Dietary alkylresorcinols and cancer prevention: a systematic review

The potential role of alkylresorcinol compound from whole grains for prevention and inhibition of human cancer cell lines has been reported in observational and in vitro studies. The objective of this study was to present an updated review on the association between alkylresorcinols and cancer risk and aspects of their bioactivity with implications for carcinogenesis. Relevant studies were identified by searching PubMed, Scopus, ProQuest, EBSCOhost, SpringerLink, ArticleFirst, Taylor & Francis, Wiley Online, and Science-Direct electronic databases using these search terms and key words: alkylresorcinols, cancer, carcinoma, risk. Furthermore, references from retrieved articles were also reviewed. Four observational and 10 in vitro studies were included in the analysis of natural or synthetic alkylresorcinols for anticancer activities. Two prospective studies reported a 52-66% risk reduction of distal colon cancer at nanomolar alkylresorcinols concentration in plasma; the remaining studies found no reduction of endometrial cancer risk and an approximate 40% increase in prostate cancer risk. In vitro studies presented inhibition of human colon, breast, lung, central nervous system, adenocarcinoma, hepatocarcinoma, cervix squamous carcinoma, and ovarian cancer cell lines, at micromolar alkylresorcinols concentration. Evidence from prospective studies confirmed significant inverse associations between whole grains intake and distal colon cancer risk. Model studies suggest a high cytotoxicity of alkylresorcinols toward cancer cells. These findings maintain that alkylresorcinols as components of whole grains are likely to find application in cancer prevention; however, the need for intervention studies to confirm their preventive action is warranted.