Daniela Gradinaru | University of Medicine and Pharmacy "Carol Davila" Bucharest (original) (raw)
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Papers by Daniela Gradinaru
Toxicology Letters, 2015
A trend in the general population has been observed in recent years regarding the orientation tow... more A trend in the general population has been observed in recent years regarding the orientation toward preventive measures in health; in this context the increased interest from the users and researchers concerning the active effect of food supplements on the health state and on longevity, is noticeable. All over the world, the consumption of natural foods and of vegetal supplements has increased spectacularly over the last 5-10 years. The decreased prevalence of cardio-vascular diseases associated with Mediterranean diet, as well as the French paradox convinced researchers to scientifically document the beneficial outcomes pointed out by traditional use of plants, and to try to develop supplements that would have the same positive effects as these noticed for diet components. The intense research dedicated to this topic revealed the fact that food supplements are linked to some problematic aspects, such as toxicological side effects when associated with classical synthetic drugs. The food supplement-drug interactions are submitted to complex issues regarding pharmacokinetic interactions leading to changes in absorption, distribution, metabolism and excretion processes with direct impact on effect and toxicological potential. The present review based on recent literature aims at discussing the food-drug interactions with direct impact on efficacy and toxicity of drugs.
Xenobiotic glucuronidation represents a major metabolic protection of the brain against chemical ... more Xenobiotic glucuronidation represents a major metabolic protection of the brain against chemical aggressions at blood-brain interfaces. We previously observed that glucuronidation of 1-naphthol was very effective in olfactory bulb, which is a pathway for the entry of foreign molecules into the brain. In this work, we showed that 1-naphthol glucuronidation varied according to age. It was very high at birth, then decreased markedly in 3-month-old rats and increased again significantly during aging. By Western blot and reverse transcription-polymerase chain reaction (RT-PCR), we demonstrated the presence in the olfactory bulb of the UDP-glucuronosyltransferase (UGT) 1A6 isoform, which catalyzes the glucuronidation of phenols, such as 1-naphthol. Quantitative RT-PCR indicated that the mRNA levels encoding UGT1A6 did not significantly change according to age, thus suggesting that other differently regulated UGT isoforms were present and would account for the variations of 1-naphthol glucuronidation observed.
Toxicology Letters, 2012
h i g h l i g h t s UGT1A6 and UGT1A7 expression and 1-naphthol enzymatic activity were analyzed ... more h i g h l i g h t s UGT1A6 and UGT1A7 expression and 1-naphthol enzymatic activity were analyzed in rat astrocytes. Cells were treated with xenobiotic compounds known to generate oxidative stress. The short term exposure inhibited the 1-naphthol glucuronidation as a result of protein oxidation. Oxidative stress induced deleterious changes in astrocyte morphology and decreased cell viability. Significantly higher glucuronidation activity and mRNA expression of detoxification enzymes in surviving impaired astrocytes.
Toxicology Letters, 2008
The study aimed at in vitro effects evaluation of vegetal antioxidants (quercetin -Q and epigallo... more The study aimed at in vitro effects evaluation of vegetal antioxidants (quercetin -Q and epigallocatechin gallate -EGCG) on plasma membrane properties of peripheral blood mononuclear cells (PBMC) isolated from diabetes patients. A number 13 type II diabetes mellitus (T2DM) and 8 type I diabetes mellitus (T1DM) patients were selected and compared them 21 healthy control subjects. The protocol was approved by the local ethics committee and the informed consent of the patients was obtained. The PBMCs were separated from à jeun blood samples drawn from the subjects, treated with the above mentioned antioxidants at room temperature for 20 minutes, and evaluated for their membrane incorporated TMA-DPH fluorescence anisotropy (r) and the fluidity (f) using data gathered in steady state fluorescence polarization measurements.
Journal of Drug Targeting, 2002
It is generally accepted that the rate of entry into and distribution of drugs and other xenobiot... more It is generally accepted that the rate of entry into and distribution of drugs and other xenobiotics within the central nervous system (CNS) depends on the particular anatomy of the brain microvessels forming the blood-brain barrier (BBB), and of the choroid plexus forming the blood-cerebrospinal fluid barrier (CSF), which possess tight junctions preventing the passage of most polar substances. Drug entry to the CNS also depends on the physicochemical properties of the substances, which can be metabolised during this transport to pharmacologically inactive, non-penetrating polar products. Finally, the entry of drugs may be prevented by multiple complex specialized carriers, which are able to catalyse the active transport of numerous drugs and xenobiotics out of the CNS. Nasal delivery is currently considered as an efficient tool for systemic administration of drugs that are poorly absorbed via the oral route, and increasing evidence suggests that numerous drugs and potentially toxic xenobiotics can reach the CNS by this route. This short review summarizes recent knowledge on factors controlling the nasal pathway, focusing on drug metabolising enzymes in olfactory mucosa, olfactory bulb and brain, which should constitute a CNS metabolic barrier.
