Comparison between in vitro chemical and ex vivo biological assays to evaluate antioxidant capacity of botanical extracts

The anti-oxidative activity of plant-derived extracts is well-known and confers health-promoting effects on functional foods and food supplements. Aim of this work is to evaluate the capability of two different assays to predict the real biological antioxidant efficiency. At this purpose, extracts from five different plant-derived matrices and commercial purified phytochemicals were analyzed for their anti-oxidative properties by using well-standardized in vitro chemical method (TEAC) and an ex vivo biological assay. The biological assay, a cellular membrane system obtained from erythrocytes of healthy volunteers, is based on the capability of phytochemicals treatment to prevent membrane lipid peroxidation under oxidative stress by UV-B radiation. Plant extracts naturally rich in phenols with different structure and purified phytochemicals showed different in vitro and ex vivo antioxidant capacities. A high correlation between phenolic contents of the plant-derived extracts and their ability to prevent oxidative injuries in a biological system was found, thus underlying the relevance of this class of metabolites in preventing oxidative stress. On the other hand, a low correlation between the antioxidant capacities was shown between in vitro and ex vivo antioxidant assay. Moreover, data presented in this work show how food complex matrices are more effective in preventing oxidative damages at biological level than pure phytochemicals, even if for these latter, the antioxidant activity was generally higher than that observed for food complex matrices

Proteomics of saliva: personal experience

The salivary proteome is a complex protein mixture resulting from the activity of salivary glands with the contribution of other components that form the oral environment such as oral tissues and micro-organisms. For diagnosis purposes, saliva collection has the great advantage of being an easy and non-invasive technique. Human saliva proteomics have proven to be a novel approach in the search for protein biomarkers for detection of different local and systemic diseases. Currently, more than 1400 salivary proteins have been identified. In the last few years, our research group has extensively studied the salivary proteomics in order to analyse the salivary composition, investigating the major families of proteins present in human and mammalian saliva, the post-translational modifications, the different contributions of glands, the physiological and pathological modifications of saliva. The aim of this report is to present our personal experience in salivary proteomics. In conclusion, salivary proteome analysis represents an important field both for diagnosis and monitoring of various diseases and could be considered a novel approach to prevention of various pathological conditions

Quenched phosphorescence as alternative detection mode in the chiral separation of methotrexate by electrokinetic chromatography

Quenched phosphorescence was used, for the first time, as detection mode in the chiral separation of methotrexate (MTX) enantiomers by electrokinetic chromatography. The detection is based on dynamic quenching of the strong emission of the phosphorophore 1-bromo-4-naphthalene sulfonic acid (BrNS) by MTX under deoxygenated conditions. The use of a background electrolyte with 3 mg/mL 2-hydroxypropyl-β-cyclodextrin and 20% MeOH in 25 mM phosphate buffer (pH 7.0) and an applied voltage of 30 kV allowed the separation of l-MTX and its enantiomeric impurity d-MTX with sufficient resolution. In the presence of 1 mM BrNS, a detection limit of 3.2 × 10−7 M was achieved, about an order of magnitude better than published techniques based on UV absorption. The potential of the method was demonstrated with a degradation study and an enantiomeric purity assessment of l-MTX. Furthermore, l-MTX was determined in a cell culture extract as a proof-of-principle experiment to show the applicability of the method to biological samples

Characterization of the binding sites of the anticancer ruthenium(III) complexes KP1019 and KP1339 on human serum albumin via competition studies

Indazolium trans-[tetrachloridobis(1H-indazole)ruthenate(III)] (KP1019) and its Na+ analogue (KP1339) are two of the most prominent non-platinum antitumor metal complexes currently undergoing clinical trials. After intravenous administration, they are known to bind to human serum albumin (HSA) in a noncovalent manner. To elucidate their HSA binding sites, displacement reactions with the established site markers warfarin and dansylglycine as well as bilirubin were monitored by spectrofluorimetry, ultrafiltration-UV-vis spectrophotometry, and/or capillary zone electrophoresis. Conditional stability constants for the binding of KP1019 and KP1339 to sites I and II of HSA were determined, indicating that both Ru(III) compounds bind to both sites with moderately strong affinity (log K (1)' = 5.3-5.8). No preference for either binding site was found, and similar results were obtained for both metal complexes, demonstrating low influence of the counter ion on the binding event

Albumin and multiple sclerosis

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Leakage of the blood–brain barrier (BBB) is a common pathological feature in multiple sclerosis (MS). Following a breach of the BBB, albumin, the most abundant protein in plasma, gains access to CNS tissue where it is exposed to an inflammatory milieu and tissue damage, e.g., demyelination. Once in the CNS, albumin can participate in protective mechanisms. For example, due to its high concentration and molecular properties, albumin becomes a target for oxidation and nitration reactions. Furthermore, albumin binds metals and heme thereby limiting their ability to produce reactive oxygen and reactive nitrogen species. Albumin also has the potential to worsen disease. Similar to pathogenic processes that occur during epilepsy, extravasated albumin could induce the expression of proinflammatory cytokines and affect the ability of astrocytes to maintain potassium homeostasis thereby possibly making neurons more vulnerable to glutamate exicitotoxicity, which is thought to be a pathogenic mechanism in MS. The albumin quotient, albumin in cerebrospinal fluid (CSF)/albumin in serum, is used as a measure of blood-CSF barrier dysfunction in MS, but it may be inaccurate since albumin levels in the CSF can be influenced by multiple factors including: 1) albumin becomes proteolytically cleaved during disease, 2) extravasated albumin is taken up by macrophages, microglia, and astrocytes, and 3) the location of BBB damage affects the entry of extravasated albumin into ventricular CSF. A discussion of the roles that albumin performs during MS is put forth

Characterization of Glyceridic and Unsaponifiable Compounds of Sacha Inchi ( Plukenetia huayllabambana

This work deals with the characterization of the main glyceridic and unsaponifiable components of oils obtained from Sacha inchi (Plukenetia huayllabambana L.) seed ecotypes collected during two harvests in the Department of Amazonas in Peru. The seed-oil yield was 30.3-41.2%; standing out are the high percentages of the ¿3- and ¿6-fatty acids series whose ranges lie within those of the present Regulation for Sacha inchi oils. Triacylglycerols with even equivalent carbon number (ECN; 36-42) were the main components. Minor glyceridic polar compounds such as oxidized triglycerides, diglycerides, monoglycerides, and free fatty acids were determined by high-performance size exclusion chromatography. The low campesterol/stigmasterol ratio (1:6), unusual in the majority of vegetable oils, stands out. Regarding aliphatic hydrocarbons, these oils showed a particular profile for the saturated series of odd and even carbon atom numbers. According to our results Sacha inchi P. huayllabambana oils can be offered as a good alternative to P. volubilis, the species mainly commercialized for this vegetable oil

Aloe barbadensis: how a miraculous plant becomes reality

Aloe barbadensis Miller is a plant that is native to North and East Africa and has accompanied man for over 5,000 years. The aloe vera plant has been endowed with digestive, dermatological, culinary and cosmetic virtues. On this basis, aloe provides a range of possibilities for fascinating studies from several points of view, including the analysis of chemical composition, the biochemistry involved in various activities and its application in pharmacology, as well as from horticultural and economic standpoints. The use of aloe vera as a medicinal plant is mentioned in numerous ancient texts such as the Bible. This multitude of medicinal uses has been described and discussed for centuries, thus transforming this miracle plant into reality. A summary of the historical uses, chemical composition and biological activities of this species is presented in this review. The latest clinical studies involved in vivo and in vitro assays conducted with aloe vera gel or its metabolites and the results of these studies are reviewed