title: Selenium Accumulating Leafy Vegetables Are a Potential Source of Functional Foods.
abstract: Selenium deficiency in humans has been associated with various diseases, the risks of which can be reduced through dietary supplementation. Selenium accumulating plants may provide a beneficial nutrient for avoiding such illnesses. Thus, leafy vegetables such as Amaranthus hybridus, Amaranthus sp., Cucurbita maxima, Ipomoea batatas, Solanum villosum, Solanum scabrum, and Vigna unguiculata were explored for their capabilities to accumulate selenium when grown on selenium enriched soil and for use as a potential source of selenium enriched functional foods. Their selenium contents were determined by spectrophotometry using the complex of 3,3'-diaminobenzidine hydrochloride (DABH) as a chromogen. The mean concentrations in the leaves were found to range from 7.90 ± 0.40 to 1.95 ± 0.12 μg/g dry weight (DW), with C. maxima accumulating the most selenium. In stems, the accumulated selenium content ranged from 1.12 ± 0.10 μg/g in Amaranthus sp. to 5.35 ± 0.78 μg/g DW in C. maxima and was hence significantly different (P < 0.01). The cancer cell line MDA-MB-231 was used in cytotoxicity assays to determine the anticancer potential of these extracts. With exception of S. scabrum and S. villosum, no cytotoxicity was detected for the selenium enriched vegetable extracts up to 100 μg/mL concentration. Hence, following careful evaluation the studied vegetables may be considered as selenium enriched functional foods.
authors.affiliation: Chemistry Department, College of Natural and Applied Sciences, University of Dar es Salaam, P.O. Box 35061, Dar es Salaam, Tanzania.
authors.forename: Petro E
authors.initials: PE
authors.lastname: Mabeyo
authors.affiliation: Botany Department, College of Natural and Applied Sciences, University of Dar es Salaam, P.O. Box 35060, Dar es Salaam, Tanzania.
authors.forename: Mkabwa L K
authors.initials: ML
authors.lastname: Manoko
authors.affiliation: Sahlgrenska Cancer Centre, University of Gothenburg, 405 30 Gothenburg, Sweden; Department of Chemistry and Molecular Biology, University of Gothenburg, 412 96 Gothenburg, Sweden.
authors.forename: Amra
authors.initials: A
authors.lastname: Gruhonjic
authors.affiliation: Sahlgrenska Cancer Centre, University of Gothenburg, 405 30 Gothenburg, Sweden.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Fitzpatrick
authors.affiliation: Sahlgrenska Cancer Centre, University of Gothenburg, 405 30 Gothenburg, Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Landberg
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg, 412 96 Gothenburg, Sweden.
authors.forename: Máté
authors.initials: M
authors.lastname: Erdélyi
authors.affiliation: Chemistry Department, College of Natural and Applied Sciences, University of Dar es Salaam, P.O. Box 35061, Dar es Salaam, Tanzania.
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Nyandoro