title: Enhancement of antibacterial effects of epigallocatechin gallate, using ascorbic acid.
abstract: Although plant polyphenols such as (-)-epigallocatechin gallate (EGCG) have antibacterial activity towards methicillin-resistant Staphylococcus aureus (MRSA), such polyphenols are unstable in solution. Because the instability of polyphenols is attributable to their oxidation, we examined the effects of antioxidants and inhibitors of polyphenol oxidation on the maintenance of polyphenol antibacterial activity. The antibacterial activity of EGCG was enhanced in the presence of ascorbic acid, and ascorbic acid was the most effective for retaining the concentration of stable EGCG. On the other hand, the antibacterial activity of EGCG was lowered in the presence of casein in spite of its suppressing effect on the EGCG decrease. The effect of EGCG on the antibiotic resistance of MRSA was also enhanced in the presence of ascorbic acid. The addition of an antioxidant may affect other pharmacological effects of polyphenols in analogous ways, although this does not mean the clinical usefulness of the addition directly.
authors: Department of Pharmacognosy, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima, Okayama 700-8530, Japan. hatano@pharm.okayama-u.ac.jp
authors: Tsutomu
authors: T
authors: Hatano
authors: Mayumi
authors: M
authors: Tsugawa
authors: Miwako
authors: M
authors: Kusuda
authors: Shoko
authors: S
authors: Taniguchi
authors: Takashi
authors: T
authors: Yoshida
authors: Sumiko
authors: S
authors: Shiota
authors: Tomofusa
authors: T
authors: Tsuchiya
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D002392:Catechin; C045651:epigallocatechin gallate; D001205:Ascorbic Acid