AIM:To explore the mechanism of the Sijunzi decoctionand another Chinese herbal recipe(SRRS)based mainly onthe Sijunzi decoction in treatment of gastric cancer.METHODS:A human gastric adenocarcinoma cell line SGC-7901 grafted onto nude mouse was used as the animalmodel.The mice were divided into 3 groups,one controland the two representative experimental conditions.Animalsin the two experimental groups received either Sijunzidecoction or SRRS over a 40-day period starting at 1st dayafter grafting.Control animals received saline on an identicalschedule.Animals were killed 41 days after being grafted.The effect of therapy was assessed by two ways:(1)tumorsize was periodically measured during the life of the animals;(2)tumor weight was determined by a electron balanceimmediately after the animals killed.For detection ofapoptotic cells,apoptotic indices(AI)were examined by theterminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate fluorescence nick end labeling(TUNEL)method.Morphological alterations were observed with electronmicroscopy.S-P immunohistochemical method was used todetect the expression of Ki-67 in xenografts.Expression ofbcl-2 and p53 was semiquantitatively detected using areverse transcriptase-polymerase chain reaction(RT-PCR)technique.RESULTS:When compared with controls,tumor growth(size and weight)was significantly inhibited by treatmentwith the Sijunzi decoction(P<0.05)or SRRS(P<0.01).Thetumor inhibitory rate in the Sijunzi decoction group was 34.33% and SRRS group 46.53 %.AI of human gastric cancerxenografts in nude mice was significantly increased to 16.24±3.21% using TUNEL method and 11.38±6.46 % byFACScan in the Sijunzi decoction group compared with thecontrols(TUNEL:2.63±1.03 %,P<0.01;FACScan:7.15±1.32 %,P<0.05).SRRS group was also found a significantlyincreased AI by using TUNEL method and flow cytometryanalysis compared with the controls(TUNEL:13.18±3.05 %,P<0.05;FACScan:11.58±5.71%(P<0.05).Under electronmicroscope,cell shrinkage,nuclear chromatin condensation, formation of membrane blebs and apoptotic bodies werefrequently observed in Sijunzi decoction group and SRRSgroup.The average labeling index(LI)for Ki-67 in SRRS groupwas significantly decreased to 8.43±2.22 % compared withthe control group(10.37±4.91%)(P<0.05).The averagelabeling index for Ki-67 in sijunzi decoction group was 7.95±2.54 % which was lower than that of the control group,butshowed no significance(P=0.07).The expression level of p53mRNA was lower in both Sijunzi decoction group and SRRSgroup than that in control group(P<0.05;P<0.01).Theexpression of bcl-2 mRNA was also decreased in SRRS groupcompared with the control(P<0.01).CONCLUSION:The inhibition of gastric cancer cell growthin vivo by Chinese 3ianpi herbs and SRRS is related toinduction of the cell apoptosis which may be involved inaberrant expression of p53 and bcl-2 genes AIM: To explore the mechanism of the Sijunzi decoction and another Chinese herbal recipe (SRRS) based mainly on the Sijunzi decoction in treatment of gastric cancer. METHODS: A human gastric adenocarcinoma cell line SGC-7901 grafted onto nude mouse was used as the animal model. mice were divided into 3 groups, one controland the two representative experimental conditions. Animal sin the two experimental groups received either Sijunzidecoction or SRRS over a 40-day period starting at 1st day after grafting. Control animals received saline on an identical diet. Animals were killed 41 days after being grafted the effect of therapy was assessed by two ways: (1) tumorsize was periodically measured during the life of the animals; (2) tumor weight was determined by an electron balanceimmediately after the animals killed. For detection ofapoptotic cells, apoptotic indices (AI) were examined by the terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate fluorescence nick end labeling (TUNEL) method . Morphological alterations were observed with electronmicroscopy. SP immunohistochemical method was used todetect the expression of Ki-67 in xenografts. Expression of bcl-2 and p53 was semiquantitatively detected using are reverse transcriptase-polymerase chain reaction (RT-PCR) technique .RESULTS: When compared with controls, tumor growth (size and weight) was significantly inhibited by treatment with the Sijunzi decoction (P <0.05) or SRRS (P <0.01). The tumor inhibitory rate in the Sijunzi decoction group was 34.33% and the SRRS group was 46.53% human gastric cancer xenografts in nude mice was significantly increased to 16.24 ± 3.21% using the TUNEL method and 11.38 ± 6.46% by FACScan in the Sijunzi decoction group compared with the controls (TUNEL: 2.63 ± 1.03%, P <0.01; FACScan: 7.15 ± 1.32% P <0.05). The SRRS group also also found a significantly increased AI by using TUNEL method and flow cytometry analysis compared with the controls (TUNEL: 13.18 ± 3.05%, P <0.05; FACScan: 11.58 ± 5.71% , cell shr inkage, nuclear chromatin condensation, formation of membrane blebs and apoptotic bodies were frequently observed in Sijunzi decoction group and SRRSgroup. The average labeling index (LI) for Ki-67 in SRRS group was reduced to 8.43 ± 2.22% compared with the control group (10.37 ± 4.91%) (P <0.05) .The averagelabeling index for Ki-67 in sijunzi decoction group was 7.95 ± 2.54% which was lower than that of the control group, butshowed no significance (P = 0.07) .The expression level of p53 mRNA was lower in both Sijunzi decoction group and SRRSgroup than that in control group (P <0.05; P <0.01). Theexpressionofclcl- 2 mRNA was also decreased in SRRS groupcompared with the control (P <0.01) .CONCLUSION: The inhibition of gastric cancer cell growth in vivo by Chinese 3ianpi herbs and SRRS is related to apoptosis of the cell apoptosis which may be involved in aberrant expression of p53 and bcl-2 genes