Analgesic and antiinflammatory activity of COX inhibitors is well documented , but pain treatment increasingly relies on the usage of combination therapies. Benfotiamine is fat-soluble and thus more bioavailable and physiologically active than thiamine. It was reported as an effective supplement in the analgesic treatment of neuropathic pain , but there are n o experimental data about the modulate activity of benfotiamine in experimental models of inflammatory pain. The aim is to assess the effects of benfotiamine alone and in combination with ibuprofen, indomethacin and parecoxib in experimental models of inflammatory pain. Male rats (Wistar, 200-220g) were used. Inflammatory hyperalgesia was induced by intraplantar injection of 0.1% carrageenan or complete Freund’s adjuvant. Changes in pain threshold were assessed with incapacitance analgesia meter (2 Biolin, Italy ). Hyperalgesia was measured by paw pressure test (PPT, Ugo Basile , Italy ). Edema was determined using a plethysmometer ( Ugo Basile , Italy ). Groups (8-10 rats each) were treated p.o. with benfotiamine (10, 50 mg/kg), parecoxib (5 mg/kg), ibuprofen (20, 40 mg/kg) or combination of benfotiamine plus parecoxib and benfotiamine plus ibuprofen. The experimental protocols were approved by the Ethics Committee of the Institute of Physiology , Bulgarian Academy of Sciences. Ibuprofen 20, 40 mg/kg, indomethacin 2, 5 mg/kg and parecoxib 5 mg/kg showed moderate analgesic activity in inflammatory pain. Benfotiamine (10, 50 mg/kg) applied alone for 5 days before carrageenan did not show analgesic activity per se on hyperalgesia. However, benfotiamine increased significantly the analgesic effect of parecoxib, ibuprofen and indomethacin, when applied in combination in models of inflammatory hyperalgesia. The data suggest that benfotiamine can be coadministered as an effective adjuvant in the therapies with selective and non-selective COX inhibitors in inflammatory pain.
Key words: complete Freund’s adjuvant; carrageenan; inflammatory hyperalgesia, benfotiamine, COX inhibitors
Topic: MEDICINE