Effects of dietary soybean lecithin on growth performance, blood chemistry and immunity in juvenile stellate sturgeon (Acipenser stellatus).

An eleven weeks feeding trial was conducted to determine the effects of different levels of dietary soybean lecithin (SBL) on growth performance, blood chemistry and immunity in juvenile stellate sturgeon (Acipenser stellatus). Fish were fed seven isoproteic (44% crude protein) and isolipidic (17% crude fat) diets containing graded levels of SBL: 0 (control), 1, 2, 4, 6, 8 and 10%. Results showed that dietary SBL supplementation significantly improved the final body weight (BW) and weight gain (WG). Fish fed 6% SBL showed the highest BW and WG values in comparison to fish fed the control diet (P < 0.05), whereas increasing SBL levels above 6% had little practical benefit in terms of somatic growth performance. The inclusion of SBL in diets significantly improved the immune response as data from lysozyme, total Ig levels, alternative complement, phagocytic and bactericidal activities indicated (P < 0.05). The broken-line regression analysis of immunological variable revealed that depending on the parameter considered, the optimal SBL levels in diets for stellate sturgeon juveniles varied. In particular, dietary SBL levels requirements in stellate sturgeon when considering the phagocytic activity rate were determined at 3.3%, whereas 4.1-4.2% were recommended when considering data from lysozyme, alternative complement and bactericidal activities. In contrast, the highest minimum dietary SBL content was estimated at 6.9% when data from total Ig levels were considered. These results indicated that dietary PLs are required for boosting innate immunity in stellate sturgeon, although their minimal level changed depending on the immunological parameter considered. Therefore, we assume that SBL levels comprised between 3.3 and 6.9% may be used as a prophylactic measure to improve the health status in stellate sturgeon. Red blood cell count, hemoglobin and hematocrit levels increased with increasing dietary SBL levels, especially in those sturgeons fed the diet with 6% SBL (P < 0.05). In addition, white blood cell counts significantly increased as dietary SBL levels increased from 4 to 8% in comparison to the control group. Blood biochemistry was also affected by different dietary SBL levels. In particular, significantly higher levels of glucose, cholesterol, HDL and triglycerides were detected in fish fed >6%, >4%, >2% and 2% SBL, respectively (P < 0.05). Based on somatic growth parameters, blood chemistry and systemic immunity parameters, diets containing ca. 6% SBL are recommended for juvenile stellate sturgeon.

Combined Extract of Heated 4T1 and a Heat-Killed Preparation of Lactobacillus Casei in a Mouse Model of Breast Cancer.

BACKGROUND: The adjuvanticity potential of Lactobacillus casei was first suggested in an old survey. The present study was designed to investigate the efficacy of a new immunotherapy against breast cancer made by mixing an extract of heated 4T1 mammary carcinoma cell line and a heat-killed preparation of Lactobacillus casei. METHODS: Female BALB/c mice (6-8 weeks old, n=40) were challenged subcutaneously in the right flanks with 4T1 cells. When all the animals developed a palpable tumor, they were allocated to 4 equal groups and immunotherapy was initiated. The tumor-bearing mice in the experimental groups received the extract of heated 4T1 or heated Lactobacillus casei and/or a combination of both, twice at a 1-week interval. The mice in the control group received phosphate-buffered saline. One week after the last immunotherapy, one half of the mice were euthanized to determine the immune response profile. The remaining animals were kept until death occurred spontaneously. RESULTS: The animals receiving the combined treatment significantly showed more favorable survival curves and slower rates of tumor development than the tumor-bearing mice receiving only the heated 4T1 and/or the negative control mice. The combined immunization significantly amplified the production of nitric oxide and the cytotoxicity of natural killer cells in the spleen cell culture of the tumor-bearing mice. Moreover, the combined immunotherapy significantly increased the secretion of IFN-γ and conversely diminished the secretion of IL-4 and TGF-ß in the splenocyte population compared to the splenocytes from the other groups. CONCLUSION: The combined immunotherapy with heated 4T1 cells and heated Lactobacillus casei conferred beneficial outcomes in our mouse model of breast cancer.