Antinociceptive effect of Tagetes lucida in an arthritic gout-pain model in rats

Gout is an inflammatory arthritis caused by urate crystal accumulation in the joints, leading to intense pain and swelling. Although non-steroidal anti-inflammatory drugs are commonly used, they may cause adverse effects, including gastrointestinal bleeding. Thus, safer alternatives are needed. Tagetes lucida Cav., traditionally known in Mexico as "pericón," is employed to alleviate rheumatic and inflammatory pain.

To provide experimental evidence supporting the traditional use of T. lucida as an antinociceptive agent in a gout model.

The antinociceptive effects of the aqueous extract of T. lucida and its compound umbelliferone were assessed using the pain-induced functional impairment in rat model. Acute toxicity of aqueous extract was also evaluated using mice according to OECD guideline 425. Phytochemical analysis was conducted to confirm the presence of umbelliferone.

Aqueous extract produced dose-dependent antinociceptive effects, with 562 mg/kg showing sustained efficacy comparable to ketorolac. Umbelliferone also exhibited significant antinociceptive activity at 316 mg/kg. Phytochemical analysis confirmed the presence of umbelliferone in aqueous extract. Acute oral toxicity tests at 2000 mg/kg of aqueous extract in mice revealed no significant toxic signs or mortality.

The results support the traditional use of T. lucida for pain management and identify aqueous extract as a potential phytotherapeutic alternative for gout, suggesting that umbelliferone is one of the metabolites responsible of its antinociceptive effect. Further research should clarify the role of additional active compounds and elucidate the mechanisms of action underlying its antinociceptive and anti-inflammatory properties.