Euryale Seed/Qiàn Shí 芡實

A 2023 review compiled literature since 1980 plus classical texts and pharmacopoeias on Euryale ferox seeds, long classed as a superior food in China. It lists polysaccharides, polyphenols, sesquineolignans, tocopherols and cyclic dipeptides, and summarises reported antioxidant, hypoglycaemic, cardioprotective, antibacterial and hepatoprotective activity, mostly from preclinical studies.

A 2025 study found that seed polysaccharides, and especially a partially degraded form, inhibited alpha-glucosidase, survived simulated digestion and improved glucose uptake in insulin-resistant liver cells. In diabetic mice the degraded polysaccharide lowered blood glucose by roughly 46%, with effects on inflammation and lipid handling comparable in direction to metformin.

In diabetic mice, a 2023 study reported that Euryale seed extracts improved blood glucose, lipid abnormalities and kidney injury markers while boosting antioxidant enzymes via Keap1/Nrf2 and AMPK/mTOR signalling. Germinating the seeds roughly doubled polyphenol and flavonoid content and produced stronger effects than ungerminated seeds.

A 2002 laboratory study found Euryale seed extracts scavenged free radicals and protected hamster lung fibroblasts from oxidative agents. The ethyl-acetate and butanol fractions were most active and dose-dependently increased superoxide dismutase, catalase and especially glutathione peroxidase, suggesting specific polar constituents contribute to antioxidant activity in cells.