Development and Evaluation of a Novel Oral Mucoadhesive Ointment Containing Pomegranate Peel Extract as an Adjuvant for Oral Hygiene of Dogs.

Herbal therapies are used worldwide to treat a variety of health conditions, including dental conditions in veterinary medicine. In this context, the use of medicinal plant-based formulations as potential therapeutics and preventatives in veterinary dentistry is worth highlighting. The objective of the present study was to develop a mucoadhesive ointment formulation, named orabase, that contained pomegranate extract for use in the oral cavity of dogs, with the aim of improving their oral hygiene. The hydroalcoholic extracts of pomegranate peels was incorporated into the orabase in 3 different concentrations. The formulations were subjected to in vitro microbiological testing by a modified disc-diffusion method to study the susceptibility of microorganisms collected from the oral cavities of the dogs. The samples were taken from the buccal mucosa of dogs having the same management and diet. The most effective formulation was submitted to physicochemical tests to evaluate the functionality of the product, namely pH, swelling index, spreadability, and mechanical properties (hardness, cohesiveness, and adhesiveness). The formulation containing 25.0% w/w of the extract was considered most suitable for the intended use as it showed antiseptic activity and demonstrated a swelling index of approximately 35% in the first 20 minutes of the test, high spreadability, and suitable mechanical properties. The results suggest that the product obtained from pomegranate peel extract is a viable option for use to improve oral hygiene, helping to reduce the bacterial component of dental plaque in dogs.

Exploratory Investigation of Bacteroides fragilis Transcriptional Response during In vitro Exposure to Subinhibitory Concentration of Metronidazole.

Bacteroides fragilis, member from commensal gut microbiota, is an important pathogen associated to endogenous infections and metronidazole remains a valuable antibiotic for the treatment of these infections, although bacterial resistance is widely reported. Considering the need of a better understanding on the global mechanisms by which B. fragilis survive upon metronidazole exposure, we performed a RNA-seq transcriptomic approach with validation of gene expression results by qPCR. Bacteria strains were selected after in vitro subcultures with subinhibitory concentration (SIC) of the drug. From a wild type B. fragilis ATCC 43859 four derivative strains were selected: first and fourth subcultures under metronidazole exposure and first and fourth subcultures after drug removal. According to global gene expression analysis, 2,146 protein coding genes were identified, of which a total of 1,618 (77%) were assigned to a Gene Ontology term (GO), indicating that most known cellular functions were taken. Among these 2,146 protein coding genes, 377 were shared among all strains, suggesting that they are critical for B. fragilis survival. In order to identify distinct expression patterns, we also performed a K-means clustering analysis set to 15 groups. This analysis allowed us to detect the major activated or repressed genes encoding for enzymes which act in several metabolic pathways involved in metronidazole response such as drug activation, defense mechanisms against superoxide ions, high expression level of multidrug efflux pumps, and DNA repair. The strains collected after metronidazole removal were functionally more similar to those cultured under drug pressure, reinforcing that drug-exposure lead to drastic persistent changes in the B. fragilis gene expression patterns. These results may help to elucidate B. fragilis response during metronidazole exposure, mainly at SIC, contributing with information about bacterial survival strategies under stress conditions in their environment.