Pre-sedation and transport of Rhamdia quelen in water containing essential oil of Lippia alba: metabolic and physiological responses.

The effects of transporting silver catfish (Rhamdia quelen) for 6 h in plastic bags containing 0 (control), 30 or 40 µL/L of essential oil (EO) from Lippia alba leaves were investigated. Prior to transport, the fish in the two experimental groups were sedated with 200 µL/L of EO for 3 min. After transport, dissolved oxygen, carbon dioxide, alkalinity, water hardness, pH, temperature and un-ionized ammonia levels in the transport water did not differ significantly among the groups. However, total ammonia nitrogen levels and net Na(+), Cl(-) and K(+) effluxes were significantly lower in the groups transported with EO of L. alba than those in the control group. PvO2, PvCO2 and HCO3(-) were higher after transporting fish in 40 µL/L of EO of L. alba, but there were no significant differences between groups regarding blood pH or hematocrit. Cortisol levels were significantly higher in fish transported in 30 µL/L of EO of L. alba compared to those of the control group. The metabolic parameters (glycogen, lactate, total amino acid, total ammonia and total protein) showed different responses after adding EO to the transport water. In conclusion, while the EO of L. alba is recommended for fish transport in the conditions tested in the present study because it was effective in reducing waterborne total ammonia levels and net ion loss, the higher hepatic oxidative stress in this species with the same EO concentrations reported by a previous study led us to conclude that the 10-20 µL/L concentration range of EO and lack of pre-sedation before transport are more effective.

Lippia alba essential oil promotes survival of silver catfish (Rhamdia quelen) infected with Aeromonas sp.

In vitro and in vivo activity of the Lippia alba essential oil (EO) against Aeromonas sp. was evaluated. In the in vitro assay the minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of EO for Aeromonas cells were determined using the microdilution method. Twenty five strains of Aeromonas sp. isolated from infected fish obtained from local fish farms were used. MIC and MBC values were 2862 and 5998 µg mL-1 for L. alba EO and 0.5 and 1.2 µg mL-1 for gentamicin, respectively. In the in vivo assay silver catfish juveniles (Rhamdia quelen) (7.50 ± 1.85 g and 10.0 ± 1.0 cm) with typical injuries associated to Aeromonas infection were divided into four treatments (in triplicate n=10): untreated fish (negative control), 10 mg L-1 of gentamicin, and 20 or 50 µL L-1 of EO. Fish were maintained in aerated 20 L plastic boxes. After 10 days survival of silver catfish infected with Aermonas sp. and treated with essential oil (50 µL L-1) was greater than 90%.

The essential oil from Lippia alba induces biochemical stress in the silver catfish (Rhamdia quelen) after transportation

This study investigated the effects of the essential oil (EO) from Lippia alba on biochemical parameters related to oxidative stress in the brain and liver of silver catfish (Rhamdia quelen) after six hours of transport. Fish were transported in plastic bags and divided into three treatments groups: control, 30 µL L- 1 EO from L.alba and 40 µL L-1 EO from L.alba. Prior to transport, the fish were treated with the EO from L. alba (200 µL L -1 for three minutes), except for the control group. Fish transported in bags containing the EO did not have any alterations in acetylcholinesterase, ecto -nucleoside triphosphate diphosphohydrolase and 5'nucleotidase activity in the brain or superoxide dismutase activity in the liver. The hepatic catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GPx), nonprotein thiol and ascorbic acid levels were significantly lower compared to the control group. However, the hepatic thiobarbituric acid- reactive substances, protein oxidation levels and the lipid peroxidation/catalase+glutathione peroxidase (LPO/CAT+GPx) ratio were significantly higher in fish transported with both concentrations of the EO, indicating oxidative stress in the liver. In conclusion, considering the hepatic oxidative stress parameters analyzed in the present experiment, the transport of previously sedated silver catfish in water containing 30 or 40 µL L-1 of EO from L. alba is less effective than the use of lower concentrations.

