Molecular Biochemistry Laboratory and Biodefensive Substances Group, Institute of Biotechnology, Chonnam National University, 300 Yongbong Dong, Kwangju 500757, South Korea.
Environ Toxicol Pharmacol. 2004 May;17(1):45-54. doi: 10.1016/j.etap.2004.02.003.
Solanum nigrum L. (SNL) has been traditionally used as an herbal plant for a long time. In the present study, SNL glycoprotein showed a dose-dependent radical scavenging activity on radicals, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, hydroxyl radical (OH), and superoxide anion (O(2)(-)). When the HT-29 cells were treated with 60μg/ml SNL glycoprotein, the cytotoxic effect was induced in a time-dependent manner. More specifically, it was more than 60% (P<0.01) after 4h, compared to the control. On the other hand, the cells treated with 100mU/ml glucose oxidase (GO) to generate the OH radical showed a cancer resistance up to 12h. Furthermore, the addition of GO to the SNL glycoprotein caused a strong cytotoxic effect, rather than a radical scavenging effect. Interestingly, when the cells were exposed to 100mU/ml GO for 4h, the DNA-binding activity of nuclear factor-kappa B (NF-κB) was increased 4.15-fold (P<0.01) compared to the control, whereas 40μg/ml SNL glycoprotein completely blocked the DNA-binding activity of OH radical-induced NF-κB by electrophoretic mobility shift assays (EMSAs). Apoptosis, according to the apoptosis assay, increased as a result of treatment with 40μg/ml SNL glycoprotein in a time-dependent manner, whereas they were weakly induced by GO in the cells. Consequently, the SNL glycoprotein may induce apoptosis through the inhibition of NF-κB activation, induced by oxidative stress in HT-29 cells.
龙葵（SNL）长期以来一直被用作草药植物。在本研究中，SNL 糖蛋白对自由基（包括 1,1-二苯基-2-苦基肼（DPPH）自由基、羟基自由基（OH）和超氧阴离子（O2(-)））具有剂量依赖性的清除活性。当 HT-29 细胞用 60μg/ml 的 SNL 糖蛋白处理时，细胞毒性呈时间依赖性诱导。更具体地说，与对照组相比，4 小时后超过 60%（P<0.01）。另一方面，用 100mU/ml 葡萄糖氧化酶（GO）处理细胞以产生 OH 自由基，其抗癌作用可持续长达 12 小时。此外，将 GO 添加到 SNL 糖蛋白中会导致强烈的细胞毒性作用，而不是自由基清除作用。有趣的是，当细胞暴露于 100mU/ml GO 4 小时时，与对照组相比，核因子-κB（NF-κB）的 DNA 结合活性增加了 4.15 倍（P<0.01），而 40μg/ml SNL 糖蛋白完全阻断了 OH 自由基诱导的 NF-κB 的 DNA 结合活性通过电泳迁移率变动分析（EMSA）。根据凋亡测定，40μg/ml SNL 糖蛋白处理后细胞凋亡呈时间依赖性增加，而 GO 处理后细胞凋亡较弱。因此，SNL 糖蛋白可能通过抑制 HT-29 细胞中氧化应激诱导的 NF-κB 激活诱导细胞凋亡。
