Luis André Luz Barbas

Oxidative stress responses of juvenile tambaqui Colossoma macropomum after short-term anesthesia with benzocaine and MS-222

The present study aimed to evaluate the effects of benzocaine and tricaine methanesulfonate on oxidative stress parameters of juvenile tambaqui tissues. Fish (n=80) were anesthetized with benzocaine (100 mg L-1) or tricaine (240 mg L-1) and two control groups were used (non-anesthetized fish and fish exposed to ethanol-only). After anesthetic induction 10 fish/anesthetic were euthanized after 3, 12 and 24 hours post-anesthesia and tissue samplings (gills, liver and brain) were performed. Samples were submitted to analyses of enzyme activity glutathione-S-transferase (GST), cellular lipid peroxidation (TBARS) and total antioxidant capacity (ACAP). ACAP increased in gills of benzocaine treatment after 12 hours. The liver showed a reduction in ACAP of tricaine treatment after 12 hours. Both anesthetic treatments showed an increase of ACAP at 24 hours compared to control group. The activity of the GST enzyme increased in the gills for treatments benzocaine and tricaine after 3 and 12 hours. Liver showed increased GST activity (benzocaine after 24 hours and tricaine after 3 and 24 hours). Lipid damage decreased in gills (both anesthetics) and brain (tricaine) after 24 hours. The results demonstrate that benzocaine and tricaine did not cause oxidative damage in juvenile tambaqui under the experimental conditions herein established.

Cunaniol-elicited seizures: Behavior characterization and electroencephalographic analyses

&NA; This study aimed at describing the characteristics and properties of seizures induced by cunaniol, a polyacetylenic alcohol isolated from the Clibadium genus, which is ubiquitous in the Amazon biodiversity and its potential use as a convulsant model. Wistar rat behavior was assessed upon cunaniol administration and animals were evaluated for neural activity through electroencephalographic records whereby epidural electrodes were positioned over the motor cortex under cunaniol‐elicited seizures and seizures control using three anticonvulsant agents, namely phenytoin, phenobarbital and diazepam. Cunaniol‐induced seizures displayed a cyclic development of electrocorticographic seizures, presenting interictal‐like spike and ictal period, which correlates to the behavioral observations and is in line with acute seizures induced by pentylenetetrazole. Cunaniol‐elicited seizures were intractable by phenytoin treatment and controlled under the GABAergic activities of phenobarbital and diazepam. The results indicate that the cunaniol‐induced changes show characteristics of seizure activity, making this plant compound a suitable animal convulsant model for seizure‐related studies that could be used to assist in the development of novel anticonvulsant agents. HighlightsThis is the first study to characterize cunaniol‐induced seizures.Cunaniol is presented as a chemoconvulsant model.Cunaniol can be used for the screening of new anticonvulsant drugs.