Effects of dietary supplementation with arboreal medicinal mushrooms on stress coping strategies, depressive and anxiety-like behavior of rats

Background Preclinical studies have demonstrated that the edible arboreal medicinal mushroom Hericium erinaceus (HE) mitigates high corticosterone levels and enhances stress-coping strategies in rodents, with emerging evidence suggesting similar neuroprotective potential for Fomitopsis officinalis (FO) and Pleurotus djamor (PDJ). However, comparative dose-dependent effects, including comprehensive anxiety and depression assessments, remain underexplored. Purpose This study investigates the dose-dependent effects of dietary supplementation with HE, FO, or PDJ on anxiety-like behaviors and stress-coping strategies in rats, building on prior findings of their anxiolytic and antidepressant-like properties, and compares these effects to fluoxetine (FLX; 20 mg/kg), a standard treatment for stress-related psychiatric disorders. Study design Male Wistar rats received 0, 100, 250, or 500 mg/kg (per os) of HE, FO, or PDJ lyophilizate from in vitro cultures for 3 weeks. Methods Behavioral outcomes were assessed using the open field test (OFT), elevated plus maze (EPM), and forced swim test (FST). Pearson’s correlations explored relationships between FST parameters. Results A middle dose of FO (250 mg/kg) increased rearing in the OFT, indicating reduced anxiety-like behavior. In the EPM, FO (100–250 mg/kg) and PDJ (100 mg/kg) increased open arm entries and time while reducing closed arm time, indicating anxiolytic-like effects consistent with prior studies on HE and extending novel insights to PDJ. In the FST, FO (250 mg/kg) reduced immobility, increased swimming, and decreased climbing, suggesting serotonergic-mediated antidepressant-like effects comparable or superior to FLX. HE and PDJ (250–500 mg/kg) reduced immobility and increased climbing or swimming, indicating dose-specific antidepressant effects. Immobility was strongly negatively correlated with swimming (r = −0.75, P < .0001) and moderately with climbing (r = −0.43, P < .001), with no significant correlation between swimming and climbing (r = −0.18, P = .06). Conclusion This study advances prior research by demonstrating that dietary supplementation with HE, FO, and PDJ exerts dose-dependent anxiolytic and antidepressant-like effects in rats, likely via serotonergic, noradrenergic, GABAergic, and anti-inflammatory pathways. The FST correlations highlight distinct coping mechanisms, supporting their potential as dietary interventions for stress-related disorders, comparable to FLX, warranting further investigation into underlying mechanisms and clinical applicability.