TY - JOUR
T1 - Inhibitory effect of pheophorbide α, a chlorophyll-related compound, on skin tumor promotion in ICR mouse
AU - Nakamura, Yoshimasa
AU - Murakami, Akira
AU - Koshimizu, Koichi
AU - Ohigashi, Hajime
N1 - Funding Information:
This study was supported in part by a grant from the Ministry of Health and Welfare for the Second Term Comprehensive IO-Year Strategy for Cancer Control, Japan, and also by a subsidy from Takeda Food Co., Ltd. We thank Dr. I. Sakata of Toyo-Hakka Co., Ltd. for his kind supply of pheophorbide a. We are also grateful to Dr. R. Sasaki of Kyoto University for the generous gift of HL-60 cells.
PY - 1996/11/29
Y1 - 1996/11/29
N2 - Anti-tumor-promoting activity of pheophorbide α (PPBα), a chlorophyll-related compound, was examined in a two-stage carcinogenesis experiment in ICR mouse skin by 7,12-dimethylbenz[a]anthracene (DMBA, O.19 μmol) and 12-O-tetradecanoylphorbol-13-acetate (TPA, 1.6 nmol). Topical application of PPBa (160 nmol) markedly reduced the average number of tumors per mouse and the ratio of tumor-bearing mice (inhibitory ratio: IR = 56%, P < 0.01 and 31%, P < 0.005, respectively). PPBα exhibited potent anti-inflammatory activity in ICR mouse ears and moderate inhibitory activity toward TPA-induced superoxide (O2-) generation in differentiated HL-60 cells. While CuPPBa, a synthetic copper complex of PPBα, exhibited higher anti-inflammatory activity than that of indomethacin, it showed little antioxidative effect against formation of lipid hydroperoxides (LOOHs) and malondialdehyde (MDA), suggesting that the antioxidative effect of PPBα might not be important for anti-inflammatory activity. These results imply that the active mechanism of PPBα for anti-tumor promotion might be partly involved in inhibition of TPA-induced inflammatory responses by suppressing leukocyte activation.
AB - Anti-tumor-promoting activity of pheophorbide α (PPBα), a chlorophyll-related compound, was examined in a two-stage carcinogenesis experiment in ICR mouse skin by 7,12-dimethylbenz[a]anthracene (DMBA, O.19 μmol) and 12-O-tetradecanoylphorbol-13-acetate (TPA, 1.6 nmol). Topical application of PPBa (160 nmol) markedly reduced the average number of tumors per mouse and the ratio of tumor-bearing mice (inhibitory ratio: IR = 56%, P < 0.01 and 31%, P < 0.005, respectively). PPBα exhibited potent anti-inflammatory activity in ICR mouse ears and moderate inhibitory activity toward TPA-induced superoxide (O2-) generation in differentiated HL-60 cells. While CuPPBa, a synthetic copper complex of PPBα, exhibited higher anti-inflammatory activity than that of indomethacin, it showed little antioxidative effect against formation of lipid hydroperoxides (LOOHs) and malondialdehyde (MDA), suggesting that the antioxidative effect of PPBα might not be important for anti-inflammatory activity. These results imply that the active mechanism of PPBα for anti-tumor promotion might be partly involved in inhibition of TPA-induced inflammatory responses by suppressing leukocyte activation.
KW - Anti-inflammation
KW - Anti-tumor promotion
KW - Cancer chemoprevention
KW - HL-60
KW - Pheophorbidea
KW - Reactive oxygen species
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UR - http://www.scopus.com/inward/citedby.url?scp=0030606269&partnerID=8YFLogxK
U2 - 10.1016/S0304-3835(96)04422-9
DO - 10.1016/S0304-3835(96)04422-9
M3 - Article
C2 - 8973602
AN - SCOPUS:0030606269
VL - 108
SP - 247
EP - 255
JO - Cancer Letters
JF - Cancer Letters
SN - 0304-3835
IS - 2
ER -
