quercetin attenuates depressive- like behavior in a rat model of alzheimer’s disease: involvement of galectin-3 signaling pathway

Background and objectives: clinical studies have consistently identified depression-related disorders as the most prevalent neuropsychiatric symptoms in alzheimer’s disease (ad). quercetin has garnered significant attention as a therapeutic approach for various neuropsychiatric conditions, particularly symptoms of depression in individuals. this study aimed to compare the neuroprotective effects of quercetin on depression-like behaviors and serum levels of anti-inflammatory cytokines, such as tumor necrosis factor (tnf)-α and galectin (gal)-3, in a rat model of ad. methods: forty-eight wistar rats were categorized into six groups: control, sham, ad, quercetin 10, quercetin 25, and quercetin 100 mg/kg body weight through gavage for 8 weeks. the rat model of ad was induced by intra-cerebroventricular administration of streptozotocin (stz; 4 mg/rat, bilaterally). depressive-like behaviors were assessed using the forced swimming test (fst), elevated plus maze (epm), and open field test (oft). additionally, serum gal-3 and tnf-α concentrations were measured. results: stz administration led to increased depression-related behaviors in oft, epm, and fst. significant elevations in serum tnf-α, coupled with a decrease in gal-3 concentrations in the hippocampus of ad rats, were observed. remarkably, quercetin treatment reversed hippocampal cytokine concentrations in stz-treated rats. quercetin at the doses of 25 and 100 mg/kg significantly increased serum gal-3 concentrations compared to other groups. conclusion: the antidepressant effects of quercetin may be linked to its capacity to reduce inflammation and increase gal-3 levels.