In vitro antioxidant and anti-inflammatory mechanism evaluation of MPB-BA. Representative immunofluorescence images for p-Nrf2 (green) in macrophages incubated without (a) or with (b) MPB-BA before LPS treatment (0, 30, and 60 min). Nuclei were stained with DAPI (blue), scale bar = 10 μm. (c) Western blot detection of p-Nrf2, Nrf2 and p-IKKβ, IKKβ, p-P65, P65 (NF-κB inflammatory pathway), with GAPDH as the internal control. (d) The antioxidant and anti-inflammatory mechanism of MPB-BA was presented as a schematic diagram.