and vegetables has a protective effect against
cancer and cardiovascular diseases (Block and others 1992; van
Poppel 1996; Basu and others 2001). A variety of biologically active
constituents other than those conventionally recognized as nutrients
may contribute to this protection (Johnson and others 1994).
The polyacetylenes, the carotenoids, and the isocoumarins are in
the group of bioactive compounds that are believed to play a significant
role for the health-promoting properties of carrots.
Polyacetylenes of the falcarinol-type are a group of highly bioactive
compounds with considerable biological activity toward a
wide range of organisms, including mammalian cells (Hansen and
Boll 1986). The major polyacetylenes in carrots (Figure 1) are falcarinol
(FaOH), falcarindiol (FaDOH), and falcarindiol-3-acetate
(FADOAc) (Lund and White 1990). FaOH, the most bioactive of the
carrot polyacetylenes, has shown a pronounced cytotoxic activity
against human tumor cells in vitro (Matsunaga and others 1990),
and it also seems to possess in vivo anti-tumor activity (Bernart and
others 1996). FaOH stimulates differentiation of primary mammalian
cells down to 1 ng/mL and shows toxic effects above 1000 ng/
mL, clearly indicating that FaOH has hormetic properties, which
is a characteristic feature of highly bioactive compounds (Hansen
and others 2003). Furthermore, FaOH may have anti-inflammatory
(Fujimoto and others 1998) and antituberculosis (Kobaisy and
others 1997) properties. It is able to stimulate the immune system
because it causes allergic dermatitis after prolonged skin exposure
(Hansen and others 1986). The bioactivity of polyacetylenes of the
falcarinol-type, in particular FaOH, strongly supports the positive