Effects of Vacuum Freeze-Drying and Traditional Hot-Air Drying on Chemical Composition and Antithrombotic Mechanism of Panax notoginseng.

Abstract

Panax notoginseng is a medicinal herb with significant antithrombotic activity. Its therapeutic effect is mainly dependent on saponins. Traditional hot air drying (HAD) is easy to cause thermal degradation of active saponins, while vacuum freeze-drying (VFD) lacks multi-dimensional comparative studies to support its processing advantages. This study comprehensively compared the chemical characteristics, antithrombotic efficacy in vivo, and serum metabolic characteristics of Panax notoginseng processed by VFD and HAD, to provide an experimental basis for the rational application of VFD in the production of high-value functional food raw materials. Fresh Panax notoginseng was treated with VFD and HAD, respectively. The UHPLC-LTQ-Orbitrap MS non-targeted metabolomics method was used to screen differential phytochemicals. A carrageenan-induced mouse tail vein thrombosis model was established, and the length of thrombus, coagulation parameters, and serum inflammatory factors were detected. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry serum metabolomics combined with KEGG pathway enrichment was used to analyze related metabolic pathways. A total of 201 differential components were screened (VIP > 1, FDR (false discovery rate) < 0.05), among which 73 were unique to VFD and 18 to HAD. Of the 44 identified components, 36 saponins-including ginsenosides Rb1, Rg1, Rd, and Re-were significantly enriched in VFD (p < 0.05 or p < 0.01). VFD exhibited superior antithrombotic, anticoagulant, and anti-inflammatory effects over HAD at equivalent doses (p < 0.05). Metabolomics revealed that both drying groups shared glycerophospholipid and retinol metabolism, whereas only VFD regulated sphingolipid metabolism (p < 0.01). In conclusion, VFD retained more saponins and engaged broader metabolic pathways, correlating with enhanced antithrombotic activity compared with HAD.