Analysis of solvent effects on polyphenols profile, antiproliferative and antioxidant activities of mulberry (Morus alba L.) extracts

A systematic study about the solvent effect on the mulberry polyphenol (MP) profile, antioxidant and antiproliferation capacities against human hepatoma HepG2 cells was conducted. Results indicated that MP profiles showed significant differences as a function of solvents including AA/W (acetic acid/water), MeOH/AA/W (methanol/ acetic acid/water), EtOH/AA/W (ethanol/ acetic acid/water) and ME2CO/AA/W (acetone/ acetic acid/water). Among the solvents, EtOH/AA/W took advantage in obtaining MP with the highest yield (49.81mg GAEg(-1) dw), and cellular antioxidant capacity in the PBS no-wash protocol (63.2molQE/100g), as well as low cell cytotoxicity (50.0mgmL(-1)). ME2CO/AA/W was the best choice for extracting MP with the most various compositions (two phenolic acids, four anthocyanins and four flavonols), greatest potential in inhibiting proliferation of HepG2 cells (EC50=28.2mgmL(-1)) and highest intracellular antioxidant activity (38.0molQE/100g). Results provide baseline information for efficient solvent extraction to obtain MP that is promising as natural antioxidants and antitumor agents.