Enhancement of Wedelolactone biosynthesis and antioxidant potential in Eclipta prostrata Linn. by corona discharge plasma treatment

The present study explored the influence of corona discharge plasma exposure on the accumulation of wedelolactone in Eclipta prostrata Linn. Seeds were subjected to plasma discharges generated at applied voltages of ±11, ±13, and ±15 kV, across a fixed 1.3 cm air gap, for exposure durations of 30, 60, and 90 s. Results indicated that −13 kV for 60 and 90 s produced the highest seed germination percentage (58%). Consequently, both polarities at ±13 kV for 90 s were selected for subsequent cultivation and biochemical analyses, revealing enhanced wedelolactone accumulation. Wedelolactone accumulated primarily in the leaves, with negligible amounts detected in stalks and levels below the detection limit in roots. Plasma treatment significantly increased wedelolactone content in three-week-old plants by 2.7-fold for positive polarity plasma and 2.5-fold for negative polarity plasma, compared to non-treated samples. In two-month-old leaves, wedelolactone content increased by approximately 1.52 times under positive plasma and 1.36 times under negative plasma. Among the selected treatment conditions, positive plasma treatment at +13 kV produced the highest wedelolactone content, which was accompanied by enhanced antioxidant activity and increased total phenolic and flavonoid contents. This finding underscores the potential of +13 kV plasma treatment to enhance bioactive compound accumulation and antioxidant potential in E. prostrata , supporting this technique as a promising approach for improving its phytochemical value and facilitating its further development for functional food applications.