Antinociceptive effects of Turkish endemic Eryngium kotschyi boiss. Roots by bioactivity guided fractionation

Eryngium species (Apiaceae) are well known plants in ethnobotanical culture throughout world and also in Turkey. They are used as antitussive, diuretic as well as for analgesic and antiinflammatory purposes in traditional medicine. This study aimed to evaluate the antinociceptive activity of endemic Eryngium kotschyi Boiss. root extracts by bioguided fractionation. The antinociceptive activity of the extracts/fractions/compound was studied in mice using acetic acid induced writhing test and and hot plate test. The methanolic extract was sequentially partitioned with hexane, dichloromethane and water saturated n-butanol. Among the fractions, the n-BuOH fraction showed the most significant results in both hot plate test (n-butanol 18,83±1.81 s p<0,05 versus control: 8.33±0.67 s) and acetic acid induced writhing test (n-butanol 19,17±2,41 p<0,005 versus control 32,67±2,23) and was chosen for further bioguided purifications by column chromatography and MPLC yielding a pure known triterpene saponin which was characterized as a derivative of A1-barrigenol, showing a moderate antinociceptive activity by hot-plate test (14,33 ± 0,33 s, P < 0.05 versus control). These findings contribute to the justification of the ethnobotanical use and relevance of Eryngium species. The results suggest there may be a synergy of compounds in the selected activity and support the usage of bioguided fractionation in the search for responsible compounds in plants for antinociceptive activity. Further studies are needed to elucidate the mechanism for action and the structure of compounds which might be responsible of the effect.