Pseuderanthemum palatiferum leaf extract inhibits the proinflammatory cytokines, TNF-α and IL-6 expression in LPS-activated macrophages

• Published in: Food and chemical toxicology Vol. 97; pp. 11 - 22
• Main Authors: Sittisart, Patcharawan, Chitsomboon, Benjamart, Kaminski, Norbert E.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-11-2016
• Subjects: Acanthaceae - chemistry; Animals; Anti-Inflammatory Agents - pharmacology; AP-1; C/EBP; Electrophoretic Mobility Shift Assay; IL-6; Interleukin-6 - antagonists & inhibitors; Lipopolysaccharides - pharmacology; Macrophages, Peritoneal - cytology; Macrophages, Peritoneal - drug effects; Macrophages, Peritoneal - metabolism; Mice; NF-kappa B - metabolism; NF-κB; Plant Extracts - pharmacology; Plant Leaves - chemistry; Polyphenols - pharmacology; Pseuderanthemum palatiferum; TNF-α; Tumor Necrosis Factor-alpha - antagonists & inhibitors; NF-κB; C/EBP; TNF-α; Pseuderanthemum palatiferum; AP-1; IL-6
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2016.08.021

The anti-inflammatory potential and underlying mechanisms of an ethanol extract of Pseuderanthemum palatiferum (EEP) leaves was investigated using LPS-activated macrophages. Our results show EEP produced a concentration-dependent suppression of TNF-α and IL-6 secretion by LPS-activated mouse peritoneal macrophages. EEP also suppressed LPS-induced TNF-α and IL-6 protein and mRNA levels in mouse-derived myeloid cell line RAW264.7. To further elucidate the molecular mechanisms responsible for impaired TNF-α and IL-6 regulation by EEP, the activation of transcription factors, NF-κB, C/EBP, and AP-1, was monitored using electrophoretic mobility shift assays. EEP suppressed LPS-induced NF-κB DNA binding activity within both the TNF-α and IL-6 promoters in RAW264.7 cells with impairment being more pronounced in the IL-6 promoter. In addition, EEP exhibited a concentration-dependent suppression of C/EBP and AP-1 DNA binding activity within the IL-6 promoter. Concordantly, IL-6 luciferase promoter reporter activity was also suppressed by EEP in transiently transfected RAW264.7 cells, upon LPS activation. EEP analysis by GC-MS and HPLC DAD-MSD revealed the presence of β-sitosterol and various polyphenols, respectively, which are known to possess anti-inflammatory activity. Collectively, these results suggest that the anti-inflammatory effects of EEP are mediated, at least in part, by modulating TNF-α and IL-6 expression through impairment of NF-κB, C/EBP, and AP-1 activity.
•Pseuderanthemum palatiferum leaf extract possesses anti-inflammatory activity.•Pseuderanthemum palatiferum-mediated anti-inflammatory activity from TNF-α and IL-6.•Pseuderanthemum palatiferum occurs transcriptionally by NF-κB, C/EBP, AP-1 activity.