Anti-inflammatory activity of flavanones isolated from the roots of Pronephrium penangianum.

Ethnopharmacological relevance: Pronephrium penangianum, a traditional Chinese Tujia Ethnomedicine, is commonly used to treat various inflammatory conditions, including strains, dysentery, and traumatic injuries.

Aim of the study: The study aimed to examine the anti-inflammatory activity of flavanones isolated from the roots of P. penangianum.

Material and methods: Extensive spectrometric and spectroscopic techniques, including HRESI-MS, 1D and 2D-NMR spectra, and CD experiments, were used to elucidate the structures of the compounds. RAW264.7 cells were used for the anti-inflammatory assay. Griess reagent method, CCK-8 cell viability assay, Enzyme-linked immunosorbent assay (ELISA), molecular docking, and Western blot experiments to assess the related mechanism.

Results: Five new flavanone glycosides, jixueqisus G-K (1-5), and seven known flavonoid derivatives (6-12), were purified from the roots of P. penangianum. Activity screening of these compounds indicated that 6 significantly inhibited the release of NO, TNF-α, and IL-6. The in-silico study of 6, examining its interactions with IL-6 and p65.

Conclusion: The phytochemical analysis of P. penangianum's roots resulted in five new flavanone glycosides, jixueqisus G-K (1-5), and seven known flavonoid derivatives (6-12). The structures of the compounds were elucidated using spectroscopic and spectrometric analysis. Compound 6 exhibited potent anti-inflammatory effects associated with NF-κB activation by inhibiting IKBα phosphorylation and p65 degradation. To predict key interactions, compound 6 was also examined using molecular docking studies.