AUTHOR=Yue Lan , Luo Jinfang , Zhao Chenliang , Zhao Jinfeng , Ye Jianghai , He Kang , Zou Juan 

TITLE=Oleanane triterpenoids with C-14 carboxyl group from Astilbe grandis inhibited LPS-induced macrophages activation by suppressing the NF-κB signaling pathway

JOURNAL=Frontiers in Pharmacology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2024.1413876

DOI=10.3389/fphar.2024.1413876

ISSN=1663-9812

ABSTRACT=<sec><title>Background</title><p>Excessive inflammation poses significant risks to human physical and mental health. <italic>Astilbe grandis</italic>, a traditional Miao medicine, is renowned for its anti-inflammatory properties. However, the specific anti-inflammatory effects and mechanisms of many compounds within this plant remain unclear. This study aims to investigate the anti-inflammatory effects and mechanisms of two characteristic oleanane triterpenoids, 3<italic>α</italic>-acetoxyolean-12-en-27-oic acid (<bold>1</bold>) and 3<italic>β</italic>-acetoxyolean-12-en-27-oic acid (<bold>2</bold>), isolated from <italic>Astilbe grandis</italic>, using lipopolysaccharide (LPS)-induced Macrophages.</p></sec><sec><title>Methods</title><p>The anti-inflammatory effects and mechanisms of compounds <bold>1</bold> and <bold>2</bold> were investigated by establishing an LPS-induced inflammation model in RAW 264.7 cells and THP-1 cells. Nitric oxide (NO) levels were assessed using the Griess method. The concentrations of tumor necrosis factor-alpha (TNF-<italic>α</italic>), interleukin-6 (IL-6), and interleukin-1beta (IL-1<italic>β</italic>) were measured via enzyme-linked immunosorbent assay (ELISA). The expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) was determined using western blotting and quantitative real-time PCR (qRT-PCR). Additionally, the phosphorylation level of p65 in nuclear factor-kappa B (NF-<italic>κ</italic>B) was assessed through western blotting. The nuclear translocation of NF-<italic>κ</italic>B p65 was assessed through immunofluorescence staining. Finally, the binding affinity of the compounds to NF-<italic>κ</italic>B p65 target was validated through molecular docking.</p></sec><sec><title>Results</title><p>Compounds <bold>1</bold> and <bold>2</bold> significantly inhibited the expression of NO, TNF-<italic>α</italic>, IL-6, IL-1<italic>β</italic>, COX-2, and iNOS in LPS-induced Macrophages. Mechanistically, they attenuated the activation of the NF-<italic>κ</italic>B signaling pathway by downregulating the phosphorylation level and nuclear translocation of p65.</p></sec><sec><title>Conclusion</title><p>This study elucidates the anti-inflammatory activities and potential mechanism of the characteristic oleanane triterpenoids with C-14 carboxyl group, compounds <bold>1</bold> and <bold>2</bold>, in LPS-induced Macrophages by inhibiting the NF-<italic>κ</italic>B signaling pathway for the first time. These findings suggest that these two compounds hold promise as potential candidates for anti-inflammatory interventions in the future.</p></sec>