Comparative evaluations on phenolic antioxidants of nine adulterants and anti-inflammation of four alternatives with their original herb Erycibe schmidtii

Abstract

Erycibe schmidtii is widely used as folk medicine in China for treatments of various inflammations. Recently, with reduction of its wild sources, various adulterants have been misused as substitutes. To distinguish reliable alternatives from various adulterants, total phenolics and antioxidant activities of E. schmidtii and its nine adulterants, as well as three marker compounds of E. schmidtii defined by Chinese Pharmacopoeia were simultaneously quantified. And HPLC fingerprints of these ten herbs were established. Compared with E. schmidtii (S1), Porana sinensis (S2), Porana sinensis var. delavayi (S3), Celastrus hindsii (S4), and Morinda umbellata (S5) exhibited similar or higher total phenols, flavonoids and tannins along with similar or greater capacities scavenging DPPH˙, ABTS⁺˙ and AAPH˙, contained similar or higher total amounts of the three marker compounds, and possessed higher similarities in HPLC profiles. The other five adulterants (S6–S10, i.e., Illigera parviflora, Morinda parvifolia, Piper puberulum, Piper kadsura and Iodes seguini in sequence) were identified as absolute fakes, thus were excluded from alternatives of S1. Further anti-inflammatory experiments with LPS-induced RAW264.7 macrophages cells on NO release and transcriptions of inflammatory factors iNOS, COX-2, IL-6 and IL-1β showed that S2 and S3 possessed higher anti-inflammation activities than and similar mechanisms to those of S1. Taken together, S2 and S3 could be the best potentially alternatives of E. schmidtii among the nine adulterants. S4 and S5 might be also considered as alternatives for they contained similar fundamental compounds and equally impressive anti-inflammatory potential with E. schmidtii concerning iNOS and COX-2.