Dâmaris Silveira

Antimicrobial and cytotoxic activities screening of some Brazilian medicinal plants used in Governador Valadares district

Os extratos etanolicos de plantas medicinais utilizadas por moradores da cidade de Governador Valadares foram avaliados quanto as atividades antimicrobiana e citotoxica. A pesquisa de campo foi realizada durante o periodo de 1997-2000, por meio de entrevistas com os raizeiros locais. Foram avaliados 33 extratos brutos de um total de 32 especies. Desses extratos, dez apresentaram toxicidade as larvas de Artemia salina (DL50<1000 ppm): Costus pisonis, Cymbopogon nardus, Eclipta alba, Eleutherine bulbosa, Erigium foetidium, Euphorbia tirucalli, Mikania hirsutissima, Momordica charantia, Solidago microglossa e Plectranthus ornatus. Quanto a atividade antimicrobiana, nenhum dos extratos apresentou atividade contra Escherichia coli. Entretanto, treze extratos mostraram-se ativos contra Staphylococcus aureus: E. alba, Scoparia sp., Arctium lappa, Chammomila tinctoria, E. bulbosa, M. hirsutissima, S. microglossa, Stachytarpheta dichotoma, Pffafia glomerata, Stenorrhyrchnus lanceolatum, Vernonia condensata e Lippia alba.

A biotechnology perspective of fungal proteases.

Proteases hydrolyze the peptide bonds of proteins into peptides and amino acids, being found in all living organisms, and are essential for cell growth and differentiation. Proteolytic enzymes have potential application in a wide number of industrial processes such as food, laundry detergent and pharmaceutical. Proteases from microbial sources have dominated applications in industrial sectors. Fungal proteases are used for hydrolyzing protein and other components of soy beans and wheat in soy sauce production. Proteases can be produced in large quantities in a short time by established methods of fermentation. The parameters such as variation in C/N ratio, presence of some sugars, besides several other physical factors are important in the development of fermentation process. Proteases of fungal origin can be produced cost effectively, have an advantage faster production, the ease with which the enzymes can be modified and mycelium can be easily removed by filtration. The production of proteases has been carried out using submerged fermentation, but conditions in solid state fermentation lead to several potential advantages for the production of fungal enzymes. This review focuses on the production of fungal proteases, their distribution, structural-functional aspects, physical and chemical parameters, and the use of these enzymes in industrial applications.

Anxiolytic and antidepressant-like effects of Melissa officinalis (lemon balm) extract in rats: Influence of administration and gender

Objective: To analyse the behavioral effects of Melissa officinalis extract in rats following acute or subacute treatment. Materials and Methods: The behavioral effects of an acute or subacute (10-day course) orally administered M. officinalis (MO; 0, 30, 100 or 300 mg/kg) ethanol extract were evaluated in male and female Wistar rats in elevated plus-maze (EPM), forced swimming (FS) and open field (OF) tests. The effects of diazepam (DZP; 1 mg/kg) and fluoxetine (FXT; 10 mg/kg) were also assessed. Results: In the EPM test, the percentage of open arm entries and open arm times of both males and females given the subacute M. officinalis ethanol extract were significantly higher than those of the vehicle-treated animals but were at levels similar to those observed in the DZP group, regardless of the treatment length. In the FS test, immobility duration was significantly lower in both males and females treated with the plant extract when compared to vehicle-treated counterparts. A 10-day treatment with FXT induced the same antidepressant response, regardless of gender, and was more effective than the M. officinalis extract. Male and female rats demonstrated distinct gender profiles, and treatment × gender interactions were observed. Locomotion in the EPM and OF tests was not significantly altered by treatments. Conclusion: The potential psychoactive properties of M. officinalis may provide a unique pharmacological alternative for certain psychiatric disorders; however, the efficacy appears to be dependent on both gender and administration length.

Genus Pouteria: chemistry and biological activity

The genus Pouteria belongs to the family Sapotaceae and can be widely found around the World. These plants have been used as building material, as food, because the eatable fruits, as well as remedies in folk medicine. Some biological activities have been reported to species of this genus such as antioxidant, anti-inflammatory, antibacterial and antifungal. However, the real potential of this genus as source of new drugs or phytomedicines remains unknown. Therefore, a review of the so far known chemical composition and biological activities of this genus is presented to stimulate new studies about the species already reported moreover that species have no reference about chemistry or biological activities could be found until now.