Clinical and Experimental Medical Journal, 2009
ATP/ADP = adenosine-triphosphate/adenosine-diphosphate; ESP = erythrocytes' susceptibility to lip... more ATP/ADP = adenosine-triphosphate/adenosine-diphosphate; ESP = erythrocytes' susceptibility to lipid peroxidation; FPG = fasting plasma glucose; G6PDH = glucose-6-phosphate dehydrogenase; HbA1c = glycated hemoglobin; IDDM = insulin dependent diabetes mellitus; LDL = low density lipoproteins; MDA = malondialdehyde; NADP + /NADPH = nicotinamide adenine dinucleotide phosphate oxidized/reduced; NIDDM = non-insulin dependent diabetes mellitus; NO = nitric oxide; NOS = nitric oxide synthase; PBMC = peripheral blood mononuclear cell; PBS = phosphate-buffered saline; PMS = phenazine methosulfate; RBC = red blood cell; ROS = reactive oxygen species; SOD = superoxide dismutase; TC = total cholesterol; TG = triglycerides; TMA-DPH = 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene ptoluensulfonate The present study aims at finding correlations between certain biochemical and biophysical blood parameters for diabetes patients, focusing on the antioxidant status of the red blood cells and the membrane fluidity of peripheral blood mononuclear cells (PBMC), the endothelial function and the risk of stable interaction between the leucocytes and the endothelium. For that purpose we evaluated blood samples from 32 diabetes patients compared to a control group of 10 subjects for erythrocytes' enzymatic activity of glucose-6phosphate dehydrogenase and of superoxide dismutase, their susceptibility to lipid peroxidation, the plasma nitric oxide stable end products level and the PBMC membrane fluidity. Our results showed that the erythrocytes' antioxidant mechanisms and the PBMC membrane fluidity are impaired under chronic hyperglycemic conditions. Since microvascular complications of diabetes are mainly determined by redox mechanisms, the evaluation of these parameters might help in characterizing the risk of vascular complication for diabetes patients.
Quantification of lipophilic vitamins in clinical or biological samples is very important from th... more Quantification of lipophilic vitamins in clinical or biological samples is very important from the medical, epidemiological and informational points of view. Adequate dietary intake of nutrients such as vitamin A (retinol) and vitamin E (tocopherol) is essential for normal ...
Molecular Brain Research, 2002
Archives of Toxicology, 2009
The presence of drug metabolizing enzymes in extrahepatic tissues such as the choroid plexus (CP)... more The presence of drug metabolizing enzymes in extrahepatic tissues such as the choroid plexus (CP) suggests that the CP, like the blood-brain barrier, aVords a metabolic protection to the brain against xenobiotics. The CP, which is the principal site of formation of the cerebrospinal Xuid (CSF), controls the exchange of many endogenous compounds and exogenous molecules between brain tissue and CSF. We present the changes in mRNA expression and enzymatic activities of UDP-glucuronosyltransferase, UGT1A6 isoform and NADPH-cytochrome P450 reductase, after in vitro treatment with xenobiotic molecules known to act in the liver as inducers or inhibitors of these drug metabolizing enzymes. Five study groups of male Sprague-Dawley rats were treated separately with 3-methylcholantrene (3-MC), phenobarbital (PB), dexamethasone (DEX), cyclosporine (CsA) or paraquat (PQ). Choroidal 1-naphthol glucuronidation activities were signiWcantly induced by 3-MC and PQ administration (354 § 85 and 257 § 49 vs. 115 § 24 nmol/h per mg protein, in control group), whereas the other molecules were without eVect. Accordingly, UGT1A6 mRNA expression, measured by RT-PCR, was 2.3-fold higher after 3-MC treatment and 2.1-fold higher after PQ administration. By contrast, reductase activities and mRNA expression remained unchanged in the isolated choroids plexus in these experimental conditions. We present for the Wrst time evidences that the choroids plexus express transcripts for both UGT1A6 and NADPH-cytochrome P450 reductase, and their mRNA expression can be diVerently regulated by exogenous factors. These results emphasize that xenobiotics could modulate the biotransformation of exogenous and/or endogenous compounds in the choroids plexus, and underline the role of UGTs in the maintenance of brain homeostasis.
