Rodrigo L. Fabri

Mitracarpus frigidus aerial parts exhibited potent antimicrobial, antileishmanial, and antioxidant effects.

The crude extract and the hexane, CH(2)Cl(2), EtOAc, n-BuOH, and hydromethanolic fractions of the aerial parts of Mitracarpus frigidus were evaluated against promastigote forms of two species of Leishmania (L. chagasi and L. amazonensis), 11 strains of bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica sorovar Tythimurium, Shigella sonnei, Klebsiella pneumoniae, Escherichia coli, Micrococcus luteus, Enterococcus faecalis, Enterobacter cloacae, Streptococcus pyogenes and Bacillus cereus) and two yeasts (Candida albicans and Cryptococcus neoformans). The antioxidant activity (DPPH radical scavenging activity and reducing power), cytotoxicity against mammalian cells, and the contents of phenolics and flavonoids were determined. Phytochemical analysis of the major groups of phytoconstituents is also reported. All samples showed antioxidant activity which was positively correlated to the content of phenolic compounds. S. sonnei, B. cereus and C. neoformans were susceptible to all extracts tested, except for the n-BuOH and hydromethanolic fractions, which demonstrated no antimicrobial activity. The lowest MIC was recorded for the CH(2)Cl(2) fraction against C. neoformans (MIC of 10 microg/ml), followed by B. cereus, S. sonnei, and E. cloacae (MIC of 20, 39 and 39 microg/ml, respectively). The CH(2)Cl(2) fraction was the most effective against L. chagasi (IC(50) of 6.7 microg/ml), and the hydromethanolic fraction exhibited the best activity against L. amazonensis (IC(50) of 9 microg/ml). A cytotoxic effect on mammalian cells was observed only for the crude extract and CH(2)Cl(2) fraction at the concentrations of 130 and 31 microg/ml, respectively. These results suggest that M. frigidus has interesting antimicrobial, antileishmanial and antioxidant activities.

Potencial antioxidante e antimicrobiano de espécies da família Asteraceae

Especies da familia Asteraceae sao amplamente utilizadas na medicina popular para diversos fins terapeuticos. Neste contexto, este estudo teve por objetivo averiguar a atividade antimicrobiana e antioxidante in vitro de extratos metanolicos de plantas pertencentes a Asteraceae, a maioria comumente utilizada na medicina tradicional. A prospeccao quimica dos extratos tambem foi realizada. A atividade antimicrobiana foi avaliada pelo metodo de susceptibilidade em microdiluicao em caldo e a atividade antioxidante determinada pelo ensaio com o radical DPPH. O extrato da folha de Baccharis dracunculifolia apresentou significativa atividade antimicrobiana para Pseudomonas aeruginosa,Bacillus cereus e Cryptococcus neoformans (CIM = 0,005; 0,005 e 0,039 mg mL-1, respectivamente). Os extratos das folhas de Bidens segetum e Matricaria chamomilla foram seletivos para Shigella sonnei e P. aeruginosa (CIM = 0,005 e 0,078 mg mL-1, respectivamente). Ja as folhas de Acanthospermun australe e Baccharis trimera apresentaram atividade significativa apenas para Candida albicans (CIM = 0,039 mg mL-1) enquanto as folhas de Taraxacum officinale foram ativos contra ambas leveduras com CIM 0,039 mg mL-1. Em relacao a atividade antioxidante, os extratos das folhas de B. dracunculifolia, T. officinale e das inflorescencias de B. segetum apresentaram significativa atividade com CI50 de 5, 5 e 4 µg mL-1, respectivamente. A prospeccao quimica dos extratos identificou presenca de compostos como flavonoides, terpenos e outros que podem ser responsaveis pelas atividades observadas.

Antibacterial, cytotoxic and phytochemical screening of some traditional medicinal plants in Brazil

As part of a program oriented towards the discovery of bioactive natural products, 44 methanol extracts from 37 Brazilian traditional medicinal plants, most of them commonly used for treating conditions likely to be associated with microorganisms, were evaluated for their antibacterial activity and toxicity to brine shrimp. The agar-well diffusion method was used against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Shigella sonnei, Klebsiella pneumoniae, Escherichia coli, and Bacillus cereus. The active extracts were subjected to serial dilution assay for determination of the minimal inhibitory concentration. Phytochemical analysis of the extracts for their major groups of phytoconstituents is also reported. Extracts of Baccharis dracunculifolia, Cajanus cajan, Eugenia uniflora, Solanum palinacanthum and Solanum concinnum presented strong antibacterial activity with MIC values below 10 μg/mL for some bacterial strains. The extracts of Mikania glomerata and Leonurus sibiricus showed significant toxicity against brine shrimp with LC50 values of 63 and 86 μg/mL, respectively.

Identification of Antioxidant and Antimicrobial Compounds of Lippia Species by Bioautography

The methanolic extracts of the leaves of Lippia species (L. pseudo-thea, L. hermannioides, L. alba, L. rubella, and L. sidoides) were tested for their antibacterial, antifungal, and antioxidant activity. Cytotoxicity was determined by using brine shrimp lethality bioassay. Phytochemical screening was also performed. The extracts showed a minimum inhibitory concentration (MIC) ranging from 78 to 5000 μg/mL for antibacterial activity against at least 2 species of bacteria, although none was active against Escherichia coli. Antifungal activity was found only for L. pseudo-thea (MIC, 625 μg/mL for Candida albicans) and L. sidoides (MIC, 625 μg/mL for both C. albicans and C. neoformans). The bioautography showed that flavonoids and coumarins are responsible for the antioxidant activity of the extracts and that the antimicrobial properties are due to flavonoids and terpenoids. The cytotoxic activity was stronger for L rubella extract. To our knowledge, this is the first report of the biological and chemical constituents of L. pseudo-thea, L. hermannioides, and L. rubella.

