Optimization of polysaccharide extraction process from burdock root using response surface methodology and study on its anti-inflammatory effect on cells
Arctium lappa L., a mature and dried fruit of the Asteraceae plant, is included in the 2020 edition of the Chinese Pharmacopoeia. Modern research shows that Arctium lappa has been widely studied because of its various pharmacological activities, such as anti-inflammatory, anti-tumor, anti diabetes nephropathy, immune regulation, anti-virus, hypoglycemic, diuretic and purgative effects. However, current research on the active ingredients of burdock seeds mainly focuses on lignans, while polysaccharides, as one of the main components rich in fruit based traditional Chinese medicine, have been less studied in burdock seeds. Inflammation is the first line of defense of the body’s immune system and a natural protective reaction of the body. However, long-term and chronic inflammation can lead to the occurrence of diseases, such as fever, asthma, atherosclerosis, arthritis, neurodegenerative diseases and even cancer. At present, the treatment of inflammation mainly focuses on steroid and nonsteroidal anti-inflammatory drugs, but they cannot be used for a long time because they can cause side effects such as hypertension, osteoporosis, immunosuppression, hemorrhagic gastritis, upper gastrointestinal ulcers, hepatotoxicity, allergies, etc. Therefore, it is urgent to develop a safe and effective new drug source. In recent years, natural polysaccharides have received widespread attention due to their safety, accessibility, and good anti-inflammatory activity.
Therefore, based on the examination of single factor conditions, this study adopted the Box Behnken method in response surface to conduct a three factor three-level experimental design. Based on the extraction rate of burdock seed polysaccharides, the optimal composition for burdock seed polysaccharide extraction process was constructed. By establishing a RAW 246.7 cell inflammation model induced by lipopolysaccharide (LPS), preliminary studies were conducted on the anti-inflammatory mechanisms of burdock seed polysaccharides, providing scientific basis for the development of new anti-inflammatory drugs and the comprehensive utilization of burdock seed polysaccharides.

This article conducts a range determination study on three factors (solid-liquid ratio, time, and temperature) in the extraction process of burdock seed polysaccharides. Based on this, a three factor combination experimental design is carried out using Box Behnken. According to the actual extraction rate of burdock seed polysaccharides, the optimal extraction process conditions for burdock seed polysaccharides are obtained (solid-liquid ratio=1:15g/mL, extraction time 3h, extraction temperature 80 ℃). By studying the mechanism of action of different concentrations of burdock seed polysaccharides in cellular inflammation, it was found that burdock seed polysaccharides can inhibit the secretion of TNF – α and IL-6 in the supernatant of RAW 264.7 cells induced by LPS, and can play an immune regulatory role by regulating relevant proteins on the TLR4/MyD88/NF – κ B pathway. This study can lay a scientific foundation for the development and application of burdock seed polysaccharides, and provide technical references for the development and application of burdock in anti-inflammatory effects.