Analgesic and Anti-inflammatory Activities of Selenium and Alpha-tocopherol in Mouse Models of Pain Induced with Fluoride Exposure

Fluoride is an ineluctable environmental pollutant and its chronic exposure causes nociception and inflammation. Alpha-tocopherol and Selenium (Se) are widely available compounds that are safe if taken in moderation and exert a wide range of antioxidant, analgesic and anti-inflammatory activities. This study examined the protective activity of dietary supplements, alpha-tocopherol (2 mg/kg BW) and Selenium (05 µg/kg BW), by using thermal (Hot plate test, Tail-flick test), chemical (writhing test, formalin test) and neuropathic (allodynia test) tests in fluoride (20mg/kg BW) induced pain models. In addition, anti-inflammatory activity was also assessed with paw oedema assay. The obtained data suggest that hyperalgesia in fluoride exposure group was significantly (p<0.05) exhibited in hot plate, tail flick, writhing response, formalin and allodynia tests. Moreover, inflammation in fluoride exposure group was also significantly (p<0.05) increased in paw oedema tests in comparison with the control group. The combined administration of Se and alpha-tocopherol significantly (p<0.05) increased response latency in hot plate and tail flick tests, reduced writhing responses in the writhing test, increased withdrawal duration in allodynia test, inhibited formalin induced pain response in both phases but it was more pronounced in the second phase and attenuated formalin induced paw oedema in comparison with independent treatment of Se and alpha-tocopherol against NaF suggesting their analgesic and anti-inflammatory activities. These findings conclude the synergistic effects of selenium and alpha-tocopherol against fluoride induced nociception and inflammation.