Vascular endothelial protective effects of longan (Dimocarpus longan Lour.) extract and underlying molecular...

Longan (Dimocarpus longan Lour.) is a traditional fruit with both nutritional and medicinal value, rich in various bioactive metabolites such as polysaccharides, phenolic acids, flavonoids, proanthocyanidins, triterpenoids, and adenosine. Following PRISMA 2020 guidelines, this narrative review systematically synthesizes the multi-target protective effects of longan's bioactive metabolites on the vascular endothelial system, drawing on a systematic literature search of PubMed and Web of Science Core Collection (January 2015-July 2026) that employed Boolean combinations of keywords spanning plant nomenclature, vascular endothelium, and cardiovascular pharmacology, supplemented by manual screening of reference lists. Extensive studies using cellular and animal models have revealed that longan extracts and their metabolites effectively alleviate endothelial oxidative damage by directly scavenging free radicals. They downregulate the MAPK/NF-κB pathway, inhibit the expression of pro-inflammatory factors, and remodel the inflammatory microenvironment of the vascular wall. Regarding the regulation of vascular tone, longan metabolites exhibit bidirectional regulation of nitric oxide homeostasis. By inhibiting angiotensin-converting enzyme (ACE) activity, they reduce angiotensin II production and synergistically lower blood glucose, regulate blood lipids, and modulate immune balance. These findings suggest that longan and its bioactive metabolites hold significant potential for functional intervention in vascular diseases.