Phenolic-Enriched Fractions From Perilla Frutescens Var. Acuta: Determinating Rosmarinic Acid and Antioxidant Activity

The objectives of this study was to determine the total phenolic and flavonoid contents and rosmarinic acid levels of Perilla frutescens fractions (PFFs) and to evaluate the antioxidant activity of the above fractions, by three complementary test systems, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, reducing power and β-carotene/linoleic acid system. The extraction efficiency of total phenolics, flavonoids and rosmarinic acid depends strongly on the fractionation conditions. Ethyl acetate fraction was determined to have good gallic acid equivalents (GAEs) value of 227.38–373.92 mg/g fraction and rutin equivalents (REs) value 73.38–86.63 mg/g fraction. Rosmarinic acid was determined by HPLC and liquid chromatography/mass spectrometry analysis and showed highest content (51.37–155.50 mg/g fraction) in ethyl acetate fractions. The ethyl acetate fractions was shown strong reducing power (1.60–1.66) and indicated effectively radical scavenging activity (89.48–90.74%). In addition, chloroform fractions presented remarkable antioxidant abilities in the linoleic acid emulsion system. PRACTICAL APPLICATIONS Perilla frutescens var. acuta has been used as an edible biologic medicine in Eastern Asia for more than a thousand years. The leaves, stem and fruit of this plant are used individually to treat a variety of diseases. More precisely, P. frutescens leaves are used to induce perspiration and dispelchills and to regulate stomach function. Phenolic compounds in this plant extract, such as rosmarinic acid, are most likely to be responsible for these bioactivities. In this study, various extracts and fractions of P. frutescens leaves were used to determine rosmarinic acid and the antioxidant activities. Our results suggest that P. frutescens could potentially be used as a natural antioxidant and effective functional and active properties to provide new marketable bio-products.