Longan/Lóng Yǎn Ròu 龍眼肉

A 2025 review summarised the botany, medicinal history and chemistry of longan pulp, peel and seed. It noted that dried pulp has traditionally been used to support immunity, while peel and seed polyphenols and flavonoids showed antioxidant, anti-tyrosinase, hypoglycaemic and antibacterial effects in laboratory studies. The authors highlighted by-product valorisation.

A 2022 review examined longan-pulp polysaccharides, a major constituent of the dried fruit. Laboratory and animal research suggests immunoregulatory, prebiotic, antioxidant, anti-inflammatory and acetylcholinesterase-inhibiting activities, with structure–activity relationships beginning to be mapped. The authors saw potential for functional-food development but noted clinical evidence is lacking.

In a 2021 mouse study modelling Alzheimer-type impairment with spleen deficiency, daily longan aril improved learning and memory in the Morris water maze, raised antioxidant enzyme levels and reduced amyloid-β, phosphorylated tau and oxidative markers. The authors proposed involvement of the RAS/MEK/ERK pathway; results have not been tested in humans.

A 2023 study in fruit flies and mice tested blends of jujube seed, longan fruit and lettuce extracts. Longan-containing mixtures increased total sleep time, including in a caffeine-induced sleeplessness model, and raised expression of GABA-receptor genes, suggesting a GABAergic mechanism. Findings are preliminary and limited to animal models.