Immunomodulatory properties of a β-glucan-rich bioflour of Bactris gasipaes shells colonized by Lentinula edodes

Lentinula edodes β-glucans have shown potential in reducing lung injury caused by inflammation associated with severe acute respiratory syndrome (SARS). This study aimed to investigate the immunomodulatory properties related to lung inflammation, both in vitro and in vivo, of a high-β-glucan content bioflour derived from peach palm (Bactris gasipaes) shells colonized by Lentinula edodes (BPL). Neutrophils, L929, and A549 cells were treated (in vitro) with different doses (1, 10, 100 μg/mL) of BPL extracts (EBPL). The cells were subjected to cell viability assays, oxidative stress evaluation, and NO₂ quantification. Male Swiss mice were divided into five groups (in vivo). Lung inflammation was induced via intranasal instillation of LPS (4 mg/kg), and the mice were treated orally with BPL. A control group received a vehicle or dexamethasone (0.5 mg/kg). Bronchoalveolar lavage (BAL) was collected to quantify total leukocytes, the mouse-to-lung weight ratio was calculated, and histological analysis was performed. Treatment with EBPL (in vitro) did not induce toxicity in cell lines and NO₂ production decreased in neutrophils treated with the extracts; however, it did not reduce oxidative stress in A549 cells. A reduction in leukocytes was observed (in vivo) in BAL [11.43 × 10⁵ (control), 9 × 10⁵ (3 mg/kg), 3.33 × 10⁵ (30 mg/kg), 1.43 × 10⁵ (300 mg/kg) leukocytes/mL), histological infiltration, and a lower lung/mouse weight ratio [91.27 (control), 78.20 (3 mg/kg), 65.37 (30 mg/kg), 71.08 (300 mg/kg)]. This study highlights the nutraceutical potential of a β-glucan-rich food ingredient as an adjunct therapy for treating lung inflammation through dietary means, promoting human health and nutrition.