Browsing by Author "Ramalhete, Luís M."
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- Effect of consumption of green tea extracts on the plasma molecular signaturePublication . Araújo, Rúben A. D.; Ramalhete, Luís M.; Ribeiro, Edna; Calado, CecíliaEpigallocatechin-3-gallate (EGCG), the major catechin present in green tea, displays diverse biological activities as anti-oxidation, anti-inflammation, anti-proliferation and anti-microbial among others. In the present work it was evaluated the effect of the consumption of EGCG along 90 days on healthy human volunteers (n=30) on plasma molecular signature acquired by mid-infrared (MIR) spectroscopy. It was observed by principal component analysis of spectra that plasma samples presented a significant different molecular profile after 90 days of EGCG consumption. Based on the corresponding loading vector, it was observed that EGCG consumption affected the profile of the major molecules as proteins and lipids. Were identified diverse ratios of spectral bands statistically different (p <; 0.01) after EGCG consumption, according to a high impact of EGCG on the general metabolism. MIR spectroscopy enabled to acquire the plasma whole molecular signature in a highly sensitive and specific mode. Since the MIR spectra is also acquired in an economic, simple, fast and high-throughput mode, the technique presents promising characteristics to acquire information in large-scale epidemiological studies towards a better understand of the in vivo effect of EGCG.
- Impact of the solvent extraction method on the plasma metabolome profilePublication . Pires, Filipa A. R.; Ramalhete, Luís M.; Ribeiro, Edna; Calado, CecíliaMetabolomics of biofluids as plasma implies the sample pre-processment to eliminate diverse macromolecules as proteins. The optimization of this procedure is conducted according to the main method to analyses the metabolome and the type of metabolites to be studied. In the present work, it was evaluated the effect of diverse processes to eliminate macromolecules from plasma samples on the metabolome profile achieved by mid-infrared spectroscopy. It was evaluated the effect on the metabolome of proteins extraction by methanol, acetone and acetonitrile. The highest efficiency of protein extraction was observed with acetone, been achieved 2.4- and 4.7-fold lower quantities of proteins in relation to methanol and acetonitrile, respectively. This resulted in acetone as the highest reproducible extraction process, i.e. with replicate samples with a more homogenous molecular signature between them, in relation to the other two extraction processes. Despite that, acetone resulted in the spectra with the lowest signal to noise (S/N) ratio that could hamper the biological information output. The extraction with acetonitrile presented a spectrum with a S/N ratio like the obtained with methanol, and 2.7-fold higher than the obtained with acetone. However, it resulted in the lowest reproductible process probably due to the presence of 2.2 more proteins in the final sample in relation to the acetone process. All these observations point that different extraction process will complement each other in the view of a more complete metabolome of a system.