Immunomodulatory properties of Olea europaea leaf extract in intestinal inflammation

Mol Nutr Food Res. 2017 Oct;61(10). doi: 10.1002/mnfr.201601066. Epub 2017 Aug 29.


Scope: Extracts from olive (Olea europaea) leaves are used in Mediterranean traditional medicine as anti-inflammatory agents. They contain antioxidant phenolic compounds, such as oleuropeoside, which could be interesting for the treatment of inflammatory conditions associated with oxidative stress in humans, including inflammatory bowel disease.

Methods and results: The anti-inflammatory effects of olive leaf extract (0.5-25 mg/kg) were studied in two mice models of colitis (DSS and DNBS). Olive leaf extract (0.1-100 μg/mL) immunomodulatory effects were also investigated in different cell types and in ex vivo organ cultures of mucosal explants of healthy donors and Crohn's disease (CD) patients. The extract showed effect in both colitis models reducing the expression of proinflammatory mediators (IL-1β, TNF-α, and iNOS), and improving the intestinal epithelial barrier integrity restoring the expression of ZO-1, MUC-2, and TFF-3. These effects were confirmed in vitro. Furthermore, it reduced the production of proinflammatory mediators (IL-1β, IL-6, IL-8, and TNF-α) in intestinal mucosal samples from CD patients.

Conclusion: Olive leaf extract presented intestinal anti-inflammatory activity in colitis mouse models, maybe be related to its immunomodulatory properties and the capacity to restore the intestinal epithelial barrier. Besides, the extract could also regulate the activity of cells involved in the inflammatory response.

Keywords: Cytokines; Human colonic explants; Inflammatory bowel disease; Mouse experimental colitis; Olive leaf extract; Polyphenols.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / pharmacology*
  • Benzenesulfonates
  • Caco-2 Cells
  • Cell Line, Tumor
  • Colitis / chemically induced
  • Colitis / drug therapy
  • Cytokines / metabolism
  • Dextran Sulfate
  • Disease Models, Animal
  • Humans
  • Inflammation / chemically induced
  • Inflammation / drug therapy*
  • Intestinal Mucosa / metabolism
  • Intestines / drug effects
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Olea / chemistry*
  • Phytotherapy
  • Plant Extracts / pharmacology*
  • Plant Leaves / chemistry
  • RAW 264.7 Cells


  • Anti-Inflammatory Agents
  • Benzenesulfonates
  • Cytokines
  • Plant Extracts
  • dinitrobenzenesulfonic acid
  • Dextran Sulfate