Antiprotozoal effect of crude extracts and flavonoids isolated from Chromolaena hirsuta (asteraceae)

Abstract

Phytochemical study of Chromolaena hirsuta (Hook. & Arn.) R. King & H. Robinson crude extract (collected in Furnas, MG-Brasil) produced fifteen flavonoids, two triterpenes and five steroids. IR, UV,(1)H and (13)C NMR spectroscopy and GC analysis were used for the identification of these compounds. The dichloromethanic and ethanolic crude extracts (flowers and leaves) and six flavonoids isolated from this specie have been assayed for antiprotozoal activity against tripomastigote forms of Trypanosoma cruzi and promastigote forms of Leishmania amazonensis. The crude extracts significantly reduced the viability of T. cruzi and Leishmania amazonensis, and the six flavonoids showed considerable antiproliferative effect of development of two parasites evaluated. This is the fi rst report of antiprotozoal activity of extracts of C. hirsuta.

Biological activities and chemical composition of crude extracts from Chresta exsucca

“…Steroids, triterpenes and flavonoids were identified in crude extracts of C. exsucca. Some of these compounds showed to be active against microorganisms (protozoal, bacteria and fungi) as reported previously by the literature Schinor et al, 2004;Taleb-Contini et al, 2003;Pena et al, 2001). However, further biological studies should be performed, including in vitro and in vivo investigations, as well as to evaluation of the toxicity, looking toward a clinical employment of these bioactive natural products.…”

Screening of Southeastern BrazilianMikania. Species onTrypanosoma cruzi.

“…In the research about the trypanocidal effects of plants, we decided to verify the trypanocidal activity of M.hoehnei, M. stipulacea, M. cordifolia, M. camporum, M. lasiandrae, and M. micrantha, considering that extracts as well as pure compounds obtained from the Asteraceae family have been reported to possess significant trypanocidal activity (Chiari et al, 1996;Muelas-Serrano et al, 2000;Taleb-Contini et al, 2004). In this study, the trypanocidal activity of 14 extracts of plants of the Mikania genus was evaluated against the trypomastigote forms of T. cruzi Y strain.…”

“…For instance, Rojas de Arias et al (1995), Chiari et al (1996), Muelas-Serrano et al (2000), and Taleb-Contini et al (2004) demonstrated that species belonging to the Asteraceae family have potential trypanocidal activity. The genus Mikania is the largest genus in the tribe Eupatorieae (Asteraceae), comprising nearly 450 species, which go under the name ''guaco'' (Herz, 1998).…”

Phytochemical and antitrypanosomal investigation of the fractions and compounds isolated fromArtemisia elegantissima

“…Acetylation of flavonoids reduced their antitrypanosomal potential which has been reported in the case of pinocembrin after acetylation (IC 50 !30 mM). In another study against T. cruzi trypomastigotes, the flavonoids, 3-methylquercetin, 3,6-dimethylquercetagetin, and 7,3-dimethylluteolin, were found to be less active (IC 50 ¼ 128, 138, and 145 mg/ml, respectively) (Taleb-Contini et al, 2004). The isoflavone, calycosin, showed selective toxicity against T.b.…”