{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T20:09:58Z","timestamp":1791230998127,"version":"4.1.0"},"reference-count":40,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2018,9,18]],"date-time":"2018-09-18T00:00:00Z","timestamp":1537228800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>(\u2212)-Epigallocatechin gallate (EGCG), is the main catechin found in green tea, and has several beneficial effects. This study investigated the stability of EGCG aqueous solution under different stored and ultrasonic conditions to determine whether it can be used with an ultrasonic dental scaler to treat periodontal infection. Four concentrations (0.05, 0.1, 0.15, 2 mg\/mL) of EGCG aqueous solution were prepared and stored under four different conditions (A: Exposed to neither sunlight nor air, B: Exposed to sunlight, but not air, C: Not exposed to sunlight, but air, D: Exposed to sunlight and air) for two days. The degradation rate of EGCG was measured by high performance liquid chromatography (HPLC). On the other hand, an ultrasonic dental scaler was used to atomize the EGCG solution under four different conditions (a: Exposed to neither air nor sunlight, b: Not exposed to air, but sunlight, c: Not exposed to sunlight, but air, d: Exposed to air and sunlight), the degradation of EGCG was measured by HPLC. We found that the stability of EGCG was concentration-dependent in water at room temperature. Both sunlight and oxygen influenced the stability of EGCG, and oxygen had a more pronounced effect on stability of EGCG than sunlight. The most important conclusion was that the ultrasound may accelerate the degradation of EGCG due to the presence of oxygen and sunlight, but not because of the ultrasonic vibration. Thus, EGCG aqueous solution has the potential to be used through an ultrasonic dental scaler to treat periodontal infection in the future.<\/jats:p>","DOI":"10.3390\/molecules23092394","type":"journal-article","created":{"date-parts":[[2018,9,18]],"date-time":"2018-09-18T11:52:29Z","timestamp":1537271549000},"page":"2394","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["The Effect of Ultrasound, Oxygen and Sunlight on the Stability of (\u2212)-Epigallocatechin Gallate"],"prefix":"10.3390","volume":"23","author":[{"given":"Jiajun","family":"Zeng","sequence":"first","affiliation":[{"name":"Department of Periodontology, Peking University School of Stomatology, Beijing 100081, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huanhua","family":"Xu","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing 100850, China"},{"name":"College of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu","family":"Cai","sequence":"additional","affiliation":[{"name":"Department of Periodontology, Peking University School of Stomatology, Beijing 100081, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan","family":"Xuan","sequence":"additional","affiliation":[{"name":"Department of Periodontology, Peking University School of Stomatology, Beijing 100081, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jia","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Periodontology, Peking University School of Stomatology, Beijing 100081, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yue","family":"Gao","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing 100850, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qingxian","family":"Luan","sequence":"additional","affiliation":[{"name":"Department of Periodontology, Peking University School of Stomatology, Beijing 100081, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,9,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1849","DOI":"10.1016\/j.phytochem.2006.06.020","article-title":"Epigallocatechin-3-gallate (EGCG): Chemical and biomedical perspectives","volume":"67","author":"Nagle","year":"2006","journal-title":"Phytochemistry"},{"key":"ref_2","first-page":"533","article-title":"Anti-inflammatory and anti-oxidative effects of the green tea polyphenol epigallocatechin gallate in human corneal epithelial cells","volume":"17","author":"Cavet","year":"2011","journal-title":"Mol. 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