Phytochemical profile and analgesic evaluation of Vitex cymosa leaf extracts

ABSTRACT

Vitex cymosa Bertero ex Spreng., Lamiaceae, is found in Central and Amazon regions of Brazil, where it is popularly used as antirheumatic. Extracts from the leaves of V. cymosa were tested in analgesia models such as abdominal contortions induced by acetic acid and formalin to test peripheral analgesia; as well as the tail flick and hot plate models, to test spinal and supraspinal analgesia. A significant reduction was observed in the number of contortions with all extracts and in all doses. In the formalin model, a reduction in the second phase (inflammatory) was observed with all extracts, whereas only the n-butanol extract was able to act in the first, neurogenic, phase. In the tail flick model, all extracts increased latency time. Naloxone treatment reverted analgesic effect of all extracts with the exception of the dichloromethane one. All extracts developed peripheral and central analgesic activity. In the hot plate model no antinociceptive effect was observed for all tested extracts. All these results taken together suggest that V. cymosa leaf extracts were able to promote peripheral and central antinociceptive activity mediated by the opioid system.Twenty three substances were isolated and identified in the extracts and include flavonoids (C-glucosyl flavones, flavones and flavonols), triterpene acids from ursane and oleanane types, iridoids (free and glucosides), as well as simple phenols.