodulator by inhibiting mast cell degranulation during allergic reactions, attenuating inflammation, and downregulating angiogenesis by modulating cytokines and growth factors. RBAC has been shown to be a safe and effective nutraceutical for improving immune health, notably in aging individuals with reduced immune function. Human clinical trials with geriatric participants have demonstrated RBAC to have prophylactic benefits against viral infection and may improve their quality of life. Further research should explore RBAC’s bioavailability, pharmacodynamics, and pharmacokinetics of the complex heteropolysaccharides within. Translational research to assess RBAC as a nutraceutical for the aging population is still required, particularly in human studies with larger sample sizes and cohort studies with long follow-up periods.

Rice bran arabinoxylan compound as a natural product for cancer treatment – an evidence-based assessment of the effects and mechanisms

“…( 2019 ), and the lead author in another related publication (Ooi et al. 2023c ). Additionally, arabinoxylan from rice bran extracted through other methods, such as acid hydrolysis and bioconversion, also exhibited potent immunomodulatory effects on the non-specific immune responses, including NK cell activity (Ji et al.…”

“…A comprehensive review of the immunomodulatory effects of RBAC on other immune cells, such as monocytes and macrophages, neutrophils, and T and B lymphocytes, in healthy participants, cells, and animals can be found in a separate publication of the lead author (Ooi et al. 2023c ).…”

Recycling of wheat gluten wastewater: separation, characterisation, and solution rheology of arabinoxylans

“…Moreover, studies have investigated the extraction of AX from by-products of conventional raw materials, revealing that AX derived from wheat bran exhibits relatively low protein content and poor emulsification (Fan et al, 2023). Additionally, AX extracted from rice bran has shown promise as a dietary supplement for regulating intestinal flora in healthy adults (Ooi et al, 2023). Furthermore, efforts have been made to extract AX from sugarcane straw to enhance the economic value of by-products (Costa Joana et al, 2023).…”

Rice Bran Arabinoxylan Compound and Quality of Life (RBAC-QoL) of Cancer Patients: An Interim Analysis of the RBAC-QoL Study

“…Although the exact chemical composition of the immunologically active ingredient of RBAC remains unclear, research based on MGN-3 found RBAC to be a complex polysaccharide with arabinoxylan as its primary structure (36%) while also containing galactan and glucan [ 2 ]. In preclinical experiments with healthy cells and animals, RBAC was shown to promote innate immune defences by upregulating macrophage phagocytosis and enhancing natural killer cell activity while lowering oxidative stress through strong antioxidant capacity [ 2 ]. RBAC has also been reported to augment adaptive immunity by promoting T and B lymphocyte proliferation through the induction of dendritic cell maturation.…”

“…RBAC has also been reported to augment adaptive immunity by promoting T and B lymphocyte proliferation through the induction of dendritic cell maturation. Moreover, in other preclinical studies, RBAC inhibited mast cell degranulation during allergic reactions to lower inflammation and downregulated angiogenesis by modulating cytokines and growth factors [ 2 ].…”