Application of nutrigenomics in skin health: nutraceutical or cosmeceutical?

Nutrigenomics is a growing field related to genetic testing based on the documentation of genetic mutations in an individual, giving us the ability to correct metabolic imbalances (personalized medicine) through specific dietary supplements or nutraceuticals. An off-shoot of nutrigenomics called dermagenetics (testing for selected genetic mutations related to skin health followed by advocating the use of either nutraceuticals or skin creams enriched by cosmeceuticals) is heading toward commercialization at a rapid rate by directly targeting the public. Although this growth represents an opportunity to explore the benefits of genetic advances in skin health, it is essential that the science, product claims, and ethical standards be critically evaluated and clear national guidelines be set in order to protect the consumer.

Studies on the nature of anti-platelet aggregatory factors in the seeds of the Amazonian Herb Guarana (Paullinia cupana).

Guarana (Paullinia cupana) is a popular herb native to the Amazon Basin and used extensively in soft drinks in Brazil, other Latin American countries, and more recently in the United States. Extracts derived from the dried seeds of guarana possess strong anti-platelet aggregatory properties. In this study, an active fraction containing this activity was purified and analyzed by high-performance liquid chromatography/mass spectrometry (HPLC/MS) techniques. It was noted that this fraction contains catechins, epicatechins, and their dimers, with a small amount of caffeine. It is suggested that complexes containing caffeine and catechins (and their dimers) might be responsible for anti-platelet aggregatory activity in guarana seeds and might offer health benefits towards decreasing risk of thrombosis and cardiovascular disease.

Understanding the nutrigenomic definitions and concepts at the food-genome junction.

The marked differences in individual response to dietary factors have led to major controversies in nutrition and puzzled nutrition scientists over the last century. The emerging field of nutrigenomics helps us to understand the basis for some of these differences and also promises us the ability to tailor diet based on individual genetic makeup. Great advances in Human Genome Project, documentation of single nucleotide polymorphisms (SNPs) in candidate genes and their association with metabolic imbalances have gradually added new tests to the nutrigenomic panel. Studies based on ethnopharmacology and phytotherapy concepts showed that nutrients and botanicals can interact with the genome causing marked changes in gene expression. This has led to the commercial development of nutraceuticals and functional foods that can modify negative health effects of individual genetic profile bringing the field to the "food/genome" junction. Despite the promise of nutrigenomics to personalize diet, there is skepticism whether it can truly bring about meaningful modification of the risk factors connected to chronic diseases, due to the lack of large scale nutrition intervention studies. Several intervention studies currently underway in the United States and abroad (Israel, Spain, and France) will further help validate nutrigenomic concepts. France has already introduced a National Nutrition and Health Program to assess nutritional status and risk of major metabolic diseases. As the field(s) related to nutritional genomics advance in their scope, it is essential that: (a) strict guidelines be followed in the nomenclature and definition of the subdisciplines; and (b) the state/federal regulatory guidelines be updated for diagnostic laboratories, especially for those offering tests directly to the public (without a physician's request) to help protect the consumer.

Nutrigenetics and nutraceuticals: the next wave riding on personalized medicine.

The Human Genome Project and subsequent identification of single nucleotide polymorphisms (SNPs) within populations has played a major role in predicting individual response to drugs (pharmacogenetics) leading to the concept of "personalized medicine." Nutritional genomics is a recent off-shoot of this genetic revolution that includes (1) nutrigenomics: the study of interaction of dietary components with the genome and the resulting proteonomic and metabolomic changes; and (2) nutrigenetics: understanding the gene-based differences in response to dietary components and developing nutraceuticals that are most compatible with health based on individual genetic makeup. Despite the extensive data on genetic polymorphisms in humans, its translation into medical practice has been slow because of the time required to accumulate population data on SNP incidence, understand the significance of a given SNP in disease, and develop suitable diagnostic tests. Nutrigenomics revitalized the field by showing that nutrients and botanicals can interact with the genome and modify subsequent gene expression, which has provided a great impetus for nutrigenetic research and nutraceutical development based on nutrigenetics. Polymorphisms in methlyene tetrahydrofolate reductase (MTHFR) (involved in folate metabolism), apolipoprotein E (Apo E) and ApoA1 (in cardiovascular disease), and leptin/leptin receptor (obesity) genes are some good examples for understanding basic nutrigenetics. Developing nutraceuticals to prevent and manage thrombosis risk in women with thrombophilic gene mutations are discussed in the context of the opportunities that exist at the nutrigenetic/pharmacogenetic interphase leading to "personalized nutrition." Further research on individual differences in genetic profiles and nutrient requirements will help establish nutrigenetics as an essential discipline for nutrition and dietetics practice.

Ergosterol (major sterol of baker's and brewer's yeast extracts) inhibits the growth of human breast cancer cells in vitro and the potential role of its oxidation products.

The derivation of chemopreventive agents from dietary sources has been the subject of considerable attention in recent years. Yeast extracts have been used as nutritional supplements for a number of years. In this communication we show that ergosterol (a 28-carbon sterol found in baker's and brewer's yeast) can prevent growth of breast cancer cells in vitro in the presence of estradiol-17 beta. Estrogen receptor (+) MCF-7 cells appear to be more sensitive to ergosterol than estrogen receptor (-) MDA-231 cells. However, MDA-231 cells were more sensitive to ergosterol in terms of apoptotic effects than MCF-7 cells, indicating that other mechanisms (antiestrogenic activity) may also be operative in estrogen receptor (+) cells. Compared to freshly prepared ergosterol, stored preparations were more potent in inhibiting growth of cancer cells, indicating that oxidation product(s) of ergosterol may be responsible for the noted effects. Further studies on in vivo effects of ergosterol and lipid extracts of yeast in animal models are warranted to determine their potential for use as supplements in humans.

Evidence of increased formation of products retaining strong antioxidant activity from estradiol-17beta oxidation in the presence of human plasma lipoproteins.

Estradiol-17beta (E2) exhibits potent antioxidant effects that cause continuous suppression of metal-catalyzed oxidation of low-density-lipoprotein in vitro. We sought to learn whether unidentified oxidation products retaining strong antioxidant property may be generated from E2 incubated with lipoproteins and subjected to oxidation by reactive oxygen species generators. E2 oxidation was markedly stimulated in the presence of both LDL and high-density lipoprotein. We have isolated two novel products (less polar than E2), formed when E2 was oxidized with copper sulfate and hydrogen peroxide in the presence of lipoproteins). Both compounds had molecular weights of 306 on gas chromatography/mass spectrometry. They appear to be as strong as E2 in inhibiting LDL oxidation in vitro. Because of their increased hydrophobicity, they have the potential of being associated with LDL and offer promise as agents that can limit LDL oxidation, thereby contributing to cardioprotection.