SOLVENT-DEPENDENT SAPONIN RECOVERY AND BIOLOGICAL ACTIVITY POTENTIAL OF BUPLEURUM CHINENSE DC
Keywords:
Bupleurum chinense; saikosaponins; extraction solvent; antioxidant activity; metabolomicsAbstract
Background: Bupleurum chinense DC (B. chinense) is widely used in traditional medicine for hepatoprotective and anti-inflammatory purposes, largely attributed to its triterpenoid saponins. This study aimed to investigate the influence of extraction solvent polarity on phytochemical composition and in vitro biological activities of B. chinense extracts.
Methods: Water, 70% ethanol, and 96% ethanol extracts were prepared and evaluated for extraction yield, total saponin content, metabolite profiles, and biological activities. Metabolites were characterized using LC–MS/MS coupled with GNPS molecular networking. Chemometric analyses were employed to assess solvent-dependent metabolite distribution. Antioxidant activity was determined by free-radical scavenging and xanthine oxidase inhibition assays, while nitric oxide (NO) inhibition and cell viability were assessed in vitro.
Results: The highest extraction yield was obtained with 96% ethanol (10.1%), whereas 70% ethanol yielded the highest total saponin content (0.16%). LC–MS/MS analysis identified oleanane-type saikosaponins, flavonoids, coumarins, and phenolic acids. Chemometric analysis revealed distinct clustering of extracts according to solvent polarity, with polar saikosaponins enriched in the water extract and flavonoid aglycones predominating in ethanol extracts, particularly the 96% ethanol extract. The 96% ethanol extract showed the strongest antioxidant and xanthine oxidase inhibitory activities (IC₅₀ = 0.79–0.88 mg/mL and 0.80–0.81 mg/mL, respectively). All extracts exhibited weak NO inhibition (IC₅₀ > 248 ppm) while maintaining over 80% cell viability.
Conclusion: Extraction polarity significantly modulates the phytochemical composition and bioactivity of B. chinense. The 96% ethanol extract represents a potent antioxidant chemotype, while 70% ethanol is optimal for saponin enrichment, supporting solvent-guided optimization of Bupleurum preparations in phytotherapy.
