Antioxidant and Hemolysis Protective Effects of Polyphenol-Rich Extract from Mulberry Fruits

Mulberry fruits are a superior source of polyphenol, especially anthocyanins that contribute potentially to the beneficial effects which include reducing the risk of cardiovascular diseases and cancers with antioxidant, anti-inflammatory, and chemoprotective properties.

In this study, purification of the polyphenol-rich extract from mulberry fruit (MPE) was purified and assessed the activities of antioxidant and hemolysis protective in vivo and in vitro.

Antioxidant activities in vitro was measured by quantifying its 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, reducing power and Fe²⁺-chelating ability. MPE was purified by high-pressure liquid chromatography (HPLC) and analyzed individual polyphenols using liquid chromatography-mass spectrometry (LC-MS)/MS.

The total polyphenol content was 147.69 ± 0.02 mg gallic acid equivalents (GAE)/g dried weight (DW) in the extract and 403.55 ± 0.02 mg GAE/g DW in the purified extract. Further identification by HPLC-ultraviolet-visible and LC-MS/MS analysis indicated in MPE, an anthocyanin compound, cyanidin-3-O-glucoside. With regard to in vitro assays, MPE possessed antioxidant effect, especially in Fe²⁺ chelating ability with an IC₅₀ value of 1.016 mg/mL. The protective effects on mouse red blood cell hemolysis and lipid peroxidation ex vivo were dose and time dependent.

It indicates that MPE could be a good candidate for future biomedical applications to promote human health with limited side effects.

Mulberry fruit is an excellent source of polyphenols, in particular, anthocyanins, which has infinite health benefits. This study determined the predominant anthocyanin, cyanidin-3-glucoside, could possibly be the rationale behind the antioxidant and antihemolytic effect of MPE. Results indicate that MPE could be a good candidate for future biomedical applications to promote human health with limited side effects. Abbreviations used: MPE: Purification of the polyphenol-rich extract from mulberry fruit, LC-MS: Liquid chromatography-mass spectrometry, HPLC: High-pressure liquid chromatography, DPPH: 2,2-diphenyl-1-picrylhydrazyl scavenging activity, RBC: Red blood cell, GAE: Gallic acid equivalent, FeCl₂: Ferrous chloride, H₂O₂: Hydrogen peroxide, EDTA-2Na: Ethylenediaminetetraacetic acid disodium salt, PBS: Phosphate-buffered saline, TCA: Trichloroacetic acid, TBA: 2-thiobarbituric acid, FeSO₄: Ferrous sulphate, MDA: Malondialdehyde, V_C: Vitamin C, DW: Dried weight.