Green tea shines as a natural powerhouse of antioxidants, with catechins leading the charge among its polyphenols, which protect cells from oxidative stress. These powerful compounds neutralize harmful free radicals generated during cancer treatment. The anti-inflammatory properties of green tea can alleviate oral mucositis, a painful inflammation of the mouth lining often caused by chemotherapy and radiation.
Building on these benefits, researchers at the Tokyo University of Science (TUS), Japan, have explored the potential of tea catechins in developing a novel treatment for oral mucositis that minimizes patient discomfort. Their findings were made available online on January 14, 2025 and published in Volume 10 and Issue 1 of ACS Omega on December 19, 2024. The research team, led by Professor Takehisa Hanawa, included Assistant Professor Kaoru Hirose, Ms. Rieko Nitto, and Mr. Shotaro Yokota from TUS, in collaboration with Dr. Yayoi Kawano (former lecturer at TUS, now Professor at Nagoya City University, Japan), as well as Mr. Akira Tabuchi, Dr. Yumeo Suzuki, and Dr. Kazuhiko Yamatoya from MP Gokyo Food & Chemical Co., Ltd., Japan.
In line with TUS's commitment to advancing research that supports the UN Sustainable Development Goals (SDGs), the team sought to develop an innovative and accessible treatment for oral mucositis, aligning with SDG 3 (good health and well-being) and SDG 9 (industry, innovation, and infrastructure). "Our goal was to create a formulation for oral mucositis that patients could use easily and comfortably, helping to prevent the decline in quality of life and difficulties with eating caused by cancer treatments," explains Prof. Hanawa.
Oral mucositis, a common and painful side effect of cancer treatments, affecting 30–40% of the patients, results from damage to rapidly dividing mucosal cells. This condition causes significant discomfort and interference with vital activities, such as eating and sleeping. To address this, the researchers designed a thin mucoadhesive film enriched with tea catechins, which can be applied directly to affected areas for prolonged relief. This film is a thin, flexible material that adheres to the inside of the mouth to deliver active ingredients, like medications, directly to the affected area. It offers a more convenient, inexpensive, and user-friendly alternative to mucoadhesive tablets, which often have limited usability.
The films were prepared by combining xyloglucan (Xylo), a water-soluble polymer extracted from tamarind seeds, with green tea extract (TE) which contains over 75% catechins, including more than 40% epigallocatechin gallate (EGCG). Xylo is a natural gelling agent, commonly used as a food thickener. It forms a structure similar to the mucin network in the mouth, giving the film its mucoadhesive properties. Given the easy availability, usage as food additive, and low cost of TE, which contains EGCG as well as various catechins, it was selected as a gelling agent for Xylo in this study. The researchers examined how Xylo and TE gelled together and explored the physical and chemical properties of the gels and films they produced.
The researchers developed two types of films: hydrogels, prepared by drying Xylo/TE solutions at 4 °C for 24 hours, and xerogels, which were dried for seven days, resulting in firmer, drier films. The hydrogel, however, transitioned into a liquid-like state at skin surface temperatures (35–37 °C) and became weak, breaking with just a small amount of pressure. In contrast, the xerogel films demonstrated better mucoadhesive properties, withstanding up to ten times more force and performing similarly to commercially available oral mucoadhesive films.
To test the adhesive strength of the xerogel, the researchers simulated oral conditions using mucin disks coated with artificial saliva. The film was pressed onto the disk with a plunger, and the force required to detach it was measured. The films adhered well, with detachment forces matching or exceeding those of over-the-counter products. The team also examined the release of EGCG by soaking the films in water, discovering that higher concentrations of Xylo facilitated greater EGCG release over time, highlighting their potential as mucoadhesive films.
"Xylo/TE xerogel films demonstrated high strength, hydrogel-like properties due to rapid water absorption, and adhesion forces comparable to commercial films," says Prof. Hanawa. The team is now focused on enhancing the film's design and evaluating its safety and efficacy through cell-based experiments, advancing toward a promising solution for oral mucositis.
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Reference
Title of original paper: Preparing and Characterizing of Xyloglucan Films Containing Tea Extract for Oral Mucositis
Journal: ACS Omega
DOI: 10.1021/acsomega.4c06410
About The Tokyo University of Science
Tokyo University of Science (TUS) is a well-known and respected university, and the largest science-specialized private research university in Japan, with four campuses in central Tokyo and its suburbs and in Hokkaido. Established in 1881, the university has continually contributed to Japan's development in science through inculcating the love for science in researchers, technicians, and educators.
With a mission of “Creating science and technology for the harmonious development of nature, human beings, and society," TUS has undertaken a wide range of research from basic to applied science. TUS has embraced a multidisciplinary approach to research and undertaken intensive study in some of today's most vital fields. TUS is a meritocracy where the best in science is recognized and nurtured. It is the only private university in Japan that has produced a Nobel Prize winner and the only private university in Asia to produce Nobel Prize winners within the natural sciences field.
Website: https://www.tus.ac.jp/en/mediarelations/
About Professor Takehisa Hanawa from Tokyo University of Science
Professor Takehisa Hanawa obtained his Ph.D. in Pharmaceutical Technology in 1991. He is currently associated with the Tokyo University of Science, where he directs his research laboratory within the Faculty of Pharmaceutical Sciences. Prof. Hanawa's research focuses on developing patient-friendly pharmaceutical formulations. He has authored over 100 research papers, contributed to 19 books, and holds one patent. Prof. Hanawa has been a distinguished member of prestigious organizations, such as the Japan Pharmaceutical Society and the Society of Pharmaceutical Machinery and Engineering.
https://www.tus.ac.jp/en/fac/p/index.php?6653
https://www.rs.tus.ac.jp/hanawa-lab/
Funding information
This research was supported by the OTC Self-Medication Promotion Foundation, Tokyo, Japan [Grant no. 32-2-13]
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