Size Matters: Influence of Particle Size on Antioxidant, β-Glucan and Anti-inflammatory Potential in Pleurotus floridanus

Abstract

Cellular damage resulting from elevated levels of free radicals can lead to persistent health issues. Pleurotus floridanus, an edible white oyster mushroom, is rich in β-glucans with potent antioxidant and anti-inflammatory properties. In this research, we examined the β-glucan content, total phenolic content, as well as antioxidant and anti-inflammatory potential of hot water extracts with varying particle sizes (<75 µm, 75-154 µm, 154-300 µm, and 300-600 µm) of both whole (WFB) and sliced (SFB) fruiting bodies of P. floridanus. The findings revealed that the β-glucan content increased as the particle size increased, though no significant differences were observed. Conversely, smaller particle sizes (<75 µm) of whole and sliced fruiting bodies of P. floridanus exhibited higher phenolic content, DPPH and ABTS scavenging activity and reducing ability compared to larger particle size (>75 µm). Out of the four samples (AW2, AW3, AS1, and AS2) with the highest antioxidant activity, selected for anti-inflammatory assays, all demonstrated the ability to reduce NO and TNF-α levels but did not enhance IL-10 expression in LPS-stimulated RAW264.7 cells. Interestingly, particle size < 75 to 300 µm did not appear to influence the anti-inflammatory activity, as no significant differences were observed among the particle sizes. Therefore, it is suggested that the particle size <300 µm of P. floridanus hot water extract could serve as a valuable source of antioxidant and anti-inflammatory compounds to counteract the harmful effects of free radicals.