Este estudo investigou os efeitos do óleo essencial (OE) de Lippia alba sobre parâmetros bioquímicos relacionados ao estresse oxidativo em cérebro e fígado de jundiá (Rhamdia quelen), após seis horas de transporte. Os peixes foram transportados em sacos plásticos e divididos em três tratamentos: controle, 30 µL L-1 e 40 µL L-1 de OE de L.alba. Antes do transporte, os peixes foram tratados com o OE de L. alba (200 µL L-1 por três minutos), exceto para o grupo controle. Os peixes transportados em sacos contendo o OE não tiveram alterações na atividade da acetilcolinesterase (AChE), ecto-nucleosídeo trifosfato difosfohidrolase (NTPDase) e 5'nucleotidase, em cérebro ou superóxido dismutase (SOD) no fígado. O tiol não proteico (NPSH), os níveis de ácido ascórbico, catalase (CAT), glutationa-S-transferase (GST) e glutationa-peroxidase (GPx) hepáticos, foram significativamente mais baixos em comparação com o grupo controle. No entanto, as substâncias reativas ao ácido tiobarbitúrico (TBARS), os níveis de oxidação proteica e a taxa de peroxidação lipídica/catalase+glutationa peroxidase (LPO/ CAT+GPx) foram significativamente maiores nos peixes transportados com ambas as concentrações de OE, indicando estresse oxidativo no fígado. Em conclusão, considerando os parâmetros de estresse oxidativo do fígado analisados no presente experimento, o transporte de jundiás previamente sedados em água contendo 30 ou 40 µL L-1 de OE de L.alba é menos efetivo que utilizando concentrações menores.

S-(+)-Linalool from Lippia alba: sedative and anesthetic for silver catfish (Rhamdia quelen).

OBJECTIVE: The present study describes the isolation of linalool from the essential oil of Lippia alba (Mill.) N. E. Brown, and its anesthetic effect in silver catfish (Rhamdia quelen) in comparison with essential oil. The potentiation of depressant effects of linalool with a benzodiazepine (BDZ) and the involvement of GABAergic system in its antagonism by flumazenil were also evaluated. STUDY DESIGN: Prospective experimental study. ANIMALS: Juvenile silver catfish unknown sex weighing mean 9.24 ± 2.83 g (n = 6 for each experimental group per experiment). METHODS: Column chromatography was used for the isolation of S-(+)-linalool. Fish (n = 6 for each concentration) were transferred to aquaria with linalool (30, 60, and 180 µL L(-1)) or EO of L. alba (50, 100, and 300 µL L(-1)) to determine the induction time for anesthesia. After induction, the animals were transferred to anesthetic-free aquaria to assess their recovery time. To observe the potentiation, fish were exposed to linalool (30, 60, and 180 µL L(-1)) in the presence or absence of BDZ (diazepam 150 µm). In another experiment, fish exposed to linalool (30 and 180 µL L(-1) or BDZ were transferred to an anesthetic-free aquaria containing flumazenil (5 µm) or water to assess recovery time. RESULTS: Linalool had a similar sedation profile to the essential oil at a proportional concentration in silver catfish. However, the anesthesia profile was different. Potentiation of linalool effect occurred only when tested at low concentration. Fish exposed to BDZ showed faster anesthesia recovery in water with flumazenil, but the same did not occur with linalool. CONCLUSIONS AND CLINICAL RELEVANCE: The use of linalool as a sedative and anesthetic for silver catfish was effective at 30 and 180 µL L(-1), respectively. The mechanism of action seems not to involve the benzodiazepine site of the GABAergic system.

Lipid stability during the frozen storage of fillets from silver catfish exposed in vivo to the essential oil of Lippia alba (Mill.) NE Brown.

BACKGROUND: Lippia alba is effective in sedating and reducing stress to fish during transportation. Because some in vitro studies have demonstrated the antioxidant activity of L. alba, we hypothesized that its use in vivo could result in antioxidant effects post mortem. Therefore, in this study we evaluated whether the essential oil of L. alba (EO) used as sedative for fish transport would increase the lipid stability of fillets from silver catfish during frozen storage. RESULTS: The exposure to the EO in vivo did not affect conjugated diene values. However, EO (30 and 40 µL L(-1)) delayed the peak formation of peroxides (from the third to the sixth month of storage) and thiobarbituric reactive substances (from the ninth to the twelfth month of storage) when compared to control fillets. After exposure to 40 µL L(-1) EO the free fatty acid content was higher than for control at the start of fillet storage, with no differences among groups thereafter. CONCLUSION: The essential oil of L. alba used as sedative in the water to transport silver catfish can delay lipid oxidation of fillets during frozen storage. Thus L. alba may be a promising source of natural active compounds for use in aquaculture and the food industry.

The anesthetic efficacy of eugenol and the essential oils of Lippia alba and Aloysia triphylla in post-larvae and sub-adults of Litopenaeus vannamei (Crustacea, Penaeidae).

