Prospects of Codonopsis pilosula polysaccharides: Structural features and bioactivities diversity

Codonopsis pilosula possesses properties related to nourishing the spleen and stomach, and tonifying qi of stomach and mind in traditional Chinese medicine. Polysaccharides, which are the primary active components of C. pilosula, are thought to be in charge of their extensive use. Now, a systematic summary structural and bioactivities diversity of polysaccharide from C. pilosula (CPs) are necessary to address their future aspects and application. In this review, the extraction and purification methods, structural features and bioactivities diversity of CPs are summarized and discussed. Structure-activity relationships (SAR) is also analyzed and discussed. Boiling water extraction, ultrasonic extraction, enzymatic hydrolysis and microwave methods, subcritical water extraction and accelerated solvent extraction are used for extracting CPs. Among them, water extraction and alcohol precipitation method is the most frequently used one. Around 15 neutral fractions and 25 acidic fractions were purified from different species of C. pilosula, while only few of them were well characterized. CPs exhibited various biological activities, including immunomodulation, antitumor, prebiotics, antifatigue, antiviral, antioxidation activity. However, most of bioactivities reported were based on crude CPs; in vivo studies of purified CPs and the potential mechanisms need to be extensively investigated. SAR illustrates that chemical and enzymatic modification of CPs could significantly increase the bioactivity of CPs, but other impact factors on SAR such as water solubility, molecular weight and chain information are still unknown.