Physiological responses of Rhamdia quelen (Siluriformes: Heptapteridae) to anesthesia with essential oils from two different chemotypes of Lippia alba

Abstract

The aim of this study was to evaluate if Lippia alba has different chemotypes according to the chemical composition of the essential oil (EO) considering collection site, and if the EO may have different effects on blood and plasma parameters in silver catfish, Rhamdia quelen, during and immediately after anesthesia. The citral (EO-C) and linalool (EO-L) chemotypes were identified, and both presented similar anesthetic effects for silver catfish. Fish were exposed to two concentrations of each EO, which induced slow and fast anesthesia (100 and 300 µL L -1 , respectively). Blood ions did not change at any time of anesthesia induction and recovery and, therefore, the electrolyte balance was not altered. Blood gases oscillated through all exposure and recovery times, but there was an increase in pO 2 after 10 min recovery in fish anesthetized with EO-C. Glucose increased in fish exposed to both EOs when compared with the control group. Overall, exposure to both EOs (except 100 µL L -1 EO-L at most times) reduced plasma cortisol levels compared to the control and/or ethanol groups. However, as plasma creatinine levels in fish anesthetized with EO-C were higher than control fish, the use of EO-L is preferable.Keywords: Blood gas, Cortisol, Glucose, Plasma ions, Silver Catfish.O objetivo deste estudo foi avaliar se Lippia alba apresenta diferentes quimiotipos de acordo com a composição química do óleo essencial (OE), considerando local de coleta e se o OE causa diferentes efeitos nos parâmetros sanguíneos e plasmáticos em jundiá, Rhamdia quelen, durante e imediatamente após a anestesia. Os quimiotipos citral (OE-C) e linalol (OE-L) foram identificados e ambos apresentaram efeito anestésico semelhante para jundiá. Os peixes foram expostos a duas concentrações de cada OE, que induziram anestesia lenta e rápida (100 e 300 mL L -1 , respectivamente). Íons sanguíneos não se alteraram em nenhum tempo e consequentemente, o equilíbrio eletrolítico não foi alterado. Os gases sanguíneos oscilaram durante todo tempo de exposição e recuperação, mas houve aumento na pO 2 após 10 min de recuperação em peixes anestesiados com OE-C. Níveis sanguíneos de glicose aumentaram nos peixes expostos a ambos OEs quando comparados com o grupo controle. De um modo geral, a exposição a ambos OEs (exceto 100 µL L -1 OE-L na maioria dos tempos) reduziu o cortisol plasmático comparado aos grupos controle e etanol. No entanto, como os níveis de creatinina plasmática em peixes anestesiados com OE-C foram maiores que nos peixes controle, é preferível o uso do OE-L.

Essential oils from Citrus x aurantium and Citrus x latifolia (Rutaceae) have anesthetic activity and are effective in reducing ion loss in silver catfish ( Rhamdia quelen )

“…Citral, another major component of EOCL, increased barbituric sleeping time of mice (Vale et al, 2002) and blocks the excitability of rat sciatic nerves (Sousa et al, 2015). Citral is also the main component of other EOs that have anesthetic effects in fish: Aloysia triphylla (Gressler et al, 2012;Parodi et al, 2014;Santos et al, 2017 Cymbopogon flexuosus (Limma-Neto et al, 2016) and L. alba citral chemotype (Souza et al, 2017). The anesthetic effects of citral in fish does not involve the benzodiazepine site of the GABAergic system γ-terpinene, also a major component of EOCL, increases dopamine release from rat brain striatum slices (Fukumoto et al, 2006), but to our knowledge, no study so far has analyzed the sedative and/or anesthetic activities of this compound.…”

“…Anesthetics have been used to reduce stress effects in animals caused by capture, handling and transportation (in this situation, at sedative concentrations), avoiding the occurrence of physiological, biochemical and molecular changes (Ross, Ross, 2008;Gressler et al, 2012;Parodi et al, 2014;Benovit et al, 2015;Souza et al, 2017). The transportation of live fish, routinely performed in aquaculture, is one of the main factors that cause stress in fish (Barcellos et al, 2001;Becker et al, 2012).…”

Antibacterial potential of phytochemicals alone or in combination with antimicrobials against fish pathogenic bacteria

“…Eugenol is a phenylpropene comprising 70-90% of the weight of clove essential oil (EO), derived from the stem, leaves and shoots of the Eugenia caryophyllata tree (Keene et al 1998). Citral is a monoterpene present in several EOs, such as the EO of Lippia alba, Ocimum americanum and Cymbopogon citratus, where its content varies around 70% (Mondello et al 2002;Gautam and Agrawal 2017;Souza et al 2017). Citral is a monoterpene present in several EOs, such as the EO of Lippia alba, Ocimum americanum and Cymbopogon citratus, where its content varies around 70% (Mondello et al 2002;Gautam and Agrawal 2017;Souza et al 2017).…”

“…Thymol is a colourless aromatic monoterpene and a major component of the Thymus vulgaris, O. vulgare and Lippia sidoides EOs (Poulose and Croteau 1978;Lambert et al 2001;Botelho et al 2007). Linalool is a monoterpene and the major component of several plant EOs, such as those of Ocimum basilicum, Aniba rosaeodora and L. alba EOs; it has antibacterial properties against A. hydrophila (Dorman and Deans 2000;Sampaio et al 2012;Avetisyan et al 2017;Souza et al 2017). Linalool is a monoterpene and the major component of several plant EOs, such as those of Ocimum basilicum, Aniba rosaeodora and L. alba EOs; it has antibacterial properties against A. hydrophila (Dorman and Deans 2000;Sampaio et al 2012;Avetisyan et al 2017;Souza et al 2017).…”

“…This phenolic compound showed good in vivo results in the treatment of bacteriosis caused by A. hydrophila in silver catfish (Rhamdia quelen) (Sutili et al 2014). Citral is a monoterpene present in several EOs, such as the EO of Lippia alba, Ocimum americanum and Cymbopogon citratus, where its content varies around 70% (Mondello et al 2002;Gautam and Agrawal 2017;Souza et al 2017). This compound has considerable antimicrobial activity against Gram-negative and Gram-positive bacteria as well as fungi (Saddiq and Khayyat 2010;Lu et al 2017).…”