EVALUATION OF IMMUNOSTIMULATORY PROPERTIES OF INDIGENOUS MEDICINAL PLANT ACHYRANTHES ASPERA IN LABEO ROHITA & CLARIAS BATRACHUS IN LABORATORY & POND CONDITIONS

Abstract

Aquaculture, the culture of aquatic organisms (viz., fish, mollusks, crabs, plants etc.) contributes immensely in world’s food basket. Aquacrops are excellent source of nutrients such as protein, lipid, amino acids, fatty acids, vitamins and minerals etc. for human consumption. Along with the food security and nutrition, aquaculture provides job opportunities in both developed and developing countries. The aquaculture industry employs more than 41 million people globally, the majority of them engaged in fish production in underdeveloped nations. Various bacteria, fungi, viruses and parasites cause diseases at larval stages of fish. Each year, larval mortality cause economic loss to aquaculture sector. Various antibiotics, vaccines and immunostimulants are used to prevent infections in fishes. The use of antibiotics and chemicals are unsustainable because they can cause negative impact on consumers and are threat to aquatic ecosystem. Immunostimulants are a group of natural and synthetic compounds that increase the non-specific cellular and humoral defense responses. Immunostimulation through medicinal plants is a natural, safe, sustainable and eco-friendly approach to enhance the fish immunity. The present investigation evaluates the immunostimulatory and disease resistant properties of Achyranthes aspera (prickly chaff flower) leaves and seeds incorporated diets on the performance of rohu Labeo rohita and magur Clarias batrachus. The experiments were conducted in aquaria under laboratory conditions and in hapas under field conditions. Fishes were fed with test diets containing leaves and seeds of A. aspera and control diet without any supplementation of plant ingredients. Fishes were either challenged with virulent Aeromonas hydrophila or with UV-B radiation or immunized with c-RBC after feeding with test diets. The survival rate, growth of fish, non-specific immune enzymes such as myeloperoxidase, nitric oxide synthase, lysozyme and hemagglutination titer levels were significantly (P<0.05) higher in 0.5% seeds supplemented diet fed fishes compared to the fishes fed with other diets. The oxidative stress indicators such as thiobarbituric acid reactive substances, carbonyl protein levels were significantly (P<0.05) lower in the enriched diets fed fishes. The anti-oxidant enzyme, superoxide dismutase was significantly (P<0.05) higher in 0.5% seeds supplemented diet fed fishes. Various immunological and stress related genes, viz. lysozyme-C, lysozyme-G, interleukin (IL-10), toll-like receptor-4 (TLR-4), tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), nuclear factor-kB (NF-kB), bcl-2-associated X protein (BAX), cytochrome complex (cytochrome-c), superoxide dismutase-c (SOD C), caspase-3, caspase-9, B-cell lymphoma 2 (BCL-2) were evaluated. The presence of various amino acids, fatty acids, vitamins and minerals in seeds and leaves of A. aspera enhanced the growth of fishes and improved their physiological conditions. The plant is growing in the tropical climatic conditions and therefore, easily available. The application of A. aspera as a immunostimulant of fishes is cost-effective.