β-glucan modulates non-specific immune gene expression, thermal tolerance and elicits disease resistance in endangered Tor putitora fry challenged with Aeromonas salmonicida

Expression of genes encoding non-specific immunity, anti-oxidative status and aquaporins in β-glucan-fed golden mahseer (Tor putitora) juveniles under ammonia stress

“…In the current study, β-glucan administration had no significant effect on the weight gain (%) of golden mahseer juveniles. Our findings are in line with earlier studies on mahseer, grass carp, sea bass, and Nile tilapia, where glucan supplementation had little to no effect on growth performance [ 21 , [28] , [29] , [30] , [31] ]. The administration of β-glucan, on the other hand, has been shown to enhance growth in a few other species [32] , [33] , [34] , [35] .…”

“…Real-time qPCR was conducted using the synthesized cDNA as a template. The relative expression levels of targeted genes namely catalase ( cat ), superoxide dismutase ( sod ), glutathione-s-transferase ( gst ), inducible nitric oxide synthase ( inos ), toll-like receptor 4 ( tlr4 ), toll-like receptor 5 ( tlr5 ), interleukin-1β ( il-1β ), complement factor 3 ( c3 ), immunoglobulin light chain ( igl ), major histocompatibility complex 1 (mch1), and aquaporins ( aqp namely aquaporins 1a: aqp1a ; aquaporins 3a: aqp3a; and aquaporins 3b: aqp3b ) were evaluated in a qPCR machine (Applied Biosystem, USA) using SYBRPremix Ex TaqII (Takara, USA) and gene-specific primers (designed according to the method described by Thornton and Basu [25] , using Primer 3.0 ( http://primer3.ut.ee/ ) software, Table 2 ) under standardized reaction conditions [21] . Then, utilizing 18S ribosomal RNA (18 s) as the reference gene, the relative expression (fold-change) of the various genes was assessed using Pfaffl's [26] mathematical model.…”

“…For instance, oral administration of feed supplements such as cineole [6] , taurine [ 5 , 16 ], inositol [17] , seaweeds and herbal extracts [ 1 , 18 , 19 ] were demonstrated to alleviate the adverse effects of ammonia stress in aquaculture species. β-Glucan is one of the promising immunostimulants used in aquaculture considering its immuno-stimulatory, anti-inflammatory, and anti-oxidant properties [ 20 , 21 ]. Recently, prolonged dietary intake of β-glucan has been proposed to mitigate the detrimental effects of stress and shown to improve the welfare of fish exposed to different stressors [ 22 , 23 ].…”

Supplementation of Dietary Crude Lentinan Improves the Intestinal Microbiota and Immune Barrier in Rainbow Trout (Oncorhynchus mykiss) Infected by Infectious Hematopoietic Necrosis Virus

“…The defense responses through the use of immunostimulants could be efficient to suppress the viral infection in fish to an extent ( 29 , 30 ). Numerous studies reported that β-glucan could enhance the resistance to bacterial infection in fish like Yersinia ruckeri , Flavobacterium columnare , Aeromonas salmonicida , and A. hydrophila ( 29 , 31 , 32 ). Its resistance to viral diseases has also been reported such as grass carp hemorrhage virus, viral hemorrhagic septicemia virus, and nervous necrosis virus ( 33 ; 30 , 34 ).…”

Effects of dietary chito-oligosaccharide and β-glucan on the water quality and gut microbiota, intestinal morphology, immune response, and meat quality of Chinese soft-shell turtle (Pelodiscus sinensis)

“…Jia et al found that COS can inhibit the growth of Pseudomonas, Aeromonas, and Shewanella in silver carp fillets, improving their meat quality during cold storage (11). Another agent that has been used as an immunomodulator and antioxidant in the aquaculture industry is b-glucan, a type of complex polysaccharide (12,13). In recent studies, both COS and b-glucan were tested as substitutes for infeed antibiotics and were found to modulate the gut microbiome and immune responses, thereby improving gastrointestinal conditions and growth performance (14).…”