Pharmacological interaction of α-bisabolol and diclofenac on nociception, inflammation, and gastric integrity in rats

(Table presented.). The combination of nonsteroidal anti-inflammatory drugs (NSAIDs) with herbal products having analgesic and anti-inflammatory effects may increase their beneficial effects and limit their side effects. In this study, the effects of an interaction between α-bisabolol and the NSAID, diclofenac on nociception (formalin test), inflammation (paw inflammation produced by carrageenan) and gastric injury in rat was assessed. Diclofenac, α-bisabolol, or diclofenac–α-bisabolol combinations produced antinociceptive and anti-inflammatory effects in rat (p <.05). The systemic administration of diclofenac, but not α-bisabolol, produced gastric damage while the diclofenac–α-bisabolol combinations produced limited gastric damage. Effective dose (ED₄₀) values were determined for each individual drug and analyzed isobolographically. The theoretical ED₄₀ values for the antinociceptive (98.89 mg/kg) and the anti-inflammatory (41.2 mg/kg) effects differed from the experimental ED₄₀ values (antinociception: 38.7 mg/kg and anti-inflammation: 13.4 mg/kg). We concluded that the interactions between diclofenac and α-bisabolol are synergistic. These data suggest that the diclofenac–α-bisabolol combinations can interact to produce minor gastric damage, thereby offering a safer therapeutic alternative for the clinical management of inflammation and/or inflammatory pain.