ESTERIFICATION IMPROVES ANTIARTHRITIC EFFECTIVENESS OF LUPEOL

Adult male Wistar rats were made arthritic by the subplantar injection of complete Freund's adjuvant. Oral treatment with the triterpenes lu peol, luepol palmitate, or lupeol linoleate (66 mg/kg BW every 2 days) from days 24 to 32 reduced synovial granulomatous growth (proximal in terphalangeal foot joints) and its invasion of the synovial cavity and reduced the destruction of articular cartilage and subchondral bone ( lupeol linoleate > lupeol palmitate > lupeol). Rats treated with the l upeol esters showed reduced periosteal bone erosion with bone repair i n the form of periosteal new bone formation. Arthritic rat blood lymph ocytes and serum levels of the joint degradative product, hyaluronate, which increased by 73% and 51%, respectively, were reduced by the tri terpenes (lupeol linoleate > lupeol palmitate > lupeol) with lupeol li noleate restoring them to normal values. The antiarthritic effectivene ss of lupeol was therefore increased by esterification with the long-c hain fatty acids. (C) 1995 Wiley-Liss, Inc.