Immune Modulation of Aloe vera: Acemannan and Gut Microbiota Modulator

Abstract

Carbohydrate-based immune adjuvants are capable of enhancing the vaccine against various infectious disease. Several natural polysaccharides originating from plants and microbes have been tested for their adjuvant potential. Adjuvant potential of plant polysaccharides mainly depends upon their solubility, molecular weight, degree of branching and the conformation of carbohydrate structural backbone. Aloe polysaccharide or acemannan as an adjuvant may interact and activate various toll-like receptors and inflammasomes, involving several innate immune system players in the ensuing immune response. Aloe polysaccharide or acemannan plays critical roles in immune system function and has strong safety and torelability records and is readily biodegradable. Antigen dependent adjuvant properties of acemannan were evaluated to both newcastle disease virus and infectious bursal disease virus in day-old broiler chicks. Acemannan enhanced the immune response to both viruses. And a pilot study of the effect of acemannan in cats infected with feline immunodeficiency virus (FIV) demonstrated that acemannan therapy may be of significant benefit in FIV-infected cats exhibiting clinical signs of disease. Recent technology to study the gut microbiota have defined new milestones for understanding the microbial ecology of the gastrointestinal ecosystem and assessing how the microbial world within us impacts our everyday life. A nobel immune-enhancing polysaccharides and an importance of gut microbiota inducing gut immunity are discussed on the basis to apply the Aloe vera for dietary supplement. In the present review, the following topics are summarized. Introduction: immune modulation and its importance for health and disease, immune modulation of plant sterols and polyphenols in Aloe vera gel, known aloe’s immune efficacy; Immune adjuvant of Aloe vera: general properties, Aloe vera gel: role of biological vehicle in drug delivery system, Aloe vera gel: role of an immune adjuvant; Immunomodulation of acemannan: acemannan properties, immunomodulation of acemannan and modified acemannan; Acemannan as an immune adjuvant: biological properties, acemannan as an immunomodulator in cats and chickens; Aloe sterols responsible for immunomodulator; Gut microbiota: importance of microbiota for health and disease, aloe’s putative efficacy based on the modulation of gut microbiota status. Section of conclusion and future perspectives focuses on biological characteristics of acemannan, and an importance of diet and host-microbial crosstalk to ensure maintenance of homeostasis.