Advances in Punica granatum polysaccharides: Isolation, structural-activity relationships, bioactivities, and potential applications

Punica granatum (Pomegranate) is a well-known plant resource with a rich history of medicinal and culinary uses since ancient times. The unique bioactivity of P. granatum polysaccharides (PGPs) has attracted increasing attention in research. However, the advancement of PGPs-based functional foods and medicines has been hindered by a lack of comprehensive understanding regarding the structure–activity relationship (SAR), structural modification, applications, and safety of PGPs. This review aims to summarize the current knowledge on extraction and purification methods, structural features, biological activities, SAR, applications, and safety considerations of PGPs. Studies have demonstrated that PGPs exhibit a wide range of bioactivities, including antioxidant, antitumor, immunomodulatory, anti-inflammatory, and hypolipidemic effects. SAR studies have indicated that PGPs with moderate molecular weight (10–422.55 kDa) exhibit excellent immunostimulatory activity, while selenium modification of PGPs enhances their antioxidant activities. Additionally, PGPs containing β-(1 → 3)-bonds are crucial for their antitumor effects. Furthermore, PGPs display remarkable rheological properties, bioavailability, and biodegradability, with no observed toxic effects, making them promising candidates for applications in the food, medicine, nanomaterials, and cosmetic industries. In conclusion, this article provides both theoretical insights and practical guidance for the development of PGPs as innovative functional foods.