Pulsed Electric Field (PEF) Treatment Results in Growth Promotion, Main Flavonoids Extraction, and Phytochemical Profile Modulation of Scutellaria baicalensis Georgi Roots

This study aims to explore the effect of pulsed electric field (PEF) treatment as a method very likely to result in reversible electroporation of <i>Scutellaria baicalensis</i> Georgi underground organs, resulting in increased mass transfer and secondary metabolites leakage. PEF treatment with previously established empirically tailored parameters [E = 0.3 kV/cm (U = 3 kV, d = 10 cm), t = 50 µs, N = 33 f = 1 Hz] was applied 1-3 times to <i>S. baicalensis</i> roots submerged in four different Natural Deep Eutectic Solvents (NADES) media (1-choline chloride/xylose (1:2) + 30% water, 2-choline chloride/glucose (1:2) + 30% water, 3-choline chloride/ethylene glycol (1:2), and 4-tap water (EC = 0.7 mS/cm). Confocal microscopy was utilized to visualize the impact of PEF treatment on the root cells in situ. As a result of plant cell membrane permeabilization, an extract containing major active metabolites was successfully acquired in most media, achieving the best results using medium 1 and repeating the PEF treatment twice (baicalein <LOQ, baicalin 12.85 µg/mL, wogonin 2.15 µg/mL, and wogonoside 3.01 µg/mL). Wogonin concentration in NADES media was on par with the control (plants harvested on the day of the experiment, ultrasound-mediated methanolic extraction, C_wogonin = 2.15 µg/mL). After successful extraction, PEF treatment allowed the plants to continue growing, with the lowest survival rate across treated groups being 60%. Additionally, an enhancement in plant growth parameters (length and fresh mass of the roots) and significant changes in the <i>S. baicalensis</i> root phytochemical profile were also observed.