João Carlos Palazzo de Mello

Effects of medicinal plant extracts on growth of Leishmania (L.) amazonensis and Trypanosoma cruzi

This study describes the screening of extracts obtained from 19 species of plants used in Brazilian traditional medicine for treatment of a variety of diseases. The extracts were tested against axenic amastigote and promastigote forms of Leishmania (L.) amazonensis, and epimastigote forms of Trypanosoma cruzi in vitro at a concentration of 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, and Tanacetum vulgare showed significant effects against one or both parasites, with a percentage of growth inhibition between 49.5 and 99%. The extracts showed no cytotoxic effect on sheep erythrocytes. These medicinal plants may be sources of new compounds that are clinically active against L. amazonensis and T. cruzi.

Toxicological studies on Stryphnodendron adstringens

This study was carried out to determine the acute toxicity of total barbatimão extract (LD(50)) after oral administration to mice, and its effect on certain biochemical parameters in plasma of rats after 30 days of administration. The LD(50) value of the extract was 2699 mg/kg. A daily oral administration of extracts at 800 and 1600 mg/kg doses for 30 days caused a decrease in body weight, thymic involution, and an increase of plasma glucose and aspartate aminotransferase levels in the animals. The results showed that the extract administered in a prolonged period produced toxic effects in the experimental animals.

Practical Cost-Based Approach for the Voltage Ancillary Service

The restructuring and deregulation of the electricity sector most noticeably involves the introduction of competition into energy supply. In parallel with this, however, there is an increasing desire amongst transmission system operators, generators, and consumers for commercial principles to be applied to transmission services, including the provision of voltage support and reactive power control. The identification of the costs of providing such services is an important first step towards developing a transmission services market. Implementing a payment structure based on the remuneration of incurred costs can be an attractive option to commercial power sector players, who wish such costs to be recoverable at an appropriate rate of retum, and system operators, who need to be assured of the availability of the necessary services. This paper addresses both the principles and practical issues involved in developing cost-based payments for reactive power, with reference to the ongoing restructuring of the Brazilian power sector.

Anti-inflammatory activity and lipid peroxidation inhibition of iridoid lamiide isolated from Bouchea fluminensis (Vell.) Mold. (Verbenaceae).

Anti-inflammatory activity of an ethanolic extract from Bouchea fluminensis leaves was demonstrated. From de ethanolic extract, the active compound was isolated and characterized as the iridoid lamiide. The activity of lamiide on rat-brain phospholipid peroxidation showed a powerful effect (IC(50)=0.92+/-0.01 mM) and an anti-inflammatory activity in carrageenin-induced paw edema test (ED(50)=62.3+/-7 mg/kg weight).

Antimicrobial and cytotoxic activities of medicinal plants of the Brazilian cerrado, using Brazilian cachaça as extractor liquid

ETHNOPHARMACOLOGICAL IMPORTANCE Many species of plants in the Brazilian cerrado (savanna) are widely used in ethnomedicine. However, the safety and effectiveness of medicinal plants used in communities with little or no access to manufactured drugs should be evaluated. AIM OF THE STUDY Evaluate the antimicrobial and cytotoxic activities of extracts from eight plant species, obtained using Brazilian cachaça as the extractor liquid. MATERIALS AND METHODS The extracts were tested against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Candida parapsilosis, promastigote forms of Leishmania amazonensis, and poliovirus. In addition, cytotoxic activity was assayed in Vero cells and in human erythrocytes. RESULTS The plant species Curatella americana, Sclerolobium aureum, and Plathymenia reticulata showed the best activity against yeasts, especially the crude extract of C. americana and its ethyl-acetate fraction. Kielmeyera lathrophyton showed a minimum inhibitory concentration of 250 μg/ml against S. aureus, and was inactive against gram-negative bacteria. The extract obtained from Annona coriacea showed the best activity against the promastigote forms of Leishmania amazonensis (IC(50)=175 μg/ml). Only C. americana showed potential for antipoliovirus activity. The concentrations of the crude extracts that showed toxicity to VERO cells had CC(50) between 31 and 470 μg/ml, and the lyophilized Brazilian cachaça showed a CC(50) of 307 μg/ml. None of the extracts showed toxicity against human erythrocytes. CONCLUSIONS Among the plant species studied, C. americana proved to be effective against microorganisms, especially as an antifungal. The results will help in the search for alternative drugs to be used in pharmacotherapy, and will contribute to establish safe and effective use of phytomedicines in the treatment of infectious diseases.

Antioxidant and antifungal activities of extracts and condensed tannins from Stryphnodendron obovatum Benth.

The antioxidant activity of stem-bark extracts from Stryphnodendron obovatum Benth., including fractions and isolated compounds, was evaluated by DPPH in thin-layer chromatography. All the fractions and isolated compounds showed antioxidant activity. Antifungal activity was determined by the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) against the yeasts Candida albicans, Candida parapsilosis, Candida krusei and Candida tropicalis. All extracts (CE, EtOAc and FW), subfractions (F1-F12) and the compounds I, II and III were inactive against the yeasts. Against C. parapsilosis and C. albicans, fractions F13-15 and F20 showed moderate antifungal activity, and fractions F16-19 and F21-22 showed good activity. Chemical isolation of the ethyl-acetate fraction resulted in the identification of three compounds: epigallocatechin, gallocatechin and epigallocatechin-(4b®8)-gallocatechin.

