A Critical Study of Dietary Administered Purified Β-Glucan of Edible Mushroom (Pleurotus Florida) Provides Immunostimulation and Protection in Broiler Experimentally Challenged with Virulent Newcastle Disease Virus

Abstract

Immunostimulants enhance the body’s resistance against various infections through increasing the oxidative activity of neutrophils, engulfment capacity of phagocytic cells and stimulating cytotoxic cells as necessary defence mechanisms. Many disorders could be treated using immunostimulants such as autoimmune diseases, viral infections and cancer (Shahbazi and Bolhassani, 2016). Several types of stimulants such as bacterial products, complex carbohydrates (e.g. glucans, schizophyllan, scleroglucan, lentinan, statolon, bestatin, acemannan), vaccines, immunoenhancing drugs (e.g. levamisole, isoprinosine, fluoro-quindone, avridine, polyribonucleotides), nutritional factors (e.g. vitamins, carotenoids, lipids, trace elements like selenium), animal extracts (e.g. chitosan from shrimp), cytokines (e.g. macrophage activating factor, interferon, interleukin-2, tumour necrosis factor) and plant extracts (e.g. Lectins, mitogens such as phytohaemagglutinin, concanavalin A) which have different mechanisms and functions (Galeotti, 1998). Immunostimulants activate different elements of the immune system in human and animals. They develop the non-specific immunotherapy and immunoprevention by stimulating the basic factors of the immune system including phagocytosis, properdin and complement systems, protective Secretory IgA antibodies, α- and γ-interferon release, T- and B-lymphocytes and synthesis of specific antibodies and cytokines. This also helps in the synthesis of pulmonary surfactant (Labh and Shakya, 2014).