Efficient extraction and excellent activity of flavonoid from Moringa oleifera leaves and its microencapsulation

Abstract

The choline chloride-to-glycerin (ChCl/Gly) as a kind of deep eutectic solvent was used to extract flavonoids from Moringa oleifera leaves (FMOL), and the extraction rate of FMOL reached 70.4 ± 0.47 mg/g dw under the optimal extraction condition. Ten flavonoids have been identified, and one of them was first reported in MOL. The antioxidant activities, antibacterial activities, anti-tumor activities of FMOL were singly investigated. IC50 of FMOL for DPPH and ABTS free radical scavenging activity were 74.6 ± 1.05 and 9.5 ± 0.23 μg/mL, respectively, and the FRAP of FMOL was 14.85 ± 0.43 mg TE/g dw, which were all better than Vc. The minimum inhibitory concentration (MIC) of FMOL on five bacteria was less than 1.25 mg/mL which was lower than propyl p-hydroxybenzoate. Results from MTT and cellular apoptosis indicated that FMOL possessed certain antitumor activity, although slightly weaker than genistein. Additionally, xylose-modified soy protein isolate was used as wall material to encapsulate FMOL to enhance its bioaccessibility in small intestine. Microencapsulation increased the bioaccessibility of FMOL by 7.4 times compared to free FMOL, indicating that microencapsulation can help FMOL can assist in the slow release of FMOL during digestion. Therefore, FMOL has favorable bioactivity, and microencapsulation may enrich its application.