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This study was conducted to evaluate the effects of Bacillus licheniformis and combined herbs extracts on the physiological and immune characteristics, intestinal microbiota, and vibriosis resistance of sea cucumber Apostichopus japonicus. The sea cucumbers were fed with basal diets supplemented with B. licheniformis (B group), combined herbs extracts (C group), or both (BC group). The BC group exhibited the better growth performance and higher digestive and immune enzyme activities, whereas the lowest parameters appeared in the control group. This revealed that dietary B. licheniformis and combined herbs extracts in combination could improve digestion, food intake, phosphatase-responsiveness, and oxidation resistance more efficiently compared with the other groups. The BC group was also more capable of regulating intestinal flora balance of sea cucumbers by increasing the beneficial bacteria related to energy synthesis and metabolic conversion, and inhibiting the potential pathogens associated with organic damage and metabolic disorders. Furthermore, the BC group showed greater ability of improving disease resistance by reducing the cumulative mortality rates and the counts of Vibrio splendidus. These results collectively demonstrated that dietary B. licheniformis and combined herbs extracts could improve the physiological and immune parameters, optimize the microbial community, and enhance the resistance to vibriosis of sea cucumbers, and the health-promoting effects were more obvious by supplying them in combination. [ABSTRACT FROM AUTHOR]

In recent years, sea cucumber has become a favorite healthcare food due to its characteristic prevention of cardiovascular diseases, suppression of tumors, as well as enhancement of immunity. In order to screen the anti-tumoral proteins or peptides from sea cucumber (Apostichopus japonicus), its cDNA library was analyzed, and a disintegrin-like and metalloproteinase with thrombospondin type 1 motif, member 13 (ADAMTS13)-like was found. ADAMTS13-like contains 10 thrombospondin 1 (TSP1) domains. Based on analysis of bioinformatics, the third TSP1 domain of this protein, which is further named Aj-Tspin, contains an arginine-glycine-aspartate (RGD) motif. Since our previous studies showed that the recombinant RGD-containing peptide from lampreys showed anti-tumoral activity, the third TSP1 domain of ADAMTS13-like was chosen to evaluate it's effect on tumor proliferation and metastasis, despite the fact it shares almost no homologue with disintegrins from other species. After artificial synthesis, its cDNA sequence, Aj-Tspin, which is composed of 56 amino acids, was subcloned into a pET23b vector and expressed as a recombinant Aj-Tspin (rAj-Tspin) in a soluble form with a molecular weight of 6.976 kDa. Through affinity chromatography, rAj-Tspin was purified as a single protein. Both anti-proliferation and immunofluorescence assays showed that rAj-Tspin suppressed the proliferation of Lewis lung carcinoma (LLC) cells through apoptosis. Adhesion assay also displayed that rAj-Tspin inhibited the adhesion of LLC cells to ECM proteins, including fibronectin, laminin, vitronectin and collagen. Lastly, rAj-Tspin also suppressed the migration and invasion of LLC cells across the filter in transwells. Thus, the above indicates that rAj-Tspin might act as a potential anti-tumoral drug in the future and could also provide information on the nutritional value of sea cucumber. [ABSTRACT FROM AUTHOR]