EVALUATION OF ANTISTRESS ACTIVITY OF ETHANOLIC EXTRACT OF CHROMOLAENA ODORATA LEAVES IN ALBINO WISTAR RATS

Objective: The objective of this study was to study the effect of ethanolic extract of Chromolaena odorata (EECO) Linn. on acute restraint stress (ARS)-induced stress-like behavior and biochemical alterations in albino Wistar rats. Methods: The ARS was induced by immobilizing the rats for a period of 12 h using rodent restraint device preventing them from any physical movement. Immediately, after 12 h rats were released and doses were given to each rat. 40 min post-release various behavioral parameters such as immobility time in force swim test and tail suspension test (TST), locomotor activity in open field test (OFT), and oxidative stress parameters and biochemical alterations in rat brain tissue were also performed. Statistical Analysis: Expression of data was done as mean±standard error of mean. The normally distributed data were subjected to one-way ANOVA followed by Dunnett’s test. p<0.05 was considered statistically significant. Results: Experimental findings revealed that rats subjected to ARS exhibited significant increase in immobility time in forced swim test and TST models, decrease in locomotor activity in OFT model, and increase in malondialdehyde formation and impaired superoxide dismutase, and catalase activities in hippocampus and cerebral cortex as compared to non-stressed rats. EECO treatment (250 mg/kg and 500 mg/kg) significantly attenuated immobility time, locomotion, and restored the antioxidant enzymes after ARS. Conclusion: EECO significantly alleviated ARS-induced stress-like behavior.

Phytochemical screening and evaluation of antidepressant activity of methanolic extract of the spadix of Colocasia affinis Schott

The objective of this study was to determine the phytoconstituents present in successive extracts and the antidepressant activity of methanolic extract of the spadix of Colocasia affinis. The preliminary phytochemical investigation indicated the presence of fats and fixed oils, steroids and triterpenoids in petroleum ether extract, steroids and triterpenoids in chloroform extract, flavonoids and tannins in methanol extract and carbohydrates in the aqueous extract. An in vivo test for antidepressant activity was performed on the methanolic extract of the plant at two different doses using force swim test and tail suspension test on an experimental animal model (rat). Imipramine was used as a standard drug for the study. The methanolic extract at 200 and 400 mg/kg, produced significant reduction (p<0.001) in the immobility period when compared with that of control group animals in both the tests. Thus, the result indicates that the methanolic extract exhibited significantly good antidepressant activity. Further investigation may be needed to understand the actual mechanism of action.

Preclinical evaluation of antidepressant activity of aqueous extract of Piper betle leaves in Swiss albino mice

Background: There is a growing demand for alternative medicines derived from indigenous plants having natural antioxidants and neuroprotective actions for the treatment of many behavioural disorders such as anxiety and depression. This study was designed to screen antidepressant activity of aqueous extract of Piper betle L. leaf (betel leaf) in Swiss albino mice.Methods: Swiss albino mice of both sexes weighing 25-30grams were used in the present study. Piper betle leaves aqueous extract (PBAE) was administered to the animals at a dose of 100, 200mg/kg body weight orally for 14 days. On the 14th day, after 1 hour of PBAE administration, experiments on force swim test (FST) and tail suspension (TST) were carried out for studying the level of depression. In FST and TST, time of immobility was noted for a period of 5 minutes.Results: Data was analyzed by one-way ANOVA followed by Tukey Kramer’s multiple comparison test at P = 0.05. The results were represented as Mean±SE. PBAE at a dose of 100mg/kg has shown significant antidepressant activity, as evidenced by decrease in the immobility time in both the screening tests of depression.Conclusions: Present results demonstrated that PBAE possess potent antidepressant property. The exact mechanism(s) related to the active compound(s) in Piper betle leaf extract have to be elucidated in future studies.

Possible modulation of PPAR-γ cascade against depression caused by neuropathic pain in rats

Background:Sciatic nerve ligation causes neuropathic pain with chronic constriction injury (CCI). However, there is no published report on the effect of pioglitazone as an antidepressant in the treatment of depression induced by neuropathic pain with CCI in rats. The aim of this study was to evaluate the effect of pioglitazone as an antidepressant by targeting oxidative stress by the peripheral neuropathic pain model using the CCI of the sciatic nerve.Methods:Behavioral studies were carried out to measure thermal hyperalgesia and cold allodynia as markers of neuropathic pain and force swim test for depression. These were followed by estimation of biochemical parameters which include lipid peroxidation (LPO), reduced glutathione, catalase, nitrite and superoxide dismutase (SOD) in the rat brains as a measure of oxidative stress. We administered two intraperitoneal doses of pioglitazone (4.5 and 9.0 mg/kg, i.p.) to the treated group for 28 consecutive days from the day of injury and behavioral as well as biochemical evaluations were performed.Results:The results suggested that the administration of pioglitazone significantly countered the neuropathic pain induced depression as interpreted through elevated pain threshold of tactile allodynia and thermal hyperalgesia followed by decreased immobility time in the 9.0 mg/kg dose group.Conclusions:It may be concluded that the oxidative stress plays a critical role in the pathogenesis of neuropathic pain and depression as evidenced by the behavioral studies and the changes in the levels of lipid peroxidase, nitrite, catalase, and glutathione and SOD.

The Antidepressant Effect ofAngelica sinensisExtracts on Chronic Unpredictable Mild Stress-Induced Depression Is Mediated via the Upregulation of the BDNF Signaling Pathway in Rats

Angelica sinensis(AS), a traditional Chinese herbal medicine, has pharmaceutical effects on menstrual illness, cerebrovascular diseases, cardiovascular diseases, and cognitive impairments. However, until recently, few studies had explored its antidepressant effect. The current study attempts to investigate the effect of AS extracts on chronic unpredictable mild stress- (CUMS-) induced depression in rats. Male SD rats were exposed to a CUMS-inducing procedure for 5 weeks, resulting in rodent depressive behaviors that included reduced sucrose consumption and lessened sucrose preference ratios in sucrose preference test, prolonged immobility times and decreased struggling time in force swim test, and decreased locomotor activity in open field test. Moreover, the expression of brain derived neurotrophic factor (BDNF) and the phosphorylation of cAMP-response element binding protein (CREB) and extracellular signal-regulated protein kinase (ERK 1/2) were markedly decreased in the hippocampus in depressed rats. However, chronically treating the depressed rats with AS (1 g/kg) normalized their depression-related behaviors and molecular profiles. In conclusion, in the present study, we show that AS extracts exerted antidepressant effects that were mediated by the BDNF signaling pathway: in AS-treated depressed rats, the expression of the BDNF protein and the phosphorylation of its downstream targets (ERK 1/2, CREB) were upregulated in the hippocampus.