Oriental medicinal herb, Periploca sepium, extract inhibits growth and IL-6 production of human synovial fibroblast-like cells.

Periploca sepium (PS) has traditionally been used in oriental medicine for treatment of rheumatoid arthritis (RA). We investigated the aqueous extract of PS (PSE) in its effects on human rheumatoid arthritis-derived fibroblast-like cells. In cell culture studies, PSE inhibited the growth and IL-6 production of the cells in dose dependent manners. The extract of Glycyrrhiza glabra (GG), which has also been used to treat RA and chosen as a reference here, slightly inhibited the growth of RA cells. A study of PSE fractionation indicated that the active material inhibiting IL-6 production is filterable by ultrafiltration, suggesting that substances with low molecular weight might be involved in an inhibition of IL-6 production. These results support the view that PSE represents a rich source of growth inhibition and anti-IL 6 production.