Food-based natural products for cancer management: Is the whole greater than the sum of the parts?

Abstract

The rise in cancer incidence and mortality in developing countries together with the human and financial cost of current cancer therapy mandates a closer look at alternative ways to overcome this burgeoning global healthcare problem. Epidemiological evidence for the association between cancer and diet and the long latency of most cancer progression have led to active exploration of whole and isolated natural chemicals from different naturally occurring substances in various preclinical and clinical settings. In general the lack of systemic toxicities of most ‘whole’ and ‘isolated’ natural compounds, their potential to reduce toxic doses and potential to delay the development of drug-resistance makes them promising candidates for cancer management. This review article examines the suggested molecular mechanisms affected by these substances focusing to a large extent on prostate cancer and deliberates on the disparate results obtained from cell culture, preclinical and clinical studies in an effort to highlight the use of whole extracts and isolated constituents for intervention. As such these studies underscore the importance of factors such as treatment duration, bioavailability, route of administration, selection criteria, standardized formulation and clinical end points in clinical trial design with both entities. Overall lack of parallel comparison studies between the whole natural products and their isolated compounds limits decisive conclusions regarding the superior utility of one over the other. We suggest the critical need for rigorous comparative research to identify which one of the two or both entities from nature would be best qualified to take on the mantle of cancer management.

Nutrigenomics in cancer: Revisiting the effects of natural compounds

“…Nutrigenetics is mainly focused on the evaluation of genetic and epigenetic alterations in response to a particular dietary component, which might lead to a change in the disease status [16,17]. A broad variety of nutrients or phytochemicals affects the genetic and epigenetic mechanisms ( Fig.…”

Oleanolic Acid Alters Multiple Cell Signaling Pathways: Implication in Cancer Prevention and Therapy

“…The researchers that are in favor of the “whole” argue that the therapeutic efficacy of an extract is the outcome of synergistic or additive effects of its various bioactive components, while those who prefer purified compounds contend that, unlike isolated compounds, several phytochemicals present as a mixture in a natural source are not bioavailable, or have limited bioavailability and, therefore, are less useful. Both arguments present valid hypotheses and, despite the fact that a significant amount of investigation has been carried out in the field, results do not proclaim a winning side [2,11]. …”

“…Referring to Western societies, there has been a decrease in most cancer-related mortality. Meanwhile incidence and mortality continue to rise quickly in developing or undeveloped countries [2,3]. …”

Hydroxytyrosol Induces Apoptosis and Cell Cycle Arrest and Suppresses Multiple Oncogenic Signaling Pathways in Prostate Cancer Cells

“…In recent years there has been a push towards exploring diet-derived factors for their anticancer potential (2). This is largely due to epidemiological studies connecting consumption of certain foods with reduced cancer incidence.…”