Optimization of Ultrasonic-assisted Extraction of Polysaccharides from Trichosanthin and Antioxidant Activities in Vitro

Trichosanthin (TCS) is a Chinese herbal medicinal that has shown hepatoprotective effects with anti-inflammatory, anti-oxidants, and antiviral activity. The objective of this study is to optimized the ultrasonic-assisted extraction of polysaccharides from TCS and then studied the antioxidant capacity of the extracted polysaccharides. On the basis of single factor experiments, the Box-Behnken experiment analyzed and optimized the ultrasonic-assisted extraction of polysaccharides from TCS by response surface methodology. The antioxidant activity of the extract's polysaccharides was then determined including the DPPH free radicals and scavenging activities against hydroxyl (center dot OH), superoxide anion (center dot O-2(-)) and total antioxidant reactivity. The optimum conditions upon ultrasonic extraction were as follows: ultrasonic temperature 52 degrees C, ultrasonic time 44 min and water-to-material ratio 23 ml/g. Under optimum conditions, the extraction of the polysaccharides was 9.37 +/- 0.45 mg/g. There were significant differences in total antioxidant reactivity, superoxide anion resistance reactivity, hydroxyl radical resistance reactivity, and the contents of polysaccharides. The ultrasound-assisted extraction saves time and offers higher extraction yield. In addition, the polysaccharides from TCS have significant antioxidant activity in vitro.