In the present study we compared the effects of the selective COX-2 inhibitor etoricoxib with those of the classical non-selective NSAID diclofenac on the inflammatory process and alveolar bone loss in an experimental model of periodontitis in rats. Ninety male Holtzman rats (250 g) were randomly sorted into four experimental groups: Sham+CMC and Ligature+CMC (control) groups which received 0.5% carboxymethylcellulose sodium (CMC) solution; Ligature+Diclofenac and Ligature+Etoricoxib groups which received Potassium Diclofenac and Etoricoxib, respectively, suspended in 0.5% CMC (10 mg/kg/day). At 7, 14 and 21 days after placing ligatures in the cervical region of both the lower right and left first molars, the animals were euthanized. At the end of each period, the mandibles were collected for radiographic examination of alveolar bone loss. In addition, alveolar bone and periodontal ligament tissue samples were collected for COX-2 expression analysis and gingival tissues were collected for measurement of PGE2 contents. Animals with ligature-induced periodontal disease showed significant increased COX-2 gene expression at days 7, 14 and 21 (p<0.05) on alveolar bone and periodontal ligament. However, both treatments resulted in significantly reduced alveolar bone loss when compared to the untreated Ligature group (p<0.05), with no statistical difference between Etoricoxib and Diclofenac Potassium groups. This study shows that both drugs were able to reduce alveolar bone loss after periodontal disease induction.

Weeds are important alternative hosts of pathogens, responsible for the survival and spread of phytopathogenic bacteria. Our study evaluated the potential of weeds as hosts of Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), causal agent of bacterial wilt, one of the main diseases of common beans. Cff survival was evaluated in the phyllosphere and in the rhizosphere of 21 weeds, in four experiments under field conditions, during the years 2018 and 2019. The aerial part of the plant was inoculated by spraying bacterial suspension (107 cfu/ml) of Cff, while the soil of the growing pots was infested with the same suspension. Cff survival was evaluated every 7 days, for 70 days. The identity of the bacterium was confirmed by PCR with the specific primers CffFOR2 and CffREV4, from strains recovered from all samples. Principal component analysis (PCA) showed that high temperatures and rainfall reduced Cff survival in the phyllosphere, while high temperatures reduced the survival of the bacterium in the rhizosphere. Our results demonstrated that Amaranthus viridis (family Amaranthaceae), Conyza bonariensis, Emilia fosbergii, Galinsoga parviflora, Gnaphalium purpureum (Asteraceae), Raphanus sativus, Lepidium virginicum (Brassicaceae), Commelina benghalensis (Commelinaceae), Ipomoea triloba (Convolvulaceae), Cyperus rotundus (Cyperaceae), Senna obtusifolia (Fabaceae), Digitaria insularis (Poaceae), Nicandra physalodes, and Solanum americanum (Solanaceae) are potential hosts for Cff. Their eradication in common bean fields is recommended, especially in fields with a history of bacterial wilt occurrence.

Protease-activated receptor 1 (PAR1) has been associated to tissue repair and bone healing. The aim of the present study was to evaluate the effect of PAR1 activation on the osteogenic activity of human periodontal ligament stem cells (PDLSCs). PDLSCs were cultured in the presence of PAR1-selective agonist peptide (100 nM), thrombin (0.1 U/mL), or PAR1 antagonist peptide (100 nM). Calcium deposits, calcium concentration (supernatant), alkaline phosphatase activity (ALP), cell proliferation, and gene (qPCR) and protein expression (ELISA assay) of osteogenic factors were assessed at 2, 7, and 14 days. PAR1 activation led to increased calcium deposits (p<0.05), calcium concentration (p<0.05), ALP activity (p<0.05), and cell proliferation (p<0.05). Further, PAR1 activation may increase gene and protein expression of Runx2 (p<0.05) and OPG (p<0.05). In conclusion, PAR1 activation increases osteogenic activity of PDLSCs, providing a possible new strategy for periodontal regenerative therapies.

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