ABSTRACT
Introduction 241
Antioxidant Activity 243
Modulation of Intracellular Communication 245
Inhibition of Cell Cycle Progression 246
Inhibition of Insulin-Like Growth Factor (IGF-1) Signaling 247
Inhibition of HMG-CoA Reductase 249
Conclusions 250
References 251
INTRODUCTION
Lycopene (Fig. 11.1) is an acyclic isomer of beta-carotene consisting of a
40-carbon atom open polyisoprenoid chain, which contains 11 conjugated and
2 unconjugated double bonds (1). It is a pigment that imparts red color to
tomatoes, rosehip, guava, apricots, watermelon, and pink grapefruit. Lycopene
is synthesized by plants and some micro-organisms, but not by animals. It
serves as an accessory light-gathering pigment and protects these organisms
against the toxic effects of oxygen and light. In plants, it tends to exist in an
all-trans configuration but easily undergoes cis/trans isomerization (1-3). The exact functions and relative activities of the different isomers are not fully under-
stood and investigations are currently underway to determine whether there are
biological differences between them (3).
