Food-medicine homologous polysaccharides from Perilla frutescens: extraction, structure, pharmacological activities...

Perilla frutescens (L.) Britton is an erect, herbaceous, annual plant belonging to the Perilla genus within the Lamiaceae family. It is one of the few natural plants recognized as both a food and a medicine. As a food and herbal remedy, perilla has many uses, including ornamental, medicinal, and culinary applications. Polysaccharides are high-molecular-weight polymers that are widely present in living organisms, including animals, plants, and microorganisms, and exhibit diverse pharmacological effects. Perilla frutescens polysaccharides are one of the key bioactive components of Perilla frutescens and exhibit pharmacological effects, including hypolipidemic, antioxidant, hypoglycaemic, and immunomodulatory activities. As living standards rise, there is an increasing emphasis on obtaining essential nutrients from food sources rather than relying solely on traditional chemical therapies. Consequently, the diverse pharmacological activities, low toxicity, safety profile, and excellent biocompatibility of Perilla frutescens polysaccharides have attracted significant attention from researchers worldwide in recent years. This review summarises the latest research on shiso polysaccharide extraction and purification, structural characteristics, pharmacological activities, structural modifications, and structure-activity relationships. The review highlights limitations in areas such as optimising the extraction process and the depth of structural elucidation, while pointing towards future research directions, including the exploration of the relationship between higher-order structures and biological activities. As technology advances, the gaps in research on shiso polysaccharides will gradually be filled.