Olmesartan alleviates symptoms of chronic fatigue syndrome in mice

Abstract Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME) is a lifestyle-related ailment that affects physical and mental abilities. The etiology is largelyunidentified but there are certain multifactorial mechanisms responsible such as mitochondrial aerobic pathways aberrations, hypothalamic-pituitary-adrenal (HPA) axis deregulation, immune hyperactivation, free radicals, pathogen infections, and central neurohumoral alterations. Olmesartan is an antihypertensive drugthat acts on the angiotensin 1 (AT1) receptor. The present research evaluatedthe efficiency of OlmesartanagainstCFS. CFSwas induced by lipopolysaccharide (LPS, 1mg/kg,i.p.) once on day 1 trailed by a forced swim (10minutes)continued for 21 consecutive times once each day. Olmesartan (1and 3mg/kg,p.o.) and dexamethasone (standard drug, 0.5mg/kg, i.p.) were given from the 1st to 21stday. Immobility time was noted in the forced swim test (FST). Elevated plus maze, raised zero maze, and open field tests were employed to assess animal behavior.Plasma glucose and cortisol, lipid peroxidation, and GSH levels were determined in the whole brain. LPS and repeated forced swim sessions instigated symptoms of CFS such as memory deficit and depression and anxiety-like symptoms. Findings suggested that Olmesartan shortened the immobility period of mice against CFS in FST. Olmesartan reduced memory deficits, increased ambulation, and exerted an anxiolytic effect. Olmesartan treatment reduced blood cortisol levels, brain TBARS, and enhanced brain GSHin the CFS mouse model. Hence, Olmesartan may prove to be an effective treatment for CFS and related behavioral discrepancies.