The Health-Promoting Properties and Clinical Applications of Rice Bran Arabinoxylan Modified with Shiitake Mushroom Enzyme-A Narrative Review

Abstract

Rice bran arabinoxylan compound (RBAC) is derived from defatted rice bran hydrolyzed with Lentinus edodes mycelial enzyme. It has been marketed as a functional food and a nutraceutical with health-promoting properties. Some research has demonstrated this rice bran derivative to be a potent immunomodulator, which also possesses anti-inflammatory, antioxidant, and anti-angiogenic properties. To date, research on RBAC has predominantly focused on its immunomodulatory action and application as a complementary therapy for cancer. Nonetheless, the clinical applications of RBAC can extend beyond cancer therapy. This article is a narrative review of the research on the potential benefits of RBAC for cancer and other health conditions based on the available literature. RBAC research has shown it to be useful as a complementary treatment for cancer and human immunodeficiency virus infection. It can positively modulate serum glucose, lipid and protein metabolism in diabetic patients. Additionally, RBAC has been shown to ameliorate irritable bowel syndrome and protect against liver injury caused by hepatitis or nonalcoholic fatty liver disease. It can potentially ease symptoms in chronic fatigue syndrome and prevent the common cold. RBAC is safe to consume and has no known side effects at the typical dosage of 2-3 g/day. Nevertheless, further research in both basic studies and human clinical trials are required to investigate the clinical applications, mechanisms, and effects of RBAC.

Keywords: BioBran; MGN-3; complementary therapy; functional food; nutraceuticals; rice bran exo-biopolymer.

Figure 1

Schematic representation of rice before the milling process with the percentage of all its components and the main constituents. Reprinted under CC-BY 4.0 license from Fraterrigo Garofalo S., Tommasi T., & Fino, D. (2021). A short review of green extraction technologies for rice bran oil. Biomass Conv. Bioref., 11, 569–587.

Figure 2

The steps to produce rice bran arabinoxylan compound: (1) Preparation: Defatted rice bran is enzymatically treated and Lentinus edodes is prepared as a seed culture. (2) Bioconversion: Inoculation of L. edodes as a bioreactor to instigate fermentation. (3) Extraction: The arabinoxylan compound is extracted through heat processing, sterilization and drying.

Figure 3

Chemical structure of MGN-3/Biobran. Reprinted from Wheat and Rice in Disease Prevention and Health, 1st ed., M. H. Ghoneum, Chapter 31—Apoptosis and arabinoxylan rice bran, pp. 401–408, Copyright 2014, with permission from Elsevier.

Figure 4

A summary of the key health-promoting attributes of rice bran arabinoxylan compound.