Nebraska Research

Development of a Metabolomic Based Approach to Study the Anti-Inflammatory and Anti-Oxidative Nutraceuticals Present in Nebraska Based Crops.

Vicki Schlegel, Ph.D. Associate Professor,
Department of Food Science and Technology
Questions or Comments? Contact author, Vicki Schlegel

Inflammation is a complex defense mechanism that is critical to the survival of mammalian systems.

This response is activated when cellular systems are damaged or infected, and can be separated into two broad categories; acute and chronic inflammation. However, chronic inflammation can manifest into “silent inflammation”, where the response is below the threshold of perceived pain, and major organs, such as the liver, heart, and brain, are under continuous assault.

Alternatively, oxidative stress is the degree of imbalance between the reactive oxygen species present in cells and their antioxidant protection. Elevated reactive oxygen species (ROS), such as superoxide anions, hydroxyl radicals, and hydrogen peroxide, can directly damage DNA, protein, and/or lipids or make them a target for damage by other means.

Mammalian cells are exposed to various inherent and environmental components that can cause oxidation and/or inflammation, which if left untreated, can lead to several types of degenerative diseases, including coronary heart diseases, Alzheimer, muscle degeneration, diabetes and cancer.

Consumption of foods containing anti-inflammatory or anti-oxidative agents (nutraceuticals) may be an effective means to prevent such cellular stressors and thus the onset of these diseases. Yet, current reports have focused on ability of a potential anti-oxidatant or anti-inflammatory to prevent serious unalterable cellular damage while disregarding other types of potential long-term damage.

Because the expectation of a nutraceutical is to consistently provide specific health benefits without causing any additional disorders, detection of subtle and temporal changes in multiple regulatory metabolic processes is needed before the biomarker of the targeted disease is exhibited or serious unintended alterations have occurred.

Towards this end, other researchers have studied the properties of anti-inflammatory / anti-oxidative agents based upon their ability to prohibit the production of certain cellular proteins and/or repress pro-inflammatory / pro-oxidation genes. Even when successfully combined, however, gene repression and protein production cannot provide a complete understanding of the diverse and interactive cellular functions in response to inflammation / oxidation because the metabolic status of the cellular system is usually not regarded.

For example, preliminary work completed in our laboratories showed that resveratrol, (a reported anti-inflammatory agent present in grapes) was unable to prevent the up-regulation of select pro-inflammatory genes at the dosage levels used but was indeed able to protect metabolism of an a typical inflammatory model system. Information on the effects of on cellular metabolism in response to the protective properties of nutraceuticals is thus needed to bridge these critical gaps in knowledge.

Such quantitative and comprehensive measurements can only be achieved via the technological advances driven by the genomic era, particularly the field of metabolomics. Metabolomics is defined as the "systematic study of the unique chemical fingerprints that specific cellular processes leave behind". This chemical fingerprint represents the metabolome, which is the end product of gene expression.

Therefore, shifts in the metabolome establish the biochemical phenotype, or function, of a cell system. Metabolomics is part of the “omics” group of sciences that also include the study of the genome, transcriptome, and proteome by genomics, transcriptomics and proteomics, respectively.

These molecular mechanisms, and their products, provide a snapshot of the physiology of a cell system at a given state, and can be used to track the progression from healthy homeostasis to a diseased state. However, research involving various aspects of the “omics” disciplines has indicated a breakdown of a previously believed linear model. Metabolomics is thus advantageous complement to the other “omics” sciences for several reasons.

1. First, the number of human metabolites, estimated at approximately 2500, is an order of magnitude less than that of genes, transcripts, and protein variants, making it a simpler screening tool.
2. Second, metabolic pathways between organisms are highly conserved, which allows for the use of model systems that reflect biochemical phenotypes in response to dietary stimuli, such as a nutraceutical.
3. Finally, metabolomics is the key to understanding the phenotype, and ultimately function at the molecular level. It is the missing link between genotype and phenotype.

Regardless, metabolomics has not progressed to the extent of genomics, transcriptomics and proteomics because this discipline, in part, has largely been ignored by the scientific community but it also includes significant challenges.

Cellular metabolites exhibit a wide range of chemical diversity and heterogeneity in contrast to the genome/transcriptome/proteome, which monitor molecules of the same basic chemistries. High throughput analytical methods that are capable of detecting the effects of a complex natural system on a complex biological system is thus critical to metabolomic based research.

As a result, metabolomic methodologies are currently under development in our laboratory, with an emphasis on

• capillary zone electrophoresis,
• Fourier Transform Mid Infrared, and
• liquid chromatography mass spectrometry-mass spectrometry.

These tools have also been successfully applied to human colon cancer cells, macrophages, and other biological samples (urine, feces, and multiple bacterial systems).

We are now in the process of monitoring the metabolome of such systems in response to various types of nutraceuticals potentially present in Nebraska based commodities, (sorghum, dry edible beans, and eventually corn) as a means to identify and study their anti-inflammatory or anti-oxidative agents.