Inula britannica exerts antioxidant and anti-inflammatory effects in SH-SY5Y cells through the Nrf2–Keap1 signaling pathway

The yellow flower of the Asteraceae family, Inula britannica (IB) of have been used as a medicinal herb since ancient times. Modern studies have widely known the anti-inflammatory effects and antioxidant effects of IB. Therefore, this study aimed to analyze the neuroprotective effects of IB extract based on its antioxidant and anti-inflammatory effects and to assess its potential for development as a functional material. After preparing the extract of IB based on the solvent with water and 70 % ethyl alcohol (EtOH), the phytochemical components were identified. The effects of the IB extracts on the Nrf2–Keap1 signaling pathway, NF-κB signaling pathway, and Bax/Bcl-2 ratio were investigated in H₂O₂-induced SH-SY5Y cells using reverse transcription-polymerase chain reaction and western blotting. Both IB extracts activated the representative antioxidant signaling pathway Nrf2–Keap1 in a concentration-dependent manner. In the inflammation-related NF-κB signaling pathway, the expression of each factor was inhibited, and the Bax/Bcl-2 ratio, which is related to apoptosis, decreased upon IB extract treatment. Phytochemical analysis using liquid chromatography-tandem mass spectrometry identified polyphenols and flavonoids as the primary active compounds in IB. These findings indicate that IB extract has potential as a functional material for the treatment of neurodegenerative diseases.