Antinociceptive effects of synthetic chalcones obtained from xanthoxyline.

A wide variety of noxious stimuli are known to induce a sensation of pain evoked in a remote region of the body. Here, we show that chalcones can inhibit the pain provoked by the administration of an intraperitoneal acetic acid (AA). This study investigates the effects of 17 synthetic chalcones in the writhing test, a visceral pain model in mice. The majority of these compounds proved more active than some analgesic drugs, such as aspirin and acetaminophen, two reference drugs used here for comparison. Four chalcones, 9, 10, 16, and 17, were selected for more detailed studies, since they exhibited significant antinociceptive activities and chemical structures of interest. They caused dose-related inhibitions, proving about 15-, 10-, 9-, and 8-fold more active than the standard drugs. When administrated orally, only chalcone 9 proved to be effective. These chalcones might be further used as a model to obtain new and more potent analgesic drugs.