Abstract
Abstract: :
Purpose: To investigate the pharmacological profile of cloricromene (AD6), a cumarine derivative, its effects on TNFα production and NO synthesis in rats subjected to endotoxin-induced uveitis (EIU) were evaluated. Pharmacokinetic profile was also investigated in rabbit using a new rapid and simple method for simultaneous separation and quantification of AD6 and its active metabolite. Methods: Endotoxin uveitis was induced in Lewis rats by a single foot pad injection of 200 µg lipopolysaccharide (LPS). Forty µg of AD6 were topical applied twice to the rat eye 1 h before and 7 h after LPS injection. The animals were killed 16 h after LPS injection and the aqueous humor collected. TNFα levels were measured by ELISA. Nitrite/nitrate production, an indicator of NO synthesis, was measured by colorimetric assay. The pharmacokinetic study was carried out on albino rabbits. A single administration was done and aqueous humor samples were collected at 15, 30, 60, 120 and 240 min. The analyses were performed by HPLC using an Hypersil ODS C18 reverse-phase column with UV detection at 318 nm. Results: TNFα levels in aqueous humor were significantly lower (p<0.01) in AD6-treated rats (79±8.0 pg/ml) compared with control group (118±7.2 pg/ml). Nitrite/nitrate levels were significantly lower (p<0.01) in AD6-treated rats (8.2±3.5 µM) compared with control group (19.5±4.7 µM). The rabbit aqueous pharmacokinetic profile of AD6 and its active metabolite showed effective levels of drug up to 240 min. The assay provided good reproducibility and accuracy for both analytes. Conclusion: The parmacodynamic profile described in this study, beside other recent data (Bucolo et al., IOVS 2001), indicates that AD6 inhibits the inflammatory pathway involved in the pathogenesis of EIU in rats. Therefore, these evidences along with the pharmacokinetic data seem to indicate that AD6 may be useful in clinical practice. CR: E
Keywords: 612 uveitis-clinical/animal model • 514 pharmacology