OBJECTIVE To investigate the effect and mechanism of the ethanol extract of Xiao-ai-fei honey ointment(EXHO) and it’s active component piperine on gastric cancer.

METHODS The subcutaneous tumor bearing model of ICR mice was established by using mouse gastric cancer MFC cells. After the model was established, different doses of EXHO were given for 14 days, and the tumor inhibition rate was calculated. EXHO was sequentially partitioned to yield different fractions; activity-guided screening was performed by MTT assay. The most potent petroleum-ether fraction was analyzed by GC-MS, and network pharmacology was employed to predict active compounds and their targets. Then MFC cells were used to establish the subcutaneous tumor bearing model of ICR mice. Piperine was administered at different doses for 14 days, and the tumor inhibition rate was calculated. HE staining was used to observe histopathological changes in the major organs of mice in each group, while proliferating cell nuclear antigen(PCNA) and vascular endothelial growth factor(VEGF) expression in tumors was evaluated immunohistochemically. CCK-8 assay measured piperine-induced growth inhibition of BGC-823 cells; caspase activities were quantified by ELISA and apoptosis- and cell-cycle-related proteins were analyzed by Western blotting.

RESULTS Compared with the model group, tumor weight was markedly reduced in EXHO low-, medium- and high-dose groups(P<0.01). Compared with blank control, the petroleum-ether fraction of EXHO exhibited the strongest inhibition on BGC-823 cells. GC-MS identified 23 compounds; target prediction singled out piperine as the most active constituent. Compared with the model group, tumor weight was significantly reduced in the piperine low-, medium-, and high-dose groups(P<0.05 or P<0.01). Histopathology showed pulmonary changes in the high-dose piperine group. Immunohistochemistry revealed pronounced down-regulation of PCNA and VEGF in tumors from the medium- and high-dose piperine groups(P<0.01). Piperine could inhibit the proliferation of BGC-823 cells, compared with the blank control group, the activities of cysteine-dependent aspartate-specific protease-3(Caspase-3), Caspase-8 and Caspase-9 in BGC-823 cells treated with piperine at different concentrations were significantly increased; The expressions of Caspase-3, Caspase-8, Caspase-9 and Bcl-2-associated X protein(Bax) were significantly increased, while the expressions of signal transducer and activator of transcription 3(STAT3), CyclinB1, CyclinD1 and B-cell lymphoma(Bcl-2) were significantly decreased(P<0.05 or P<0.01).

CONCLUSION EXHO and its monomer piperine can inhibit the tumor growth of MFC gastric cancer mice, and its mechanism may be related to inhibiting the proliferation of tumor cells, regulating the expression of Caspase, Bax/Bcl-2 signaling pathway and CyclinB1, CyclinD1.