Plants from Brazilian Cerrado with Potent Tyrosinase Inhibitory Activity

The increased amount of melanin leads to skin disorders such as age spots, freckles, melasma and malignant melanoma. Tyrosinase is known to be the key enzyme in melanin production. Plants and their extracts are inexpensive and rich resources of active compounds that can be utilized to inhibit tyrosinase as well as can be used for the treatment of dermatological disorders associated with melanin hyperpigmentation. Using in vitro tyrosinase inhibitory activity assay, extracts from 13 plant species from Brazilian Cerrado were evaluated. The results showed that Pouteria torta and Eugenia dysenterica extracts presented potent in vitro tyrosinase inhibition compared to positive control kojic acid. Ethanol extract of Eugenia dysenterica leaves showed significant (p<0.05) tyrosinase inhibitory activity exhibiting the IC50 value of 11.88 µg/mL, compared to kojic acid (IC50 value of 13.14 µg/mL). Pouteria torta aqueous extract leaves also showed significant inhibitory activity with IC50 value of 30.01 µg/mL. These results indicate that Pouteria torta and Eugenia dysenterica extracts and their isolated constituents are promising agents for skin-whitening or antimelanogenesis formulations.

Active compounds and medicinal properties of Myrciaria genus.

The genus Myrciaria occurs in various Brazilian biomes. Its species contains several active components, including phenolic compounds, such as tannins, flavonoids, ellagic acid and anthocyanins. Biological activities reported for Myrciaria fruits and leaf and bark extracts include antioxidant, antibacterial and antifungal effects. This work aims to provide an overview of the active compounds of Myrciaria, highlighting its secondary metabolites and medicinal properties for stimulating new studies regarding this genus.

Regulation of herbal medicines in Brazil: advances and perspectives

The National Policy of Integrative and Complementary Practices (PNPIC) in the Brazilian Unified Health System (SUS), and The National Policy of Medicinal Plants and Herbal Medicines (PNPMF) were launched in 2006. Based on these, the Brazilian Health Surveillance Agency (ANVISA) re-edited rules related to herbal medicines such as the Guideline to herbal medicine registration (RDC 14/10), the Good Manufacture Practices Guideline (RDC 17/10) and the List of references to assess the safety and efficacy of herbal medicines (IN 05/10). The requisites to prove herbal medicines safety and efficacy were updated. Therefore, this review aims at presenting and commenting these new rules.

Synthesis and biological evaluation of new salicylate macrolactones from anacardic acids

In connection with our ongoing investigation in the search for new bioactive compounds using non-isoprenoid phenolic lipids from Anacardium occidentale as starting material, we describe the synthesis and cytotoxicity screening of some novel salicylate macrolactones prepared from anacardic acids, the major constitutents of natural cashew nut-shell liquid (CNSL).

Characterization and biological properties of Pouteria torta extracts: a preliminary study

Hexane, ethanol and aqueous extracts and fractions from leaves of Pouteria torta (Mart.) Radlk (Sapotaceae), a perennial tree, widespread in the Brazilian Cerrado, were tested for cytotoxicity with the Artemia salina toxicity model. Only the aqueous crude extract and the MeCN:CHCl3 fraction of the ethanol extract presented toxicity (0.28 mg/mL and 0.27mg/mL, respectively). Lupeol acetate was isolated from the hexane extract. It is the first report of lupeol acetate from the genus Pouteria.

Cytotoxic effect of tobacco extracts on human oral squamous cell carcinoma cell-line

Cancer is a public health problem worldwide. Incidences of oral carcinomas are increasing in the last decades, and the developed countries are the most affected. Current therapeutic options for this type of cancer are aggressive and/or invasive, including surgery, radiotherapy and chemotherapy. In addition, they have not yet translated into an improvement of life quality or expectancy to patients. In this scenario, new therapeutics are urgently needed and actively sought after. The goal of this study was to investigate the cytotoxic effects of tobacco crude extract (TCE) and two fractions thereof in the human lineage of oral squamous cell carcinoma, OSCC-3. Exposure of human oral cancer cells to TCE-induced cell death and decreased cell viability in a dose-dependent manner. Of the fractions tested, one was able to induce significant cell death (over 50%) after 48 h treatment. DNA fragmentation and caspase-3 activation indicated that the type of cell death induced by TCE and its fraction was apoptosis. Our results indicate that tobacco contains compounds that could be useful in inducing apoptosis in cancer cells. More specifically, because of the neutral chemical nature of the fraction capable of inducing apoptosis, we postulate that the putative compound responsible for the cell death is non-polar. Further investigation is needed to uncover its chemical nature and structure.