Antioxidant and Anti-Inflammatory Activities of Astilboides tabularis (Hemsl.) Engl. Root Extract.

Here, we examined the antioxidant and anti-inflammatory activities of the ethyl acetate (EtOAc) fraction of Astilboides tabularis (Hemsl.) Engl. root extracts, initially prepared from a 70% ethanol extraction. This EtOAc fraction exhibited significant scavenging activity against DPPH radicals (IC50: 11.38 ± 0.48 µg/mL) and ABTS radicals (IC50: 7.46 ± 0.58 µg/mL), and had a high total phenolic content (i.e., 407.02 ± 13.56 mg GAE/g). In addition, the EtOAc fraction demonstrated concentration-dependent protective effects in a RAW264.7 macrophage cell model subjected to oxidative stress. In lipopolysaccharide (LPS)-stimulated RAW264.7 cells, nitric oxide (NO) production and the expression of inflammatory mediators (iNOS, COX-2, TNF-α, IL-1β, IFN-β) were inhibited in a concentration-dependent manner. Western blot and real-time PCR (RT-PCR) analyses revealed that the EtOAc fraction also suppressed inflammatory mediator expression via inhibiting the activation of the NF-κB and MAPK signaling pathways. Finally, LC-QTOF-MS and LC-MS/MS analyses identified gallic acid and bergenin as compounds contributing to observed antioxidant and anti-inflammatory effects. In conclusion, the EtOAc fraction of A. tabularis root extracts exhibited strong anti-oxidant and anti-inflammatory properties, suggesting potential usage for treating various inflammatory diseases.