Magnetized water: A way to enhance isoflavonoids in cultured Pueraria candollei var. mirifica cells

Magnetic fields can alter plant growth and development. In this study, the effect of magnetized water on the growth and secondary metabolite production of Pueraria candollei var. mirifica (PM) suspension cells was evaluated. Magnetized water was generated by passing water through a magnetic field (400 mT) at a 6 L/min flow rate. The suspension cells exposed to magnetized water for 10 (M2, 1.37 g) and 5 min (M1, 1.23 g) showed 21% and 9% higher biomass accumulation, respectively, compared with the control cells after 5 days. Compared with that in the control cells, the biomass was increased by approximately 43% when the cells were exposed to M2 (3.01 g) after 28 days. In addition, the use of magnetized water altered the accumulation pattern of isoflavonoids after 5 days of treatment. Isoflavonoid accumulation was the highest after treatment with M2 for 5 days and yielded 4.20 mg/g dry weight (DW) daidzein, 0.58 mg/g DW genistein, and 3.98 mg/g DW kwakhurin. When the cells were maintained in the treatment for a relatively long duration (28 days), a short span of magnetization (M1) resulted in the highest accumulation of isoflavonoids with the amounts of 3.51, 0.55, and 2.58 mg/g DW for daidzein, genistein, and kwakhurin, respectively. After 28 days of exposure to magnetized water, the expression of 2-hydroxyisoflavanone synthase and 2-hydroxyisoflavanone dehydratase increased, and this phenomenon coincided with the increased amount of isoflavonoids in the suspension cells. The magnetized water-treated PM cells also exhibited higher antioxidant activities than the control cells. The lowest half-maximal inhibitory concentration (37.93 mg/mL) was observed in the cells treated with magnetized water after 15 min (M3). The enhanced total antioxidant activity of the cells treated with M3 may be attributed to the presence of other compounds in addition to isoflavonoids. This study represents an innovative attempt at a low-cost and environmentally friendly approach that can enhance the growth, secondary metabolite production, and antioxidant activity of PM suspension cells.

Automated summary

The study evaluated the impact of magnetized water on the growth and secondary metabolite production of Pueraria candollei var. mirifica (PM) suspension cells. The results showed that magnetized water treatment increased biomass accumulation, altered the accumulation pattern of isoflavonoids, and enhanced antioxidant activity in the cells.