Phytosterols isolated from Clinacanthus nutans induce immunosuppressive activity in murine cells

Cheng Foh Le, Thina Hareesh Kailaivasan, Sek Chuen Chow, Zunoliza Abdullah, Sui Kiong Ling, Chee Mun Fang

Research output: Contribution to journalArticleResearchpeer-review

49 Citations (Scopus)

Abstract

Clinacanthus nutans (Burm. f.) Lindau is a traditional medicinal plant belonging to the Acanthaceae family. Its therapeutic potentials have been increasingly documented particularly the antiviral activity against Herpes Simplex Virus (HSV), anti-cancer, anti-oxidant, anti-inflammatory and immunomodulatory activities. However, majority of these studies used crude or fractionated extracts and not much is known about individual compounds from these extracts and their biological activities. In the present study, we have isolated four compounds (CN1, CN2, CN3 and CN4) from the hexane fractions of C. nutans leaves. Using NMR spectroscopic analysis, these compounds were identified to be shaftoside (CN1), stigmasterol (CN2), β-sitosterol (CN3) and a triterpenoid lupeol (CN4). To determine the immunosuppressive potential of these compounds, their effects on mitogens induced T and B lymphocyte proliferation and the secretion of helper T cell cytokines were examined. Among the four compounds, stigmasterol (CN2) and β-sitosterol (CN3) were shown to readily inhibit T cell proliferation mediated by Concanavalin A (ConA). However, only β-sitosterol (CN3) and not stigmasterol (CN2) blocks the secretion of T helper 2 (Th2) cytokines (IL-4 and IL-10). Both compounds have no effect on the secretion of Th1 cytokines (IL-2 and IFN-γ), suggesting that β-sitosterol treatment selectively suppresses Th2 activity and promotes a Th1 bias. CN3 was also found to significantly reduce the proliferation of both T helper cells (CD4+ CD25+) and cytotoxic T cells (CD8+ CD25+) following T cell activation induced by ConA. These results suggested that phytosterols isolated from C. nutans possess immunomodulatory effects with potential development as immunotherapeutics.

Original languageEnglish
Pages (from-to)203-210
Number of pages8
JournalInternational Immunopharmacology
Volume44
DOIs
Publication statusPublished - Mar 2017

Keywords

  • Clinacanthus nutans
  • Cytokines
  • Flow cytometry
  • Immunosuppression
  • Stigmasterol
  • β-Sitosterol

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