Optimization of ultrasound-assisted enzymatic extraction and in vitro antioxidant activities of polysaccharides extracted from the leaves of Perilla frutescens

Huizhen Li,Lixia Cui,Zhijun Zhang,Hongjiao Zhang

doi:10.1590/fst.29518

Abstract

Abstract A Box-Behnken design was employed to optimize ultrasound-assisted enzymatic extraction of polysaccharides from perilla leaves. Four independent variables, namely, liquid-to-solid ratio, enzymatic time, enzymatic temperature, and ultrasonic power were investigated. Under the optimal liquid-to-solid ratio of 41:1, enzymatic time of 40 min, enzymatic temperature of 49 °C, and ultrasonic power of 204 W, the experimental polysaccharide yield was 3.84% (n = 3), which was close to the value predicted by response surface methodology (3.9%). Four polysaccharides (PLP1, PLP2, PLP3, and PLP4) were obtained with DEAE-cellulose-52 and Sephadex G-100 chromatography, and their antioxidant activities were investigated with various antioxidant assays in vitro. All the four polysaccharides possessed good antioxidant properties in a concentration-dependent manner, and PLP3 presented the highest antioxidant activity. Thus, the novel polysaccharides extracted from perilla leaves could be promising bioactive macromolecules that can be applied as potential antioxidants in medical and food industries.

Highlights

Perilla frutescens (L.) Britton, an annual herbaceous plant belonging to the Labiatae family (Peiretti et al, 2011), is an important cash crop widely used for cooking and medicinal purposes in several Asian countries such as China, Korea, Japan, and Thailand (Li et al, 2015)
Reducing power of 1.178 at 1.0 mg/mL, and the reducing powers of perilla polysaccharides were lower than that of ascorbic acid. These results revealed that the purified polysaccharide fractions extracted from perilla leaves had potent reducing power in vitro, and that PLP3 might contain more reductone-associated groups than PLP1, PLP2, and PLP4
Under the optimal extraction conditions, the experimental polysaccharides yield was 3.84% (n = 3), which was correlated with the value of 3.9% predicted by Response surface methodology (RSM) model

Summary

Introduction

Perilla frutescens (L.) Britton, an annual herbaceous plant belonging to the Labiatae family (Peiretti et al, 2011), is an important cash crop widely used for cooking and medicinal purposes in several Asian countries such as China, Korea, Japan, and Thailand (Li et al, 2015). Polysaccharides have been extensively studied as additives in food and pharmaceutical industries owing to their unique bioactive properties and chemical structures (Liao et al, 2015). Polysaccharides from plants possess several biological activities, including antitumor (Zhu et al, 2011), antioxidation (Souza et al., 2012; Tian et al, 2012), anti-inflammatory (Chen et al, 2012; Wang et al, 2015), antibacterial, antifungal, and antiviral activities (Komatsu et al, 1997). Several methods are available for the extraction of plant polysaccharides, including organic solvent extraction, enzyme‐assisted extraction, microwave‐assisted extraction, ultrasonic extraction, and supercritical fluid extraction (Wang et al, 2015; Hu et al, 2016), to the best of the authors’

Methods

Results

Conclusion