Intraspecific C-value variation and the outcomes in Psidium cattleyanum Sabine essential oil.

Polyploidy, a numerical alteration of the karyotype, is one of the most important mechanisms in plant speciation and diversification, but could also be detected among populations, the cytotypes. For example, Psidium cattleyanum, a polyploid complex, has chromosome numbers ranging from 2n=3x=33 to 2n=12x=132. Polyploidization causes an increase in DNA content, and both modifications may cause alteration in plant growth, physiology, and epigenetics. Based on this possibility, here we aim to verify the influence of the polyploidization on the production of P. cattleyanum essential oil chemotypes. Differences in the DNA contents, as a proxy to different ploidies, were observed and three distinct chemotypes were identified through the chromatographic profile analysis. The Psidium cattleyanum DNA content and qualitative and quantitative characteristics of the essential oils presented a positive relationship. Plants with higher DNA contents presented higher levels of oil production, which was mostly composed of hydrogenated sesquiterpenes, while plants with lower DNA contents produced lower amount of oil, which was mostly composed of hydrogenated monoterpenes. Based on the importance of essential oils, polyploid plants, which present higher DNA content, are recommended as possible matrices for the propagation of new plants with the potential to produce major compounds of agronomic and pharmacological interest.

Phytotoxicity and cytogenetic action mechanism of leaf extracts of Psidium cattleyanum Sabine in plant bioassays.

The search for more environmental friendly herbicides, aiming at the control of agricultural pests, combinated with less harmfulness to human health and the environment has grown. An alternative used by researchers is the application of products of secondary plant metabolism, which are investigated due to their potential bioactivities. Thus, species belonging to the Myrtaceae family are potential in these studies, since this family is recognized for having high biological activity. A species belonging to this genus is Psidium cattleyanum, which has a medicinal effect and its fruits are used in human food. Thus, the objective of this research was to evaluate and compare the phyto-cyto-genotoxicity of aqueous and ethanolic leaf extracts of the specie P. cattleyanum, from plant bioassays, as well as to identify the main classes of compounds present in the extracts. For this, the extracts were prepared, characterized and biological tests were carried out by evaluating, in seeds and seedlings of lettuce and sorghum, the variables: percentage of germination, germination speed index, root growth and aerial growth; and in meristematic lettuce cells the variables: mitotic phases, mitotic index, nuclear alterations and chromosomal alterations. Flavones, flavonones, flavonols, flavononols, flavonoids, alkaloids, resins, xanthones and anthraquinone glycoside were characterized in the ethanolic extract. Both evaluated extracts, in the highest concentration, inhibited the initial plant development. All treatments caused alterations in the mitotic phases and inhibited mitotic index. In addition, the treatments promoted an increase in nuclear and chromosomal alterations. The mechanism of action presented was aneugenic, clastogenic and determined in epigenetic alterations. The ethanolic extract was more cytotoxic, since it had a more expressive effect at a lower concentration. Despite the cytotoxicity of the extracts under study, they promoted alterations at lower levels than the glyphosate positive control.

Acaricide activity in vitro of Acmella oleracea against Rhipicephalus microplus.

Cattle tick control has been limited by the resistance of these parasites to synthetic acaricides. Natural products are a possible alternative as they have different mechanisms of action. Acmella oleracea is a native plant with a large cultivated area in the Amazon region and could be easily used for large-scale preparation of a commercial product. This study evaluated the in vitro action of the hexane extract of the aerial parts of A. oleracea on larvae and engorged females of the cattle tick Rhipicephalus microplus. Spilanthol was the major constituent with a content of 14.8% in the extract. The hexane extract of A. oleracea was highly effective against larvae of R. microplus with an LC50 of 0.8 mg mL(-1). Against engorged females, hexane extract of A. oleracea reduced oviposition and hatchability of eggs with an LC50 of 79.7 mg mL(-1). Larvae and engorged females were killed by the hexane extract with high efficiency (>95%) at concentrations of 3.1 and 150.0 mg mL(-1), respectively. These results demonstrate that the hexane extract of A. oleracea has significant activity against R. microplus and has potential to be developed into formulations for tick control.

Brazilian scientific production on herbal medicines used in dentistry / Produção científica brasileira sobre o uso de plantas medicinais na odontologia

The objective of this study was to critically analyze the scientific production published in specialized Brazilian journals concerning the use of medicinal plants in dentistry. A literature review was carried out using an indirect documentation technique by means of a bibliographical study. Four examiners performed independent searches in Brazilian journals of medicinal plants indexed in the database SciELO (Brazilian Journal of Pharmacognosy; Brazilian Journal of Medicinal Plants; Brazilian Journal of Pharmaceutical Sciences; and Acta Botanica Brasilica) using the descriptors "herbal medicine/phytotherapy" or "medicinal plants" and "dentistry ". The articles published from 2002 to 2012 addressing the use of medicinal plants in dentistry were included and analyzed. The searches based on the descriptors and reading of abstracts, resulted in 155 articles. Of these, 44 were read in full and a total of 16 publications met the eligibility criteria and were selected. Laboratory studies predominated (10) and were limited to the evaluation of antimicrobial properties by means of tests for determining inhibitory, fungicidal and bactericidal concentrations. Three literature reviews and only one clinical trial with no blinding and randomization were found. It is highlighted the need for better methodological designs in the researches and greater production of clinical or in vivo studies.

O objetivo deste estudo foi analisar criticamente a produção científica acerca do uso de plantas medicinais em Odontologia nos periódicos brasileiros especializados. Realizou-se uma revisão da literatura, utilizando técnica de documentação indireta a partir de um estudo bibliográfico. Quatro pesquisadores procederam, de forma independente, uma busca nas revistas brasileiras de plantas medicinais indexadas na base de dados Scielo (Revista brasileira de farmacognosia; Revista brasileira de plantas medicinais; Brazilian journal of pharmaceutical sciences; Acta botânica. brasílica) utilizando como descritores "fitoterapia" ou "plantas medicinais" e "Odontologia". Os artigos publicados de 2002 a 2012 que envolveram o uso de plantas medicinais em Odontologia foram incluídos e analisados. A busca por descritores e leitura de resumos gerou 155 artigos, dos quais 44 foram lidos na íntegra, sendo selecionadas 16 publicações que se enquadraram aos critérios requeridos. Estudos laboratoriais foram majoritários (10), e limitaram-se em avaliar propriedades antimicrobianas através das concentrações inibitórias, fungicidas e bactericidas. Três foram revisões da literatura e apenas um ensaio clínico esteve presente, sendo o cegamento e a randomização ausentes. Evidenciou-se a necessidade de um melhor delineamento metodológico das pesquisas e de uma maior produção de estudos clínicos ou in vivo.