Methanol extract from mycelium of endophytic fungus Rhizoctonia sp. induces antinociceptive and anti-inflammatory activities in mice

The present study aimed to elucidate the antinociceptive and anti-inflammatory properties of the methanol extract from the mycelium of the endophytic fungus Rhizoctonia sp . (MEMRh) in mice. The antinociceptive activity was assessed using the abdominal constriction, hot plate, and formalin tests. The anti-inflammatory activity was assessed using a murine model of paw edema. Intraperitoneal administration of MEMRh (0.1, 1, 10 and 100 mg/kg, i.p.) produced an inhibition of acetic acid-induced writhing in mice for at least 8 h. In addition, all doses tested of the methanol extract were able to prevent thermal nociception in the hot-plate test. Furthermore, treatment with MEMRh (10 mg/kg, i.p.) inhibited both the early and late phases of formalin-induced nociception. This antinociceptive effect exhibited by MEMRh in the formalin test was reversed by the systemic administration of naloxone. MEMRh produced inhibition in a carrageenan-induced edema model at a dose of 10 mg/kg. The same extract also displayed significant activity against a histamine- or PGE 2 -induced edema model. The experimental data demonstrated that MEMRh showed remarkable anti-inflammatory and antinociceptive activities. Further studies are warranted to define and isolate the active anti-inflammatory and antinociceptive components from this endophytic fungus, which may yield effective agents for the treatment of inflammatory disorders.