Protective effects of Hydrocotyle umbellata var. bonariensis Lam. (Araliaceae) on memory in sleep-impaired female mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Hydrocotyle umbellata var.bonariensis Lam. (Hb), popularly known in Brazil as acariçoba and outside Brazil Hb by a number of names including marsh-pennywort, and many-flower, has traditionally been used in Ayurvedic medicine in the retardation of aging (Rasayana effect). AIM OF THE STUDY: The present study evaluated the effect of Hb treatment before and during paradoxical sleep deprivation (PSD) and sleep restriction (SR) on learning, memory, and acetylcholinesterase (AChE) brain activity. MATERIAL AND METHODS: Adult Swiss nulliparous female mice were randomly distributed among the experimental groups. The treated groups received the aqueous solution of Hb leaves orally at concentrations of 500 and 1.000 mg/kg. PSD and SR were induced by the multiple platform method, in which the animals remained for 3-days in PSD or 15-days in SR for 22 h per day. The collection of the vaginal epithelium occurred daily to determine the estrous cycle. Body mass gain was determined. The animals were submitted to the passive avoidance test and were then euthanized for the collection of brain tissue and the determination of cerebral cholinesterase activity. RESULTS: The aqueous solution of Hb was associated with a significant reduction in cholinesterase activity at both doses in the SR model, and at the dose of 1.000 mg/kg in the PSD model. Regarding the learning and memory test, the PSD group treated with 1.000 mg/kg presented significant improvement, whereas in the SR experiment none of the treated-groups showed any improvement in learning and memory. In the analysis of SR/PSD interference and/or Hb treatment on the estrous cycle, it was possible to observe that the treatment acted as a protector in the SR group, maintaining a normal cycle. CONCLUSIONS: The analyses showed that Hb was safe to use during periods of SR or PSD, acting as an adaptogen for these situations, in addition to being able to reduce cholinesterase activity, which suggests its neuroprotective action. In relation to the estrous cycle, Hb can act as a protector in SR situations.

Avaliação do perfil eletrocardiográfico pré e trans-anestesia em lobos-guará / Evaluation of electrocardiographic profile pre and trans-anesthesic in maned wolves

O presente estudo tem como objetivo avaliar o efeito da administração do Zolazepam/Tiletamina nas funções cardiorrespiratórias e eletrocardiográficas em lobos-guará (Chrysocyon brachyurus) mantidos em cativeiro. Foram utilizados dez lobos-guará clinicamente saudáveis (seis machos e quatro fêmeas), com média de peso 23,5±3,5kg, e idade de 6,5±2,8 anos. Os lobos eram mantidos em cativeiro e foram capturados pelos tratadores, proporcionando o mínimo de estresse possível para avaliação dos parâmetros pré-anestésicos. Foram avaliadas frequência cardíaca e respiratória, temperatura retal, pressão arterial média e eletrocardiografia. Após coleta dos parâmetros fisiológicos e eletrocardiográficos pré-anestesia, foi administrada a dose de 5,1±0,7mg/kg de Zolazepam/Tiletamina intramuscular. Depois da anestesia, colocaram-se os eletrodos do eletrocardiograma nos membros torácicos e pélvicos. Os animais eram monitorados durante uma hora, sendo que, a cada 10 minutos, era realizado o registro dos valores eletrocardiográficos, assim como os valores dos parâmetros fisiológicos e cardiorrespiratórios. Os resultados mostraram alteração significativa na amplitude da onda P entre 10 a 50 minutos pós-anestesia. Frequência cardíaca (153±20bmp), frequência respiratória (29±6mpm), temperatura corporal (38,4±1oC), pressão arterial média (114±20mmHg) e as outras variáveis eletrocardiográficas não apresentaram alterações. O aumento da amplitude da onda P nos animais deste trabalho sugeriu um aumento atrial, oriundo de doenças cardíacas ou simplesmente pelo aumento da frequência cardíaca durante a contenção.

The aim of this study was to assess the effects of the anesthetic combination of Tiletamine/Zolazepam on the cardiorespiratory function and electrocardiographic profile in captive maned wolves (Chrysocyon brachyurus). Ten maned wolves were used in this study (6 males and 4 females). All animals were healthy, with an average body weight of 23.5±3.5kg, and age of 6.5±2.8years. The wolves were conditioned to be physically restrained by their keepers in order to minimize stress during assessment of pre-anesthetic parameters. Data on heart and respiratory rates, rectal temperature, mean arterial blood pressure and electrocardiography were collected. Pre-anesthetic physiological an eletrocardiographic parameters were collected before the administration of 5.1±0.73mg/kg Tiletamine/Zolazepam intramuscularly. Under anesthesia, electrocardiogram electrodes were placed on thoracic and pelvic limbs and eletrocardiographic data was recorded every 10 minutes for approximately one hour, totaling 6 electrocardiograms. Heart rate 153±20bmp, respiratory rate 29±6mpm, rectal temperature 38,4±1oC, mean arterial blood pressure 114±20mmHg, and the other electrocardiographic parameters did not change; however, the P wave amplitude changed from 10 to 50 minutes after anesthesia. The increase in the P wave on the animals in this study suggested an atrial increase, probably due to cardiac disease or just by increasing the heart rate during the capture.