To assess the efficacy of human placental extract (HPE) in an animal model of rheumatoid arthritis (RA).

We used (i) KRN C57BL/6 TCR transgenic x NOD mice (KBx/N) serum transfer arthritis and (ii) collagen-induced arthritis (CIA) mice to evaluate the effi cacy of HPE (1 ul or 100 ul, intra-peritoneal, three times per week) on RA. Incidence, severity of arthritis, and hind-paw thickness were quantifi ed. Joint destruction was analyzed using modifi ed mammographic imaging. Histopathological analysis for inflammation, cartilage, and osteoclasts was performed using Hematoxylin-eosin (H-E), safranin-O, and tartrate-resistant acidic phosphatase (TRAP). ELISAs were used for detection of various cytokines in serum and joint tissue.

There were no significant differences in incidence of arthritis, clinical scores of arthritis, and hind-paw thickness between HPE-treated and vehicle-treated groups for up to 2 weeks in the KBx/N serum transfer arthritis model. Histopathological analysis also showed no differences 2 weeks after treatment. Levels of TNF-α, IL-1β, IL-6, IL-10, and RANKL in serum and joint tissues were similar in all groups. Furthermore, there were no differences in clinical, radiological, and histological parameters between HPE-treated and vehicle-treated group for 3 weeks in the CIA model.

Systemic treatment with HPE has no beneficial effects on arthritis in animal models of RA. Therefore, indiscreet use of HPE in RA should be forbidden.