Foliar application of zinc and selenium alleviates cadmium and lead toxicity of water spinach – Bioavailability/cytotoxicity study with human cell lines

• Published in: Environment international Vol. 145; p. 106122
• Main Authors: Tang, Lin, Hamid, Yasir, Liu, Di, Shohag, Md. Jahidul Islam, Zehra, Afsheen, He, Zhenli, Feng, Ying, Yang, Xiaoe
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01-12-2020; Elsevier
• Subjects: Biofortification; Biological Availability; Caco-2; Caco-2 Cells; Cadmium - analysis; Co-contaminated soil; Essential nutrients; HL-7702; Humans; Ipomoea; Lead - toxicity; Selenium - toxicity; Soil; Soil Pollutants - analysis; Soil Pollutants - toxicity; Toxic metals; Zinc - analysis; Zinc - toxicity; Biofortification; Essential nutrients; Co-contaminated soil; Caco-2; Toxic metals; HL-7702
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/j.envint.2020.106122

•Foliar application of Zn and Se promoted growth of water spinach.•Foliar fertilizers increased Zn and Se bioavailability in Caco-2 cell line.•Biofortification reduced Cd and Pb concentrations but not bioavailability.•Cytotoxicity of HL-7702 was bioavailable dose-dependent.•Nutrition quality improved by foliar application of Zn and Se fertilizers.
The present study investigated the effects of foliar application of zinc (Zn) and selenium (Se) on bioavailability of Zn and Se and toxicity of cadmium (Cd) and lead (Pb) to different water spinach ecotypes (LA and HA) grown in slightly (XZ) or moderately (LJY) contaminated fields via in vitro digestion combined with Caco-2/HL-7702 cell model. The obtained results revealed that foliar application of Zn and Se promoted yield, increased total, bioaccessible and bioavailable fractions of Zn and Se in plants, indicating that foliar application is a feasible way of biofortification. Although there was no significant effect on liver cell proliferation (MTT), membrane stability (LDH) and hepatocyte enzyme (ALT and AST) activities, the obvious ecotype and soil dependent fluctuations of lipid peroxidation (MDA) and antioxidant enzyme (SOD, POD and CAT) activities in serum highly suggest that the low accumulator and clean field should be used in agricultural production rather than the high accumulator and contaminated farmland. Moreover, foliar application of Zn and Se improved nutritional quality of all water spinach genotypes in both fields, including increased Fe, vitamin C, cellulose and chlorophyll, maintained concentrations of potassium (K), manganese (Mn), copper (Cu), protein, and nitrate. These results demonstrate that this agricultural management practice may prove to be an effective approach for minimizing health risk and alleviating “hidden hunger” in the developing countries.