Antidepressant-like activity of ethanol extract of leaves of Caesalpinia pulcherrima in unstressed and stressed mice

In the present study, antidepressant-like activity of ethanol extract of leaves of Caesalpinia pulcherrima was evaluated in Swiss young male albino mice. Stress was induced in mice by subjecting them to unpredictable mild stress for 21 successive days. Ethanol extract of the leaves (100, 200 and 400 mg/ kg, p.o.) and fluoxetine (20 mg/kg, p.o.) were administered for 21 consecutive days to separate groups of unstressed and stressed mice. Ethanol extract (200 and 400 mg/kg) and fluoxetine significantly decreased immobility period of unstressed as well as stressed mice in tail suspension test (TST). However, the lowest dose (100 mg/kg) of the extract also significantly decreased immobility period of stressed mice in TST. The extract significantly restored reduced sucrose preference in stressed mice. There was no significant effect on locomotor activity of mice. Ethanol extract of the leaves significantly decreased plasma nitrite and corticosterone levels; brain MAO-A activity and MDA level; and increased brain reduced glutathione and catalase activity in unstressed as well as stressed mice as compared to their respective vehicle treated controls. Thus, ethanol extract of leaves of Caesalpinia pulcherrima showed significant antidepressant-like activity in unstressed and stressed mice probably through inhibition of brain MAO-Aactivity, reduction of oxidative stress and plasma corticosterone levels.

Avaliação comportamental pelo teste de preferência a sacarose em camundongos suíços machos tratados com extrato de Tribulus terrestris L / Behavioral evaluation by sucrose preference test in male swan mice treated with extract of Tribulus terrestris L

Introdução: O déficit de hormônios sexuais associa-se à depressão e, neste contexto, buscam-se plantas medicinais, como o Tribulus terrestris L. (TT). Objetivo: Investigar o efeito do declínio de testosterona, da suplementação com o propionato de testosterona e o TT no comportamento de animais. Métodos: O procedimento utilizou 40 camundongos suíços machos divididos em 4 grupos. Os grupos denominados controle e castrado receberam veículo aquoso durante o experimento. O grupo testosterona recebeu 20mg/kg do fármaco e o grupo TT recebeu 10 mg/kg do extrato das flores da planta. O comportamento foi avaliado pelo teste de preferência a sacarose. Ao fim do experimento o sangue coletado para dosagem de testosterona livre. Resultados e Discussão: O processo cirúrgico como um todo e o uso do anestésico quetamina evidenciaram suposto efeito ansiogênico. Conclusão: A alteração hormonal causada pela castração, além do estresse da cirurgia e da complexa farmacologia do anestésico, possui a capacidade de alterar o comportamento dos animais.

Introduction: Sexual hormone deficiency is associated with depression, and in this context, medicinal plants such as Tribulus terrestris L. (TT) are sought. Objective: To investigate the effect of testosterone decline, supplementation with testosterone propionate and TT on animal behavior. Methods: The procedure used 40 male Swiss mice divided into 4 groups. The groups called control and castrated received an aqueous vehicle during the experiment. The testosterone group received 20 mg / kg of the drug and the Tribulus group received 10 mg / kg of the plant extract. The behavior was evaluated by the sucrose preference test. At the end of the experiment the blood collected for free testosterone dosage. Results and Discussion: The surgical process as a whole and the use of the anesthetic ketamine evidenced an anxiogenic effect. Conclusion: The hormonal alteration caused by castration, besides the stress of surgery and the complex pharmacology of the anesthetic, has the capacity to alter the behavior of the animals.

Effects of different light on the ethology and melatonin secretion in depressive rats / 中国职业医学

