Effect of macelignan on inhibiting biomarkers of gouty inflammation in rat chondrocytes in vitro
Gout is an inflammatory disease caused by the increased production of pro-inflammatory cytokines and enzymes in cartilage cells, i.e. macrophages, chondrocytes, and osteoclasts, that lead to the accumulation of monosodium urate crystal within the joint tissues. Most conventional gout treatments using non steroidal anti-inflammatory drugs (NSAIDs) have been commercially used, however, they posted side effects on hepatic functions and hypoactive immune functions. We examined the potential macelignan isolated from nutmeg seed extract (Myristica fragrans Houtt.) on decreasing biomarker expression of gouty inflammation at protein and gene levels, i.e. interleukin (IL)-6, tumour necrosis factor (TNF)-α, cyclooxygenase (COX)-2, and matrix metalloproteinase (MMP)-9, in rat chondrocytes treated with lipopolysaccharide (LPS) in vitro by conducting ELISA, Western blot, and reverse transcriptase-polymerase chain reaction (RT-PCR) assays. Macelignan was isolated from the ethyl acetate fraction of M. fragrans methanol extract using silica gel column chromatography and identified by 13C-NMR, 1H-NMR, DEPT and FAB-MS. Macelignan (1–10µg/ml) did not affect cell morphology and cell growth, suggesting it may be safely used for further treatment. LPS at 2µg/ml activated the protein and mRNA expression of IL-6, TNF-α, COX-2, and MMP-9 in chondrocytes. Macelignan dose-dependently blocked the expression of IL-6, TNF-α, COX-2, and MMP-9at protein and gene levels in LPS-induced chondrocytes, indicating its potential effect for prevention of inflammation-related gout. Hence, it may be used as an alternative natural therapeutic agent for management of gout.