Chemical composition and antiproliferative, antioxidant and trypanocidal activities of the fruits from Campomanesia xanthocarpa (Mart.) O. Berg (Myrtaceae).

Chemical investigation of the extracts of the fruits from Campomanesia xanthocarpa resulted in the isolation of six known compounds identified by NMR and comparison with literature data (2',4'-dihydroxy-5'-methyl-6'-methoxychalcone (1), 2',4'-dihydroxy-3',5'-dimethyl-6'-methoxychalcone (2), 2'-hydroxy-3'-methyl-4',6'-dimethoxychalcone (3), 2',6'-dihydroxy-3'-methyl-4'-methoxychalcone (4), 5-hydroxy-7-methoxy-8-methylflavanone (5) and 7-hydroxy-5-methoxy-6-methylflavanone (6)). The considerable antioxidant capacity of the extracts was demonstrated by ORAC-FL and DPPH tests. The antiproliferative assay of the extracts and 5 was done in vitro, against many different cancer cell lines besides a healthy one. The extracts presented low cytotoxicity and the substance demonstrated promising results against all the cancer cell lines tested, with IC50 values ranging from 4.75 to 45.81 µmol L-1. The in vitro trypanocidal activity was evaluated against the epimastigote form of the Y strain of Trypanosoma cruzi and an improvement in the activity of the substances 2 (221.81 µmol L-1) and 5 (61.87 µmol L-1) was observed regarding the values obtained for the extracts.

Trypanosoma cruzi: analysis of two different strains after piplartine treatment.

The hemoflagellate protozoan, Trypanosoma cruzi, mainly transmitted by triatomine insects through blood transfusion or from mother-to-child, causes Chagas' disease. This is a serious parasitic disease that occurs in Latin America, with considerable social and economic impact. Nifurtimox and benznidazole, drugs indicated for treating infected persons, are effective in the acute phase, but poorly effective during the chronic phase. Therefore, it is extremely urgent to find innovative chemotherapeutic agents and/or effective vaccines. Since piplartine has several biological activities, including trypanocidal activity, the present study aimed to evaluate it on two T. cruzi strains proteome. Considerable changes in the expression of some important enzymes involved in parasite protection against oxidative stress, such as tryparedoxin peroxidase (TXNPx) and methionine sulfoxide reductase (MSR) was observed in both strains. These findings suggest that blocking the expression of the two enzymes could be potential targets for therapeutic studies.

Trypanosoma cruzi: analysis of two different strains after piplartine treatment

ABSTRACT The hemoflagellate protozoan, Trypanosoma cruzi, mainly transmitted by triatomine insects through blood transfusion or from mother-to-child, causes Chagas' disease. This is a serious parasitic disease that occurs in Latin America, with considerable social and economic impact. Nifurtimox and benznidazole, drugs indicated for treating infected persons, are effective in the acute phase, but poorly effective during the chronic phase. Therefore, it is extremely urgent to find innovative chemotherapeutic agents and/or effective vaccines. Since piplartine has several biological activities, including trypanocidal activity, the present study aimed to evaluate it on two T. cruzi strains proteome. Considerable changes in the expression of some important enzymes involved in parasite protection against oxidative stress, such as tryparedoxin peroxidase (TXNPx) and methionine sulfoxide reductase (MSR) was observed in both strains. These findings suggest that blocking the expression of the two enzymes could be potential targets for therapeutic studies.

Chemical profile and biological potential of non-polar fractions from Centroceras clavulatum (C. Agardh) Montagne (Ceramiales, Rhodophyta).

The present study reports the Gas Chromatography-Mass Spectrometry (GC-MS) evaluation of the hexanes and dichloromethane fractions from extracts of the red alga Centroceras clavulatum (C. Agardh) Montagne. Twenty three compounds were identified, totaling ca. 42% of both fractions (0.18 g mass extract). The main constituents of the fractions were hexadecanoic acid (17.6%) and pentadecanoic acid (15.9%). Several secondary metabolites with interesting biological activity, such as (-)-loliolide, neophytadiene, phytol were identified. In addition, several classes of secondary metabolites, including phenolic compounds (e.g., phenylacetic acid), terpene derivatives, fatty acids, halogenated compound (e.g., 2-chlorocyclohexenol), lignoids, steroids, esters, amides (e.g., hexadecanamide), ketones, carboxylic acids, aldehydes and alcohols were observed. The occurrence of several of these structural classes is described for the first time in this species. The same fractions analyzed by GC-MS, and a separate set of polar fractions, were evaluated against two life cycle stages (epimastigote and trypomastigote forms) of the protozoan Trypanosoma cruzi and against phytopatogenic fungi Cladosporium cladosporiodes and C. sphaerospermum. The dichloromethane fraction was active against both T. cruzi forms (epimastigote IC(50) = 19.1 µg.mL-1 and trypomastigote IC(50) = 76.2 µg.mL-1). The hexanes and ethyl acetate fractions also displayed activity against both fungi species (200 µg) by TLC-bioautography.

In vitro trypanocidal activity of phenolic derivatives from Peperomia obtusifolia.

The trypanocidal activity of crude extracts and fractions from the leaves and stems of Peperomia obtusifolia (Piperaceae) was evaluated in vitro against the epimastigote forms of Trypanosoma cruzi. Bioactivity-guided fractionation of the most active extracts afforded seven known compounds, including three chromanes, two furofuran lignans and two flavone C-diglycosides. The most active compounds were the chromanes peperobtusin A and 3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(2''-methyl-2''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2 H-1-benzopyran-6-carboxylic acid, with IC (50) values of 3.1 microM (almost three times more active than the positive control benznidazole, IC (50) 10.4 microM) and 27.0 microM, respectively. Cytotoxicity assays using peritoneal murine macrophages indicated that the chromanes were not toxic at the level of the IC (50) for trypanocidal activity. This is the first report on the trypanocidal activity besides unspecific cytotoxicity of chromanes from Peperomia species. Additionally it represents the first time isolation of 3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(2''-methyl-2''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2 H-1-benzopyran-6-carboxylic acid from P. obtusifolia.

In vitro activity of compounds isolated from Piper crassinervium against Trypanosoma cruzi.

This study describes the antichagasic potential of five compounds isolated from leaves of Piper crassinervium (Piperaceae). Two prenylated benzoic acid derivatives, one prenylated hydroquinone and two flavanones, were evaluated. The in vitro trypanocidal activity was determined against epimastigote forms of Trypanosoma cruzi (Y strain), the etiologic agent of Chagas disease. The most active compound was the prenylated hydroquinone [1,4-dihydroxy-2-(3(0),7(0)-dimethyl-1(0)-oxo-2(0)-E,6(0)-octadienyl)benzene] with an IC(50) value of 6.10 microg mL(-1), which was in the same order of activity if compared with the positive control benznidazole (IC(50) = 1.60 microg mL(-1)). This is the first report of trypanocidal activity for prenylated hydroquinone and benzoic acid derivatives.