竹叶提取物抗肿瘤和神经保护作用研究

Study for anti-tumor and neuroprotection of extract from bamboo leaf

目的研究竹叶提取物抑制肿瘤细胞增殖的活性及其分子生物学机制。方法选取血管内皮生长因子(VEGF)诱导型肿瘤细胞人肝癌细胞Hep G2和不诱导型肿瘤细胞人神经母细胞瘤细胞SH-SY5Y为模型,用不同质量浓度竹叶提取物处理Hep G2和SH-SY5Y细胞。采用MTT法检测竹叶提取物对2种细胞增殖的抑制作用;采用RT-PCR法检测VEGF和血管内皮生长因子受体2(VEGFR2)基因在Hep G2和SH-SY5Y细胞中的表达差异以及竹叶提取物处理后Hep G2细胞中VEGF基因表达的变化;用荧光倒置显微镜观察竹叶提取物处理后SH-SY5Y细胞神经突触的生长情况;采用RT-PCR法检测竹叶提取物处理后SH-SY5Y细胞中神经生长因子(NGF)表达的变化。结果竹叶提取物对Hep G2细胞增殖的抑制活性高于对SH-SY5Y细胞的增殖抑制作用。进一步研究发现Hep G2细胞中VEGF和VEGFR2基因的表达显著高于SH-SY5Y细胞,且竹叶提取物可显著抑制Hep G2细胞的VEGF表达。适当剂量的竹叶提取物可以刺激SH-SY5Y细胞神经突触的生长,并可上调其NGF的表达。结论竹叶提取物可能通过抑制VEGF的表达影响VEGF诱导型肿瘤细胞的增殖,同时,可能通过上调NGF的表达刺激神经细胞神经突触的生长,竹叶提取物可能具有潜在的抗肿瘤和神经保护的双重功效。

Objective In this study,we selected two types of tumor cell lines,Hep G2（VEGF-dependent） and SH-SY5Y（VEGFindependent） to investigate the anti-tumor activity of flavones extract from bamboo leaf（bamboo-leaf flavones） and their molecular mechanism.Methods The bamboo-leaf flavones were used to treat Hep G2 and SH-SY5 Y cells.The activity of bamboo-leaf flavones in inhibition of the proliferation of Hep G2 and SH-SY5 Y cells was determined by MTT method.Gene expression of VEGF and VEGFR2 in Hep G2 and SH-SY5 Y cells was determined by RT-PCR method,so did gene expression of VEGF in Hep G2 cells and NGF in SH-SY5 Y cells after cells treated by bamboo-leaf flavones.Outgrowth of neurite in SH-SY5 Y cells after treated by bamboo-leaf flavones was investigated by inverted fluorescence microscope.Results Data showed that bamboo-leaf flavones had a significantly higher inhibition to the proliferation of Hep G2 cells than that of SH-SY5 Y cells.We further observed that Hep G2 cells expressed higher levels of VEGF and VEGFR2 cells than those of SH-SY5 Y cells and bamboo-leaf flavones down-regulated VEGF expression in Hep G2 cells.In addition,we also found bamboo-leaf flavones stimulate the neurite outgrowth in SH-SY5 Ycells and up-regulated their NGF expression.ConclusionBamboo-leaf flavones could inhibit the proliferation of VEGF-dependent tumor cells by the probable down-regulation of VEGF expression.Meanwhile,bamboo-leaf flavones could stimulate the neurite outgrowth of neurons by the probable up-regulation of the NGF expression.Therefore,bamboo-leaf flavones probably have the dual functions in anti-tumor and neuroprotection.