Andrej Šmidovnik

Relative Bioavailability of Two Forms of a Novel Water-Soluble Coenzyme Q10

Background: Coenzyme Q10 (CoQ10) is a naturally occurring compound that plays a fundamental role in cellular bioenergetics and is an effective antioxidant. Numerous health benefits of CoQ10 supplementation have been reported, resulting in growing demands for its use in fortifying food. Due to its insolubility in water, the enrichment of most food products is not easily achievable and its in vivo bioavailability is known to be poor. Water solubility was increased significantly with the use of an inclusion complex with β-cyclodextrin. This complex is widely used as Q10Vital® in the food industry, while its in vivo absorption in humans has not previously been studied. Methods: A randomized three-period crossover clinical trial was therefore performed in which a single dose of CoQ10 was administered orally to healthy human subjects. The pharmacokinetic parameters of two forms of the novel CoQ10 material were determined and compared to soft-gel capsules with CoQ10 in soybean oil that acted as a reference. Results: The mean increase of CoQ10 plasma concentrations after dosing with Q10Vital® forms was determined to be over the reference formulation and the area under the curve values, extrapolated to infinity (AUCinf), were also higher with the tested forms; statistically significant 120 and 79% increases over the reference were calculated for the Q10Vital® liquid and powder, respectively. Conclusions: The study revealed that the absorption and bioavailability of CoQ10 in the novel formulations are significantly increased, probably due to the enhanced water solubility.

Bioavailability of water-soluble CoQ10 in beagle dogs

The bioavailability of a novel water-soluble inclusion complex of CoQ10, prepared in our laboratory was determined and compared with the bioavailability of commercially available oil-based form of CoQ10. Experimental work consisted of single dose comparative bioavailability study on seven beagle dogs, with a 14-day washout period between treatments. Identification and quantification of CoQ10 was done with HPLC-MS method using positive APCI ionization and SIM mode, M+ m/z 863.4. The bioavailability results confirm that the water-soluble formulation has nearly three times higher AUC(0-48 h), two times higher Cmax, and Tmax is shortened from 6 to 4 h.

Routine and sensitive method for determination of nicorandil in human plasma developed for liquid chromatography with ultraviolet and m0ass spectrometric detection

A rapid and sensitive method using HPLC has been developed for the quantification of nicorandil (SG-75) in human plasma samples for routine bioequivalence studies. The sample preparation needs two liquid-liquid extractions, first with CH3Cl and HClO4 as denaturation reagent and second with addition of ethyl acetate and Na2CO3(aq). Detection wavelength was 256 nm. The obtained correlation coefficient for weighted linear curve in the range from 5.0 to 300 ng/ml was higher than 0.9950. The limit of quantitation (LOQ) was established at 5.0 ng/ml. The HPLC separation was accomplished on Nucleosil Phenyl (5 microm) stainless steel column within 7 min. The mixture of 0.01 M ammonium acetate buffer (pH 6.2) and acetonitrile 10:3 (v/v) was used as the mobile phase. The same separation method was examined on HPLC-MS system. Using this system, the LOQ was established at 1.0 ng/ml and the linearity was obtained in the range from 1.0 to 150 ng/ml.

Direct analysis of carbohydrates in animal plasma by ion chromatography coupled with mass spectrometry and pulsed amperometric detection for use as a non-invasive diagnostic tool

The present paper demonstrates that electrochemical detection (ECD) coupled to ion chromatography and electrospray ionization tandem mass spectrometry (IC-ECD-ESI/MS/MS) can be used to rapidly estimate some indications of the health status of organisms. The lactulose to mannitol ratio (L/M) is used as a non-invasive assay to investigate small intestinal absorption pathways and mucosal integrity. In the present study, an evaluation of the negative effects of nonsteroidal anti-inflammatory drug meloxicam perorally administrated to a group of dogs was carried out by determining the lactulose/mannitol index using the IC-ECD-ESI/MS/MS hyphenated technique. According to the results of the study, meloxicam altered gastrointestinal permeability. Coenzyme Q(10) (CoQ(10)) was tested to determine if it could prevent meloxicam induced gastrointestinal damage and it was found that CoQ(10) could be an effective preventive treatment. Furthermore, plasma glucose concentration level was determined to be an indirect indicator of the oxidative state in the blood. To find out the beneficial effects of a double antioxidant combination (α-lipoic acid (ALA) and CoQ(10)) on the total glucose level in chickens, ALA and CoQ(10) were provided as food additives in factory farm raised chicken. The results of the pilot study indicate that the glucose level in the plasma of chickens group fed with CoQ(10) and ALA was significantly decreased compared to the control group. Ion chromatography (IC) utilizing pulsed amperometric detection (PAD) was compared to ion chromatography coupled with tandem mass spectrometry (MS/MS) as an analytical tool for monitoring the carbohydrate level in biological fluids. In electrochemical detection, the newly developed two-pulse waveform successfully withstands matrix effects in biological samples. Continuous on-line desalting of the high salt concentrations used as the eluent for carbohydrate separation from the anion-exchange column allows coupling of IC and MS techniques. A make-up solution (0.5mM LiCl) was delivered prior to MS detection for efficient ionization of eluted carbohydrates. Method validation showed that both used techniques are practically comparable and some advantages of each are presented.

