n-Hexane extract of Anacardium occidentale ameliorates spatial memory impairment, anxiety, and depressive-like behavior through the suppression of gut-brain inflammation and cholinergic disruption in acetic acid-induced experimental colitis

Inflammatory bowel disease has been implicated in mood disorders and neurodegeneration through systemic inflammation and the tryptophan-kyneurin pathway, and cashew kernel has been reported to possess anti-inflammatory and antioxidant potential in models of ulcerative colitis. However, little is known about the potential of n -Hexane extract of Anacardium occidentale (HEAO) in ameliorating ulcerative colitis and associated neuroinflammation, which this study was designed to evaluate. Thirty female Wistar rats assigned into six groups (n = 5) were used for this study. Group I (10 mL/kg vehicle), group II received acetic acid (A.A) only (0.2ml of 3% AA i.r). Groups III-IV received A.A + (50, 100, 200 mg/kg p. o) of HEAO, while group VI received A.A + prednisolone 2 mg/kg p.o. The animals received treatments after intrarectal administration of acetic acid for 14 days. Followed by an assessment of anxiety, depression, and cognitive deficit, the brain and colon were harvested for biochemical and histological assessments. All data are expressed ± standard error of mean (SEM), and statistical analysis was conducted using ANOVA (P < 0.05). HEAO treatment significantly increased the time spent in the open arm, reduced immobility time, and increased alternation preference in the EPM, FST, and Y-maze tests, respectively. HEAO also significantly improved redox status balance, suppressed proinflammatory cytokine levels, and modulated acetylcholinesterase activities. This was supported by the preservation of neuronal and enterocyte integrity in the brain and colon. n -Hexane extract of Anacardium occidentale (HEAO) exerted its anxiolytic, antidepressant, and nootropic effects by suppressing oxido-inflammatory damage and modulation of cholinergic transmission in the colon and the brain.