Studies on process of ultrasonic-assisted extraction of pigments from leaves of Acanthopanax gracilistylus and their bioassays in vitro

To optimize the conditions of the ultrasonic-assisted extraction of pigments from leaves of Acanthopanax gracilistylus W. W. Smith and to investigate further whether the pigments could have cytotoxicity and anti-inflammatory activities, an ultrasonic-assisted procedure was investigated using response surface methodology (RSM). The effects of five factors on the yield of pigments were studied. The optimized conditions were as follows: extraction temperature 64°C, ultrasonic frequency 40 kHz, ultrasonic power 130 W, ratio of solid to liquid 10:1 and extracted three times with 95% ethanol, each for 27 min. Under the proposed conditions, the experimental yield of pigments was 0.3708%, which was well matched with the predictive yield of 0.3737%. Anti-inflammatory activities and cytotoxicity experiments of total pigments extracted by this method are preliminary studied in vitro, which display better NO inhibitory abilities in LPS-induced RAW 264.7 cells and have cytotoxicity in a certain dose.