Extract of Rhus verniciflua bark, its fraction, gallate compound isolated from the fraction and composition containing them for enhancing fish immunity, preventing and treating fish pathogenic bacteria-induced infection, or inhibiting the proliferation of fish pathogenic bacteria

摘要

A composition comprising the extract of Rhus verniciflua bark is provided to inhibit proliferation of fish pathogenic bacteria, and enhance fish immunity by increasing activity of lysozyme in blood, so that the composition is useful for prevention and treatment of fish pathogenic bacteria-induced infection. A composition for prevention and treatment of fish pathogenic bacteria-induced infection comprises the extract of Rhus verniciflua bark which is prepared by suspending Rhus verniciflua bark in distilled water and extracting the suspension of Rhus verniciflua bark with non-polar organic solvent selected from n-hexane, chloroform, ethylacetate and n-butanol, or methyl-3,4,5-trihydroxybenzoate represented by the formula(I) isolated from the Rhus verniciflua bark extract, wherein the fish pathogenic bacteria include Edwardsiella tarda, Vibrio anguillarum, Flexibacter maritimus and Photobacterium damselae subsp. piscicida.