Patrícia de Aguiar Amaral

Evaluation of the genotoxic and antigenotoxic potential of Melissa officinalis in mice

Melissa officinalis (L.) (Lamiaceae), a plant known as the lemon balm, is native to the east Mediterranean region and west Asia. Also found in tropical countries, such as Brazil, where it is popularly known as “erva-cidreira” or “melissa”, it is widely used in aqueous- or alcoholic-extract form in the treatment of various disorders. The aim was to investigate in vivo its antigenotoxicity and antimutagenicity, as well as its genotoxic/mutagenic potential through comet and micronucleus assaying. CF-1 male mice were treated with ethanolic (Mo-EE) (250 or 500 mg/kg) or aqueous (Mo-AE) (100 mg/kg) solutions of an M. officinalis extract for 2 weeks, prior to treatment with saline or Methyl methanesulfonate (MMS) doses by intraperitoneal injection. Irrespective of the doses, no genotoxic or mutagenic effects were observed in blood and bone-marrow samples. Although Mo-EE exerted an antigenotoxic effect on the blood cells of mice treated with the alkylating agent (MMS) in all the doses, this was not so with Mo-AE. Micronucleus testing revealed the protector effect of Mo-EE, but only when administered at the highest dose. The implication that an ethanolic extract of M. officinalis has antigenotoxic/antimutagenic properties is an indication of its medicinal relevance.

Total synthesis of (−)-epimyrtine by a gold-catalyzed hydroamination approach

Summary A new approach to the total synthesis of (−)-epimyrtine has been developed from D-alanine. The key step to access the enantiopure pyridone intermediate was achieved by a gold-mediated cyclization. Finally, various transformations afforded the natural product in a few steps and good overall yield.

Kavain analogues as potential analgesic agents

BACKGROUND Kavalactones are pharmacologically active compounds present in preparations of the root trunk of Piper methysticum Forst, known as kava. This work describes the analgesic activity of some synthesized analogues of synthetic kavain, which is the main component of kava. METHODS The essays were initially performed against the writhing test in mice, and the most promising compound was analyzed using other classical models of nociception, including formalin-, capsaicin-, glutamate-induced nociception, the hot plate test, and measurement of motor performance. RESULTS The results indicated that compound 6-(4-fluorophenyl)-4-methoxy-5,6-dihydropyran-2-one (2d) exerts potent and dose-dependent analgesic activity, inhibiting abdominal constrictions caused by acetic acid in mice, and being more active than some reference drugs. It also presented activity in the other models of pain, with the exception of the hot plate test and the measurement of motor performance. CONCLUSIONS Although compound 2d exerts antinociceptive activity, the mechanism of action remains uncertain, but it does not involve the opioid system and does not appear to be associated with non-specific effects such as changes in locomotor activity or motor coordination.

Popular medicinal uses of Calea uniflora Less. (Asteraceae) and its contribution to the study of Brazilian medicinal plants

Calea uniflora Less. is widely used in southern Santa Catarina (Brazil), but there are no scientific studies which support its use. Then, this study was proposed to determine of the percentage use of C. uniflora in a city of southern Brazil and documentation of the knowledge that the population has about this species. The survey was conducted with semi-structured interviews using a questionnaire applied to 372 participants. In analyzing the results, it was observed that of the 94.1% who recognized C. uniflora, 74.3% utilize it as a medicinal plant and 65.4% of such knowledge originates in childhood, mainly through the family (84.6%). 93% reported using inflorescences macerated in alcohol or rum; this extract is generally used topically for wound healing and muscle pain. Furthermore, some reported using small quantities of this extract orally to treat cold and flu. Regarding effectiveness and safety, 97% stated an improvement in symptoms with the use of the plant, while 98.5% stated that it has no toxicity. In light of these results, future phytochemical, pharmacological and toxicological analyses should be designed in order to ensure rational and safe use of this species.

Influence of Mikania laevigata Extract over the Genotoxicity Induced by Alkylating Agents

Medicinal plants are still widely used worldwide; yet for some species, little or no information is available concerning their biological activity, specially their genotoxic and antimutagenic potential. Mikania laevigata (Asteraceae) is a native plant from South America, and its extracts are largely used to treat respiratory complaints. The aim of the present work was then to evaluate, in vivo, the potential biological activity of M. laevigata on the genotoxicity induced by methyl methanesulfonate (MMS) and cyclophosphamide (CP), using the comet assay. Male CF1 mice were divided into groups of 5-6 animals, received by gavage 0.1 mL/10 g body wt of water, Mikania laevigata extract (MLE), MMS, and CP. Results showed that treatment with 200 mg/kg of the MLE previously to MMS and CP administration, respectively, reduced the damage index (DI) in 52% and 60%, when compared to DI at 24 h. Pretreatment also reduced the damage frequency (DF) in 56% (MMS) and 58% (CP), compared to DF at 24 h. MLE administration has been shown to protect mouse DNA from damage induced by alkylating agents; this corroborates to the biological activities of M. laevigata and points towards the need of plant compounds isolation to proceed with further studies.

