Comparison of cytotoxicity and radical scavenging activity between tea extracts and Chinese medicines.
Three hot water extracts of black tea, green tea and powdered green tea and five Chinese medicines (Shosaiko-tou, Orengedoku-tou, Goshuyu-tou, Choto-san, Keishininjinn-tou) were investigated for their ability to modify nitric oxide (NO) production by lipopolysaccharide (LPS)-stimulated mouse macrophage-like Raw 264.7 cells, and for their cytotoxicity, radical intensity and scavenging activity. All eight materials significantly reduced the extracellular concentration of NO in the LPS-stimulated Raw 264.7 cells. ESR spectroscopy shows that tea extracts, which had higher cytotoxicity, generated higher amounts of radicals, and more efficiently scavenged O2- (generated by hypoxanthine-xanthine oxidase reaction), hydroxyl radical (generated by Fenton reaction) and NO (generated by 1-hydroxyl-2-oxo-3-(N-3-methyl-3-aminopropyl)-3-methyl-1-triazene) than Chinese medicines. Close association between the radical intensity and radical scavenging activity suggests their bimodal (anti-oxidant and pro-oxidant) action. Pretreatment of mice with tea extracts significantly reduced the lethality of Escherichia coli-infection. All tea extracts showed no apparent anti-HIV activity. The present study demonstrates, for the first time, several attractive features of tea extracts in comparison with Chinese medicines, suggesting the possible application of the tea extracts for radical-mediated diseases.
Okayasu
Haruo
H
Department of Dental Pharmacology, Meikai University School of Dentistry, Sakado, Saitama, 350-0283, Japan. sakagami@dent.meikai.ac.jp
Suzuki
Fumika
F
Satoh
Kazue
K
Shioda
Seiji
S
Dohi
Kenji
K
Ikeda
Yukio
Y
Nakashima
Hideki
H
Komatsu
Nobuhiko
N
Fujimaki
Masato
M
Hashimoto
Ken
K
Maki
Jun
J
Sakagami
Hiroshi
H
D000818:Animals; D021461:Animals, Outbred Strains; D000975:Antioxidants / Q000494:pharmacology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000821:virology; D002478:Cells, Cultured; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology*; D015658:HIV Infections / Q000188:drug therapy / Q000378:metabolism; D015497:HIV-1; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008516:Medicine, Chinese Traditional; D051379:Mice; D018384:Oxidative Stress / Q000187:drug effects; D013662:Tea
D000975:Antioxidants; D004365:Drugs, Chinese Herbal; D016166:Free Radical Scavengers; D008070:Lipopolysaccharides; D013662:Tea