Research progress on active mechanism and structure feature of polysaccharides from Zizyphus jujube in Rhamnaceae plants

The genus jujube (Ziziphus jujuba Mill.) within the Rhamnaceae family encompasses numerous varieties, such as Ziziphus jujuba Mill. var. jujuba, Ziziphus jujuba var. inermis, and var. spinosa, etc. Among these, the jujube fructus has the most abundant cultivated variants across the country, including Ziziphus jujuba cv. Hamidazao and Ziziphus jujuba cv. Huanghetanzao. Jujube plants are rich in variety and are used for both medicinal and food purposes. Polysaccharides, one of the main active ingredients of jujube, are important medicinal components that contribute to its efficacy. Jujube polysaccharides have been found to promote hematopoiesis, exhibit antioxidant and anti-tumor activities, repair liver damage, regulate the immune system, and provide anti-inflammatory effects. By comprehensively summarizing and analyzing the literature on jujube polysaccharides from different varieties and origins, this paper reviews the potential mechanisms of action of jujube polysaccharides in exerting biological activities. It also summarizes the primary structural features, such as relative molecular mass, monosaccharide composition, glycosidic linkage, and the substituent modifications of jujube polysaccharides by sulfation, phosphorylation, carboxymethylation, selenization, and acetylation. This review aims to provide a reference for the research and development of jujube in the fields of innovative polysaccharide drugs and functional foods.