Bio-Organic Chemistry Laboratory, Dr. B.R. Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, India.
Medical Biotechnology Laboratory, Dr. B.R. Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, India.
Pharmacol Rep. 2017 Aug;69(4):813-821. doi: 10.1016/j.pharep.2017.03.006. Epub 2017 Mar 14.
Diallyl disulfide (DADS), a principal organosulfur component of garlic, is known for its medicinal properties including anti-cancer activity. Prior studies have demonstrated that the compounds containing Diallyl disulfide moieties exhibited diverse therapeutic potential with promising biological activities. In the present study, we have investigated the in vitro anticancer activity of Diallyl disulfide derivatives (5a-5l and 7e-7m) against human cancer cell lines.
The effect of DADS analogs on different cancer cell lines was measured through MTT assay. Cell cycle progression, apoptosis, DNA fragmentation and levels of ROS were analyzed through FACS and confocal imaging.
Bis[3-(3-fluorophenyl)prop-2-ene]disulfide (compound 5b) was the most potent compound among the tested DADS derivatives. FACS analysis revealed that increase in ROS generation by compound 5b was accompanied by cell cycle arrest in the G2/M phase and apoptosis in MIA PaCa-2 cells. Further, the apoptosis was confirmed by TUNEL assay. Western blot analysis showed that compound 5b induces G2/M phase arrest via ROS mediated DNA-damage, which in turn, induces phosphorylation of Chk1/Cdc25c/Cdc2 pathway. Furthermore, altered levels of ROS triggers intrinsic apoptotic cascade, as evidenced by dissipated mitochondrial membrane potential (ψ), decrease in Bcl-2/Bax ratio, cytochrome c release and cleavage of procaspase-3. Scavenging of ROS by antioxidant N-acetyl-cysteine (NAC) reversed the compound 5b induced augmented intracellular ROS levels and cell death.
Taken together, the anti-proliferative effects of compound 5b were attributed to intracellular ROS accumulation, which in turn, triggers apoptosis by mediating DNA damage-induced G2/M phase arrest and evoking mitochondrial apoptotic pathway in MIA PaCa-2 cells.
二烯丙基二硫（DADS）是大蒜的主要有机硫成分，具有多种药用特性，包括抗癌活性。先前的研究表明，含有二烯丙基二硫基的化合物具有广泛的治疗潜力，具有有前途的生物学活性。在本研究中，我们研究了二烯丙基二硫代衍生物（5a-5l 和 7e-7m）对人癌细胞系的体外抗癌活性。
通过 MTT 测定法测量 DADS 类似物对不同癌细胞系的影响。通过 FACS 和共聚焦成像分析细胞周期进展、细胞凋亡、DNA 片段化和 ROS 水平。
双[3-(3-氟苯基)丙-2-烯]二硫（化合物 5b）是测试的 DADS 衍生物中最有效的化合物。FACS 分析表明，化合物 5b 引起的 ROS 生成增加伴随着 MIA PaCa-2 细胞中细胞周期停滞在 G2/M 期和细胞凋亡。进一步通过 TUNEL 测定法证实了凋亡。Western blot 分析表明，化合物 5b 通过 ROS 介导的 DNA 损伤诱导 G2/M 期阻滞，进而诱导 Chk1/Cdc25c/Cdc2 途径的磷酸化。此外，ROS 水平的改变引发内在的凋亡级联，这表现为线粒体膜电位（ψ）耗散、Bcl-2/Bax 比值降低、细胞色素 c 释放和前半胱氨酸蛋白酶-3 的裂解。抗氧化剂 N-乙酰半胱氨酸（NAC）清除 ROS 逆转了化合物 5b 诱导的增强的细胞内 ROS 水平和细胞死亡。
总之，化合物 5b 的抗增殖作用归因于细胞内 ROS 的积累，这反过来又通过介导 DNA 损伤诱导的 G2/M 期阻滞和引发 MIA PaCa-2 细胞中的线粒体凋亡途径来触发细胞凋亡。
