Unlocking the potential of ginger leaf pectin polysaccharide: A novel antioxidant and therapeutic agent for tau toxicity

Ginger is widely cultivated for its medicinal and culinary benefits and for its medicinal properties, but its leaves are often discarded as waste. These leaves contain valuable polysaccharides that have been largely overlooked. In this study, we successfully isolated a pectin polysaccharide, designated GLP1, from ginger leaves. Structural analysis of GLP1 revealed a complex composition comprising four distinct chains linked to →2,4)-α-L-Rhap-(1→4)-α-D-GalpA-(1→, including β-D-Galp-(1→4)-β-D-Galp-(1→, α-L-Araf-(1→5)-α-L-Araf-(1→, β-D-Galp-(1→4,6)-β-D-Galp-(1→ with α-L-Araf-(1→5)-α-L-Araf-(1→ linked, and β-D-Xylp-(1→2,3,4)-β-D-Xylp-(1→ with β-D-Galp-(1→ or α-L-Araf-(1→linked. Additionally, GLP1 exhibited strong antioxidant activity in vitro and could reduce the oxidative damage to Hep G2 cells under H2O2. Moreover, GLP1 extended both maximum lifespan and median survival of Alzheimer’s disease model Caenorhabditis elegans BR5270 under 25 °C. it also increased their movement distance by 53.05% at 10 min and 16.25% at 20 min. Furthermore, GLP1 alleviated neurological damage in BR5270, increasing their chemotaxis index towards sodium chloride by 63.64%. These findings provided a new potential for exploiting the resource of ginger leaves and facilitated the development of novel bioactive compounds for therapeutic applications.