Nanoencapsulation of apocynin and vanillic acid extracted from Picrorhiza kurroa Royle ex Benth plant roots and its characterisation

Abstract

Picrorhiza kurroa Royle ex Benth (P. kurroa) is an important medicinal plant in the ayurvedic system for treating various liver and inflammatory conditions. The present study aimed to extract the phytocompounds from various extracts (Acetone, Chloroform, Ethanol, Ethyl acetate, Hexane, and Methanol) of P. kurroa. Further, the major phytocompounds were nano-encapsulated by PLGA (Poly-lactic-co-glycolic acid) method and characterized to enhance activity towards the target. The highest polyphenolic value was found to be 323.2 ± 16.6 and 316.3 ± 12.1 μg GAEq./mg in ethanolic and methanolic extracts. The highest flavonoid value was found to be 280.3 ± 19.8 and 300.8 ± 15.2 in ethanolic and methanolic extracts μg QEq./mg. P. kurroa exhibited DPPH radical scavenging with IC50 of 38.2 ± 1.1 and 43.7 ± 1.8 μg/mL and also showed potent ferric reducing power and total antioxidant activities. The major phytocompounds, such as apocynin (AP) and vanillic acid (VA), were confirmed using HPLC. Further, the nano-encapsulation of apocynin and vanillic acid successfully achieved by PLGA methods. The average particle size of nano-encapsulated apocynin, vanillic acid is 350 nm, 204.4 nm, and zeta potential were −25.3 mv and −11.2 mv. Nanoformulations showed an apocynin and vanillic acid encapsulation efficiency of 93.6% and 93.3%, respectively. SEM and AFM confirmed the round and smooth morphology of the nanoparticles. The results of XRD confirmed the amorphous nature of nanoformulations. FTIR technique confirm the presence of biomolecules inside the polymer. The thermal stability of nanoformulations determined by DSC analysis showed endothermic peak. The prepared and characterization apocynin, vanillic acid nanoparticles revealed their good quality index, suggesting that potential use in pharmacy and phytotherapy as a source of natural antioxidant.