Affiliations 

  • 1 Department of Pharmaceutical Chemistry, School of Pharmacy, International Medical University Bukit Jalil, Malaysia
  • 2 Department of Life Sciences, School of Pharmacy, International Medical University Bukit Jalil, Malaysia
  • 3 School of Postgraduate Studies and Research, International Medical University Bukit Jalil, Malaysia
  • 4 Atta-ur-Rahman Institute for Natural Products Discovery, Universiti Teknologi MARA Shah Alam, Malaysia
  • 5 Institute of Bioscience, Universiti Putra MalaysiaSerdang, Malaysia; Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra MalaysiaSerdang, Malaysia
  • 6 Institute of Bioscience, Universiti Putra Malaysia Serdang, Malaysia
  • 7 Perdana University-Royal College of Surgeons Ireland, Perdana University Serdang, Malaysia
Front Pharmacol, 2016;7:7.
PMID: 26869924 DOI: 10.3389/fphar.2016.00007

Abstract

Clinacanthus nutans has had a long history of use in folk medicine in Malaysia and Southeast Asia; mostly in the relief of inflammatory conditions. In this study, we investigated the effects of different extracts of C. nutans upon lipopolysaccharide (LPS) induced inflammation in order to identify its mechanism of action. Extracts of leaves and stem bark of C. nutans were prepared using polar and non-polar solvents to produce four extracts, namely polar leaf extract (LP), non-polar leaf extract (LN), polar stem extract (SP), and non-polar stem extracts (SN). The extracts were standardized by determining its total phenolic and total flavonoid contents. Its anti-inflammatory effects were assessed on LPS induced nitrite release in RAW264.7 macrophages and Toll-like receptor (TLR-4) activation in TLR-4 transfected human embryonic kidney cells (HEK-Blue(TM)-hTLR4 cells). The levels of inflammatory cytokines (TNF-α, IFN-γ, IL-1β, IL-6, IL-12p40, and IL-17) in treated RAW264.7 macrophages were quantified to verify its anti-inflammatory effects. Western blotting was used to investigate the effect of the most potent extract (LP) on TLR-4 related inflammatory proteins (p65, p38, ERK, JNK, IRF3) in RAW264.7 macrophages. All four extracts produced a significant, concentration-dependent reduction in LPS-stimulated nitric oxide, LPS-induced TLR-4 activation in HEK-Blue(TM)-hTLR4 cells and LPS-stimulated cytokines production in RAW264.7 macrophages. The most potent extract, LP, also inhibited all LPS-induced TLR-4 inflammatory proteins. These results provide a basis for understanding the mechanisms underlying the previously demonstrated anti-inflammatory activity of C. nutans extracts.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.