Caffeic acid biological activity

We comprehensively summarized chlorogenic acids and related compounds in absorption, metabolism and biological activity. Chlorogenic, caffeic and quinic acids are well absorbed in humans and rats. Metabolic transformations of chlorogenic acids in the human system may be crucial for their biological effect. 

Despite the abundance of biological data demonstrating antioxidant activities of chlorogenic acids, the controversy whether these compounds are potent antioxidants or pro-oxidants, remains. The pro-oxidant characteristics of chlorogenic and caffeic acids have been suggested in the several papers [44, 52, 117-121],... 

Horigome and Kandatsu (63) prepared a Fuki (Petasites japon-icus miq. a traditional food plant in Japan) acetone-powder with a high o-diphenol oxidase activity. When the powder was added to a mixture of caffeic acid and casein, casein was gradually pigmented. A feeding test with rats demonstrated that there was a close relationship between the decrease in biological value of the pigmented casein and its color intensity. 

Jiang, R.W. et al., Chemistry and biological activities of caffeic acid derivatives from Salvia miltiorrhiza, Curr. Med. Chem., 12, 237, 2005. 

Proteins have strong binding properties with flavonoid antioxidants in foods and biological systems, and generally increase the oxidative stability of liposomes. The addition of bovine serum albumin (BSA) increased the oxidative stability of a lecithin-liposome and changed the relative antioxidant activity of various pairs of flavonoids and phenolic acids (Table 10.13). In the absence of BSA, the activity of phenolic antioxidants decreased in the order ferulic acid > epicatechin > catechin > malvidin > caffeic acid quercetin > propyl gallate. In the presence of BSA, the activity of malvidin increased, followed by rutin and ferulic acid, but the activity of epicatechin and catechin decreased. 

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