Kumar Sasidharan Nishanth, Nambisan Bala, Kumar B S Dileep, Vasudevan Nisha Girija, Mohandas Chellapan, Cheriyan Vino T, Anto Ruby John
Division of Crop Protection/Division of Crop Utilisation, Central Tuber Crops Research Institute, Sreekariyam, Thiruvananthapuram, 695017, India,
Arch Pharm Res. 2013 Jul 17. doi: 10.1007/s12272-013-0207-2.
3,5-Dihydroxy-4-isopropylstilbene is a natural phytoalexin and was first identified as bacterial secondary metabolites. The aim of this study is to investigate in vitro antioxidant and anticancer activity of 3,5-dihydroxy-4-isopropystilbene purified from the cell free culture filtrate of Bacillus sp. N strain associated with rhabditid entomopathogenic nematode. Antioxidant activity was evaluated by five separate methods: free radical scavenging, reducing power assay, chelating effects on ferrous ions, NBT superoxide radical scavenging assay and hydroxyl radical scavenging activity. The stilbene recorded powerful antioxidant activity at various antioxidant systems in vitro. The superoxide radical scavenging (92.1 %) and hydroxyl radical scavenging (83.4 %) activities of the stilbenes at 100 μg/ml were higher than the butylated hydroxyanisole, the known antioxidant agent. Anticancer activity of stilbene was tested against breast cancer (MDAM B-231), cervical cancer (HeLa), lung cancer (A 549), colon cancer (HTL 116) cell lines using MTT method. The induction of apoptosis was studied by morphological analysis, apoptotic cell staining, caspase 3 activation assay and cell cycle analysis using flow cytometry. Stilbene induced significant morphological changes and DNA fragmentation associated with apoptosis in HeLa cells. Acridine orange/ethidium bromide stained cells indicated apoptosis induction by stilbene. Up-regulation of caspase 3 activity was also found in cells treated with stilbene. Flow cytometry analysis showed an increase in the percentage of apoptotic cells in sub G0 phase (2.4 % in control plates to 11.4 % in 25 μg/ml of stilbene) confirming the stilbene induced apoptosis. The results of the present study showed that stilbene demonstrated a strong antioxidant and anticancer effects. These suggest that stilbene may be used as possible natural antioxidant and anticancer agents to control various human diseases.
3,5-二羟基-4-异丙基芪是一种天然植保素，最初被鉴定为细菌的次生代谢产物。本研究旨在探讨从与小杆科昆虫病原线虫相关的芽孢杆菌N菌株的无细胞培养滤液中纯化得到的3,5-二羟基-4-异丙基芪的体外抗氧化和抗癌活性。通过五种不同的方法评估抗氧化活性：自由基清除、还原能力测定、对亚铁离子的螯合作用、NBT超氧阴离子自由基清除测定和羟基自由基清除活性。该芪在体外各种抗氧化系统中均表现出强大的抗氧化活性。在100μg/ml时，该芪的超氧阴离子自由基清除率（92.1%）和羟基自由基清除率（83.4%）高于已知抗氧化剂丁基羟基茴香醚。采用MTT法检测芪对乳腺癌（MDAM B-231）、宫颈癌（HeLa）、肺癌（A 549）、结肠癌（HTL 116）细胞系的抗癌活性。通过形态学分析、凋亡细胞染色、半胱天冬酶3激活测定和流式细胞术细胞周期分析研究凋亡诱导情况。芪在HeLa细胞中诱导了与凋亡相关的显著形态变化和DNA片段化。吖啶橙/溴化乙锭染色细胞表明芪诱导了凋亡。在用芪处理的细胞中还发现半胱天冬酶3活性上调。流式细胞术分析显示亚G0期凋亡细胞百分比增加（对照平板中为2.4%，25μg/ml芪处理组中为11.4%），证实芪诱导了凋亡。本研究结果表明，芪具有强大的抗氧化和抗癌作用。这些结果表明，芪可能作为潜在的天然抗氧化剂和抗癌剂用于控制各种人类疾病。
