title: Melaleuca alternifolia essential oil enhances the non-specific immune system and prevents oxidative damage in Rhamdia quelen experimentally infected by Aeromonas hydrophila: Effects on cholinergic and purinergic systems in liver tissue.
abstract: The aim of this study was to evaluate the effects of M. alternifolia essential oil used to treat silver catfish (Rhamdia quelen) experimentally infected by Aeromonas hydrophila on oxidative stress variables, and for the first time, on hepatic enzymes of the cholinergic and adenosinergic systems. For that, fish were divided into six groups (A-F), each containing seven animals. Groups A, B and C were composed of uninfected animals, while animals in groups D, E and F were intramuscularly inoculated with A. hydrophila. Groups B and E received a prophylactic bath with M. alternifolia essential oil (50 μL/L, diluted in ethanol) for seven days, while groups C and F were exposed to ethanol. After the prophylactic baths, groups D, E and F were inoculated with 100 μL of A. hydrophila solution (2.1 × 109colony-forming unit). Two days after inoculation, the animals were euthanized and liver samples were collected. Infected animals (the group D) showed increased TBARS and protein carbonylation levels, while CAT, AChE and ADA activities decreased compared to uninfected animals (the group A). The prophylactic treatment with M. alternifolia essential oil (the group E) prevented the alterations caused by A. hydrophila, but it did not change AChE activity. Thus, the prophylactic treatment prevents damage caused by lipids and proteins, as well as alterations of the adenosinergic system, demonstrating that the anti-inflammatory effect of TTO is mediated by the adenosinergic pathway. In addition, TTO prophylactic treatment might be considered an important approach to prevent the hepatic damage caused by A. hydrophila.
authors.affiliation: Department of Microbiology and Parasitology, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil. Electronic address: matheusd.biomed@yahoo.com.br.
authors.forename: Matheus D
authors.initials: MD
authors.lastname: Baldissera
authors.affiliation: Department of Physiology and Pharmacology, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
authors.forename: Carine F
authors.initials: CF
authors.lastname: Souza
authors.affiliation: Department of Physiology and Pharmacology, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
authors.forename: Guerino B
authors.initials: GB
authors.lastname: Júnior
authors.affiliation: Department of Preventive Veterinary Medicine, Universidade Federal de Santa Maria, RS, Brazil.
authors.forename: Agueda C
authors.initials: AC
authors.lastname: de Vargas
authors.affiliation: Laboratory of Phytochemistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil.
authors.forename: Aline A
authors.initials: AA
authors.lastname: Boligon
authors.affiliation: Laboratory of Phytochemistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil.
authors.forename: Marli M A
authors.initials: MMA
authors.lastname: de Campos
authors.affiliation: Animal Science Graduate Program, Universidade do Estado de Santa Catarina (UDESC), Chapecó, SC, Brazil.
authors.forename: Lenita M
authors.initials: LM
authors.lastname: Stefani
authors.affiliation: Department of Physiology and Pharmacology, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil. Electronic address: bbaldisserotto@hotmail.com.
authors.forename: Bernardo
authors.initials: B
authors.lastname: Baldisserotto
mesh_terms: D016980:Aeromonas hydrophila / Q000502:physiology; D000818:Animals; D002397:Catfishes; D005393:Fish Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D007113:Immunity, Innate / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D031650:Melaleuca / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects*; D015398:Signal Transduction; D020947:Tea Tree Oil / Q000494:pharmacology*
chemical_list: D020947:Tea Tree Oil
keywords: Adenosine deaminase; Immune response; Inflammation; Tea tree oil (TTO)