Inhibitory Effect of Cayratia albifolia C. L. Li Extract on LPS-induced Inflammation of RAW264.7 Cells by Regulating the Nrf2/HO-1 Axis

Background: Cayratia albifolia C. L. Li (Jiao Mei Gu (JMG)) has potential therapeutic effects in inflammatory diseases. Purpose: The primary goal of the research was to focus on the antioxidant and anti-inflammatory qualities of C. albifolia and the underlying mechanisms that contribute to these benefits. Methods: To explore the anti-inflammatory abilities of JMG, we employed enzyme-linked immunosorbent assay and nitric oxide (NO) assay in a lipopolysaccharide (LPS)-induced macrophage inflammation model. Furthermore, flow cytometry was employed to assess the antioxidant effects of C. albifolia, and Western blotting was used to reveal the underlying mechanisms. Results: Ethyl acetate extract of C. albifolia effectively reduced the release of NO, interleukin-6, tumor necrosis factor-alpha, and prostaglandin E2 in macrophages. Additionally, it prevented the expression of reactive oxygen species. Mechanistically, the extract may downregulate the expression of inducible nitric oxide synthase, cyclooxygenase-2, the nuclear factor-erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) protein expression. Conclusion: The ethyl acetate extract of C. albifolia demonstrated remarkable anti-inflammatory and antioxidant effects by modulating the Nrf2/HO-1 axis.