Potential of Spice-Derived Phytochemicals for Cancer Prevention

Although spices have been used for thousands of years and are known for their flavor, taste and color in the food, they are not usually recognized for their medicinal value. Extensive research within the last two decades from our laboratory and others has indicated that there are phytochemicals present in spices that may prevent various chronic illnesses including cancerous, diabetic, cardiovascular, pulmonary, neurological and autoimmune diseases. For instance, the potential of turmeric (curcumin), red chilli (capsaicin), cloves (eugenol), ginger (zerumbone), fennel (anethole), kokum (gambogic acid), fenugreek (diosgenin), and black cumin (thymoquinone) in cancer prevention has been established. Additionally, the mechanism by which these agents mediate anticancer effects is also becoming increasingly evident. The current review describes the active components of some of the major spices, their mechanisms of action and their potential in cancer prevention. Abbreviations ADT:anethole ditholethione Bcl-3:B cell lymphoma protein-3 CDK7:cyclin-dependent kinase 7 cIAP:inhibitor of apoptosis COX-2:cyclooxygenase-2 DNA:deoxyribonucleic acid EGF:epidermal growth factor ELAM-1:endothelial leukocyte adhesion molecule-1 ERK or Erk:extracellular signal-regulated kinases GA:gambogic acid GSH:glutathione GST:glutathione S-transferase H 2 O 2 :hydrogen peroxide hTERT:human telomerase reverse transcriptase ICAM-1:intercellular adhesion molecule-1 IKK:IκBα kinase IL:interleukins JAK:Janus kinases 5-LOX:5-lipoxygenase MM:multiple myeloma MMP:matrix metalloproteinase NADH:nicotinamide adenine dinucleotide hydride NF-κB:nuclear factor kappa B NIK:NF-κB inducing kinase NNK:nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone RANKL:receptor activator for nuclear factor κB ligand RHD:Rel homology domain RTX:resiniferatoxin STAT:signal transducer and activator of transcription TNF:tumor necrosis factor TNFR:TNF receptor TQ:thymoquinone TRAF:TNF receptor associated factor uPA:urokinase plasminogen activator VCAM:vascular cell adhesion molecule VEGF:vascular endothelial growth factor VEGFR2:VEGF receptor 2 Key Words spice - cancer - chemoprevention - phytochemicals - molecular targets