[Effects of quercetin on photosensitized oxidation of alpha-tocopherol in human blood cells in the presence of hematoporphyrin].
alpha-Tocopherol contained in human blood cells was oxidized by a photosensitized reaction in the presence of hematoporphyrin as a photosensitizer. Participation of singlet molecular oxygen, superoxide radical and hydrogen peroxide in the photooxidation was not so significant, although hematoporphyrin can generate singlet molecular oxygen on illumination. Quercetin inhibited the photooxidation of alpha-tocopherol. Both in the presence and in the absence of linoleic acid, photooxidation of alpha-tocopherol which was suspended in the PBS solution was also inhibited by quercetin. The rate of the photooxidation of alpha-tocopherol in the presence of linoleic acid was faster than that in the absence of the fatty acid. When quercetin inhibited the photooxidation of alpha-tocopherol contained in blood cells or suspended in PBS solution, quercetin was oxidized. The photooxidation of quercetin, which was suspended in the PBS solution, was inhibited by alpha-tocopherol in the absence of linoleic acid, but stimulated in the presence of the fatty acid.
Jan
C Y
CY
Department of Pedodontics, Kyushu Dental College.
Kimura
M
M
Takahama
U
U
D000975:Antioxidants / Q000494:pharmacology*; D001773:Blood Cells / Q000737:chemistry; D006415:Hematoporphyrins; D006801:Humans; D008041:Linoleic Acids; D010084:Oxidation-Reduction / Q000187:drug effects; D010777:Photochemistry; D011794:Quercetin / Q000494:pharmacology*; D014810:Vitamin E / Q000097:blood / Q000737:chemistry / Q000378:metabolism*
D000975:Antioxidants; D006415:Hematoporphyrins; D008041:Linoleic Acids; D014810:Vitamin E; D011794:Quercetin