Inhibitory effect of ethyl acetate fraction from Cudrania tricuspidata on the expression of nitric oxide synthase gene in RAW 264.7 macrophages stimulated with interferon-gamma and lipopolysaccharide - Seo, W G; Pae, H O; Oh, G S; Chai, K Y; Yun, Y G; Kwon, T O; Chung, H T (Gen Pharmacol, 2000)