Abstract Solidago microglossa is used as an anti-inflammatory agent in traditional Brazilian medicine, and this work evaluated the anti-inflammatory potential of the crude ethanolic extract of the flowers of S. microglossa in vivo, as assayed by paw edema models induced by carrageenan, prostaglandin E2, bradykinin and compound 48/80. In the chemical profile, we identified compounds by electrospray ionization mass spectrometry and quantified them by HPLC-DAD. Additionally, this study analyzed the potential to activate the in vitro transcriptional activity of PPARγ, which is a nuclear receptor linked to the anti-inflammatory response. It was possible to identify five compounds: quinic acid, quercetin, chlorogenic acid, hyperoside, and rutin. In the paw edema evaluation, it was possible to show the potential of reducing edema during the inflammatory process. The crude ethanolic extract of the flowers of S. microglossa activated PPARγ compared to the full agonist rosiglitazone and in a dose-response manner. It is possible to conclude that the extract of the flowers of S. microglossa showed anti-inflammatory activity, and the phenolic compounds present in this species might be responsible for this activity.

Abstract Porphyromonas gingivalis is one of the most important Gram-negative anaerobe bacteria involved in the pathogenesis of periodontitis. P. gingivalis has an arsenal of specialized virulence factors that contribute to its pathogenicity. Among them, fimbriae play a role in the initial attachment and organization of biofilms. Different genotypes of fimA have been related to length of fimbriae and pathogenicity of the bacterium. Objectives The aim of this study was to identify 5 types of fimA genotype strains in smokers and nonsmokers with periodontitis, before and after periodontal therapy. Material and Methods Thirty-one patients with periodontitis harboring P. gingivalis were selected: 16 nonsmokers (NS) and 15 smokers (SM). Clinical and microbiological parameters were evaluated at baseline and 3 months after periodontal treatment, namely: plaque index, bleeding on probe, probing depth, gingival recession and clinical attachment level. The frequency of P. gingivalis and fimA genotype strains were determined by polymerase chain reaction. Results Type I fimA was detected in the majority of SM and NS at baseline, and the frequency did not diminish after 3 months of treatment. The frequency of type II genotype was higher in SM than NS at baseline. After 3 months, statistical reduction was observed only for types II and V fimA genotypes in SM. The highest association was found between types I and II at baseline for NS (37.5%) and SM (53.3%). Conclusion The most prevalent P. gingivalis fimA genotypes detected in periodontal and smoker patients were genotypes I and II. However, the presence of fimA genotype II was higher in SM. Periodontal treatment was effective in controlling periodontal disease and reducing type II and V P. gingivalis fimA.

RNA interference (RNAi) is a natural endogenous process by which double-stranded RNA molecules trigger potent and specific gene silencing in eukaryotic cells and is characterized by target RNA cleavage. In mammals, small interfering RNAs (siRNAs) are the trigger molecules of choice and constitute a new class of RNA-based antiviral agents. In an efficient RNAi response, the antisense strand of siRNAs must enter the RNA-induced silencing complex (RISC) in a process mediated by thermodynamic features. In this report, we hypothesize that silent mutations capable of inverting thermodynamic properties can promote resistance to siRNAs. Extensive computational analyses were used to assess whether continuous selective pressure that promotes such mutations could lead to the emergence of viral strains completely resistant to RNAi (i.e., prone to transfer only the sense strands to RISC). Based on our findings, we propose that, although synonymous mutations may produce functional resistance, this strategy cannot be systematically adopted by viruses since the longest RNAi-refractory sequence is only 10 nt long. This finding also suggests that all mRNAs display fluctuating thermodynamic landscapes and that, in terms of thermodynamic features, RNAi is a very efficient antiviral system since there will always be sites susceptible to siRNAs.