Effects of carnosine supplementation on glucose metabolism: Pilot clinical trial.

OBJECTIVE: Carnosine is a naturally present dipeptide in humans and an over-the counter food additive. Evidence from animal studies supports the role for carnosine in the prevention and treatment of diabetes and cardiovascular disease, yet there is limited human data. This study investigated whether carnosine supplementation in individuals with overweight or obesity improves diabetes and cardiovascular risk factors. METHODS: In a double-blind randomized pilot trial in nondiabetic individuals with overweight and obesity (age 43 ± 8 years; body mass index 31 ± 4 kg/m(2) ), 15 individuals were randomly assigned to 2 g carnosine daily and 15 individuals to placebo for 12 weeks. Insulin sensitivity and secretion, glucose tolerance (oral glucose tolerance test), blood pressure, plasma lipid profile, skeletal muscle ((1) H-MRS), and urinary carnosine levels were measured. RESULTS: Carnosine concentrations increased in urine after supplementation (P < 0.05). An increase in fasting insulin and insulin resistance was hampered in individuals receiving carnosine compared to placebo, and this remained significant after adjustment for age, sex, and change in body weight (P = 0.02, P = 0.04, respectively). Two-hour glucose and insulin were both lower after carnosine supplementation compared to placebo in individuals with impaired glucose tolerance (P < 0.05). CONCLUSIONS: These pilot intervention data suggest that carnosine supplementation may be an effective strategy for prevention of type 2 diabetes.

Standardization of solvent extracts from Onopordum acanthium fruits by GC-MS, HPLC-UV/DAD, HPLC-TQMS and 1H-NMR and evaluation of their inhibitory effects on the expression of IL-8 and E-selectin in immortalized endothelial cells (HUVECtert).

In this work we have characterized and standardized the solvent extracts of the fruits of Onopordum acanthium, a plant widely distributed from Europe to Asia and used in different traditional medicines. Fruits were extracted with methanol (ME) and n-hexane (HE) and the extract compositions determined by GC-MS, HPLC-UV/DAD, HPLC-TQMS and 1H NMR spectroscopy. Anti-inflammatory activity (IL-8 and E-selectin, qPCR and ELISA) was investigated in HUVECtert cells stimulated with TNF-alpha and LPS. Arctiin and isochlorogenic acid were found in ME (87 +/- 2%, w/w, and 10.2 +/- 0.2%, w/w; 38.0 +/- 3.2 mg/gFRUITS and 3.5 +/- 0.4 mg/gFRUITS) and (ii) paraffins in the HE (195.6 +/- 5.6 mg/g). A dose dependent (from 15 to 40 microgME/mL corresponding to 20-75 microM arctiin) inhibition of E-selectin and of the induction of IL-8 was induced by LPS. The results of this study support the use of O. acanthium fruits in traditional medicine as an anti-inflammatory agent and for cancer prevention and treatment.

Mass spectrometric strategies for the identification and characterization of human serum albumin covalently adducted by amoxicillin: ex vivo studies.

This study addresses the detection and characterization of the modification of human serum albumin (HSA) by amoxicillin (AX) in ex vivo samples from healthy subjects under oral amoxicillin administration (acute intake of 1 g every 8 h for 48 h). To reach this goal, we used an analytical strategy based on targeted and untargeted mass spectrometric approaches. Plasma samples withdrawn before AX oral intake represented the negative control samples to test the method selectivity, whereas HSA incubated in vitro with AX was the positive control. Different MS strategies were developed, particularly (1) multiple reaction monitoring (MRM) and precursor ion scan (PIS) using a HPLC system coupled to a triple quadrupole MS analyzer and (2) a dedicated data-dependent scan and a customized targeted MS/MS analysis carried out using a nano-LC system coupled to a high-resolution MS system (LTQ Orbitrap XL). Lys 190 was identified as the only modification site of HSA in the ex vivo samples. The AX adduct was identified and fully characterized by complementary targeted approaches based on triple quadrupole (MRM mode) and orbitrap (SIC mode) mass analyzers. The SIC mode also permitted the relative amount of AX-adducted HSA to be measured, ranging from 1 to 2% (6-12 µM) at 24 and 48 h after the oral intake. No adduct in any ex vivo sample was identified by the untargeted methods (PIS and data-dependent scan mode analysis). The results on one hand indicate that MS, in particular high-resolution MS, analysis represents a suitable analytical tool for the identification/characterization of covalently modified proteins/peptides; on the other hand, they give deeper insight into AX-induced protein haptenation, which is required to better understand the mechanisms involved in AX-elicited allergic reactions.

A rapid profiling of gallotannins and flavonoids of the aqueous extract of Rhus coriaria L. by flow injection analysis with high-resolution mass spectrometry assisted with database searching.

Hydrolysable tannins appear to have some extremely important biological roles including antioxidant, antibacterial, anti-inflammatory, anti-hypoglycemic, anti-angiogenic, and anticancer activities. The aim of this work was to set up a flow injection high-resolution mass spectrometric approach combined with database searching to obtain rapidly a profiling of gallotannins and other phenolics in a crude extract from plant tissue. The flow injection analysis (FIA) takes place in an electrospray ionization source of an hybrid orbitrap high resolution mass spectrometry system (ESI-HR-MS/MS(2), resolution 100,000, negative ion mode) and polyphenols are tentatively identified by matching the monoisotopic masses of the spectra with those of polyphenols databases. This leads to the most probable molecular formulas and to the possible structures among those reported in the database. The structures confirmation occurs by the compliance of MS(2) fragments with those of a prediction fragment commercial database. With this method we identified in the aqueous extract of sumac leaves, with a maximum error of 1.7 ppm, a group of ten gallotannins from mono- to deca-galloyl glycosides of the class of hydrolysable tannins and a set of coextracted flavonoid derivatives including myricetin, quercetin-3-O-rhamnoside, myricetin-3-O-glucoside, myricetin-3-O-glucuronide, and myricetin-3-O-rhamnoglucoside. The separation of isomers of gallotannins and flavonoids present in the same extract occurred by high-performance liquid chromatography with electrospray ionization tandem mass spectrometry (HPLC/ESI-HR-MS(2)); this approach allowed the structure resolution of the isobaric flavonoids quercetin-3-O-glucoside and myricetin-3-O-rhamnoside.