Abstract: The effect of matnne (Mat) on lipopolysaccharides (LPS)-induced fatal hepatitisand tumor necrosis factor (TNF) production in Propionibacterium acnes (PA)-pnmed mice werestudied. Mice were injected ip LPS (10 μg/mouse) 7 d after ip PA (0.5 ml/mouse) to induce fatalhepatitis. Aster ip LPS, serum TNF activity rose to 1657 ± 406 kU. L^-1 at 1.5 h and ALT activityincreased up to 1496 ± 890 U. L^-1 at 5 h. Six of 8 mice died within 5 h and the massive hemorrhagicnecrosis of the liver was observed in all mice. Administration of Mat ( 10, 50 mg.kg -1 , ip, bid × 3 d)before the LPS injection markedly reduced the elevation of serum TNF and ALT activity in a dose-dependent manner, and diminished the mortality induced by LPS. Liver congestion and necrosisinduced by LPS in PA-primed mice were ameliorated markedly by Mat pretreatment. Mat (62.5～250mg. L^-1) inhibited LPS-induced TNF release from PA-primed mouse peritoneal macrophage in vitroin a concentration-dependent manner. These results seggest that Mat protected PA-primed mice fromthe development of fatal hepatitis induced by LPS due to inhibition of TNF production.