OBJECTIVETo explore the inhibition of Hedyotis diffusa Willd Injection (HDI) on the proliferation of RPMI 8226 cells and its mechanisms.

METHODSThe inhibition of HDI on the proliferation of RPMI 8226 cells was detected by MTT and the drug concentrations for further researches were screened out. The apoptosis rate was detected using Annexin V-PI of flow cytometry. The cell cycle distribution was detected by PI. The expressions of adhesion molecule FITC-CD44 and PE-CD49d were detected. The IL-6 and VEGF concentrations of cell supernatants were tested by ELISA. The mRNA expressions of Bax, Bcl-2, Caspase-3, Survivin, IL-6, and VEGF were detected by RT-PCR.

RESULTSHDI could inhibit the proliferation of RPMI 8226 cells. Meanwhile, it induced their early apoptosis, arresting them at G1 phase in a concentration-dependent manner. The VEGF concentrations were down-regulated after acted by 0, 20, 40, and 60 microL/mL HDI in a dose-dependent manner (P< 0.01). The IL-6 content increased (P<0.01). The expressions of CD44 and CD49d were up-regulated in a concentration-dependent manner. After acted by 40 microL/mL HDI, the Survivin mRNA level was significantly downregulated (P<0.01), the mRNA levels of Bcl-2, IL-6, and VEGF were significantly up-regulated (P<0.01), but the up-regulation of Bax and Caspase-3 mRNA levels were not so obvious (P>0.05).

CONCLUSIONSHDI could inhibit the proliferation of RPMI 8226 cells. Its mechanisms might be correlated with early apoptosis induction, G1 phase arresting, VEGF secretion lowering, and Survivin mRNA transcription level down-regulating.