Propolis: Is there a potential for the development of new drugs?

Introduction: Propolis has plenty of biological and pharmacological properties and its mechanisms of action have been widely investigated in the last years, using different experimental models in vitro and in vivo. Researchers have been interested in the investigation of isolated compounds responsible for propolis action; however, there is lack of clinical research on the effects of propolis.Strategy and objectives: Since propolis-containing products have been marketed and humans have used propolis for different purposes, the goal of this review is to discuss the potential of propolis for the development of new drugs, by comparing data from the literature that suggest candidate areas for the establishment of drugs against tumors, infections, allergy, diabetes, ulcers and with immunomodulatory action.Conclusions: The efficacy of propolis in different protocols in vitro and in vivo suggests its therapeutic properties, but before establishing a strategy using this bee product, it is necessary to study: (a) the chemical nature of the propolis sample. (b) Propolis efficacy should be compared to well-established parameters, e.g. positive or negative controls in the experiments. Moreover, possible interactions between propolis and other medicines should be investigated in humans as well. (c) Clinical investigation is needed to evaluate propolis potential in patients or healthy individuals, to understand under which conditions propolis may promote health. Data point out the importance of this research field not only for the readers and researchers in the scientific community waiting for further clarification on the potential of propolis but also for the pharmaceutical industry that looks for new drugs. (C) 2010 Elsevier B.V. All rights reserved.

Anti-coagulase-negative Staphylococcus activity of ethanolic extracts of propolis from two Brazilian regions and synergism with antimicrobial drugs by the E-test method

Propolis is a natural resinous substance collected by bees from vegetal sources and its therapeutic properties have been investigated. In this work, we evaluated the inhibitory activity of ethanolic extracts of propolis (EEP) from the Southeast and South of Brazil on coagulase-negative Staphylococcus (CNS) growth as well as the EEP in vitro synergism with antimicrobial drugs by using the diffusion method (E-test). The EEP chemical characteristics (dry weight, pH, flavonoid and phenolic compounds) were determined. Seven drugs were tested, and synergism was observed between three drugs and Southeast EEP, six drugs and South EEP, and one drug and ethanol control. Ethanolic extracts of propolis from the South of Brazil presented the greatest flavonoid content and synergism rate, while EEP from the Southeast presented the greatest anti-CNS activity and phenolic compound content. Results showed the correlation among anti-CNS activity, synergism rate and chemical characteristics of propolis.

On the search for potential anti-Trypanosoma cruzi drugs: Synthesis and biological evaluation of 2-hydroxy-3-methylamino and 1,2,3-triazolic naphthoquinoidal compounds obtained by click chemistry reactions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cytogenetic damage of oral mucosa by consumption of alcohol, tobacco and illicit drugs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Enzymatic Activity, Sensitivity to Antifungal Drugs and Baccharis dracunculifolia Essential Oil by Candida Strains Isolated from the Oral Cavities of Breastfeeding Infants and in Their Mothers' Mouths and Nipples

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Electrochemical, Spectrophotometric and Liquid-Chromatographic Approaches for Analysis of Tropical Disease Drugs

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Patents of drugs extracted from Brazilian medicinal plants

Background: Plants synthesise a vast repertoire of chemicals with various biological activities. Brazilian enormous botanical diversity facilitates the development of novel ethical drugs for the treatment of diseases in humans. Objective: To present therapeutic patent applications comprising Brazilian native plants published in the 2003 - 2008 period in light of legal aspects of patentability of biodiversity and public health concerns. Methods: Therapeutic patent applications related to Brazilian medicinal plants available at both the European Patent Office and the Brazilian National Institute of industrial Property databases were reviewed. Results/conclusion: Twenty-five patents are presented, most of which concern inflammatory, allergic, parasitic, infectious or digestive diseases, including extracts from Carapa guianensis, Copaifera genus, Cordia verbenacea, Erythrina mulungu, Physalis angulata and other pharmaceutical compositions with antileishmanial, antimalarial or trypanocidal activity. Brazilian research centres and universities are responsible for most of these inventions.

