Differential functional genomic effects of anti-inflammatory phytocompounds on immune signaling

Shao-Chih Chiu,Staniforth Vanisree,Shan-Wen Tsao,Ning-Sun Yang,Pei-Ing Hwang,Yi-An Chen

doi:10.1186/1471-2164-11-513

Abstract

BackgroundFunctional comparative genomic analysis of the cellular immunological effects of different anti-inflammatory phytocompounds is considered as a helpful approach to distinguish the complex and specific bioactivities of candidate phytomedicines. Using LPS-stimulated THP-1 monocytes, we characterize here the immunomodulatory activities of three single phytocompounds (emodin, shikonin, and cytopiloyne) and a defined phytocompound mixture extracted from Echinacea plant (BF/S+L/Ep) by focused DNA microarray analysis of selected immune-related genes.ResultsShikonin and emodin significantly inhibited the early expression (within 0.5 h) of approximately 50 genes, notably cytokines TNF-α, IL-1β and IL-4, chemokines CCL4 and CCL8, and inflammatory modulators NFATC3 and PTGS2. In contrast, neither cytopiloyne nor BF/S+L/Ep inhibited the early expression of these 50 genes, but rather inhibited most late-stage expression (~12 h) of another immune gene subset. TRANSPATH database key node analysis identified the extracellular signal-regulated kinase (ERK) 1/2 activation pathway as the putative target of BF/S+L/Ep and cytopiloyne. Western blot confirmed that delayed inactivation of the ERK pathway was indeed demonstrable for these two preparations during the mid-stage (1 to 4 h) of LPS stimulation. We further identified ubiquitin pathway regulators, E6-AP and Rad23A, as possible key regulators for emodin and shikonin, respectively.ConclusionThe current focused DNA microarray approach rapidly identified important subgenomic differences in the pattern of immune cell-related gene expression in response to specific anti-inflammatory phytocompounds. These molecular targets and deduced networks may be employed as a guide for classifying, monitoring and manipulating the molecular and immunological specificities of different anti-inflammatory phytocompounds in key immune cell systems and for potential pharmacological application.

Highlights

Functional comparative genomic analysis of the cellular immunological effects of different antiinflammatory phytocompounds is considered as a helpful approach to distinguish the complex and specific bioactivities of candidate phytomedicines
Analysis of the kinetics of cytokine production during the inflammatory response reveals that macrophage activation is the product of an underlying process that impacts the genome within minutes and continues for several hours
The highest concentrations that led to no significant decrease in cell viability were used in subsequent experiments

Summary

Introduction

Functional comparative genomic analysis of the cellular immunological effects of different antiinflammatory phytocompounds is considered as a helpful approach to distinguish the complex and specific bioactivities of candidate phytomedicines. At the onset (~0.5 h) and in the early stages (within the first 2 h) of an inflammatory response, NF-B, signal transducer and activator of transcription (STAT), activator protein-1 (AP-1), and CCAAT enhancer-binding protein (CEBP) control macrophage gene expression [5,6]. A secondary response or mid-term stage commences around 4 h, which primes the immune system for the resolution, and there is a final late stage response around 12 h after stimulus [7]. The interplay of these three stages determines the outcome of the specific and/or the overall inflammatory responses [5,8]. We hypothesized at the outset of this study that different phytochemicals with reputed anti-inflammatory activities may exhibit distinctive patterns of effects and kinetics as they intervene in specific steps in the inflammatory cascade, and that such phytochemicals may be subgrouped on those grounds, at the pharmacogenomic level, for systematic mechanism studies or therapeutic applications

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