Mutual inversion of flurbiprofen enantiomers in various rat and mouse strains

Mouse Models to Study Peroxisomal Functions and Disorders: Overview, Caveats, and Recommendations

During the last three decades many mouse lines were created or identified that are deficient in one or more peroxisomal functions. Different methodologies were applied to obtain global, hypomorph, cell type selective, inducible, and knockin mice. Whereas some models closely mimic pathologies in patients, others strongly deviate or no human counterpart has been reported. Often, mice, apparently endowed with a stronger transcriptional adaptation, have to be challenged with dietary additions or restrictions in order to trigger phenotypic changes. Depending on the inactivated peroxisomal protein, several approaches can be taken to validate the loss-of-function. Here, an overview is given of the available mouse models and their most important characteristics.

Comparison of percutaneous permeation profiles of flurbiprofen enantiomers

Flurbiprofen is clinically effective for the treatment of acute or long-term rheumatoid arthritis and osteoarthritis. Studies showed that S-flurbiprofen had better anti-inflammatory effect than R-flurbiprofen. As flurbiprofen racemates are usually used in the form of transdermal preparations, such as Flurbiprofen Cataplasms (Zepolas), it is of great significance to investigate the percutaneous permeation profiles of flurbiprofen enantiomers for considering whether it is necessary to develop the transdermal preparation with single optical enantiomer. Taking the economy into consideration, the flurbiprofen enantiomers as the mode drug and the CHIRALPAKAAGP column we had as instrument were used to perform the following experiments. On the basis of experiences provided by predecessors, we made some improvements to the analytical conditions, and method validation was developed to verify the feasibility of the method. The results showed that the established method could be used to analyze the percutaneous permeation profiles of flurbiprofen enantiomers in the flurbiprofen cataplasms accurately and effectively, and the percutaneous permeation profiles of flurbiprofen enantiomers had no significantly difference no matter under what conditions (P > 0.05).

Effects of R-flurbiprofen and the oxygenated metabolites of endocannabinoids in inflammatory pain mice models

Pain is one of the cardinal signs accompanying inflammation. The prostaglandins (PGs), synthetized from arachidonic acid by cyclooxygenase (COX)-2, are major bioactive lipids implicated in inflammation and pain. However, COX-2 is also able to metabolize other lipids, including the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (AEA), to give glycerol ester (PG-G) and ethanolamide (PG-EA) derivatives of the PGs. Consequently, COX-2 can be considered as a hub not only controlling PG synthesis, but also PG-G and PG-EA synthesis. As they were more recently characterized, these endocannabinoid metabolites are less studied in nociception compared to PGs. Interestingly R-profens, previously considered as inactive enantiomers of nonsteroidal anti-inflammatory drugs (NSAIDs), are substrate-selective COX inhibitors. Indeed, R-flurbiprofen can selectively block PG-G and PG-EA production, without affecting PG synthesis from COX-2. Therefore, we compared the effect of R-flurbiprofen and S-flurbiprofen in models of inflammatory pain triggered by local administration of lipopolysaccharides (LPS) and carrageenan in mice. Remarkably, the effects of flurbiprofen enantiomers on mechanical hyperalgesia seem to depend on (i) the inflammatory stimuli, (ii) the route of administration, and (iii) the timing of administration. We also assessed the effect of administration of the PG-Gs, PG-EAs, and PGs on LPS-induced mechanical hyperalgesia. Our data support the interest of studying the nonhydrolytic endocannabinoid metabolism in the context of inflammatory pain.