Phytochemical characterization and anti-inflammatory evaluation of compounds extracted from Ficus erecta roots

Ethnopharmacology relevance: The roots of Ficus erecta have been historically used in East Asian ethnomedicine for the treatment of various inflammatory conditions, particularly rheumatic and arthritic disorders. In regions such as southern China, Korea, and Japan, decoctions or topical formulations derived from the root are traditionally applied to alleviate symptoms of rheumatoid arthritis, joint swelling, and chronic musculoskeletal pain. These practices reflect longstanding empirical knowledge and suggest the presence of bioactive constituents with potential anti-inflammatory and immunomodulatory activities, warranting scientific validation and mechanistic exploration.

Aim of the study: This study aimed to investigate the chemical constituents of Ficus erecta roots and elucidate the pharmacodynamic basis of its anti-inflammatory activity.

Materials and methods: Fourteen compounds were isolated through solvent-gradient extraction and chromatographic techniques, and the structures were characterized via spectroscopic analysis. Network pharmacology was employed to perform a comprehensive analysis of these 14 compounds. A TNF-α-induced inflammatory model in SW982 cells was established to evaluate the anti-inflammatory effects of these compounds using CCK-8, Griess, and ELISA assays. The selected bioactive compound, 3,4-dihydropsoralen (DP), was further investigated through RNA-seq, RT-PCR, Western blot and molecular docking.

Results: The isolated compounds were identified as vanillic acid (1), p-hydroxybenzoic acid (2), 3,4-dihydropsoralen (3), 7-hydroxycoumarin (4), bergapten (5), psoralen (6), bis(2-ethylhexyl)phthalate (7), apigenin (8), isoimperatorin (9), rutin (10), quercetin (11), isorhamnetin (12), (+)-catechin (13), and hesperidin (14). Notably, compounds 3-5, 7-9, and 11-14 were firstly reported from F. erecta roots, with compounds 7 and 9 being newly identified within the genus Ficus. The compound (3) DP significantly suppressed NO release and inhibited the extracellular secretion of IL-6, IL-8, and IL-1β in a dose-dependent manner. RNA-seq analysis and RT-PCR validated that DP downregulated IL-17 signaling-related genes (MMP1, MMP3, CCL2, CXCL5 and CXCL11) and decreased the expression of p-IκBα and p-p65 at protein level, thereby blocking the activation of inflammatory NF-κB pathway. Network pharmacology analysis identified the potential anti-inflammatory targets and clarified the enriched signaling pathways. Molecular docking further simulated the binding interactions between DP and key inflammatory targets.

Conclusions: The current phytochemical investigations revealed the bioactive constituents of Ficus erecta roots and explored that DP exertd anti-inflammatory effects by inhibiting NF-κB signaling downstream of IL-17 pathway. These findings provide mechanistic insights and support the potential therapeutic application of Ficus erecta in managing inflammation-related diseases.

3,4-Dihydropsoralen; Anti-inflammation; Ficus erecta; Phytochemicals; RNA-Seq.