Effect of two flavonoid compounds on central nervous system. Analgesic activity.

ABSTRACT

The psychopharmacological profile of quercetin (Q) and penta-O-ethylquercetin (PQ) showed for both compounds a sedative effect on central nervous system in mice. In this set of pharmacological tests (hypothermia, spontaneous motility, psychomotor activity) penta-O-ethylquercetin always exerted a more pronounced effect than quercetin, probably due to the difference of lipophilicity. In analgesia experiments such as acetic acid-induced writhings, penta-O-ethylquercetin showed a significant dose-related effect whereas quercetin was inactive. As pretreatment with naloxone failed to antagonize the analgesic activity of penta-O-ethylquercetin, it was suggested that penta-O-ethylquercetin acted mainly peripherally.