ABSTRACT
Objective: Psychosocial stress has been implicated in the genesis of psychiatric disorders such as memory deficits, depression, anxiety and addiction. Aqueous leaf extract of Cymbopogon citratus (CYC) otherwise known as lemongrass tea has antidepressant, anxiolytic and anti-amnesic effects in rodents. This study was designed to evaluate if C. citratus could reverse the neurobehavioral and biochemical derangements induced by social defeat stress (SDS) in the resident/intruder paradigm. Methods: Intruder male mice were divided into five groups (n = 7): group 1 received saline (10 mL/kg, p.o.; non-stress control), group 2 also received saline (10 mL/kg, p.o.; SDS control) while groups 3–5 had C. citratus (50, 100 and 200 mg/kg, p.o.) daily for 14 d. The SDS was carried out 30 min after each treatment from day 7 to day 14 by exposing each intruder mouse in groups 2–5 to a 10 min confrontation in the home cage of an aggressive resident counterpart. The neurobehavioral features (spontaneous motor activity-SMA, anxiety, memory, social avoidance and depression were then evaluated. The concentrations of nitrite, malondialdehyde and glutathione as well as acetylcholinesterase activity in the brain tissues were also determined. Results: C. citratus (50, 100 and 200 mg/kg) attenuated hypolocomotion, heightened anxiety, depressive-like symptom, memory deficit and social avoidance induced by SDS. The altered levels of oxidative stress and acetyl-cholinesterase in SDS-mice were positively modulated by C. citratus. Conclusion: The results of this study suggest that C. citratus might mitigate psychosocial stress-induced neurologic diseases in susceptible individuals.
ABSTRACT
Introducción: el uso inadecuado de los antimicrobianos es un importante factor de resistencia a estos. En medicina veterinaria, este factor puede influir en el rendimiento de los animales, como en el caso de la mastitis bovina. Objetivo: evaluar la actividad antibacteriana de los aceites esenciales e hidroalcohólicos, de Cymbopogon citratus (DC.) Stapf., Elionurus sp. y Tagetes minuta L. contra bacterias aisladas de leche bovina. Métodos: la actividad antimicrobiana de plantas se evaluó utilizando la técnica de microdilución con la determinación de la concentración inhibitoria mínima. Resultados: los aceites esenciales eran más activos que los hidroalcohólicos, con valores de concentración mínima inhibitoria entre 0,39 y 6,32; 0,10 y 6,32 %; así como de 0,62 a 5 %, para Cymbopogon citratus, Elionurus sp. y Tagetes minuta, respectivamente; mientras que en los extractos hidroalcohólicos, excepto para Tagetes minuta, solo se inhibió Streptococcus uberis con Elionurus sp., pero el extracto hidroalcohólico de Cymbopogon citratus no mostró actividad antibacteriana. Conclusiones: los resultados sugieren el uso de estas plantas como un antimicrobiano natural, que es eficaz sobre bacterias de la mastitis bovina.
Introduction: the inappropriate use of antimicrobials is a major driver of antimicrobial resistance. In veterinary medicine, this factor can influence on animal performance, as in the case of bovine mastitis. Objective: this study is aimed to evaluate the antibacterial activity of essential oils and hydroalcoholic of Cymbopogon citratus (DC.) Stapf., Elionurus sp. and Tagetes minuta L. and the bacteria isolated from bovine milk. Methods: the antimicrobial activity of plants was evaluated using the microdilution technique, determining minimum inhibitory concentration values. Results: the essential oils were more active than the hydroalcoholic, with minimum inhibitory concentration values between 6,32 to 0,39 %; 0,10 and 6,32 %; as well as 0,62 to 5 %, for Cymbopogon citratus, Elionurus and T. minuta, respectively; while EHAs, except for Tagetes minuta, only inhibited Streptococcus uberis to Elionurus sp., being that the hydroalcoholic the Cymbopogon citratus showed no antibacterial activity. Conclusions: these results suggest the use of these plants as natural antimicrobial, being effective against bacteria of bovine mastitis.