A Natural Phenolic Compound Quercetin Showed the Usefulness by Targeting Inflammatory, Oxidative Stress Markers and Augment 5-HT Levels in One of the Animal Models of Depression in Mice.

Abstract

In the present study quercetin was studied for its role in inflammation, oxidative stress markers and 5-HT levels in unpredictable chronic mild stress (UCMS) animal model of depression. The mice were randomized into different groups trained for UCMS protocol followed by different drug treatments. Treatments were started after 2 weeks from the start of UCMS protocol and continued up to 6 weeks. The behavioral tests such as modified forced swimming (MFST), tail suspension (TST) and open field tests were performed on week 6, at least 24 h after the last drug treatment. Behavioral tests were preceded following animal sacrifice for biochemical estimations. A significant decrease in swimming, climbing times and increase in immobility time in MFST and TST was observed in UCMS group. Administration of quercetin (25 mg/kg per orally (p.o) reversed these times in MFST and TST. A decrease in no. of field crossing, time spent in centre and no. of rearing were observed in UCMS group. Quercetin reduced these observations in open field test. There was a decrease in superoxide dismutase (SOD), glutathione (GSH), catalase and 5 HT levels in the brain tissue. Quercetin treatment significantly augmented SOD, GSH, catalase and 5 HT levels. Glutamate, TNF-α and IL-6 levels were increased in UCMS group while quercetin decreased these cytokines. Quercetin resulted antidepressant-like effect by its antioxidant, anti-inflammatory activities, reduced excitotoxicity and augmented 5 HT levels. This pointed out the usefulness of this phenolic compound as adjuvent drug along with other antidepressant drugs.