Synthesis and Biological Evaluation of New Tyrosol-Salicylate Derivatives as Potential Anti-Inflammatory Agents.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly used medications in inflammatory illnesses. However, the gastrointestinal bleeding and toxicity associated with NSAIDs long term use prompted the quest towards investigations for new anti-inflammatory agents. Natural and natural-derived molecules proved its anti-inflammatory efficacy in vitro as well as in vivo. Given this background, the scope of this research involves structural changes of the natural polyphenol (tyrosol) generating two new salicylate derivatives and testing their biological properties, focusing on anti-inflammatory effects assessed in vitro and in vivo assays. The first molecular modification was the introduction of a carboxylic acid group adjacent to the phenol group present in this compound, which creates a new salicylate-like tyrosol. In addition, the acetylation of phenol group in this molecule produced an acetylsalicylate derivative, which may be regarded as aspirin-like natural polyphenol. Interestingly, tyrosol and its novel derivatives attenuated the edema in acute inflammatory response on carrageenan- induced local inflammation in mice. In addition, our results demonstrated that tyrosol and its novel derivatives were able to reduce the chemotaxis of neutrophil assessed in vitro model by chemo attractant (fMLP). Furthermore, only derivative 2 was able to reduce this effect in the acute inflammatory model. In (DPPH)- scavenging activity, tyrosol derivatives demonstrated a minor antioxidant activity, which may suggest that radical scavenging is not a major pathway involved in the anti-inflammatory effects of these derivatives. Salicylate-like tyrosol derivatives are of particular interest for future studies.

Synergistic effects of anethole and ibuprofen in acute inflammatory response.

This study assessed the effect of the combination of anethole and ibuprofen in comparison with monotherapy by either drug alone, using two in vivo inflammatory models, namely the pleurisy and paw edema in rats. We also measured the levels of the TNF protein in plasma, and the ability of anethole to inhibit, in vitro, the activity of the cyclooxygenase 1 and cyclooxygenase 2 enzymes. The test drugs (anethole; ibuprofen; anethole + ibuprofen), at different doses, were administered once (p.o.) 60 min before the induction of the inflammatory response. The association of anethole + ibuprofen inhibited the development of the inflammatory response in both models used. This effect can be partially explained by the inhibitory action on the production of TNF and of COX isoforms. The isobologram analysis evidenced a synergistic effect between ibuprofen and anethole, because the combination of drugs showed a higher inhibitory potential than either drug alone.