Antimicrobial synergism and antagonism of salicylaldehyde in Filipendula vulgaris essential oil

The leaf essential oil of Filipendula vulgaris, consisting mainly of salicylaldehyde (68.6%), was screened for its antimicrobial activity by the disk diffusion and microdilution broth assays. The essential oil remarkably inhibited the growth of all of the tested bacteria and fungi. It seems that the antimicrobial nature of F. vulgaris essential oil can be attributed to the synergistic interactions of the compounds constituting the oil rather than to the presence of a single inhibitory agent. A synergy in salicylaldehyde/linalool mixtures was observed with a maximum interaction situated in the range between 60:40 and 80:20 (mol ratio). At this concentration range (at a dose of 1.7 microg/disk) no microbial growth was observed while the respective pure compounds, at the corresponding quantities, are shown to be dramatically less active. The MIC value for the 60:40 mixture was determined to be less that 0.009 mg/ml. In addition, an antagonistic relationship between salicylaldehyde and methyl salicylate was established. The maximum (negative) interaction was shown to correspond approximately to the mixture at the 40:60 (methyl salicylate/salicylaldehyde) mol ratio resulting in the complete loss of activity at the investigated dose.

Nitric oxide synthesis is decreased in periodontitis

OBJECTIVES

In order to study the possible role of nitric oxide (NO) in the development of periodontitis, we measured the concentration of its stable metabolite nitrite (NO2-) in the saliva of patients with periodontitis and healthy subjects.

MATERIALS AND METHODS

We have analysed salivary NO2- concentrations in 25 subjects with rapidly progressive periodontitis (RPP), 25 with adult periodontitis (AP) and in 25 periodontally-healthy persons. The concentrations of NO2- were determined by the Griess reaction in microtitration plates. Periodontal tissue destruction was determined by measuring the attachment level loss using standard methods.

RESULTS

Subjects with periodontitis had significantly less NO2- in saliva than healthy subjects. Subjects with RPP had lower NO2- concentrations than those with AP Parotid gland saliva contained less NO2- than sublingual gland or total saliva.

CONCLUSIONS

Local NO production is decreased in patients with periodontitis. This effect is more pronounced in those with severe types of disease.

The role of dopamine in the formation of gastric ulcers in rats

A single dose of the dopamine agonists L-dopa, bromocriptine or apomorphine produced a protective effect by significantly shortening of the length of stomach ulcerations. A single dose of the dopamine antagonists haloperidol, sulpiride or domperidone potentiated the ulcerogenic effect by extending the length of stomach ulcerations. These results point to the fact that dopamine is involved in the rise and development of experimental stomach ulcers.