Phytochemical investigation of the leaf extracts from Miconia ferruginata (Melastomataceae) led to the isolation and characterization of the flavonoids 5,6,7-trihydroxy-4'-methoxyflavone, 5-hydroxy-7,4'-dimethoxy-8-methylflavone and 5,7,4'-trihydroxy-6,8-dimetilflavone, triterpenes ursolic acid and oleanolic acid, in addition to the steroids β-sitosterol and stigmasterol. The structures of these compounds were proposed by spectroscopic analysis and comparison with literature data. This paper also describes the insecticidal effects of leaf extracts from M. ferruginata to one of the main pests of maize, the fall armyworm (Spodoptera frugiperda). The ingestion bioassays, the leaf extracts showed an elongation of the larval stage of 16.56 days as compared to the control.

ABSTRACTThe antimicrobial activity of the myrsinoic acid A isolated from Myrsine coriacea (Sw.) R.Br. ex Roem. & Schult., Primulaceae, and a two semi-synthetics derivatives was tested against Bacillus subtilis, Escherichia coli, Salmonella enterica subsp. enterica serovar typhi, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Micrococcus luteus, Candida albicans, Candida krusei and Candida tropicalis. The microdilution method was used for the determination of the minimum inhibitory concentration during evaluation of the antimicrobial activity. The myrsinoic acid A showed no activity against the selected microorganisms but the hydrogenated and acetylated derivatives were active against B. subtilis, E. coli, S. aureus and P. aeruginosa.

OBJECTIVE: The aim of this study was to evaluate the capacity of potassium oxalate, fluoride gel and two kinds of propolis gel to reduce the hydraulic conductance of dentin, in vitro. MATERIAL AND METHODS: The methodology used for the measurement of hydraulic conductance of dentin in the present study was based on a model proposed in literature. Thirty-six 1-mm-thick dentin discs, obtained from extracted human third molars were divided into 4 groups (n=9). The groups corresponded to the following experimental materials: GI-10% propolis gel, pH 4.1; GII-30% propolis gel; GIII-3% potassium oxalate gel, pH 4,1; and GIV-1.23% fluoride gel, pH 4.1, applied to the dentin under the following surface conditions: after 37% phosphoric acid and before 6% citric acid application. The occluding capacity of the dentin tubules was evaluated using scanning electron microscopy (SEM) at ×500, ×1,000 and ×2,000 magnifications. Data were analyzed statistically by two-way ANOVA and Tukey's test at 5% significance level. RESULTS: Groups I, II, III, IV did not differ significantly from the others in any conditions by reducing in hydraulic conductance. The active agents reduced dentin permeability; however they produced the smallest reduction in hydraulic conductance when compared to the presence of smear layer (P<0.05). The effectiveness in reducing dentin permeability did not differ significantly from 10% or 30% propolis gels. SEM micrographs revealed that dentin tubules were partially occluded after treatment with propolis. CONCLUSIONS: Under the conditions of this study, the application of 10% and 30% propolis gels did not seem to reduce the hydraulic conductance of dentin in vitro, but it showed capacity of partially obliterating the dentin tubules. Propolis is used in the treatment of different oral problems without causing significant great collateral effects, and can be a good option in the treatment of patients with dentin sensitivity.