PharmacoNutrition Reviewed

Source: Chemistry & Physics of Lipids, 4 March 2008 [Epub]
Article Type: Review
Authors: Chapkin RS et al.

Cells, particularly those of the gastrointestinal tract, are exposed to a - often rapidly - changing environment. In their present review, Robert Chapkin and colleagues summarize how docosahexaenoic acid (DHA) and related fatty acids might help to maintain cell health in the colon:

“…we present data demonstrating that DHA selectively modulates the subcellular localization of lipidated signaling proteins depending on their transport pathway, which may be universally applied to other lipidated protein trafficking. An interesting possibility raised by the current observations is that lipidated proteins may exhibit different subcellular distribution profiles in various tissues, which contain a distinct membrane lipid composition. In addition, the current findings clearly indicate that subcellular localization of proteins with a certain trafficking pathway can be subjected to selective regulation by dietary manipulation. This form of regulated plasma membrane targeting of a select subset of upstream signaling proteins may provide cells with the flexibility to coordinate the arrangement of signaling translators on the cell surface. Ultimately, this may allow organ systems such as the colon to optimally decode, respond, and adapt to the vagaries of an ever-changing extracellular environment.”

Also noteworthy:

“Recently, the U.S. Food and DrugAdministration (FDA) has approved the use of a health claim on labels for foods containing DHA. As part of an ongoing commitment to provide consumers with innovative-healthy products, food companies are now scrambling to incorporate omega-3 fatty acids into a range of novel commercial foods in order to provide for the wider public consumption of DHA. It is both appropriate and timely, therefore, to precisely determine how DHA modulates cell signaling networks and reduces the risk of developing colon cancer and intestinal inflammatory disorders.”

Source: BMC Medical Genomics (Open Access, 20 March 2008)
Article Type: Original Research
Authors: Pan Z et al.

Pterostilbene, a dimethylether analog of resveratrol, has long been known for its antioxidant, antifungal and antiinflammatory activities (to mention just a few). However, little is known on its mechanism(s) of action. In the present study, Pan et al. incubated S. cerevisiae (a common model organism for the identification of therapeutic compounds) with 70 µM (= IC50) pterostilbene prior running extensive transcript profiling experiments.
In a nutshell, pterostilbene affected the expression of >1000 genes (up: 1007; down: 182).

“We have identified the molecular pathways affected by pterostilbene, and our results show that pterostilbene affects the expression of a diverse group of genes in yeast cells.Using Gene Ontology-based analysis, the most significant effects were observed in genes involved in methionine metabolism, response to drug, transcription factor activity, and mitochondrion functions. Additional analyses indicated that many genes involved in lipid metabolism were also affected. The observed response of lipid metabolism genes is in agreement with the known hypolipidemic properties of pterostilbene mediated through the activation of PPARalpha. The induction of a large number of mitochondrial genes by pterostilbene is consistent with its previously-demonstrated role in apoptosis in human cancer cells.Our data also show that pterostilbene has a significant effect on methionine metabolism, perhaps resulting in the depletion of methionine by the inhibition of methionine biosynthesis. The effect of pterostilbene on methionine metabolism has not been previously observed and merits further investigation.”

The effects on methionine might be of particular interest, as methionine metabolism has also been linked to aging.
Does this possibly mean that resveratrol and its analogs enhance, e.g. C. elegans, lifespan by modulating methionine levels? PubMed, at least, does not provide a sufficient answer….