Search

Background: The Amazon is the largest rainforest in the world and is home to a rich biodiversity of medicinal plants. Several of these plants are used by the local population for the treatment of diseases, many of those with probable anti-inflammatory effect. The aim of the present investigation was to evaluate the in vitro antioxidant and anti-peroxidases potential of the ethanol extracts of five plants from the Brazilian Amazon (Byrsonima japurensis, Calycophyllum spruceanum, Maytenus guyanensis, Passiflora nitida and Ptychopetalum olacoides)., Methods: DPPH, ABTS, superoxide anion radical, singlet oxygen and the β-carotene bleaching methods were employed for characterization of free radical scavenging activity. Also, total polyphenols were determined. Antioxidant activities were evaluated using murine fibroblast NIH3T3 cell. Inhibition of HRP and MPO were evaluated using amplex red® as susbtract., Results: The stem bark extracts of C. spruceanum and M. guyanensis provided the highest free radical scavenging activities. C. spruceanum exhibited IC50 = 7.5 ± 0.9, 5.0 ± 0.1, 18.2 ± 3.0 and 92.4 ± 24.8 μg/mL for DPPH(•), ABTS(+•), O2 (-•) and (1)O2 assays, respectively. P. olacoides and C. spruceanum extracts also inhibited free radicals formation in the cell-based assay. At a concentration of 100 μg/mL, the extracts of C. spruceanum, B. japurensis inhibited horseradish peroxidase by 62 and 50 %, respectively. C. spruceanum, M. guyanensis, B. japurensis also inhibited myeloperoxidase in 72, 67 and 56 %, respectively., Conclusions: This work supports the folk use these species that inhibited peroxidases and exhibited significant free radical scavenging and antioxidant activities what can be related to treatment of inflammation.

Aim of the Study: To investigate the activities of the 217 plant extracts in traditional medicine of the Brazilian Cerrado against protozoans and yeasts., Materials and Methods: Plant extracts were prepared by the method of maceration using solvents of different polarities. The growth inhibition of chloroquine-resistant Plasmodium falciparum strain (FcB1) was determined by measuring the radioactivity of the tritiated hypoxanthine incorporated. Activity against Leishmania (Leishmania) chagasi and Trypanosoma cruzi was measured by the MTT colorimetric assay. The antifungal tests were carried out by using the CLSI method. The active extracts were tested also by cytotoxicity assay using NIH-3T3 cells of mammalian fibroblasts., Results: Two hundred and seventeen extracts of plants were tested against Plasmodium falciparum. The eleven active extracts, belonging to eight plant species were evaluated against L. (L.) chagasi, Trypanosoma cruzi, yeasts and in NIH-3T3 cells. The results found in these biological models are consistent with the ethnopharmacological data of these plants. The ethyl acetate extract of Diospyros hispida root showed IC(50) values of 1 microg/mL against Plasmodium falciparum. This extract demonstrated no toxicity against mammalian cells, resulting in a significant selectivity index (SI) of 435.8. The dichloromethane extract of Calophyllum brasiliense root wood was active against Cryptococcus gattii LMGO 01 with MIC of 1.95 microg/mL; and Candida albicans ATCC 10231 and Candida krusei LMGO 174, both with MIC of 7.81 microg/mL. The same extract was also active against Plasmodium falciparum and L. (L.) chagasi with IC(50) of 6.7 and 27.6 microg/mL respectively. The ethyl acetate extract of Spiranthera odoratissima leaves was active against Cryptococcus gattii LMGO 01 with MIC of 31.25 microg/mL, and against Plasmodium falciparum with IC(50) of 9.2 microg/mL and Trypanosoma cruzi with IC(50) of 56.3 microg/mL., Conclusion: The active extracts for protozoans and human pathogenic yeasts are considered promising to continue the search for the identification and development of leading compounds., ((c) 2010 Elsevier Ireland Ltd. All rights reserved.)