The aim of this study was to evaluate the anesthesia induction and recovery times of sub-adult and post-larvae white shrimp (Litopenaeus vannamei) that were treated with eugenol and the essential oils (EOs) from Lippia alba and Aloysia triphylla. Oxidative stress parameters in the hemolymph of this species were also analyzed. The concentrations of eugenol, A. triphylla EO and L. alba EO recommended for anesthesia were 200, 300 and 750 µL L(-1) for sub-adults and 175, 300 and 500 µL L(-1) for post-larvae, respectively. The concentrations studied during the transport of sub-adults were between 20 and 50 µL L(-1) eugenol, 20-30 µL L(-1)A. triphylla EO and 50 µL L(-1)L. alba EO. For post-larvae, the optimal concentrations for transport were 20 µL L(-1) eugenol and between 20 and 50 µL L(-1)A. triphylla EO. The white shrimp sub-adults that were exposed to A. triphylla EO (20 µL L(-1)) showed increases in their total antioxidant capacities (150%), catalase (70%) and glutathione-S-transferase (615%) activity after 6 h. L. alba EO (50 µL L(-1)) and eugenol (20 µL L(-1)) also increased GST activity (1292 and 1315%) after 6 h, and eugenol (20 µL L(-1)) decreased the total antioxidant capacity (100%). Moreover, concentrations above 30 µL L(-1) for the EOs of A. triphylla and L. alba and 20 µL L(-1) eugenol were effective at inducing anesthesia and improving the antioxidant system against reactive oxygen species (ROS) after 6 h.

Transportation of silver catfish, Rhamdia quelen, in water with eugenol and the essential oil of Lippia alba.

This study investigated the effectiveness of eugenol and of the essential oil (EO) of Lippia alba when used in the transport of the silver catfish (Rhamdia quelen). These investigations involved measurements of blood (pH, PvO(2), PvCO(2) and HCO(3) (-)) and water parameters, survival and ionoregulatory balance. Fish (301.24 ± 21.40 g, 28.90 ± 1.30 cm) were transported at a loading density of 169.2 g L(-1) for 4 h in fifteen plastic bags (7 L) divided into five treatments: control, 1.5 or 3.0 µL L(-1) of eugenol and 10 or 20 µL L(-1) of EO of L. alba. The water parameters were measured before (0 h) and after (4 h) transportation. The net Na(+), Cl(-) and K(+) losses were higher in fish from the control treatment compared to the other treatments. The PvO(2), PvCO(2) and HCO(3) (-) increased significantly in all of the treatments at the end of the transport period. In conclusion, based on the water (total ammonia nitrogen) and ionoregulatory indicators determined in the present study, our findings indicate that eugenol and the EO of L. alba are recommended for use in the transport of this species because these anesthetics apparently reduce stress.

Composição química, atividade antibacteriana in vitro e toxicidade em Artemia salina do óleo essencial das inflorescências de Ocimum gratissimum L., Lamiaceae / Chemical composition, antibacterial activity in vitro and brine-shrimp toxicity of the essential oil from inflorescences of Ocimum gratissimum L., Lamiaceae.

O óleo essencial das inflorescências de Ocimum gratissimum L., Lamiaceae foi obtido por hidrodestilação e analisado por CG/EM. Os constituintes majoritários identificados foram eugenol (81,94 por cento) e γ-muuroleno (12,58 por cento). O óleo essencial das inflorescências demonstrou atividade antibacteriana frente a todas as cepas bacterianas testadas pelo método de microdiluição em caldo. Merece destaque a atividade verificada frente às cepas resistentes de Enterococcus faecalis, Staphylococcus aureus e Escherichia coli. Os valores obtidos de concentração inibitória mínima (CIM) e a concentração bactericida mínima (CBM) variaram, respectivamente, entre 0,5-2 mg/mL e 1-4 mg/mL. Valores de CL50 de 233,8 (200,7-272,0) µg/mL para o óleo essencial e 186,1 (144,1-228,5) µg/mL para o eugenol, utilizado como controle positivo, foram observados frente à Artemia salina L.

The essential oil obtained by hydrodistillation of the inflorescences of Ocimum gratissimum L. was analyzed by GC/MS. The main constituents were eugenol (81.94 percent) and γ-muurolene (12.58 percent). Antibacterial activity was shown against all assayed strains by the broth microdilution method. It's worth noting the activity against resistant strains of Enterococcus faecalis, Staphylococcus aureus and Escherichia coli. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranged between 0.5-2 mg/mL and 1-4 mg/mL, respectively. Preliminary toxicity assayed by the brine-shrimp (Artemia salina L.) test showed LC50 values of 233.8 (200.7 - 272.0) µg/mL and 186.1 (144.1 - 228.5) µg/mL, respectively for the essential oil and eugenol (positive control).