The study of antioxidant and antityrosinase activity of extract from mulberry root (Morus alba L.)

Objective: The objective of this study was to investigate the antioxidant and antityrosinase activities of the extract of mulberry root related to oxyresveratrol content and to find out that which kind of solvent giving the highest antioxidant and antityrosinase activities. Methods: Powdered mulberry root passed through a 40-mesh sieve and extracted by maceration with ultrasonic using ethanol and methanol into various portions. Extraction solvents were used ethanol 50% (E50), 70% (E70), 96% (E96) and methanol 60% (M60), 85% (M85), 100% (M100). All of the extracts were tested antioxidant activities by DPPH method and antityrosinase activities. High-performance liquid chromatography (HPLC) analysis was employed to determine the oxyresveratrol content in all of the extract mulberry root. Results: The levels of the oxyresveratrol varied in different portions of the varieties of solvents. The amount of oxyresveratrol was very low in all samples, 0.85 – 2.17%. Oxyresveratrol levels were the highest in the M85 extract. TLC identification of compounds was fluorescent under UV 254 and 366 nm, spotting of E96 and M100 of the mulberry root extract had fluorescence which was stronger than the other mulberry root extract. All extract might serve as a natural antioxidant and tyrosinase inhibitor. The E96 extract exhibited the highest radical scavenging and tyrosinase inhibitory activity than the extract with another solvent. Conclusion: Antityrosinase and antioxidant activity of 96% ethanol extract of mulberry root were stronger than the five other extracts, not related to oxyresveratrol content in extracts. Oxyresveratrol levels was the most highest in the methanol extract 100%.