title: Evaluation of the antibacterial activity of leaf and twig extracts of stout camphor tree, Cinnamomum kanehirae, and the effects on immunity and disease resistance of white shrimp, Litopenaeus vannamei.
abstract: Effects of essential oils and hot-water extracts isolated from leaf and twig of stout camphor tree, Cinnamomum kanehirae on antibacterial activity to pathogen of fish, abalone, marine fish and freshwater prawn, and the white shrimp, Litopenaeus vannamei immunity and disease resistance to Vibrio alginolyticus were carried out in this study. A better antibacterial activity against nine selected pathogen bacteria was recorded in twig essential oil, and the selected pathogens of both Gram-positive bacteria and Gram-negative bacteria were sensitive to the leaf and twig essential oils in the present study. No antibacterial activity was recorded in the hot-water extracts of leaf and twig. In challenge trial, a significant decrease of sensitivity to V. alginolyticus (1 x 10(6) cfu shrimp(-1)) was found in that of shrimp received hot-water extract from twig at the levels of 2 microg g shrimp(-1) compared to control. In addition, the how-water extract of twig in vitro showed greater enhanced effects on phenoloxidase activity, respiratory burst and phagocytosis of white shrimp compared to the hot-water extract of leaf. It is considered that the extracts of stout camphor tree could be a candidate to replace the chemo-therapeutants through the inhibitory effects against the growth of pathogens, and enhanced effects on shrimp immunity and disease resistance.
authors.affiliation: Division of Wood Cellulose, Taiwan Forestry Research Institute, Taipei, Taiwan, ROC.
authors.forename: Ruo-Yun
authors.initials: RY
authors.lastname: Yeh
authors.forename: Ya-Li
authors.initials: YL
authors.lastname: Shiu
authors.forename: Shu-Chiu
authors.initials: SC
authors.lastname: Shei
authors.forename: Sheng-Chi
authors.initials: SC
authors.lastname: Cheng
authors.forename: Sung-Yan
authors.initials: SY
authors.lastname: Huang
authors.forename: Jiunn-Cheng
authors.initials: JC
authors.lastname: Lin
authors.forename: Chun-Hung
authors.initials: CH
authors.lastname: Liu
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D027424:Cinnamomum / Q000737:chemistry*; D007113:Immunity, Innate / Q000187:drug effects*; D014442:Monophenol Monooxygenase; D033561:Penaeidae / Q000187:drug effects / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry*; D016897:Respiratory Burst / Q000276:immunology; D044149:Vibrio alginolyticus / Q000276:immunology
chemical_list: D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D014442:Monophenol Monooxygenase