Anti-Inflammatory Effects of Camellia fascicularis Polyphenols via Attenuation of NF-κB and MAPK Pathways in LPS-Induced THP-1 Macrophages

Abstract

Plant polyphenols possess beneficial functions against various diseases. This study aimed to identify phenolic ingredients in Camellia fascicularis (C. fascicularis) and investigate its possible underlying anti-inflammatory mechanism in lipopolysaccharide (LPS)-induced human monocytes (THP-1) macrophages. Methods: C. fascicularis polyphenols (CFP) were characterized by ultra-performance liquid chromatography (UPLC) combined with quadrupole-time-of-flight mass/mass spectrometry (Q-TOF-MS/MS). The THP-1 cells were differentiated into macrophages under the stimulation of phorbol 12-myristate 13-acetate (PMA) and then treated with LPS to build a cellular inflammation model. The cell viability was detected by CCK-8 assay. The levels of reactive oxygen species (ROS) were assessed by flow cytometry. The secretion and expression of inflammatory cytokines were tested by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR). In addition, the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways were analyzed by Western blotting. Results: Twelve phenolic constituents including (-)-epicatechin, casuariin, agastachoside, etc. in CFP were identified. The CCK-8 assay showed that CFP exhibited no significant cytotoxicity between 100 and 300 μg/mL. After treated with CFP, the release of ROS was significantly suppressed. CFP inhibited inflammation in macrophages by attenuating the polarization of LPS-induced THP-1 macrophages, down-regulating the expression of the pro-inflammatory cytokines IL-6, IL-1β and TNF-α, and up-regulating the expression of the anti-inflammatory cytokine IL-10. Western blotting experiments manifested that CFP could markedly inhibit the phosphorylation of p65, ERK and JNK, thereby suppressing the activation of NF-κB and MAPK signaling pathways. Conclusion: These findings indicated that CFP exerted anti-inflammatory activity by inhibiting the activation NF-κB and MAPK pathways which may induce the secretion of pro-inflammatory cytokines. This study offers a reference for C. fascicularis as the source of developing natural, safe anti-inflammatory agents in the future.

Kaempferol attenuates inflammation in lipopolysaccharide‐induced gallbladder epithelial cells by inhibiting the MAPK/NF‐κB signaling pathway

“…The NF‐κB/MAPK signaling pathway is involved in the development and progression of cholecystitis (Gao et al., 2022). To further investigate the mechanism of KPR in cholecystitis, we examined the expression levels of NF‐κB/MAPK signaling pathway‐related proteins.…”

“…Therefore, the cell inflammation of human gallbladder epithelial cells (HGBECs) induced by LPS stimulation is a method to construct an in vitro model of cholecystitis (Zheng et al., 2023). MAPK/NF‐κB signaling has been proven to be involved in the development of cholecystitis by regulating the expression of inflammatory factors (Gao et al., 2022).…”

Comparative Analysis of Pigments, Phenolics, and Bioactivities of Three Camellia Species Growing in Vietnam

“…38,39 C. fascicularis phenolics-rich extract down-regulated the expression of TNF-α, IL-6, and IL-1β while up-regulating the expression of IL-10 in lipopolysaccharide-induced human monocytes (THP-1) macrophages. 40 It was suggested that phenolics in Camellia extracts, such as catechins, ellagitannin, and flavonoid glycosides, contributed to the anti-inflammatory properties.…”

Diversity and Recruitment Strategies of Rhizosphere Microbial Communities by Camellia fascicularis, a Plant Species with Extremely Small Populations in China: Plant Recruits Special Microorganisms to Get Benefit out of Them

“…In recent years, anti-inflammation, antioxidation, and antitumor effects of C. fascicularis polyphenols and flavonoids have been reported [1][2][3]. Therefore, the artificial cultivation of C. fascicularis is not only beneficial to its restoration and protection as a plant species with extremely small populations (PSESPs), but also provides a material guarantee for the development and utilization of C. fascicularis resources in the future.…”