Antitumor, antibiotic and antileishmanial properties of the Pyranonaphthoquinone Psychorubrin from Mitracarpus frigidus

The bioactivity guided fractionation of the dichloromethane extract of Mitracarpus frigidus afforded the pyranonaphthoquinone psychorubrin. This compound, hitherto unknown in the genus Mitracarpus, had its biological activity evaluated against one panel of bacteria and two fungi, three tumor cell lines (HL60, Jurkat and MCF-7) and four Leishmania species. Its identity was confirmed unambiguously by (1)H, (13)C, (1)H-COSY, IR and UV-Vis spectroscopy and mass spectrometry. Psychorubrin displayed a very promising antitumor with IC(50) of 4.5, 5.6 and 1.1 µM for HL60, Jurkat and MCF-7 cell lines, respectively. Antimicrobial activity, mainly against Cryptococcus neoformans (MIC of 87.3 µM) was observed. A pronounced antileishmanial potential was also verified with IC(50) varying from 1.7 to 2.7 µM for the Leishmania species tested. This is the first report of the presence of pyranonapthoquinones in the Mitracarpus genus, which may serve as a chemotaxonomical marker.

Vernonia condensata Baker (Asteraceae): A Promising Source of Antioxidants

The present study evaluated the antioxidant potential of Vernonia condensata Baker (Asteraceae). Dried and powdered leaves were exhaustively extracted with ethanol by static maceration followed by partition to obtain the hexane, dichloromethane, ethyl acetate, and butanol fractions. Total phenols and flavonoids contents were determined through spectrophotometry and flavonoids were identified by HPLC-DAD system. The antioxidant activity was assessed by DPPH radical scavenging activity, TLC-bioautography, reducing power of Fe+3, phosphomolybdenum, and TBA assays. The total phenolic content and total flavonoids ranged from 0.19 to 23.11 g/100 g and from 0.13 to 4.10 g/100 g, respectively. The flavonoids apigenin and luteolin were identified in the ethyl acetate fraction. The IC50 of DPPH assay varied from 4.28 to 75.10 µg/mL and TLC-bioautography detected the antioxidant compounds. The reducing power of Fe+3 was 19.98 to 336.48 μg/mL, while the reaction with phosphomolybdenum ranged from 13.54% to 32.63% and 56.02% to 135.00% considering ascorbic acid and rutin as reference, respectively. At 30 mg/mL, the ethanolic extract and fractions revealed significant effect against lipid peroxidation. All these data sustain that V. condensata is an important and promising source of bioactive substances with antioxidant activity.

The effect of essential oil of Syzygium cumini on the development of granulomatous inflammation in mice

The anti-inflammatory and apoptotic activity of the essential oil of Syzygium cumini (L.) Skeels, Myrtaceae, leaves was investigated in vivo. The antiinflammatory action and chronic granulomatous inflammation in BALB/c mice, intravenously infected with Mycobacterium bovis, BCG, (Bacillo Calmet Guerim), was judged by measuring and classifying the granulomas formed in the hepatic parenchyma. The degree of apoptosis in the inflammatory cells was also measured. A reduction in the granulomatous area and a change in the pattern of the granulomas were found. Anti-mycobacterial activity of the essential oil against M. bovis was detected in vitro by an interferometric method in liquid culture medium. The chemical constituents of the essential oil were determined by GC/MS. Higher yields of the essential oil of S. cumini leaves were obtained by extraction in a Clevenger apparatus when the fresh leaves were previously frozen as a pre-processing step. The essential oil obtained from this plant demonstrated a statistically significant and dramatic effect in the chosen model system.

Anti‐inflammatory and antioxidative effects of the methanolic extract of the aerial parts of Mitracarpus frigidus in established animal models

This study reports the in vivo anti‐inflammatory and antioxidative effects of the methanolic extract of the aerial parts of Mitracarpus frigidus (MFM) and its chemical fingerprint.

Antimicrobial, antioxidant and cytotoxicity potential of Manihot multifida (L.) Crantz (Euphorbiaceae)

Manihot multifida (L.) Crantz (Euphorbiaceae) is widely used in popular medicine for the treatment of infected wounds. This study evaluated the in vitro antioxidant and antimicrobial potential of this species against strains of Gram-positive and Gram-negative bacteria and fungi, known to cause infections in humans. The extracts showed minimal inhibitory concentration (MIC) varying from 39 to 2500 µg/mL for antimicrobial activity. The methanolic extract of fruits, aqueous and hexane extracts of leaves showed a very strong activity against Candida albicans (ATCC 18804) with MIC of 39 µg/mL. Furthermore, the methanolic extract of M. multifida leaves exhibited DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging potential with inhibitory concentration (IC50) values of 46.9 μg/mL, followed by hexane extract of leaves with IC50 values of 59.2 μg/mL. The cytotoxic activity against brine shrimp was stronger for the methanolic extract of leaves (lethal concentration - LC50 of 15.6 µg/mL). These results suggest that M. multifida has interesting antimicrobial and antioxidant activities. Moreover, these results corroborate the popular use of this specie in treating fungal infections since it demonstrates significant activity against C. albicans.

In‐vivo laxative and toxicological evaluation and in‐vitro antitumour effects of Mitracarpus frigidus aerial parts

Objectives  To evaluate the in‐vitro antitumour properties, and the in‐vivo laxative and toxicological effects of the methanolic extract of the aerial parts of Mitracarpus frigidus (MFM).