The effect of olive leaf extract in decreasing the expression of two pro-inflammatory cytokines in patients receiving chemotherapy for cancer. A randomized clinical trial

Saudi Dent J. 2013 Oct;25(4):141-7. doi: 10.1016/j.sdentj.2013.09.001. Epub 2013 Nov 9.


Background: Oral mucositis is the most common side effects of chemotherapy of all cancer with intensive treatments regimen, and is the most common side effects of head and neck radiation therapy. For steam cell transplantation, its also regarded as the most debilitating side effects.

Aims of the study: The objectives of this study were to assess the effect of a mouth rinse containing olive leaf extract (OLE) in preventing severe oral mucositis in patients receiving chemotherapy, and to estimate its effect in decreasing pro-inflammatory cytokine production after chemotherapy.

Materials and methods: This study utilized a placebo-controlled, randomized, double-blind, and cross-over design. Twenty-five patients undergoing intensive chemotherapy were randomly assigned to receive a mouth wash containing OLE, benzydamine hydrochloride, or placebo in 3 different cycles of chemotherapy. Oral mucositis severity was assessed using the World Health Organization criteria and Oral Mycositis Assessment Scale. Patients were evaluated weekly until 15 days after chemotherapy for each cycle. Salivary levels of interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) were evaluated by enzyme-linked immunosorbant assay.

Results: Oral mucositis rates and severity after 2 weeks were significantly lower in the OLE and benzydamine groups compared to the placebo group. The IL-1β and TNF-α levels were significantly decreased in the OLE group compared to the other groups.

Conclusion: Preliminary findings indicate that OLE is effective in reducing IL-1β and TNF-α levels after chemotherapy and exert a therapeutic effect and prevent development of severe oral mucositis.

Keywords: Benzydamine hydrochloride (Benzydamine HCl); Interlukien-1 β (IL-1β); Olive leaf extract (OLE); Oral mucositis; Proinflammatory cytokine; Tumor necrosis factor-α (TNF-α).