Extraction and In Vitro and In Vivo Antioxidant Activity Evaluation of Polyphenols from Lychee Pericarp

Abstract

Background Finding a new promising plant antioxidant to combat or prevent cardiovascular disease remains a major challenge for researchers. Lychee pericarp, which includes a variety of polyphenols, is a prospective source of botanical antioxidants. Purpose In response to this issue, we assessed the effect of lychee bark extract on oxygen radical scavenging capacity and separate vascular protective ability in vivo. Methods In the current study, the lychee pericarp enrichment product (RLP) was obtained by optimizing an extraction method and separated using modern separation methods. The structure of the isolated compounds was assessed using 1H-NMR, 13C-NMR, and electrospray ionization-mass spectrometry, and the content of polyphenols obtained from the extract was quantified using the area normalization method. In addition, the capacity of RLP to scavenge oxygen radicals in vitro was assessed using the DPPH (1,1-diphenyl-2-picrylhydrazyl) and T-AOC (total antioxidant capacity) techniques. Furthermore, an isoprenaline hydrochloride (ISO)-induced rat model of acute myocardial ischemia was established, and four biochemical indicators were used to assess the effect of lychee bark extract on oxygen radical scavenging capacity and cardiovascular protective ability in vivo. Results RLP extraction produced 11 chemicals, 6 of which were structurally assessed. Quantitative analysis revealed that epicatechin, PC-C(epicatechin-(4β↓8,2β↓O↓7)-epicatechin-(4β↓8)-epicatechin), type A proanthocyanidin trimer, proanthocyanidin A2, and type B proanthocyanidin dimer were the most abundant polyphenols. The in vitro DPPH and T-AOC findings revealed that RLP exhibited strong free radical scavenging activity, approximately 1.5-fold that of vitamin C. The four biochemical indicators confirmed the antioxidant activity and cardiovascular protective ability of RLP in vivo. Conclusion RLP has good in vivo and in vitro antioxidant activity, confirming lychee pericarp as a prospective source of botanical antioxidants.