Antitumor Activities Of Pufa From Nitzschial Laevis

PUFA purified from Nitzschia.Laevis significantly elevated the mRNA expression of TNF-a, IL-2and IFN-γ in splenic lymphocyte.Anti-tumor activity of PUFA was demonstrated by its inhibition on the proliferation of BEL-7402cells in a time-and dose-dependent manner, AA,5:1AA/EPA significantly promoted cell proliferation, EPA、5:1EPA/AA、1:1EPA/AA significantly repressed cell proliferation in a time and dose dependent manner. After treatment with80μg/mL of EPA, apoptosis on the treated cells was observed with Hoechst33258staining.Kun Ming mice were treated with EPA for20day by sintragastric administration at doses of20mg/kg (low-dose),40mg/kg (mid-dose) and80mg/kg (high-dose) before H22tumor cells were implanted. EPA could significantly inhibited the growth and occurrence of H22tumor, blocked the cell cycle and induced the apoptosis of H22cells, Cell shinkage, nuclear condensation and apoptotic body could be detected by cell morphological observation. The cellcycle of H22cells which treated by EPA was blocked in G2phase, and the apoptotic rate significantly increased during the stage of24-48h. and also significantly elevated immunocytes’activity. EPA significantly enhanced the proliferation ability of spleen lymphocytes. HC50value, monocyte-phagocytic exponent at low-dose and mid-dose, EPA also significantly elevated the mRNA expression of TNF-α, IL-2and IFN-γ in splenic lymphocytes.