title: In vitro cytotoxicity of silver nanoparticles and zinc oxide nanoparticles to human epithelial colorectal adenocarcinoma (Caco-2) cells.
abstract: With the increasing applications of silver nanoparticles (Ag NPs) and zinc oxide nanoparticles (ZnO NPs) in foods and cosmetics, the concerns about the potential toxicities to human have been raised. The aims of this study are to observe the cytotoxicity of Ag NPs and ZnO NPs to human epithelial colorectal adenocarcinoma (Caco-2) cells in vitro, and to discover the toxicity mechanism of nanoparticles on Caco-2 cells. Caco-2 cells were exposed to 10, 25, 50, 100, 200μg/mL of Ag NPs and ZnO NPs (90nm). AO/EB double staining was used to characterize the morphology of the treated cells. The cell counting kit-8 (CCK-8) assay was used to detect the proliferation of the cells. Reactive oxygen species (ROS), superoxide dismutase (SOD) and glutathione (GSH) assay were used to explore the oxidative damage of Caco-2 cells. The results showed that Ag NPs and ZnO NPs (0-200μg/mL) had highly significant effect on the Caco-2 cells activity. ZnO NPs exerted higher cytotoxicity than Ag NPs in the same concentration range. ZnO NPs have dose-depended toxicity. The LD50 of ZnO NPs in Caco-2 cells is 0.431mg/L. Significant depletion of SOD level, variation in GSH level and release of ROS in cells treated by ZnO NPs were observed, which suggests that cytotoxicity of ZnO NPs in intestine cells might be mediated through cellular oxidative stress. While Caco-2 cells treated with Ag NPs at all experimental concentrations showed no cellular oxidative damage. Moreover, the cells' antioxidant capacity increased, and reached the highest level when the concentration of Ag NPs was 50μg/mL. Therefore, it can be concluded that Ag NPs are safer antibacterial material in food packaging materials than ZnO NPs.
authors.affiliation: Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, China Jiliang University, Hangzhou 310018, China.
authors.forename: Yijuan
authors.initials: Y
authors.lastname: Song
authors.affiliation: Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, China Jiliang University, Hangzhou 310018, China. Electronic address: rongfaguan@163.com.
authors.forename: Rongfa
authors.initials: R
authors.lastname: Guan
authors.affiliation: Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou 310014, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Lyu
authors.affiliation: Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, China Jiliang University, Hangzhou 310018, China.
authors.forename: Tianshu
authors.initials: T
authors.lastname: Kang
authors.affiliation: Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, China Jiliang University, Hangzhou 310018, China.
authors.forename: Yihang
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Hubei University of Technology, Wuhan 430068, China.
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Chen
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D018938:Caco-2 Cells; D002470:Cell Survival / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000473:pathology*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism; D053768:Metal Nanoparticles / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D012834:Silver / Q000633:toxicity*; D018675:Toxicity Tests; D015034:Zinc Oxide / Q000633:toxicity*
chemical_list: D017382:Reactive Oxygen Species; D012834:Silver; D015034:Zinc Oxide
keywords: Cytotoxicity; Human epithelial colorectal adenocarcinoma cells; Silver nanoparticles; Zinc oxide nanoparticles