[Analysis on multiple pharmaceutical ingredients and antioxidant capacities of Prunellae Spica based on multivariate...

Prunellae Spica is a perennial edible and medicinal plant, rich in antioxidant substances. Total flavonoids (TFC), Phenolics (TPC), triterpenoids (TSC), polysaccharides (PC) and their antioxidant capacities (by the FRAP, DPPH and ABTS⁺ methods) of ethyl acetate fraction, n-butanol fraction and other fractions of aqueous extract from Prunellae Spica were investigated in this study. Then the multivariate statistical method was adopted to analyze the relationship between the multiple pharmaceutical ingredients and antioxidant capacities of Prunellae Spica. The results showed that ethyl acetate fraction had relatively high concentration of TFC (0.61±0.10) g·g⁻¹DW, TPC (0.52±0.09) g·g⁻¹DW, and TSC (0.21±0.03) g·g⁻¹DW, with high scavenging capacity of DPPH (3.1±0.38) mmol·L⁻¹·g⁻¹DW and FRAP (2.56±0.35) mmol·L⁻¹·g⁻¹DW. Hierarchical clustering analysis (HCA) and principal component analysis (PCA) results indicated the information from chemical compositions and antioxidant capacity can represent the "differences" of different fractions. Canonical correlation analysis (CCorA) revealed a high positive correlation between the amounts of multiple chemical compositions and the antioxidant capacities (r=0.970 0), and the first canonical variate had been reached. Moreover, ABTS⁺ method showed a low response to the compositions of different fractions, so this method may not be suitable for evaluation of Prunellae Spica antioxidant capacities, while DPPH evaluation method was more suitable for TSC and TPC. The results of this study have important reference significance for the evaluation method on antioxidant activity of Prunellae Spica in the field of food or medicine as well as for the development of related extracts.