Efficient isolation of polyunsaturated amides from Zanthoxylum bungeanum and assessment of their anti-inflammatory potential

Abstract

A targeted extraction, enrichment and separation method for polyunsaturated amides from Zanthoxylum bungeanum was established. Three main polyunsaturated amide monomers with high purity were isolated at the same time: hydroxyl-α-sanshool (HAS), hydroxyl-β-sanshool (HBS), hydroxyl-ε-sanshool (HES). This efficient method combined high-pressure supercritical fluid extraction (HPSFE) and industrial chromatography purification technology. By studying the extraction kinetics of target polyunsaturated amide monomers, the operation parameters of HPSFE were optimized. Meanwhile, a HPLC method for simultaneous determination of three polyunsaturated amide monomers was established in order to optimize process. Under the optimal conditions of high-pressure extraction, the extraction equilibration time was 45 min, the content of total polyunsaturated amides reached 27.53 %, and the yield was 2.89 %. At last, three high-purity polyunsaturated amide monomers were obtained, namely HES (95.16 %), HAS (98.43 %), and HBS (98.72 %). The in vitro cell assay showed that IC50 values of HES, HAS and HBS on the inflammatory factor NO were 14.5, 14.7 and 13.4 μg/mL, respectively. IC50 values on TNF-α and IL-6 were 21.2, 29.4, 23.9 μg/mL and 8.2, 7.0, 8.7 μg/mL, similarly. The Pharmacological studies showed that PA have obvious anti-inflammatory activity as one of the main effective components of ZB.