ABSTRACT
Cytogenetic studies in Primulaceae are mostly available for herbaceous species, and are focused on the chromosome number determination. An accurate karyotype characterization represents a starting point to know the morphometry and class of the chromosomes. Comparison among species within Myrsine, associating these data with the nuclear 2C value, can show changes that led the karyotype evolution. Here, we studied three Myrsine species [Myrsine coriacea (Swartz, 1788) Brown ex Roemer et Schultes, 1819, Myrsine umbellata Martius, 1841 and Myrsine parvifolia Candolle, 1841] that show different abilities to occupy the varied types of vegetation within the Brazilian Atlantic Forest. Cytogenetic characterization showed some individuals with 2n = 45 chromosomes for Myrsine parvifolia and Myrsine coriacea, with most individuals of the three species having 2n = 46. The first karyograms for Myrsine were assembled and presented morphologically identical and distinct chromosome pairs. In addition, differences in the mean 2C nuclear value and chromosome morphometry were found. Therefore, the first description of the Myrsine karyotype has been presented, as well as the nuclear 2C value. The procedures can be applied to other Myrsine species for future investigations in order to better understand its effects on the differential spatial occupation abilities shown by the species in Brazilian Atlantic Forest.
ABSTRACT
The aim of this study was to develop nanoemulsion containing soft extract of stem bark of Rapanea ferruginea to improve the topical delivery and anti-inflammatory activity. The extract of R. ferruginea stem bark was incorporated into the oily phase of the nanoemulsion by the method of phase inversion at low energy. The developed nanoemulsion had an average droplet size of 47.88±8.20 nm and a polydispersibility index of 0.228. Uniformity of size, spherical shape of droplet, and absence of clusters were confirmed by transmission electronic microscopy. The zeta potential was -34.7±1.15 mV. The nanoemulsion showed a moderate degree of skin irritation in the agarose overlay assay in vitro. The content of the extract markers, myrsinoic acids A and B, was 54.10±0.08 and 53.03 µg/g in the formulation, respectively. The formulation demonstrated pseudoplastic and thixotropic rheological behavior. In vitro release of chemical markers was controlled by diffusion mechanism. An extract-loaded nanoemulsion showed a topical anti-inflammatory activity in a croton oil-induced edema ear model, with a decrease in tumor necrosis factor release and myeloperoxidase activity. The nanoemulsion was 160% more efficient than the conventional cream containing 0.13% of the extract. The nanoemulsion showed suitable properties as a carrier for topical use of R. ferruginea extract and the approach for improving the topical anti-inflammatory activity.
ABSTRACT
The stressful conditions associated with the Brazilian savanna (Cerrado) environment were supposed to favor higher levels of allelochemicals in Rapanea umbellata from this ecosystem. The allelopathic potential of R. umbellata leaf extracts was studied using the etiolated wheat coleoptile and standard phytotoxicity bioassays. The most active extract was selected to perform a bioassay-guided isolation, which allowed identifying lutein (1) and (-)-catechin (2) as potential allelochemicals. Finally, the general bioactivity of the two compounds was studied, which indicated that the presence of 1 might be part of the defense mechanisms of this plant.