Clinical research on new drugs (Phase I). Profile of scientific publications: data from the pre-clinical phase and bioethical aspects

OBJETIVO: Traçar o perfil das publicações científicas de fase I e procurar saber se a publicação oferece dados da fase pré-clínica com ênfase nos aspectos bioéticos. MÉTODOS: Foram analisados 61 artigos científicos publicados no ano de 2007, que relatam pesquisas envolvendo seres humanos com novos fármacos, medicamentos ou vacinas em fase I. Foi elaborado um roteiro para coleta de dados, com o qual fosse possível analisar e avaliar os artigos científicos. O roteiro contempla itens referentes à fase pré-clínica (associados à fase clínica) e itens referentes às características da amostra. RESULTADOS: Nos artigos analisados, a maioria das pesquisas foi realizada nos EUA. Devido ao grande número de publicações destinadas às doenças oncológicas a maioria delas foi realizada com voluntários doentes. Quanto às informações sobre a fase pré-clínica presente nas publicações de fase I observamos que são pobres ou inexistentes. Mesmo que os autores julguem a pesquisa fase I como promissora e sugiram estudos futuros de fase II, ao leitor não é possível este mesmo julgamento pela escassez de informações da fase pré-clínica. CONCLUSÃO: O perfil das publicações levanta dados que merecem reflexão e análise para melhor avaliação do que está ocorrendo com as publicações de fase I.

Oral drugs for hypertensive urgencies: systematic review and meta-analysis

CONTEXTO E OBJETIVO: Urgências hipertensivas são definidas como elevações graves na pressão arterial sem evidência de danos agudos ou progressivos a órgãos-alvo. A necessidade de tratamento é considerada urgente, mas permite um controle gradual, utilizando-se drogas orais ou sublinguais. Se o aumento na pressão arterial não está associado a risco de vida ou danos a órgãos alvo, o controle pressórico deve ser feito lentamente durante 24 horas. em relação às urgências hipertensivas, não é conhecida qual a classe de drogas anti-hipertensivas que promove os melhores resultados e há controvérsia em relação a quando e quais as drogas devem ser utilizadas nestas situações. O objetivo desta revisão foi avaliar a efetividade e a segurança de drogas orais para urgências hipertensivas. METODOS: Esta revisão sistemática da literatura foi desenvolvida no Centro Cochrane do Brasil, e na Disciplina de Medicina de Urgência e Medicina Baseada em Evidências da Universidade Federal de São Paulo (UNIFESP) - Escola Paulista de Medicina (Unifesp-EPM), de acordo com a metodologia da Colaboração Cochrane. RESULTADOS: Os 16 ensaios clínicos aleatórios selecionados incluíram 769 participantes e demonstraram um efeito superior dos inibidores da enzima conversora de angiotensina no tratamento da urgência hipertensiva, avaliada em 223 participantes. Os efeitos adversos mais frequentes para os bloqueadores de canal de cálcio foram cefaleia (35/206), rubor (17/172) e alterações do ritmo cardíaco (14/189); para os inibidores da enzima conversora de angiotensina, o efeito colateral mais frequente foi disgeusia (25/38). CONCLUSÕES: Há evidências importantes a favor do uso de inibidores da enzima conversora da angiotensina para o tratamento de urgências hipertensivas, quando comparados aos bloqueadores dos canais de cálcio, devido a maior efetividade e à menor frequência de efeitos adversos, como cefaléia e rubor facial.

Effects of tea from Turnera ulmifolia L. on mouse gastric mucosa support the Turneraceae as a new source of antiulcerogenic drugs

