Oral administration of botryosphaeran [(1 → 3)(1 → 6)-β-d-glucan] reduces inflammation through modulation of leukocytes and has limited effect on inflammatory nociception.

Abstract

Several biological activities of the fungal exopolysaccharide (1 → 3)(1 → 6)-β-d-glucan (botryosphaeran) have been described in the literature, but its effects on inflammation have not been evaluated. This study aimed to investigate the action of botryosphaeran on experimental mice models of carrageenan-induced acute pleurisy and acute paw edema, and complete Freund's adjuvant-induced persistent paw edema. All botryosphaeran doses tested (1.0, 2.5, 5.0, and 10.0 mg/kg birth weight [b.w.], orally administered) reduced leukocyte recruitment, nitric oxide (NO) levels, and protein extravasation in the pleural cavity. Botryosphaeran (5 mg/kg b.w.) did not diminish edema and mechanical hyperalgesia in the paw within 4 h; however, cold allodynia was alleviated within the first 2 h. In the persistent paw inflammation model, the effects of daily oral administration of botryosphaeran (5 mg/kg b.w.) were evaluated over 3 and 7 days. The fungal β-glucan significantly reduced the levels of the cytokines, tumor necrosis factor(TNF)-α, interleukin (IL)-6), and IL-10, in the paw homogenates in both protocols, while paw edema and the levels of advanced oxidation protein products (AOPP) only diminished on Day 7. No effect in mechanical hyperalgesia was observed. Oral treatment for 3 or 7 days also decreased the plasma levels of NO, AOPP, TNF-α, and IL-10. On Day 7, the number of leukocytes in the blood was also reduced by this treatment. Importantly, botryosphaeran did not induce inflammation in mice when administered alone over 7 days. This study demonstrated the anti-inflammatory and antinociceptive potential of botryosphaeran in these experimental models, making this fungal β-glucan a new possibility for complementary treating acute and chronic inflammation.