Haematopoiesis radioprotection in Balb/c mice by an aqueous mycelium extract from the Basidiomycete <i>Pleurotus ostreatus</i> mushroom

<div><p>The study examined the radioprotective activity of an aqueous extract from <i>Pleurotus ostreatus</i> mycelium administered to Balb/c mice. Male mice were whole-body irradiated on day 0 (<sup>60</sup>Co, at 0.43 Gy/min) and divided into two groups. The extract was administered intraperitoneally to one group (100 mg/kg) on days − 10 to − 6 and − 2 to +1 with respect to the irradiation. The irradiated-control group was injected with saline solution; non-irradiated mice were used as negative controls. The radioprotective effect was evident by increases in bone marrow cellularity (5.1 × 10<sup>6</sup>/femur vs. 1.1 × 10<sup>6</sup>/femur in saline-control mice, <i>p</i> < 0.05), leucocyte counts (10.5 × 10<sup>9</sup>/L vs. 4.5 × 10<sup>9</sup>/L, <i>p</i> < 0.05), and spleen cellularity (11.2 × 10<sup>7</sup>/spleen vs. 6.2 × 10<sup>7</sup>/spleen, <i>p</i> < 0.05). The extract stimulated macrophage phagocytic activity as judged by a faster rate of carbon clearance in terms of absorbance ratios (1.62 vs. 2.01, <i>p</i> < 0.05). Therefore, this extract may be a candidate therapeutic agent with radioprotective activity for haematopoiesis damage, particularly to cells involved in immune function.</p></div>