ABSTRACT
Lactic acid bacteria (LAB) have been recognized as safe microorganism that improve micro-flora disturbances and enhance immune response. A well-know traditional herbal medicine, Acanthopanax senticosus (As) was extensively utilized in aquaculture to improve growth performance and disease resistance. Particularly, the septicemia, skin wound and gastroenteritis caused by Aeromonas hydrophila threaten the health of aquatic animals and human. However, the effects of probiotic fermented with A. senticosus product on the immune regulation and pathogen prevention in fish remain unclear. Here, the aim of the present study was to elucidate whether the A. senticosus fermentation by Lactobacillus rhamnosus improve immune barrier function. The crucian carp were fed with basal diet supplemented with L. rhamnosus fermented A. senticosus cultures at 2 %, 4 %, 6 % and 8 % bacterial inoculum for 8 weeks. After trials, the weight gain rate (WGR), specific growth rate (SGR) were significantly increased, especially in LGG-6 group. The results confirmed that the level of the CAT, GSH-PX, SOD, lysozyme, and MDA was enhanced in fish received with probiotic fermented product. Moreover, the L. rhamnosus fermented A. senticosus cultures could trigger innate and adaptive immunity, including the up-regulation of the C3, C4, and IgM concentration. The results of qRT-PCR revealed that stronger mRNA transcription of IL-1ß, IL-10, IFN-γ, TNF-α, and MyD88 genes in the liver, spleen, kidney, intestine and gills tissues of fish treated with probiotic fermented with A. senticosus product. After infected with A. hydrophila, the survival rate of the LGG-2 (40 %), LGG-4 (50 %), LGG-6 (60 %), LGG-8 (50 %) groups was higher than the control group. Meanwhile, the pathological damage of the liver, spleen, head-kidney, and intestine tissues of probiotic fermentation-fed fish could be alleviated after pathogen infection. Therefore, the present work indicated that L. rhamnosus fermented A. senticosus could be regard as a potential intestine-target therapy strategy to protecting fish from pathogenic bacteria infection.
Subject(s)
Aeromonas hydrophila , Antioxidants , Carps , Eleutherococcus , Fermentation , Fish Diseases , Lacticaseibacillus rhamnosus , Probiotics , Animals , Lacticaseibacillus rhamnosus/metabolism , Carps/microbiology , Probiotics/pharmacology , Probiotics/administration & dosage , Antioxidants/metabolism , Fish Diseases/prevention & control , Fish Diseases/microbiology , Fish Diseases/immunology , Gram-Negative Bacterial Infections/veterinary , Gram-Negative Bacterial Infections/prevention & control , Gram-Negative Bacterial Infections/immunology , Animal Feed , Inflammation/prevention & control , Cytokines/metabolism , AquacultureABSTRACT
OBJECTIVE: To observe the effect of electroacupuncture (EA) pretreatment at "Quchi "(LI11) and "Xuehai "(SP10) on expression of interleukin (IL)-33, suppression of tumorigenicity 2 (ST2) and mast cell degranulation in sensitive area of skin tissue in rats with urticaria, so as to explore its mechanisms underlying prevention of urticaria. METHODS: A total of 32 male SD rats were randomly divided into blank control, model, EA preconditioning and medication groups, with 8 rats in each group. The urticaria model was established by topical injection of the prepared anti-ovalbumin serum (foreign serum, 0.1 mL/spot) along the bilateral sides of the spinal column on the back, followed by injection of mixture solution of ovalbumin, 0.5% evans blue and normal saline via the tail vein 48 h later. EA intervention (2 Hz/15 Hz, 1 mA) was applied to bilateral LI11 and SP10 for 20 min, once daily for 7 d before modeling.Back sensitization was started from the 5th day on. Rats of the medication group received gavage of loratadine, and those of the model group received gavage of the same volume of normal saline. The diameter of evans blue spots at the back skin tissue was measured; the histopathological changes of the blue spot tissues were observed by light microscope after H.E. staining. The state of degranulation of mast cells in the subcutaneous loose connective tissue was observed by using toluidine blue staining. Serum IgE and histamine contents were detected by ELISA, and the immunoactivity of IL-33 and ST2 in the skin and subcutaneous tissues of the sensitized spots (evans blue exudation spots) was observed by immunohistochemistry. RESULTS: Compared with the blank control group, the diameter of evans blue spot, degranulation rate of mast cells, serum IgE and histamine contents, and the immunoactivity of IL-33 and ST2 in the evans blue exudation spot tissues were significantly increased in the model group (P<0.01). In comparison with the model group, the increase of the above-mentioned indexes was reversed in both EA and medication groups (P<0.01ï¼P<0.05). No significant differences were found between the EA and medication groups in down-regulating the levels of the 6 indexes. H.E. staining of the blue spot tissues of rats in the model group showed incomplete structure of the epidermal layer of the skin, unclear interface of tissues, incomplete keratinization, chaotic epidermal cells, disorderly arrangement of fibers in the dermis, and infiltration of inflammatory cells and edema, which was relatively milder in the EA and medication groups. CONCLUSION: EA preconditioning can prevent urticaria (reduce size and sensitive reactions) in rats, which may be associated with its functions in lowering the level of IgE through inhibiting IL-33 and ST2.