OBJECTIVES: The aim of this study was to evaluate the effects of a biological response modifier, glucomannan (GM), isolated from Candida utilis, on the progress of adjuvant arthritis in Lewis rats.
METHODS: Adjuvant arthrithis was induced in Lewis rats by a single intradermal injection of Mycobacterium butyricum. GM was administered in two different doses of 5 and 7.5 mg/kg b.w. The treatment involved daily oral or intraperitoneal administration of the substance from day 0, i.e. the day of immunization to the end of the experiment - day 28. Cyclosporin A was used as a therapeutic standard in daily oral dose of 2.5 mg/kg b.w. The following parameters were monitored: hind paw volume, total antioxidant status, protein carbonyl groups, activity of N-acetyl-beta-D-glucosaminidase in plasma, lysozyme and peroxidase activity of peritoneal macrophages and activity of gamma-glutamyltransferase in homogenates of spleen, hind paw muscle and hind paw joint.
RESULTS: Beneficial action of GM was revealed mainly in hind paw volume decrease. Further decrease of the activity of the enzyme gamma glutamyltransferase (GGT) in the spleen, hind paw joint and muscle tissue homogenates, decrease of the plasmatic activity of N-acetyl-beta-D-glucosaminidase (NAGA), and finally suppression of lysozyme and peroxidase activity assessed in peritoneal macrophages were observed in arthritic animals treated with GM. All these findings speak in favor of the anti-inflammatory activity of glucomannan. Moreover, a significant improvement of the arthritis induced suppression of total antioxidant status and decrease of the level of the arthritis-associated protein carbonyls in plasma were detected.
CONCLUSIONS: The important characteristics of GM isolated from Candida utilis, such as good water solubility and relatively small molecular weight, along with the observed in vivo anti-inflammatory and antioxidant effects, appear to be promising features for its prospective use as a natural agent in prevention and supplementary therapy of rheumatoid arthritis.