ALOX5 and rheumatoid arthritis: To further elucidate the anti-inflammatory effects of 5-LOX inhibitors in the rheumatoid arthritis, human synovial fibroblasts were pretreated with 5-LOX inhibitors NDGA (10 μM) and MK-886 (5 μM) for 1 hr and then treated with TNF-α (10 ng/ml) for another 6 hr.