Effects of oral moisturizing gel containing propolis following head and neck radiotherapy: randomized controlled pilot trial

Ryoma Nakao,Takao Ueno

doi:10.1038/s41405-021-00068-3

Abstract

AimTopical administration of oral gel may reduce radiotherapy-related oral complications. The aim of this study was to examine clinical and microbiological effects of self-administration of different gel formulations to oral mucosa in head and neck cancer patients.Materials and methodsTwenty-seven subjects were recruited from outpatients who underwent radiotherapy of at least 50 Gy to the head and neck area. They were randomly assigned to oral gel with the following different ingredients: placebo, chlorhexidine, curry leaf, propolis, and turmeric. Before and after intervention, oral symptoms were evaluated, and nine oral pathogens in saliva were also quantified using real-time PCR.ResultsTwenty-five subjects completed the study and their data were analyzed. The number of Porphyromonas gingivalis in saliva significantly decreased after treatment with propolis gel, but not after any other treatments. Propolis gel treatment also relieved oral pain in all subjects who had oral pain at the baseline.ConclusionsTopical administration with propolis gel may not only reduce P. gingivalis carriage in saliva, but also relieve oral pain.DiscussionA future larger-scale clinical trial of oral propolis gel is needed to determine its clinical efficacy in radiotherapy-related oral complications of head and neck cancer patients.

Highlights

Radiotherapy in the head and neck area is usually intense, high dose, and continuous, and often used in conjunction with chemotherapy, acute and late radiotherapy-related complications frequently occur.[1]
A previous report noted that radiationinduced oral mucositis was found in up to 100% of head and neck cancer patients who received a dosage of 25 Gy.[2]
We have reported a mechanism of the antibacterial activity of propolis against the major periodontopathic bacterium Porphyromonas gingivalis.[8]

Summary

Introduction

Radiotherapy in the head and neck area is usually intense, high dose, and continuous, and often used in conjunction with chemotherapy, acute and late radiotherapy-related complications frequently occur.[1] A previous report noted that radiationinduced oral mucositis was found in up to 100% of head and neck cancer patients who received a dosage of 25 Gy.[2] Resultant damage to oral mucosa, mainly due to injury of epithelial and lamina propria cells and/or salivary gland cells, results in a wide range of the complications, including pain, dryness, ulceration, and pseudomembranous formation, as well as infectious diseases in the oral cavity. We have reported that administration of a propolis ointment into periodontal pockets reduced the amount of P. gingivalis in gingival crevicular fluid, and improved clinical attachment level (CAL),[9] which is regarded as one of the most clinically relevant parameters for periodontitis.[10]

Methods

Results

Conclusion