Immunostimulating influence of herbal biomedicines on nonspecific immunity in Grouper Epinephelus tauvina juvenile against Vibrio harveyi infection

Abstract

Herbals such as Cynodon dactylon, Piper longum, Phyllanthus niruri, Tridax procumbens, and Zingiber officinalis were extracted with acetone, benzene, butanol, and petroleum ether and screened against the pathogen Vibrio harveyi isolated from the infected Grouper Epinephalus tauvina. Among the different solvent extractions screening to V. harveyi, petroleum ether extracts were suppressed significantly (P < 0.05). Equal proportions of the all-plant extracts were mixed with the artificial feeds at concentrations of 100, 200, 400, and 800 mg kg-1 of diet and fed to grouper juveniles of 20 × 2 g average weight for a period of 60 days. Every 20 days, fish juveniles were challenged with V. harveyi and the immune response was studied. The herbal diets significantly (P < 0.05) increased the survival, growth, and immune responses compared to the control group. The herbal diets were significantly improved (P < 0.01) in immune parameters such as phagocytic activity and albumin-globulin (A-G) ratio. Among the different concentrations of the herbals in the diet, the 400 mg kg-1 diet was the most effective in the experiment. © The Author(s) 2008.