Optimization of ultrasound-assisted extraction of Lingzhi polysaccharides using response surface methodology and its inhibitory effect on cervical cancer cells

In this work, an ultrasound-assisted procedure for the extraction of Lingzhi polysaccharides was established. Response surface methodology (RSM) was used to optimize the ultrasound-assisted extraction parameters (ultrasonic frequency (X1), extraction temperature (X2), extraction time (X3), and ratio of water to raw material (X4)) for enhancing the forward extraction efficiency of Lingzhi polysaccharides by implementing a three-level, four-variable Box–Behnken experimental design. The independent variable with the largest effect on response was X1 (ultrasonic frequency), followed by X2 (extraction temperature) and X3 (extraction time). The optimum extraction conditions were found to be ultrasonic frequency 8 kHz, extraction temperature 95 °C, extraction time 3 h and ratio of water to raw material 12. Under these conditions, the forward extraction efficiency of Lingzhi polysaccharides can increase from 42% to 75%. Pharmacological experiment showed that Lingzhi polysaccharides could decrease CyclinB1 mRNA expression in CaSki cells and inhibit CaSki and HeLa cells proliferation. Results indicated that Lingzhi polysaccharides possessed strong antitumor activity.