Hibiscus acetosella extract protects against alkylating agent-induced DNA damage in mice

Hibiscus acetosella was shown to exert beneficial effects in humans and animal models however, the effects of this plant on DNA are unknown. The aim of this study was to determine the antigenotoxic and antimutagenic effects of H. acetosella extracts on alkylating agent methyl methanesulfonate (MMS) in vivo in mice. Initially, we performed analysis of phenolic compounds in extracts of H. acetosella by high-performance liquid chromatography (HPLC). Next, mice were divided into 8 groups and treated with distilled water or plant extract (0.1 ml/10 g) by gavage for 15 days, followed by intraperitoneal (ip) administration of saline solution or MMS (40 mg/Kg b.w) on day 16. Caffeic acid, following by gallic acid, gallocatechin, coumaric acid, and 3,4-dihydroxybenzoic acid were found to be present in extracts of H. acetosella leaves. In peripheral blood analysis of groups receiving pretreatment with H. acetosella at doses of 50 or 100 mg/kg plus MMS decreased DNA damage as evidenced by comet assay and Micronucleus assays relative to MMS alone. These results suggested that H. acetosella extracts exerted protective effects dose dependent against genotoxicity and mutagenicity induced by alkylating agents.

FLUOROUS SUPPORTED SYNTHESIS OF PYRAZOLONE DERIVATIVES FROM ALLYLIC ALCOHOLS USING A PALLADIUM-CATALYZED STRATEGY

Ten substituted pyrazolone derivatives were easily synthesized from perfluorinated allylic alcohols, via a straightforward two steps reaction involving a Heck-coupling/isomerization reaction and subsequent condensation of hydrazines. This fluorous supported methodology, that combines a cyclo-release approach and F-SPE purification allows for the obtaining of the final products with a good purity.

PELARGONIUM SIDOIDES DC. (UMCKALOABO): HISTÓRICO DO USO, ASPECTOS TAXONÔMICOS, ECOLÓGICOS, FITOQUÍMICOS, FARMACOLÓGICOS E TOXICOLÓGICOS

Considerando que Pelargonium sidoides DC. e usado tradicionalmente na Africa do Sul e na Alemanha para infeccao das vias respiratorias, incluindo sinusite e tuberculose, alem de apresentar baixo potencial de efeitos adversos, tanto para adultos como para criancas, objetivou-se realizar um levantamento bibliografico observando as publicacoes disponiveis nas bases Google Academico, Biblioteca Virtual em Saude (BVS), Portal CAPES, PUBMED, MEDLINE, publicadas nos ultimos 20 anos sobre os aspectos etnobotânicos, taxonomicos, ecologicos, fitoquimicos, farmacologicos e toxicologicos da especie, na perspectiva de fornecer informacoes para sua utilizacao segura e racional.

A Síntese Fluorosa Assistida por Micro-ondas

A Sintese Fluorosa emprega um suporte fluoroso soluvel (cadeias perfluoroalquiladas – Rf) para aumentar a eficiencia da purificacao das misturas de reacao. Esta tecnica aliada a irradiacao com micro-ondas, geralmente, fornece compostos em maiores rendimentos e com grande diversidade quimica num curto espaco de tempo. Este manuscrito apresenta a sintese fluorosa e explora as suas vantagens quando assistida por micro-ondas. Em adicao, algumas publicacoes da literatura recente sao brevemente apresentadas. DOI: 10.5935/1984-6835.20100027

The use of microwave irradiation in the fluorous synthesis

Abstract: Fluorous Synthesis employs perfluoroalkyl (Rf) hai s as phase tags to i prove the effi ie y of the purification of reaction mixtures. This method allied to microwave irradiation led to compounds in high yields and chemical diversity in shorter time. This manuscript presents the fluorous synthesis and explores the advantages of the microwave fluorous synthesis. Futhermore, some papers from the recent literature are quickly presented.