Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Structure-stability relationship of anthocyanins under cell culture condition

This work aims to evaluate the structure-stability relationship of anthocyanins in cell culture. An early degradation time ( C T 10 ) and half-degradation time ( C T 50 ) were used to characterise the stability of 10 of the most common anthocyanins, incubated with DMEM at 37 °C, pH = 7.4, 5% CO 2 for different time periods. According to the glycosylation, the glycosylated forms were more stable than the not glycosylated forms. The methylation at 3’' or 5' position at ring B enhanced their stability; contrarily, the hydroxylation at 3' or 5' position at ring B weakened their stability. Glycosylated forms were much more stable in water than in the culture medium. Although not glycosylated forms were also instable in water, their stability was improved compared with culture medium. Together with the cell culture experiments and, in order to avoid artefacts, stability tests of polyphenols should be performed in parallel experiments with DMEM

Health-promoting properties as a target for selecting strawberry cultivars in breeding programmes

Strawberries are among the most valuable fruits for fresh consumption in the world. Besides their pleasant taste, fruits are highly appreciated by consumers because of their health benefits, which have been related to the antioxidant capacity of the polyphenolic compounds they contain. However, strawberry cultivars present different amount and type of this antioxidants. This, joined to the fact that the digestion process can affect their release and alter their composition, could result in differences on the health effects (i.e., bioactivity; BA) of these cultivars, and therefore, it could be important to consider the digestion process for selecting a bioactivity indicator. Thus, the antioxidant capacity (TEAC) of the fruits of five strawberry cultivars was determined before (i.e., fresh fruit material) and after being subjected to an in vitro digestion process (i.e., digested fractions). Thus, on each cultivar, an effect of in vitro digestion was observed, decreasing the TEAC of potentially absorbed extracts (i.e., bioavailable; TEACBA) with respect to the TEAC of the fruit (TEACF), although the decrease in antioxidant capacity was not in the same proportion in all cultivars, there being no correlation between TEACF and TEACBA. To evaluate the correlation between TEACBA and its BA, a ROS (reactive oxygen species) quantification in hepatic cells treated with bioavailable extracts of two strawberry cultivars, previously selected for their higher and lower TEACBA, ('Marquis' and 'Primoris', respectively) was carried out, showing a higher BA in 'Marquis' (i.e., cultivar with higher TEACBA). These results show the importance of performing the in vitro digestion process to reveal the health potential of strawberry cultivars. Besides, TEACBA is proposed as an indicator of BA. However, for selecting parents in breeding programmes, more efforts must be done in order to find a BA indicator that can be determined by faster and more direct techniques