Apigenins

Phlomis consists of about 100 species, a dozen of which occur in Mediterranean Europe (Mabberley, 1997, p. 549). The study of interest here involves a study of the flavonoids of R lychnitys L., a small plant native to Mediterranean Spain (Tomas et ah, 1986). Those workers identified the common flavones apigenin, luteolin, and luteolin 3 -methyl ether (chrysoeriol) 7-0-glucosides and their respective /7-coumaroyl derivatives. A brief review of the literature revealed that Mediterranean species of Phlomis are characterized by the presence of the flavone methyl ether, whereas continental species appear to lack 0-methylated flavones. Species from India have been reported to lack flavones but accumulate flavonols. The suggestion was made that accumulation of flavonols represents an ancestral feature of the genus. 

Subsequently, Porter (1981) expanded the survey by looking at specimens collected over a much larger part of the range of the species 23 sites in Europe, five in North America, and six in Asia. The majority of compounds identihed were again revealed as derivatives of apigenin, luteoUn, and chrysoeriol, with the major... 

Vicinin-2 and lucenin-2 = apigenin and luteolin 6,8-di C-glucosides Gin = glucuronic acid Rhm = rhamnose. 

Compounds 1-7 acacetin, acacetin sulfate, diosmetin 7-Glc, diosmetin 7-GlcRhm, luteoUn 7-DiAra, and luteolin 7-sulfate 8 = apigenin 7-Glc-sulfate 9=luteoUn 7-GlcRhm 10 = diosmetin 7-Glc 11-14 acacetin 7-Glc-sulfate, diosmetin C-GlcAra, diosmetin 7-GlcAra, and diosmetin 7-sulfate. 

The cell-to-cell interaction following the expression of adhesion molecules (ICAM-1, VCAM-1 and selectin) in endothelial cells induced by cytokines treatment has been reported to be blocked by hydroflavones and flavanols. Apigenin, the most potent flavone tested in this study, inhibited the expression... 

LIN J K, CHEN Y c, HUANG Y T and LiN-SHiAU s Y (1997) Snppression of protein kinase C and nuclear oncogene expression as possible molecnlar mechanisms of cancer chemoprevention by apigenin and curciunin Journal Cell Biochemistry Suppl. 28-9, 39-48. 

WEI H, TYE L, BRESMiK E and BiRT D F (1990) Inhibitory effect of apigenin, a plant flavonoid, on epidermal ornilthine decarboxylase and skin tumor promotion in mice . Cancer Res, 50, 499-502. 

L (1999) Effect of parsley intake on urinary apigenin excretion, blood antioxidant enzymes and on biomarkers for oxidative stress in hiunans, Brit J Nutr, 81, 447-55. 

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