Processing-induced modulation of polysaccharide structure and immunologic efficacy in <italic>Aconiti Lateralis Radix Praeparata</italic>

<x>Abstract</x> <sec> <title>Objectives:</title> Heating treatment is vital for developing polysaccharide activity in Baifupian, the processed <italic>Aconiti Lateralis Radix Praeparata</italic>. This study investigated the effects of heating treatment, including boiling, steaming, and drying on physicochemical properties, structure, and bioactivity of Baifupian polysaccharides (BFPs). </sec> <sec> <title>Methods:</title> This study assessed hygroscopicity, stability, solubility, and rheology of BFPs from each heat stage. Molecular mass, monosaccharide composition, and structure were analyzed using high-performance gel permeation chromatography (HPGPC), physicochemically modified polysaccharides-high-performance liquid chromatography (PMP-HPLC), Fourier transform infrared spectroscopy (FT-IR), circular dichroism (CD), and nuclear magnetic resonance (NMR). Anti-inflammatory activity was evaluated using lipopolysaccharide (LPS)-induced inflammatoary cells, and immunomodulatory activity was detected using a cyclophosphamide-induced immunosuppression model. </sec> <sec> <title>Results:</title> Heating treatment increased BFP hygroscopicity and solubility, but decreased their stability. At 5 mg/mL, BFP viscosity initially increased then decreased; at 15 mg/mL, BFP viscosity gradually decreased. The molecular mass of the untreated BFP was 46,342, and the monosaccharide composition was glucose (Glc) : fructose (Fru) : arabinose (Ara) = 1.687:0.433:0.007. After boiling, it decreased to 9,373, with Glc:Fru:Ara at 1.593:0.402:0.032. After steaming, it decreased to 5,436, with Glc : Fru : Ara at 1.707:0.427:0.022. After drying, it slightly increased to 8,108 with Glc : Fru : Ara at 1.719:0.409:0.018. Congo red, FT-IR, CD, and NMR showed that the triple helix and main chain conformation remained unchanged throughout. Boiling significantly enhanced anti-inflammatory activity <italic>versus</italic> untreated BFP (<italic>P</italic>&lt;0.01), but steaming and drying did not. Heating treatment significantly enhanced immunoregulatory activity, particularly during boiling. </sec> <sec> <title>Conclusions:</title> Heating treatment modifies the physicochemical properties, molecular mass, and monosaccharide composition of BFP, but not its characteristic or main chain structure. Boiling is likely the key stage for generating BFP activity. </sec>