HPTLC and HPLC-MS quantification of coenzyme Q10 and cholesterol in fractionated chicken-breast tissue

Coenzyme Q10, an essential factor of oxidative phosphorylation and an important antioxidant, is used as food additive in industrial production of poultry meat. In this study chickens were fed with water-soluble coenzyme Q10-β-cyclodextrin complex for 40 days and the distribution of CoQ10 and cholesterol in the chicken-breast cells was then measured. Cell fractions were analyzed by HPTLC and results were confirmed with a new HPLC-MS method. Both methods are suitable for quantitative evaluation, but HPTLC is particularly suitable for screening purposes. Validation revealed HPTLC is a reliable, sensitive, and flexible analytical tool in comparison with HPLC-MS, despite its inherently lower sensitivity and selectivity.

TLC identification and quantification of coenzyme Q10- β -cyclodextrin complex

TLC is often set aside as a result of unjustified simplification of analytical knowledge and, at the same time, over-emphasis of the use of metrological solutions. Some analysts assume that techniques with smaller measurement uncertainty automatically improve the reliability of their analytical results. This is not true. The reliability of some TLC techniques is demonstrated by analysis of an inclusion complex of coenzyme Q10 (CoQ10) with β-cyclodextrin, which was prepared because it is a water-soluble food additive. The products obtained were analyzed by one-dimensional, two-dimensional, and multi-dimensional TLC (according to Ebel). These inexpensive, rapid, and very informative methods were used in-line during the preparation steps. Separation was performed in two steps, with dioxane-water, 50 + 50 (v/v), as the first mobile phase and chloro-form-methanol, 55 + 45 (v/v), as the second. The development distance was 7.5 cm. The separated spots were visualized in two steps, first with 5% phosphomolybdic acid in EtOH and drying at 110°C, then with 50% H2SO4 and heating at 120°C for 5 min. After the first treatment blue spots on yellow background were observed for CoQ10. After spraying with H2SO4 dark blue spots of CoQ10 were observed on a light blue background. Images were acquired with a scanner and quantification was performed by use of TLC software. The synthetic yield was calculated from the concentrations determined. The results obtained were later confirmed by use of IR, NMR, and HPLC-MS.

Endogenous plasma coenzyme Q10 concentration does not correlate with plasma total antioxidant capacity level in healthy untrained horses.

Coenzyme Q10 (CoQ10) is an essential cofactor in the mitochondrial electron transport pathway, and is also the only known endogenously synthesized lipid-soluble antioxidant. The aim of the present study was to determine, for the first time, endogenous plasma CoQ10 concentration and its correlation with plasma total antioxidant capacity (TAC) and serum total cholesterol (TC) in a population of healthy untrained horses. Thirty-one horses were included in the study. Plasma CoQ10 concentration ranged from 0.380 to 2.090 mg/L, which is in general agreement with plasma CoQ10 concentration in humans. The study demonstrated no significant correlation between plasma CoQ10 and TAC, which indicates that CoQ10 does not contribute to the TAC of equine plasma significantly. In contrast to humans, no significant correlation was found between CoQ10 and TC in investigated horses. The results warrant further studies on CoQ10 supplementation in healthy untrained horses and subsequent determination of correlations between CoQ10 and TAC.

Contents Vol. 52, 2008

115 New Aspects in Quality and Biofunctionality of Foods First Symposium of the Vienna Research Platform of Nutrition and Food Sciences (VRPNFS) April 25, 2008, Vienna, Austria Guest Editors: Elmadfa, I.; Wagner, K.-H. (Vienna) (available online only) 174 The Official FENS Calendar 175 FENS News 176 IUNS News