Dietary Plants and Spices

We are exposed daily to a multitude of secondary metabolites from edible plants and spices that have accompanied us during evolution, playing a role in the shaping of our genome and making us not what we eat, but rather what our ancestors have eaten.90 Many dietary secondary metabolites appear to play a role, still undefined in molecular terms, for the maintenance of health and there is, therefore, great interest in their identification and in the characterisation of their biological profiles. 

Dietary compounds are represented in a number of highly successful drugs such as lovastatin 31 and salicylic acid, the archetypal statin and non-steroid anti-inflammatory drugs, respectively. Lovastatin occurs in the red yeast of rice Monascus ruber),91 an ingredient of Eastern cuisine used to give a red colour to the Pekinese duck, while salicylic acid is ubiquitous in plants.92 Other important dietary drug candidates are curcumin 32 from turmeric and capsaicin from hot pepper 33,93 while traces of pharmaceutical benzodiazepines (including diazepam) occur in common edible plants such as potatoes and cherries.5 

In addition, negative dietary correlations can afford clues to drug discovery. Thus, the potent immunosuppressant dammarane triterpenoid 36 was discovered because of epidemiological correlations between the incidence of cancer and the consumption of Palmyrah flour (Borassus flabellifer), a staple for Sri Lankan Tamils.97 

The major limitation of the many dietary clues is that they are often difficult to interpret, since the observed beneficial or detrimental effects of food resist a reductionistic analysis, being the results of a combination of compounds and their bacterial and hepatic metabolites. 

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