Identification of JAK–STAT pathways as important for the anti-inflammatory activity of a Hypericum perforatum fraction and bioactive constituents in RAW 264.7 mouse macrophages

• Published in: Phytochemistry (Oxford) Vol. 71; no. 7; pp. 716 - 725
• Main Authors: Hammer, Kimberly D.P., Yum, Man-Yu, Dixon, Philip M., Birt, Diane F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.05.2010; Elsevier
• Subjects: Amentoflavone; Animals; Anti-Inflammatory Agents - pharmacology; Base Sequence; Biological and medical sciences; Cell Line; Chemical constitution; Chlorogenic acid; Cluster Analysis; DNA Primers; Fundamental and applied biological sciences. Psychology; Gene expression; General pharmacology; Hypericaceae; Hypericum - chemistry; Hypericum perforatum; Interactions; Janus Kinase 1 - metabolism; Macrophages - drug effects; Medical sciences; Mice; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Plant physiology and development; Polymerase Chain Reaction; Pseudohypericin; Quercetin; RAW 264.7 mouse macrophages; St. John’s wort; STAT Transcription Factors - metabolism; Hypericum perforatum; Amentoflavone; St. John’s wort; Pseudohypericin; Quercetin; Hypericaceae; Chlorogenic acid; Interactions; Gene expression; RAW 264.7 mouse macrophages; Guttiferae; Identification; Flavonoid; Medicinal plant; Polyphenol; Dicotyledones; Angiospermae; St. John's wort; Weed; Pharmacognosy; Interaction; Rodentia; Antiinflammatory agent; Chemical structure; Vertebrata; Mammalia; Mouse; Animal; Plant origin; Phenols; Spermatophyta; Macrophage
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2010.02.006

A set of bioactive constituents, the 4-component-system, were combined at the concentrations detected in a Hypericum perforatum fraction. LPS was used to model an inflammatory response in RAW 264.7 macrophages and the differentially expressed genes were compared for the fraction and 4-component-system, respectively. JAK–STAT and eicosanoid pathways were identified as being important for the Hypericum-mediated anti-inflammatory activity. Hypericum perforatum extracts have been used to treat diseases, including mild-to-moderate depression and inflammatory conditions. It is particularly important to identify which constituents present in the H. perforatum extracts are responsible for its anti-inflammatory activity since consumers are taking H. perforatum preparations to treat inflammation. We used a combination of four putative bioactive constituents, called the 4-component-system that interacted synergistically to explain the light-activated anti-inflammatory activity of an H. perforatum fraction in RAW 264.7 mouse macrophages. We also combined the constituents at concentrations detected in the fraction to identify key molecular targets. LPS was used to model an inflammatory response, and the 4-component-system and H. perforatum fraction were used as treatments that inhibited LPS-induced prostaglandin E 2 (PGE 2) production in RAW 264.7 mouse macrophages in the studies of gene expression profiles. We used Affymetrix genechips, statistical analysis, and quantitative real-time PCR to identify key gene targets of the 4-component-system and the sub-fraction from an H. perforatum ethanol extract. The H. perforatum sub-fraction, with or without LPS stimulation, affected far more genes than the 4-component-system with and without LPS. Genes involved in Janus kinase, as well as a signal transducer and activator of transcription (JAK–STAT) and eicosanoid pathways were identified that could account for the reduction in PGE 2 observed with both treatments in LPS-stimulated macrophages. Ten genes may be particularly important targets for activity of the 4-component-system and the fraction with LPS stimulation and these genes were involved in inflammatory signaling pathways, namely the JAK–STAT and eicosanoid pathways.