Effects of different drying methods on antioxidant activity, anti-inflammatory, anticancer and metabolome of Tetrastigma hemsleyanum Diels et Gilg

This is the authors' abstract. We don't add key points for this paper.

The aim of this study was to investigate the effects of three different drying treatments (natural drying (ND), vacuum freeze drying (VFD), and vacuum freezing-hot air combined drying (FHD)) on the active components and antioxidant capacity of Tetrastigma hemsleyanum Diels et Gilg root. The active components, including polysaccharides, total polyphenols, and total flavonoids, were determined, and antioxidant assays (DPPH, ABTS, and FRAP) were performed. Metabolomic analysis using UPLC-Q-TOF-MS E , combined with PCA and OPLS-DA, identified significant differences in secondary metabolites. Results showed that ND preserved the highest levels of active components and exhibited superior antioxidant activity, while FHD led to the lowest retention and notable metabolite degradation. Comparative bioactivity analysis revealed that VFD extracts exhibited the strongest anticancer activity against HepG2 cells, and ND extracts showed the greatest inhibition of the TNF-α inflammatory factor. As an industrial crop grown on a large scale, our study analyzes for the first time the effect of different drying methods on the active ingredients of T. hemsleyanum , and we identify the most suitable methods for the bulk processing of T. hemsleyanum in different categories of enterprises, which are effective in retaining the active ingredients of the product. This work provides a method for enterprises to batch process T. hemsleyanum . • Natural drying best preserves polysaccharides, polyphenols, and flavonoids. • Natural drying shows strongest antioxidant activity in DPPH, ABTS, Fe 3+ assays. • Vacuum freeze-drying yields highest anticancer activity against HepG2 cells. • Drying method significantly impacts active compounds and bioactivity. • Findings support optimized drying strategies for T. hemsleyanum processing.