Compared to saline-challenged rats, rats exposed to 50 microg intratracheal lipopolysaccharide showed an increase of total white cells (from 0.3 x 10(6) to 2.4 x 10(6)), neutrophils (from 0.09 x 10(6) to 1.8 x 10(6)), the levels of tumor necrosis factor (TNF)-alpha (from 200 pg ml(-1) to 1200 pg ml(-1)), and interleukin (IL)-1beta (from 220 pg ml(-1) to 650 pg ml(-1)) in the bronchial lavage fluid. However, after pretreatment with extracts of Phellinus gilvus and Phellinus baumii, the total white cells, neutrophils, and the level of IL-1beta in lipopolysaccharide-challenged rats were similar to those in saline-challenged rats, except for TNF-alpha. The results indicate that extracts of P. gilvus and P. baumii may be useful in preventing acute pulmonary inflammation in human diseases.