title: Influence of triterpenoids present in apple peel on inflammatory gene expression associated with inflammatory bowel disease (IBD).
abstract: Various ursanic, oleanic and lupanic pentacyclic triterpenoids found in apple peel were studied for anti-inflammatory effects in vitro using T84 colon carcinoma cells. After pretreatment with single triterpenoids, cells were stimulated with pro-inflammatory cytokines (TNF-α, INF-γ, IL-1β). Regulation of mRNA expression was analysed for three specific inflammation-associated marker genes (TNF-α, IL-8, IP-10) using qRT-PCR. Furthermore, the effects of ursolic acid (UA) and oleanolic acid (OA) on the synthesis of certain pro-inflammatory proteins were examined. IP-10 expression was inhibited in a dose-dependent manner by all the tested compounds at concentrations ≥25 μM. The mRNA expression of TNF-α was slightly affected and the IL-8 level was increased. At the protein level, UA and OA (25 μM) reduced the synthesis of IP-10; sICAM-1, IL-23 and GROα were slightly repressed. The TNF-α level was not modulated, whereas induction of IL-8 was increased. UA also enhanced the synthesis of IL-1ra, while OA suppressed the level of I-TAC. The present study confirms that triterpenoids present in apple peel and β-damascone may be implicated in the anti-inflammatory properties of apple constituents, suggesting that these substances might be helpful in the treatment of IBD as nutrient supplements.
authors.affiliation: Department of Food Chemistry and Toxicology, Molecular Nutrition, University of Kaiserslautern, Kaiserslautern, Germany.
authors.forename: Dolores
authors.initials: D
authors.lastname: Mueller
authors.forename: Sven
authors.initials: S
authors.lastname: Triebel
authors.forename: Olga
authors.initials: O
authors.lastname: Rudakovski
authors.forename: Elke
authors.initials: E
authors.lastname: Richling
mesh_terms: D002460:Cell Line; D016207:Cytokines / Q000235:genetics* / Q000276:immunology; D005638:Fruit / Q000737:chemistry; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy / Q000235:genetics* / Q000276:immunology*; D027845:Malus / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D013729:Terpenes / Q000494:pharmacology*
chemical_list: D016207:Cytokines; D010936:Plant Extracts; D013729:Terpenes