Cold Plasma Treatment on Mustard Green Seeds and its Effect on Growth, Isothiocyanates, Antioxidant Activity and Anticancer Activity of Microgreens

Abstract

The aims of this work were to study growth, isothiocyanate (ITC), bioactive content, antioxidant activity and anticancer activity of mustard green (MG) microgreens grown from seeds treated with cold plasma at 21 and 23 kV for 5 min. Microgreens from plasma-treated seeds at 23 kV showed almost 2-fold increased ITC content (1.57 ± 0.05 mmol/100 g DW) compared to MG from seeds without plasma (control), showed the highest total phenolic content (TPC) (6.76 ± 0.14 mg GAE/g DW) and total flavonoid content (TFC) (0.16±0.01 mg RE/g DW). However, MG plasma-treated seeds at 21 kV showed the highest antioxidant activity from 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay (3.51 ± 0.38 mg TE/g DW). Allyl isothiocyanate and 3-butenyl isothiocyanate were the dominant ITCs in MG. The highest cytotoxicities using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against MCF-7 (IC50 of 32.44 ± 1.64 µg/mL) and HepG2 (IC50 of 28.58 ± 1.04 µg/mL) after 72 h exposure were found in MG from plasma-treated seeds at 23 kV and MG from control seeds, respectively. However, MG from plasma-treated seeds at 21 kV exhibited the highest antiproliferative effect against MCF-7 (IC50 of 23.23 ± 0.23 µg/mL) and HepG2 (IC50 of 20.44 ± 0.56 µg/mL) for 14 days and also the most potent antimigratory effect. MG from cold plasma inhibited MMP-9 protein expression in both cancers indicating antimigratory property. MG from cold plasma also significantly reduced MMP-9 mRNA expression in both cancers when compared to the control and untreated cells. In conclusion, cold plasma treatment on seeds seemed to be an innovative tool to enhance ITC, TPC, TFC and anticancer properties of MG microgreens for better health implications. © 2021 Friends Science Publishers