The Effect of Traditional and Cyclodextrin-Assisted Extraction Methods on Trifolium pratense L. (Red Clover) Extracts Antioxidant Potential.

Jurga Bernatoniene,Mindaugas Marksa,Jurga Andreja Kazlauskaite,Liudas Ivanauskas

doi:10.3390/antiox11020435

Jurga Bernatoniene, Mindaugas Marksa + Show 2 more

Open Access

https://doi.org/10.3390/antiox11020435

Copy DOI

Abstract

Red clover is the subject of numerous studies because of its antioxidant properties, the positive influence of isoflavones on the health, and its potential use in the prevention and treatment of chronic diseases. The right excipients, such as cyclodextrins, can increase the profile of valuable phenolic compounds in extraction media to obtain rich in antioxidants, extracts that can be used in nutraceuticals production. The aim of this study was to investigate and compare the total phenolic content, flavonoid content, and antioxidant activity of red clover aerial parts, aqueous and ethanolic extracts prepared using traditional and cyclodextrins-assisted methods. The antioxidant activity of the extracts was established using ABTS, DPPH, FRAP, and ABTS-post column methods. It was determined that cyclodextrins significantly increased total phenolic content (compared with control)—using β-cyclodextrin 20.29% (in aqueous samples); γ-cyclodextrin 22.26% (in ethanolic samples). All the samples prepared with excipients demonstrated a strong relationship between total phenolic content and DPPH assay. Study showed that for extraction with water, the highest amounts of phenolic compounds, flavonoids and antioxidant activity will be achieved with β-cyclodextrin, but extractions with ethanol will give the best results with γ-cyclodextrin. Therefore, cyclodextrins are a great and safe tool for obtaining rich, red clover flower extracts that are high in antioxidant activity, which can be used in the pharmaceutical industry for nutraceuticals production.

Highlights

Red clover (Trifolium pratense L.) has high concentrations of phenolic compounds, especially isoflavonoids, which are largely distributed in the Leguminosae family [1]
The optimal extraction conditions were determined to conceive high isoflavones daidzein and genistein yields from red clover aerial parts [22]. These conditions were used to study the effects of CDs on total phenolic compounds, flavonoids content, and antioxidant activity in Trifolium pratense L. flowers extracts
The results showed that when using excipients in aqueous extractions, phenolic compound content increased significantly (p < 0.05) compared to that of control samples

Summary

Introduction

Red clover (Trifolium pratense L.) has high concentrations of phenolic compounds, especially isoflavonoids, which are largely distributed in the Leguminosae family [1]. Flavonoids are an important class of phenolic compounds that includes flavones, flavonols, and isoflavones, all characterized by a phenylbenzopyran moiety [4]. Isoflavones are a group of flavonoids typical of some legume species only. They exhibit estrogenic activity and represent the main phytoestrogens of current interest as nutraceuticals and dietary supplements. The role of flavonoids (isoflavones) and other phenolic compounds as protective dietary constituents, with their estrogenic, antimicrobial, anti-inflammatory, antiallergenic, and antitumor activities, have become an increasingly important area of research. These compounds are Antioxidants 2022, 11, 435.

Objectives

Methods

Results

Conclusion