Identification of Coumarins from Lemon Fruit (Citrus limon) as Inhibitors of in Vitro Tumor Promotion and Superoxide and Nitric Oxide Generation

Three coumarins were isolated as siginificant inhibitors of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein−Barr virus (EBV) activation in Raji cells from the peel of lemon fruit. They were identified as 8-geranyloxypsolaren (LE−1), 5-geranyloxypsolaren (bergamottin, LE−2),...

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Published inJournal of agricultural and food chemistry Vol. 47; no. 8; pp. 3151 - 3157
Main Authors Miyake, Yoshiaki, Murakami, Akira, Sugiyama, Yukiteru, Isobe, Minoru, Koshimizu, Koichi, Ohigashi, Hajime
Format Journal Article
LanguageEnglish
Published Washington, DC American Chemical Society 01.08.1999
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Summary:Three coumarins were isolated as siginificant inhibitors of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein−Barr virus (EBV) activation in Raji cells from the peel of lemon fruit. They were identified as 8-geranyloxypsolaren (LE−1), 5-geranyloxypsolaren (bergamottin, LE−2), and 5-geranyloxy-7-methoxycoumarin (LE−3), respectively, by spectroscopic analysis. Three isolates had no potential O2-scavenging and markedly suppressed TPA-induced superoxide (O2 -) generation in differentiated human promyelocytic HL-60 cells. Furthermore, LE−1 and LE−3 reduced both lypopolysaccharide (LPS) and interferone-γ (IFN-γ)-induced nitric oxide (NO) generation in mouse macrophage RAW 264.7 cells. Similarly, they were found to be NO generation inhibitors rather than scavengers by measuring the extracellular l-citrulline levels. The occurrence of these coumarins in a lemon fruit was abundant in the flavedo of the peel based on quantitative analysis using high-performance liquid chromatography (HPLC). The present study suggests that the coumarins in lemon fruit are promising chemopreventive agents by inhibiting radical generation. Keywords: Citrus limon; coumarin; psoralen; chemopreventive agent; Epstein−Barr virus; superoxide; nitric oxide
Bibliography:ark:/67375/TPS-Z0JHQLH8-9
istex:7833F1E1042640FDB8725AD3310BA66337B93A42
ISSN:0021-8561
1520-5118
DOI:10.1021/jf980999y