Avalia†‡o das atividades biolˆgicas de esp‰cies do gŠnero Lychnophora (arnicas) e Estudo fitoqu‹mico do extrato ativo de Lychnophora staavioides Mart. / Avalia†‡o das atividades biolˆgicas de esp‰cies do gŠnero Lychnophora (arnicas) e Estudo fitoqu‹mico do extrato ativo de Lychnophora staavioides Mart.

Zilma Schimith Ferraz Filha

Twenty-two extracts from five Lychnophora species and one Lychnophoriopsis species, traditionally used in Brazil as analgesic, antiinflammatory, and to treat bruise and rheumatism were examined for the inhibition of xanthine oxidase (XO), the antioxidant activity, the citotoxic activity and the phytochemical study of the chloroform extracts from Lychnophora staavioides. Sixteen extracts were tested for the inhibition of xanthine oxidase (XO), the enzyme that catalyses the metabolism of hypoxanthine and xanthine into uric acid. All of them were found to have excellent XO inhibitory activity, with inhibitions greater than 38% at 100 ‘g/mL in the assay mixture. The most active plants examined were Lychnophora ericoides, Lychnophora trichocarpha, Lychnophora staavioides, Lychnophoriopsis candelabrum, with inhibitions of 78%, 77%, 67% e 66% at 100 ug/mL, respectively, and IC50 values of 8,28; 6,16; 51,07 and 49,34 respectively. For available antioxidant activity, were used the DPPH (2,2 dyphenil-1-picryl- hydrazil) as free radical. The formation of frees radicals occurs naturalnees in the organism due to exhibition oxigen. They are alterations and dangers moleculares cells. Twenty-two extracts were tested. Notice antioxidant activity greater 25% in twelve from extracts at concentration of the 100 ‘g/mL in the assay mixture. The most active plants examined were Lychnophora passerina, Lychnophora trichocarpha, Lychnophora pinaster and Lychnophora ericoides, with inhibitions of 76,0%, 63,0%, 63,0% and 55,0% at 100 ‘g/mL, respectively. Twenty-two extracts from Lychnophora and Lychnophoriopsis species were available to citotoxic activity using brine shrimp (Artemia salina). Notice activity citotoxic in the crude ethanolic extracts of L. trichocarpha, L. passerina, L. pinaster, L. ericoides e Lychnophoriopsis candelabrum, in the hexanic fracions of L. candelabrum e L. ericoides, in the chloroformic fracions of L. candelabrum and L. staavioides, in the ethyl acetate fracions of L. pinaster, L. trichocarpha, L. ericoides and ethanolic fracion of L. candelabrum that showed the DL50 smaller than 1000 ‘g/mL. Therefore these extracts may contain actives substances. The fractionation of the chloroformic extracts from Lychnophora staavioides was carrying out because this species showed signficative biological activities. These aerial parts were extracted with hexane, chloroform and ethanol. The chloroform fraction was xii submitted to new fractionations and afforded a mixture of lupeol, α-amyrin and β- amyrin, addition four flavonoids: 5-hydroxy-7-metoxyflavone (tectochrysin), 5-hydroxy- 7-metoxyflavanone (pinostrobin), 5-hydroxy-7-metoxyflavonol (izalpin) e 3β-O-acetoxy- 5,7-dihydroxi-2,3-diidroflavanone (pinobanksin -3-O-acetate). These purified flavonoids were assayed for XO inhibitory activity. The most actives flavonoid examined was the pinobanksin-3-O-acetate at concentration of the 100 ‘g/mL. The

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