Abstract: BACKGROUND ＆ AIM: To study the effects and mechanisms of pleurotas sapidus(PS) extract on function of 5-fluorouracil(5-Fu) in chemotherapy. MATERIALS AND METHODS： Nude mice transplanted with human cervical carcinoma were divided into four groups randomly，model group , 5-Fu group , PS group and PS＋5-Fu group. After 14 days the markers in nude mice were assessed. RESULTS： The weight and volume of tumor in model group were higher than that in other three groups. The weight and volume of tumor in PS＋5-Fu group(0.19±0.03) g and(0.134±0.016) cm3,respectively, were lower than that in 5-Fu group(0.30±0.03) g and (0.210±0.018) cm3,respectively.The number of leukocytes in peripheral blood in 5-Fu group(3.52±0.43)×10 9/L was lower than that in PS＋5-Fu group(5.00±0.74)×10 9/L and model group(5.51±0.50)×10 9/L. Significantly higher expressions of Bax and caspase-3 protein of tumour tissues were observed in nude mice exposed to combination of 5-Fu plus PS compared with the nude mice exposed to 5-Fu alone. CONCLUSION： The extract from pleurotas sapidus had the synergistic antitumor effect and increased the number of leukocytes in 5-Fu chemotherapy，which were related to the upregulation of Bax and caspase-3 protein expressions.

Key words: pleurotas sapidus, 5-fluorouracil, chemotherapy