Comparison of Different Dietary Fatty Acids Supplement on the Immune Response of Hybrid Grouper (Epinephelus fuscoguttatus × Epinephelus lanceolatus) Challenged with Vibrio vulnificus.

Aquaculture has been expanding in Malaysia due to the increased demand for fish products. In addition, aquaculture faces challenges in maintaining feed suitability in support of the global growth of fish production. Therefore, improvements in diet formulation are necessary to achieve the optimal requirements and attain a desirable growth efficiency and health performance in fish. Seven weeks of study were conducted to compare the equal amounts of different fatty acids (2%) (oleic acid, stearic acid, palmitic acid, and behenic acid) on the survival, the growth, and the immune response of hybrid grouper (Epinephelus fuscoguttatus × Epinephelus lanceolatus) against V. vulnificus. After six weeks of the feeding trial, fish were challenged with V. vulnificus for 30 min before continuing on the same feeding regime for the next seven days (post-bacterial challenge). Fish supplemented with dietary oleic acid showed significantly (p < 0.05) enhanced immune responses, i.e., lysozyme, respiratory burst, and phagocytic activities compared to the control diet group for both pre-and post-bacterial challenges. Following the Vibrio challenge, no significant effects of supplemented fatty acid diets on survival rate were observed, although dietary oleic acid demonstrated the highest 63.3% survival rate compared to only 43.3% of the control diet group. In addition, there were no significant effects (p > 0.05) on specific growth rate (SGR), white blood cell (WBC), and red blood cell (RBC) counts among all experimental diets. The results from this study suggest that among the tested dietary fatty acids, the oleic acid diet showed promising results in the form of elevated immune responses and increased disease resistance of the hybrid grouper fingerlings challenged with V. vulnificus.

LC-qTOF-MS analysis of fish immune organs reveals the distribution of amino acids in response to metabolic adaptation of the survival phenotype in grouper against Vibrio infection.

Epinephelus fuscoguttatus is economically crucial to various Southeast Asia countries where they are reared in fish farms to meet the demand for supply. However, a systemic infectious disease known as vibriosis has steadily and extensively affected the fish farming industry. The disease is caused by Vibrio spp., which are pathogenic gram-negative bacteria. This study focused on understanding the host's metabolic adaptation against Vibrio vulnificus infection, which features a survival phenotype, by profiling the metabolites in grouper fingerlings that survived the experimental infection. Mapping of the pathways is crucial to explain the roles of metabolites in fish immunity. A solvent extraction method was used on the grouper's immune organs (gills, liver and spleen) prior to Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry (LC-qTOF-MS) analysis. The metabolites identified in fingerlings that survived experimental infections were mostly amino acids (primary metabolites). Glutamine (0.44%), alanine (0.68%), phenylalanine (2.63%) and tyrosine (2.60%) were highly abundant in survived-infected gills. Aspartic acid (13.57%) and leucine (4.01%) were highly abundant in the livers of the survived-infected fish and lysine was highly abundant in both gills (2.94%) and liver (3.64%) of the survived-infected fish. Subsequent bioinformatics analysis revealed the involvement of the identified functional amino acids in various immune-related pathways. The current findings facilitate the comprehension of the metabolic adaptation of grouper fingerlings that exhibited a survival phenotype against Vibrio infection. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03269-1.

Protective effect of apple mangrove Sonneratia caseolaris extract in Edwardsiella tarda-infected African catfish, Clarias gariepinus.

Outbreaks of edwardsiellosis have severe impact on the aquaculture production of African catfish Clarias gariepinus. In this study, feed supplemented with apple mangrove Sonneratia caseolaris extract was evaluated for its protective effect against Edwardsiella tarda infection in African catfish. Results showed an increase in growth performance and higher survival rate in the treatment groups in a dose dependent manner. Haematological analyses showed an increase in white blood cell count in the treatment groups. Histopathological analysis revealed degenerative changes and regeneration of liver tissue architecture in both the control and treatment groups. However, the presence of inflammatory cells was found exclusively in the kidney of T3 treatment group that was supplemented with the highest dose of extract at 3.17 mg/ml, which inferred the activation of immune response in the fish. Contrast to the deteriorative alteration observed in the kidney of the control group due to E. tarda infection, treatment group exhibited tissue regeneration and well-defined kidney tissue architecture at 3 dpi. Taken together, these results demonstrated that supplementation with the methanol extract of S. caseolaris possesses protective effect in African catfish against the infection of E. tarda.

The antioxidant effect of Beackea frutescence microemulsions dietary supplements on skin absorption studies.

Objective: To study the effect of two different microemulsions containing Beackea frutescence supplements composed of nerolidool, selenium and vitamin E on absorption effect related to skin health and skin aging. Materials and methods: A total of 39 volunteers with normal and healthy skin were divided into three groups (n = 13) and supplemented for a period of 12 weeks. Group 1 received a mixture of lutein (3 mg/day), lycopene (3 mg/day), α-tocopherol (10 mg/day), selenium (75 µg/day) and ß-nerolidool (4.8 mg/day) and Group 2 was supplemented with a mixture of ß-nerolidool (4.8 mg/day), lycopene (6 mg/day), selenium (75 µg/day) and α-tocopherol (10 mg/day). Group 3 was the placebo control. Wrinkling, smoothness, scaling and roughness of the skin were determined by Surface Evaluation of Living Skin (Visioscan). Results: Upon supplementation, serum levels of selected nerolidool increased in both groups. Skin thickness and density were determined by ultrasound measurements. A significant increase for both parameters was determined in the serum groups. Roughness and scaling were improved by the supplementation with antioxidant micronutrients. In the placebo group, no changes were found for any of the parameters. Conclusion:Beackeafrutescence microemulsion supplements have shown significant change in the texture of human skin as well as scaling, wrinkling, smoothness and roughness were improved by the supplementation.