Analgesic and anti-inflammatory bioactivities of eburicoic acid and dehydroeburicoic acid isolated from antrodia camphorata on the inflammatory mediator expression in mice

Eburicoic acid (TR1) and dehydroeburicoic acid (TR2), an active ingredient from Antrodia camphorata (AC) solid-state culture, were evaluated for analgesic and anti-inflammatory effects. Treatment with TR1 and TR2 significantly inhibited a number of acetic acid-induced writhing responses and formalin-induced pain in the late phase. In the anti-inflammatory test, TR1 and TR2 decreased paw edema at the fourth and fifth hour after λ-carrageenan (Carr) administration and increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the paw edema tissue. We also demonstrated that TR1 and TR2 significantly attenuated the malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor (TNF-α), and interleukin-1β (IL-1β) levels in either edema paw or serum at the fifth hour after Carr injection. Western blotting revealed that TR1 and TR2 decreased Carr-induced inducible nitric oxide synthase (iNOS) and cycloxyclase (COX-2) expressions at the fifth hour in paw edema. Treatment with TR1 and TR2 also diminished neutrophil infiltration into the paw edema at the fifth hour. The present study suggests that the anti-inflammatory mechanisms of TR1 and TR2 might be related to the decrease of inflammatory cytokines and an increase of antioxidant enzyme activity.