OBJECTIVE: To observe the impact of energy saving light,incandescent light and circadian light on the ethology of depressive rats and explore its possible mechanism on affecting the secretion of melatonin. METHODS: Thirty rats aged 6weeks were randomly selected from 40 specific pathogen free health female SD rats after they adapted to the living environment,depressive rat models were established in the rats by bilateral ovariectomy combined with isolated living and chronic unpredictable mild stress stimulation at the age of 11-14 weeks. Then these 30 ovariectomized rats were randomly divided into 3 intervention groups,including an energy saving light group,an incandescent light group and a circadian light group,with 10 rats in each group. The rats in these 3 groups were given specific experimental light intervention for 3 weeks respectively at the age of 17 weeks. The other 10 rats were raised in conventional environment as the control group. Their body weights were measured at the age of 17,19,20 and 21 weeks. The ethology tests were carried out by sucrose preference test and the open-field test at the age of 7,14 and 20 weeks respectively. The melatonin levels in peripheral blood of 7 time points from 19: 30 to 8: 30 were measured in the rats at age of 21 weeks. One rat in each group at every time point was randomly selected for examination. RESULTS: At the age of 17 weeks before light-intervention,the body weights of rats in 4 groups showed no significant difference( P > 0. 05). After light-intervention,at the age of 17-20 weeks,the body weights of rats in 3 intervention groups were gradually increased with the increase of age( P < 0. 05).There was no significant difference between body weights of rats at the age of 21 weeks and those at the age of 20 weeks in each group( P > 0. 05). At age of 7 weeks,no significant differences were found in sucrose consumption and standing scores among these 4 groups( P > 0. 05). After the depressive models were established,at the age of 14 weeks before light-intervention,in rats of these 3 intervention groups,the sucrose consumption and standing scores were lower than those of the control group( P < 0. 05),and there was no significant difference found in the above 2 indexes among these 3intervention groups( P > 0. 05). At the age of 20 weeks after light-intervention,the sucrose consumption and standing scores were not significantly different from each other among the 4 groups( P > 0. 05). The peak levels of melatonin in the peripheral blood of rats in these 3 intervention groups were higher than that in the control group. The peak levels onsets of melatonin in peripheral blood of rats in the circadian light group and the energy saving light group were earlier or 2 hours delayed compared to that of control group,while it was similar between the incandescent light group and control group.CONCLUSION: The circadian light,the energy saving light and the incandescent light are similarly effective in improving the behaviors of depressive rats. The circadian light can delay the onset of peak level of melatonin in peripheral blood.

Punarnavine, an alkaloid isolated from ethanolic extract of Boerhaavia diffusa Linn. reverses depression-like behaviour in mice subjected to chronic unpredictable mild stress.

Punarnavine (20 and 40 mg/kg) and fluoxetine (20 mg/kg) per se administered orally for 14 successive days significantly decreased immobility periods of both unstressed and stressed mice in forced swim test. These drugs also significantly decreased sucrose preference in both stressed and unstressed mice as compared to their respective controls, indicating significant antidepressant-like activity. The drugs did not show any significant effect on locomotor activity of mice. The alkaloid also significantly decreased monoamine oxidase (MAO-A) activity, malondialdehyde levels in both unstressed and stressed mice; and significantly reversed the stress-induced decrease in reduced glutathione and catalase activity. It also significantly attenuated the stress-induced increase in plasma nitrite and corticosterone levels. Thus, punarnavine showed antidepressant-like activity in unstressed and stressed mice probably through inhibition of brain MAO-A activity, decrease in plasma nitrite levels and due to its antioxidant activity. In addition, punarnavine also showed antidepressant-like activity in stressed mice possibly through decrease in plasma corticosterone levels.

Antidepressant-like Activity of Celastrus paniculatus Seed Oil in Mice Subjected to Chronic Unpredictable Mild Stress.

Aims: The present study was done to evaluate the antidepressant-like effect of Celastrus paniculatus seed oil in Swiss young albino mice subjected to chronic unpredictable mild stress. Study Design: Prospective. Place and Duration of Study: Department of Pharmaceutical Sciences, Guru Jambheshwar University of Science and Technology, Hisar, Haryana, India, between August 2012 to February 2013. Methodology: The behavioral models such as forced swim test (FST) and sucrose preference test were used to evaluate the effect of seed oil on depression in mice. The oil (50, 100 and 200 mg/kg, p.o.) and fluoxetine (20 mg/kg, p.o.) per se were administered for 14 successive days to unstressed and stressed mice. The effect of oil on locomotor activity of mice was also evaluated. In addition, the effects of oil on brain monoamine oxidase-A, malondialdehyde levels, reduced glutathione and catalase activities; and plasma corticosterone and nitrite levels were also assessed. Results: The oil significantly decreased immobility period of both unstressed and stressed mice in FST as compared to the control. The oil also prevented the stressinduced decrease in sucrose preference, indicating significant antidepressant-like activity There was no significant effect on locomotor activity of mice by the oil. Antidepressant-like activity of the oil was comparable to the standard drug, fluoxetine. The oil also significantly decreased monoamine oxidase-A (MAO-A) activity, malondialdehyde levels in both unstressed and stressed mice; and significantly prevented stress-induced decrease in reduced glutathione and catalase activities. It also significantly attenuated stress inducedincrease in plasma nitrite and corticosterone levels. Conclusion: Celastrus paniculatus seed oil showed significant antidepressant-like activity in both unstressed and chronic unpredictable mild stressed mice probably due to inhibition of MAO-A activity, decrease in plasma nitrite levels; and through scavenging of free radicals. In addition, the oil also showed antidepressant-like activity in stressed mice probably through decrease in plasma corticosterone levels.