Ionic liquid based ultrasonic assisted extraction of flavonoids from Artemisia vulgaris and in vitro evaluation of anticancer activity

Abstract

This study was focused on an effective technique of flavonoids extraction from Artemesia vulgaris using ionic liquids (ILs) as green solvents. The findings showed that the hydrophilic IL, [Bmim][Br] coupled with ultrasonic-assisted extraction (UAE) was able to extract flavonoids better than hydrophobic IL, [Bmim][PF6]. Single-factor experiments reported that the optimum extraction time, 30 min and solid-to-liquid ratio, 1:10 could obtain high extraction yield (9.3 %) and flavonoid content (5.30 mg/g). With the assistance of ultrasonic energy, [Bmim][Br] was successfully to lysis cells and leach out flavonoids as explained by the morphological observation of SEM and functional groups in FTIR spectrum. UHPLC-MS/MS detected few intense flavonoids such as rutin, kaempferol-3-rutinoside, and quercetin-3-glucopyranoside in the extract. The monitoring of Kamlet-Taft parameters such as polarity, acidity and basicity explained the formation of hydrogen bonding between IL, cellulose and flavonoids. The extraction of flavonoids in [Bmim][Br] based UAE followed Peleg's kinetic model satisfactorily (R2 > 0.95). [Bmim][Br] could be reused up to 5 cycles before lost its extractability. The recovered flavonoids extract exhibited high anticancer activity against HeLa cells (IC50 = 347.37 µg/mL) without any significant cytotoxic effect on normal cervical cells at the concentration up to 300 µg/L. Therefore, this technique was likely to be an efficient extraction of plant flavonoids.