Seedling growth enhancement of sunflower seeds by DC atmospheric non-thermal Ar-O 2 plasma has been proposed. The plasma reactor was simply designed by the composition of multi-pin electrodes bonded on a solderable printed circuit board (PCB) anode. A stable plasma was exhibited in the non-periodical self-pulsing discharge mode during the seed treatment. The experimental results showed that non-thermal plasma treatment had a significant positive effect on the sunflower seeds. Ar-O 2 mixed gas ratio, treatment time and power source voltage are the important parameters affecting growth stimulation of sunflower sprouts. In this research, the sunflower seeds treated with 3 : 3 liters per minute (LPM) of Ar-O 2 plasma at a source voltage of 8 kV for 1 min showed the best results in stimulating the seedling growth. The results in this case showed that the dry weight and average shoot length of the sunflower sprouts were 1.79 and 2.69 times higher and heavier than those of the untreated seeds, respectively.

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

No abstract

BACKGROUND: Raphanus sativus var. caudatus or Thai rat-tailed radish (RTR) contains glucosinolates and isothiocyanates with chemopreventive effects; however, only mature plants have been investigated to date. Thus, the present study aimed to determine isothiocyanates, phenolic compounds and flavonoid compounds, antioxidant activity, cytotoxicity, and antiproliferative activity of RTR microgreens grown from seeds treated with cold plasma (21 kV for 5 min), organic elicitor (160 mmol L −1 NaCl, 10 mmol L −1 CaCl 2 or 176 mmol L −1 sucrose) or both in combination. Seeds were germinated on vermiculite and sprayed with deionized water or elicitor for 7 days before harvest. RESULTS: Cold plasma had insignificant effect on growth, whereas NaCl and CaCl 2 increased fresh weight. Plasma with CaCl 2 led to the highest total isothiocyanate (ITC) content [1.99 g kg −1 dry weight (DW)] in RTR microgreens containing raphasatin as the only ITC detected. Plasma treatment gave the highest total phenolic content (7.56 mg gallic acid equivalents g −1 DW), antioxidant activity from a 2,2-diphenyl-1-picrylhydrazyl assay (7.70 mg trolox equivalents g −1 DW) and ferric reducing antioxidant power assay (21.72 mg Fe 2+ g −1 DW). Microgreen extracts from plasma showed an IC 50 value of 29.28 and 13.83 ∼g mL −1 towards MCF-7 and HepG2, respectively, with inhibitory properties on matrix metalloproteinase (MMP)-2 and MMP-9 proteins. Plasma enhanced Bax and Caspase-3 gene expression but reduced Bcl-2 and MMP-9 expression, indicating activation of apoptosis. CONCLUSION: Cold plasma shows promise as an innovative tool to enhance bioactive compounds with chemopreventive benefits in microgreens.

No abstract