METABOLOMICS
Metabolomics can be defined as a new emerging –omic science in systems biology that is aimed to decipher the metabolic profile in complex systems through the combination of data-rich analytical techniques (NMR, MS) and multivariate data analysis. Metabolomics leaves behind the reductionist method of investigating single component effects on a biological system and goes a little further offering a holistic approach in the exploration of the molecular details of multiple factors on an entire biological organism. Metabolomic techniques allows for a high throughput analysis of small molecules (metabolites) in biofluids and tissues giving metabolic profiles as the end product. Comparison of such profiles from different phenotypes can be used to identify specific metabolic changes leading to the understanding of biochemical pathways, complex biomarker combinations, toxic effects and disease progression.
APPLICATIONS
The main application of metabolomics to mammalian systems are related, among others, to: phenotyping, biomarker discovery, clinical studies (diagnosis disease and therapeutic efficacy), toxicology (pre-clinical drug candidate safety assessment), etc.
METABOLOMICS WITH RESPECT TO OTHER-OMIC SCIENCES
Metabolomics is an emerging and promising field in many biological areas of application since metabolite levels change with developmental, physiological and pathological state. Many metabolites change far faster than nucleic acids or proteins. Thus metabolites appear to reflect more adequate changes in cell functions. Unlike genomics and transcriptomics, metabolomics is sensitive to both, the genetic and the modifying environmental influences that determine the metabolic fingerprint of an individual. Therefore, metabolic profiling observes the biochemical effects in an organism representing a closer approach to biological end-point than genomics, transcriptomics and proteomics do.
METABOLOMICS APPROACHES
There are two basic different approaches to metabolomics: Fingerprinting and Profiling.
Fingerprinting is the most commonly used method in NMR metabolomics and it is based upon the multivariate analysis of a dataset consisting on a large amount of sample NMR spectra, where each spectrum can be considered as a fingerprint of unassigned signals arising from low molecular weight analytes.
Profiling is a more challenging but ultimately more meaningful approach for analysing NMR spectra. It is based on the analysis of an array of metabolites known to be involved in a given biochemical pathway. It does not allow for fast and high throughput automated measurements since considerable human intervention is needed to guide the process of identifying and quantifying metabolites in NMR spectral data, especially when dealing with complex mixtures such as biofluids (i.e., serum or urine).
REFERENCES
• Griffiths, W. J. Metabolomics, Metabonomics and Metabolite Profiling; The Royal Society of Chemistry: Cambridge, U.K, 2008.
• Lindon, J. C.; Nicholson, J. K.; Holmes, E. The Handbook of Metabonomics and Metabolomics; Elsevier: Amsterdam, 2007.
