Combination Treatment of Rat Adjuvant-Induced Arthritis with Methotrexate, Probiotic Bacteria Enterococcus faecium, and Selenium

doi:10.1196/annals.1361.101

^aNational Institute of Rheumatic Diseases, 921 12 Pie $s$ t'any, Slovak Republic
^bIVAX, Pharmaceuticals s.r.o., Opava, Czech Republic
^cInstitute of Cell Biology, Faculty of Science, ^dInstitute of Immunology, Faculty of Medicine, Comenius University, 811 07 Bratislava, Slovak Republic

The effects of the probiotic bacteria Enterococcus faecium (EF)and selenium were studied on methotrexate (MTX) treatment inrats with adjuvant arthritis. Arthritic rats were treated orallywith the following substances: lyophilized EF (15 mg/kg/day,5 days a week), sodium selenite pentahydrate (SSe; 0.050 mg/kgcontaining 0.015 mg/kg selenium, 5 days a week), MTX (0.6 mg/kg/week),and their combinations for the period of 50 days from adjuvantapplication. Levels of serum albumin, serum nitrite/nitrateconcentrations, hind paw swelling, arthrogram scores, whole-bodybone mineral density (BMD), and bone erosions were evaluatedas markers of inflammation and destructive changes associatedwith arthritis. Long-term preventive treatment with low-doseMTX significantly inhibited the markers of both inflammationand arthritis. EF or SSe when administered singly or in combinationhad no significant effect on the given parameters in arthriticrats. EF, but not SSe, potentiated the beneficial effects ofMTX, which resulted in a more significant reduction of hindpaw swelling, arthrogram scores, and whole-body BMD decrease.EF also had a tendency to improve the effect of MTX on serumalbumin and nitrite/nitrate concentrations. Our results indicatethat EF may increase the preventive effect of MTX treatmentin rat adjuvant arthritis by improving its anti-inflammatoryand antiarthritic effects.