Cell Proliferation and Antioxidative Effects of Ultrasonic Coffee Extracts

Recently, coffee is the most popular beverage for modern people. A great number of substances are found in coffee beans and have been studied for many years such as aliphatic and aromatic compounds. However, studies on the physiological activity of coffee extracts are insufficient. This study was performed to determine the contents of caffeine and chlorogenic acid in coffee extracts according to the solvent and to investigate the physiological activity of coffee extracts. Coffee extracts were extracted by ultrasonication method with various types of solvents including distilled water, ethanol, and other organic solvents under $50^{\circ}C$ and $80^{\circ}C$. The contents of caffeine and chlorogenic acid in coffee extracts were determined by Liquid Chromatography-Mass Spectrometry (LC-MS). Also, cytotoxic and antioxidative effects of coffee extracts were evaluated with MTT and DPPH assays to analyze the physiological activity. As a result, it was confirmed that caffeine and chlorogenic acid contents were extracted in distilled water with the highest rate. Antioxidative activity was observed below 10-fold dilute of coffee extracts, however cytotoxicity was not observed. In conclusion, distilled water was the best solvent for extracting caffeine and chlorogenic acids from coffee bean with ultrasonication and these coffee extracts are less cytotoxic in human skin cell lines and have antioxidant effect.