Background: Chronic arthralgia and arthritis are the most common causes of
activity limitation and disability among middle-aged and older adults. Rheumatoid arthritis
is a persistent inflammation of the synovium of the joints, leading to destruction of the surrounding
bone and cartilage and ultimately joint de formities. Several studies reported that
carotenoid intake, including lutein, was associated with a decreased risk of rheumatoid arthritis.
We examined the effects of lutein extract (LE) from Tagetes erecta on inflammatory
suppression in the collagen-induced arthritis (CIA) model rat.
Method: CIA model rats were induced by injection of emulsion containing bovine type II
collagen and Freund’s incomplete adjuvant to DA/slc male rats. The study was designed
with four experimental groups referred to as: normal, vehicle, ibuprofen (30 mg/kg) and
LE (1.5 mg/kg). Test substances were administrated orally after immunization for 31 days
Results: Arthritis scores and paw swelling were significantly suppressed by LE or ibuprofen
administration. Histopathological analysis showed that LE suppressed synovial fibroblast
proliferation, plasma cell accumulation, pannus formation and new bone formation in
the hind paw, although no changes in inflammation and cartilage metabolism biomarkers
in plasma were detected after LE administration. Furthermore, proliferation of rabbit synovial
cells (HIG-82) was inhibited by the addition of lutein.
Conclusion: We provide direct evidence that lutein suppresses inflammation in the collagen-
induced arthritis model rat. It is expected that lutein may play a beneficial role in