Optimization of Polysaccharides and Essential Oils Extraction from Artemisia argyi Leaves and the Antioxidant Activity of Polysaccharides

Artemisia argyi leaves (AL) are a common traditional Chinese herbal medicine that possess significant biological activities, including antioxidant, antibacterial, anticancer, promoting blood circulation and reducing inflammation. AL contains many natural bioactive substances. In this study, Soxhlet extraction method was implemented to extract polysaccharides and essential oils (EOs) from AL, and the process was optimized by multi-response optimization. To explorer the best extraction conditions, three experimental parameters, soaking time (2–10 h), extraction time (1–3 h), and material liquid ratio (1:12–1:24 g/mL), were investigated in single-factor experiments. The Box-Behnken design of response surface analysis was used to optimize the extraction conditions. Further, the antioxidant ability of polysaccharides was evaluated using DPPH clearance rate. The results showed that the optimum extraction parameters of soaking time, extraction time and ratio of material to liquid were: 10 h, 2.5 h, and 1:27, respectively. The extraction rate of crude polysaccharides from AL reached 11.21% under the optimized conditions. The polysaccharide content in crude polysaccharides was about 50% according to anthrone-sulfuric acid method. Moreover, the crude polysaccharides from AL exhibited good antioxidant activity, with the ability of scavenging DPPH free radical being about 60% of that of L-ascorbic acid (Vc). These findings indicated that crude polysaccharides extracted from AL showed good free radical scavenging ability and possess potential for developed as natural antioxidanst. This study aims to provide a basic reference for the optimization of extracting process of polysaccharides from AL and further development and utilization.