Evaluation of the Effect of Natural Astaxanthin in a Preclinical Study: Comparison to Antiarthritic Effect of Other Carotenoids.

During rheumatoid arthritis (RA), there is a shift in redox balance. Natural compounds play a major role as an adjuvant in reducing the symptoms of RA. In this study we evaluated the effect of carotenoids (astaxanthin, beta-carotene, and beta-cryptoxanthin) in monotherapy or in combination therapy with methotrexate (MTX) on clinical parameters during adjuvant arthritis (AA). Male Lewis rats were divided into 8 groups. The AA was induced by an injection of Mycobacterium butyricum into the base of the tail. The clinical data were assessed every 7 days until the 28th day. MTX was administrated twice a week (0.3 mg/kg of body weight). Synthetic astaxanthin (ASYN, 20 mg/kg) and natural astaxanthin (ASTAP, 20 mg/kg, source: Blakeslea trispora) were both administrated alone and in combination with MTX. Dosage of beta-carotene was 20 mg/kg and of beta-cryptoxanthin was 10 µg/kg. Administration per os was used. In amelioration of the weight loss caused by arthritis we observed that combination of both astaxanthins with MTX was more effective as MTX alone. Further all carotenoids improved this parameter also in monotherapy. ASTAP had the highest effect. In the most important clinical outcome--changes of the hind paw volume--were all carotenoids effective excluding beta-carotene and ASYN. In conclusion, carotenoids could be a prospective addition to RA therapy. Further evaluation of inflammation and oxidative stress should be aimed. [ABSTRACT FROM AUTHOR]