Turnera ulmifolia is a plant belonging to the family Turneraceae, popularly known in Brazil as chanana. This species is distributed from Guyana to southern Brazil where it is considered a weed. The plant occurs in tropical rain forest, fields, and gardens. Chanana tea is used in Brazilian folk medicine for the treatment of diseases related mainly to gastric dysfunction including gastric and duodenal ulcers. In this study, the ability of a lyophilized infusion, as an aqueous fraction (AqF) of the aerial parts of T. ulmifolia, was investigated for its ability to prevent ulceration of the gastric and duodenal mucosa was examined in mice and rats, respectively. The AqF significantly reduced the formation of lesions associated with HCl/ethanol administration by 39% and 46%, respectively, at doses of 500 mg/kg and 1000 mg/kg, p.o. The AqF also significantly reduced the incidence of gastric lesions induced by a combination of indomethacin and bethanechol by 58% and 72% at doses of 500 mg/kg and 1000 mg/kg, respectively. In stress-induced gastric ulcer, the inhibition by the AqF was 48%, 57%, and 58% at doses of 250 mg/kg, 500 mg/kg, and 1000 mg/kg, respectively (p<0.05). A pyloric ligature experiment showed that the highest dose of the AqF significantly affected the gastric juice parameters by increasing the pH from 2.5 (control) to 5.3 and decreasing the acid output from 11.3 (control) to 3.7 mEq/ml/4 h. The AqF had no significant effect on duodenal ulcers induced by cysteamine. Preliminary phytochemical screening confirmed that flavonoids were the major constituents of the AqF of T. ulmifolia. These results indicate that this extract has a significant antiulcerogenic effect, as popularly believed.

In vitro susceptibility testing of Microsporum gypseum isolated from healthy cattle and soil samples against itraconazole, terbinafine, fluconazole and topical veterinarian drugs

The present study evaluated in vitro susceptibility testing of dermatophytes isolates from healthy cattle and soil samples against three antifungal agents and three topical veterinarian drugs. Itraconazole and terbinafine showed a higher in vitro fungicidal activity than fluconazole. The veterinarian drugs LEPECID (R) and iodine 5% were more active in vitro than the UNGUENTO (R) spray. All drugs showed fungicidal activity against Microsporum gypseum, and they may be considered as efficient agents for the topical treatment of dermatophytoses in cattle.

A 4.2 kDa synthetic peptide as a potential probe to evaluate the antibacterial activity of coumarin drugs

The coumarin antibiotics are potent inhibitors of DNA replication whose target is the enzyme DNA gyrase, an ATP-dependent bacterial type II topoisomerase. The coumarin drugs inhibit gyrase action by competitive binding to the ATP-binding site of DNA gyrase B protein. The production of new biologically active products has stimulated additional studies on coumarin-gyrase interactions. In this regard, a 4.2 kDa peptide mimic of DNA gyrase B protein from Escherichia coli has been designed and synthesized. The peptide sequence includes the natural fragment 131-146 (coumarin resistance-determining region) and a segment containing the gyrase-DNA interaction region (positions 753-770). The peptide mimic binds to novobiocin (K-a = 1.4 +/- 0.3 x 10(5) m(-1)), plasmid (K-a = 1.6 +/- 0.5 x 10(6) m(-1)) and ATP (K-a = 1.9 f 0.4 x 10(3) m(-1)), results previously found with the intact B protein. on the other hand, the binding to novobiocin was reduced when a mutation of Arg-136 to Leu-136 was introduced, a change previously found in the DNA gyrase B protein from several coumarin-resistant clinical isolates of Escherichia coLi. In contrast, the binding to plasmid and to ATP was not altered. These results suggest that synthetic peptides designed in a similar way to that described here could be used as mimics of DNA gyrase in studies which seek a better understanding of the ATP, as well as coumarin, binding to the gyrase and also the mechanism of action of this class of antibacterial drugs. Copyright (C) 2004 European Peptide Society and John Wiley Sons, Ltd.

New anti-Alzheimer drugs from biodiversity: the role of the natural acetylcholinesterase inhibitors

Alzheimer's disease (AD) is a progressive neurodegenerative pathology with severe economic and social impact. There is currently no cure, although cholinesterase inhibitors provide effective temporary relief of symptoms in some patients. Nowadays, drug research and development are based on the cholinergic hypothesis that supports the cognition improvement by regulation of the synthesis and release of acetylcholine in the brain. There are only four commercial medicines approved for treatment of AD, and natural products have played an important alternative role in the research for new acetylcholinesterase inhibitors, as exemplified through the discovery of galantamine. This profile conducts us to give in this paper an overview relating the several classes of natural products with anti-cholinesterasic activity as potential templates to the design of new selective and powerful anti-Alzheimer drugs.