Protective effect of Chromobacterium violaceum and violacein against bone resorption by periodontitis.

Objectives: The aim of this study was to evaluate the potential protective effect of Chromobacterium violaceum and violacein against periodontitis, in experimental models.

Materials And Methods: A double-blind experimental study on the exposure to C. violaceum or violacein in experimentally ligature-induced periodontitis, as preventive factors against alveolar bone loss by periodontitis.

Phototoxic assessment of a sunscreen formulation and its excipients: An in vivo and in vitro study.

Background: Cosmetic preservatives are used to protect cosmetic formulations and improve its shelf-life. However, these substances may exert phototoxic effects when used under sunlight.

Objective: To assess safety, efficacy and putative phototoxic effects of a sunscreen formulation SPF 30 and its excipients.

In Vitro and In Vivo Evaluation of DMSO and Azone as Penetration Enhancers for Cutaneous Application of Celecoxib.

Background: Celecoxib (CXB) has been explored as an anti-inflammatory or chemopreventive drug for topical treatment of skin diseases and cancer.

Objective: The main aim of this work was to investigate the potential of dimethylsufoxide (DMSO) and Azone (AZ) as penetration enhancers (P.Es) for topical delivery of CXB.

Mutagenic and genotoxic potential of direct electric current in Escherichia coli and Salmonella thyphimurium strains.

Direct electric current has several therapeutic uses such as antibacterial and antiprotozoal action, tissues scarring and regeneration, as well as tumor treatment. This method has shown promising results in vivo and in vitro, with significant efficacy and almost no side effects. Considering lack of studies regarding direct electric current mutagenic and/or genotoxic effects, the present work evaluated both aspects by using five different bacterial experimental assays: survival of repair-deficient mutants, Salmonella-histidine reversion mutagenesis (Ames test), forward mutations to rifampicin resistance, phage reactivation, and lysogenic induction.

Effects of a sunscreen formulation on albino hairless mice: a morphological approach.

The purpose of the study was to evaluate the effects of a sunscreen formulation on the skin of albino hairless mice subjected to simulated solar light (SSL) in terms of morphological changes. Young adult albino hairless mice HRS/J (n = 36) were used as an experimental model for determining skin photoaging changes. Mice were irradiated with SSL, and the sunscreen (estimated SPF 30, PF-UVA) was obtained from the Pharmacy College/UFRJ, Brazil.

Overexpression of Escherichia coli nucleotide excision repair genes after cisplatin-induced damage.

Cisplatin is currently used in tumor chemotherapy to induce the death of malignant cells through blockage of DNA replication. It is a commonly used chemotherapeutic agent binding mono- or bifunctionally to guanines in DNA. Escherichia coli K12 mutant strains deficient in nucleotide excision repair (NER) were submitted to increasing concentrations of cisplatin, and the results revealed that uvrA and uvrB mutants are sensitive to this agent, while uvrC and cho mutants remain as the wild type strain.

New insights on how nucleotide excision repair could remove DNA adducts induced by chemotherapeutic agents and psoralens plus UV-A (PUVA) in Escherichia coli cells.

Chemotherapeutic agents such as mitomycin C or nitrogen mustards induce DNA inter-strand cross-links (ICL) and are highly toxic, thus constituting an useful tool to treat some human degenerative diseases, such as cancer. Additionally, psoralens plus UV-A (PUVA), which also induce ICL, find use in treatment of patients afflicted with psoriasis and vitiligo. The repair of DNA ICL generated by different molecules involves a number of multi-step DNA repair pathways.