As monografias sobre plantas medicinais

The medicinal plants monographs are very important information collections about some of the most consumed plants all over the world that attend not only the regulatory agencies but also pharmaceutical industries and the general consumer. This manuscript reviews the origins, objectives and formats of the most important monographs, like Commission E, American Botanical Council, ESCOP, PDR and WHO. Two recently published Brazilian experiences organized by FIOCRUZ and the contributions from Brazilian Pharmacopoeia are also evaluated.

Thiophene Derivatives with Antileishmanial Activity Isolated from Aerial Parts of Porophyllum ruderale (Jacq.) Cass.

Porophyllum ruderale (Jacq.) Cass. is a plant native to Brazil and in the northwest region of the state of Paraná, Brazil, aerial parts of P. ruderale have been used popularly in the treatment of lesions caused by Leishmania sp.. In this study the antileishmanial and cytotoxic activities of the crude extract, fractions, and isolated compounds from aerial parts of P. ruderale was evaluated. The dichloromethane extract was submitted to chromatography to yield compounds active against Leishmania amazonensis. Their structures were established by comparison of their spectroscopic data with literature values. The activities of crude extract against promastigote and axenic amastigote forms of L. amazonensis (IC50) were 60.3 and 77.7 μg/mL, respectively. Its cytotoxic activity against macrophage cells (CC50) was 500 μg/mL. The thiophene derivatives isolated were: 5-methyl-2,2′:5′,2″-terthiophene (compound A) and 5′-methyl–[5–(4–acetoxy-1–butynyl)]–2,2′-bithiophene (compound B). The activity of compound A against promastigote and axenic amastigote forms were 7.7 and 19.0 μg/mL and of compound B were 21.3 and 28.7 μg/mL, respectively. The activity of the isolated compounds against promastigote and axenic amastigote forms was better than that of the crude extract and more selective against protozoa than for macrophage cells.

Acute and subchronic toxicological evaluation of the semipurified extract of seeds of guaraná (Paullinia cupana) in rodents.

We evaluated the toxicity of a semipurified extract (EPA fraction, containing caffeine and several flavan-3-ols and proanthocyanidins) of seeds of the native Amazon plant Paullinia cupana (guaraná) in rodents. Acute toxicity was tested in male Swiss mice, which received different doses orally (OR) and intraperitoneally (ip); control groups received water. These tests produced acute mortality, with LD(50) of 1.825 g/kg (OR) and 0.827 g/kg (ip), and a significant weight decrease in lungs of mice receiving a dose of 0.1g/kg. In the repeated-dose toxicity test, the EPA was administered OR daily to male and female Wistar rats at doses of 30, 150, and 300 mg/kg/day/90 days. Their behavior, mortality, weight changes, laboratory tests, and the weights and histopathology of organs were evaluated. No rats died during the tests. Males dosed at 150 or 300 mg/kg gained weight more slowly and lost kidney weight (absolute and relative weights, compared to the control group). Hematological and biochemical tests showed few changes, differing somewhat between males and females; the histopathological evaluation indicated no significant changes. These results indicate that the EPA fraction of guaraná caused no toxicity in rats at the smallest dose evaluated (30 mg/kg). No other species was evaluated.

Dual effects of crude extracts obtained from Petiveria alliacea L. (Phytolaccaceae) on experimental anxiety in mice.

AIM OF THE STUDY Different preparations obtained from P. alliacea have been traditionally used in South America and Brazil for many medical conditions. To investigate the effects of fresh whole plant (WP) extract, aerial part (AP) extract, and root (R) extract obtained from Petiveria alliacea using the elevated plus maze (EPM) model of anxiety in mice. Total flavonoid content present in Petiveria alliacea extracts was also determined. MATERIALS AND METHODS WP, AP, or R (300-900 mg/kg) extracts were orally administered to mice 30 min before they were subjected to the EPM and open field test. Total flavonoid content present in the extracts was determined by spectrophotometry. RESULTS The WP extract (300 and 900 mg/kg) caused anxiolytic-like effects, and the AP extract (300 mg/kg) induced anxiogenic-like effects in mice subjected to the EPM. No effect on anxiety-like behavior was observed with acute administration of the R extract. The content of flavonoids present in the AP extract (1.34%) was almost threefold higher than the flavonoid content present in the WP extract (0.52%). CONCLUSIONS Preparations using different fresh parts of Petiveria alliacea caused opposite effects on experimental anxiety in mice. However, predicting the extent to which flavonoid content present in Petiveria alliacea extracts differentially induces anxiolysis or anxiogenesis in mice was not possible. Further studies will be necessary to elucidate the effects of flavonoids or other substances present in Petiveria alliacea extracts on experimental anxiety.