Redox Biology, 2015
Protein carbonyls are widely analysed as a measure of protein oxidation. Several different method... more Protein carbonyls are widely analysed as a measure of protein oxidation. Several different methods exist for their determination. A previous study had described orders of magnitude variance that existed when protein carbonyls were analysed in a single laboratory by ELISA using different commercial kits. We have further explored the potential causes of variance in carbonyl analysis in a ring study. A soluble protein fraction was prepared from rat liver and exposed to 0, 5 and 15 min of UV irradiation. Lyophilised preparations were distributed to six different laboratories that routinely undertook protein carbonyl analysis across Europe. ELISA and Western blotting techniques detected an increase in protein carbonyl formation between 0 and 5 min of UV irradiation irrespective of method used. After irradiation for 15 min, less oxidation was detected by half of the laboratories than after 5 min irradiation. Three of the four ELISA carbonyl results fell within 95% confidence intervals. Likely errors in calculating absolute carbonyl values may be attributed to differences in standardisation. Out of up to 88 proteins identified as containing carbonyl groups after tryptic cleavage of irradiated and control liver proteins, only seven were common in all three liver preparations. Lysine and arginine residues modified by carbonyls are likely to be resistant to tryptic proteolysis. Use of a cocktail of proteases may increase the recovery of oxidised peptides. In conclusion, standardisation is critical for carbonyl analysis and heavily oxidised proteins may not be effectively analysed by any existing technique.
Mechanisms of ageing and development, Jan 21, 2015
Oxidized LDL (oxLDL) and nitric oxide (NO) exert contradictory actions within the vascular endoth... more Oxidized LDL (oxLDL) and nitric oxide (NO) exert contradictory actions within the vascular endothelium microenvironment influencing key events in atherogenesis. OxLDL and NO are so far regarded as representative parameters of oxidative stress and endothelial dysfunction, new targets in prevention, diagnosis and therapy of cardiovascular diseases, and also as candidate biomarkers in evaluating the human biological age. The aim of this review is to explore recent literature on molecular mechanisms and pathophysiological relationships between LDL oxidation, NO synthesis and vascular endothelium function/dysfunction in ageing, focusing on the following aspects: (1) the impact of metabolic status on both LDL oxidation and NO synthesis in relation with oxidative stress, (2) the use of oxidized LDL and NO activity as biomarkers in human studies reporting on cardiovascular outcomes, and (3) evidences supporting the importance of oxidized LDL and NO activity as relevant biomarkers in vascula...
Toxicology Letters, 2015
A trend in the general population has been observed in recent years regarding the orientation tow... more A trend in the general population has been observed in recent years regarding the orientation toward preventive measures in health; in this context the increased interest from the users and researchers concerning the active effect of food supplements on the health state and on longevity, is noticeable. All over the world, the consumption of natural foods and of vegetal supplements has increased spectacularly over the last 5-10 years. The decreased prevalence of cardio-vascular diseases associated with Mediterranean diet, as well as the French paradox convinced researchers to scientifically document the beneficial outcomes pointed out by traditional use of plants, and to try to develop supplements that would have the same positive effects as these noticed for diet components. The intense research dedicated to this topic revealed the fact that food supplements are linked to some problematic aspects, such as toxicological side effects when associated with classical synthetic drugs. The food supplement-drug interactions are submitted to complex issues regarding pharmacokinetic interactions leading to changes in absorption, distribution, metabolism and excretion processes with direct impact on effect and toxicological potential. The present review based on recent literature aims at discussing the food-drug interactions with direct impact on efficacy and toxicity of drugs.
Xenobiotic glucuronidation represents a major metabolic protection of the brain against chemical ... more Xenobiotic glucuronidation represents a major metabolic protection of the brain against chemical aggressions at blood-brain interfaces. We previously observed that glucuronidation of 1-naphthol was very effective in olfactory bulb, which is a pathway for the entry of foreign molecules into the brain. In this work, we showed that 1-naphthol glucuronidation varied according to age. It was very high at birth, then decreased markedly in 3-month-old rats and increased again significantly during aging. By Western blot and reverse transcription-polymerase chain reaction (RT-PCR), we demonstrated the presence in the olfactory bulb of the UDP-glucuronosyltransferase (UGT) 1A6 isoform, which catalyzes the glucuronidation of phenols, such as 1-naphthol. Quantitative RT-PCR indicated that the mRNA levels encoding UGT1A6 did not significantly change according to age, thus suggesting that other differently regulated UGT isoforms were present and would account for the variations of 1-naphthol glucuronidation observed.
Toxicology Letters, 2012
h i g h l i g h t s UGT1A6 and UGT1A7 expression and 1-naphthol enzymatic activity were analyzed ... more h i g h l i g h t s UGT1A6 and UGT1A7 expression and 1-naphthol enzymatic activity were analyzed in rat astrocytes. Cells were treated with xenobiotic compounds known to generate oxidative stress. The short term exposure inhibited the 1-naphthol glucuronidation as a result of protein oxidation. Oxidative stress induced deleterious changes in astrocyte morphology and decreased cell viability. Significantly higher glucuronidation activity and mRNA expression of detoxification enzymes in surviving impaired astrocytes.
Toxicology Letters, 2008
The study aimed at in vitro effects evaluation of vegetal antioxidants (quercetin -Q and epigallo... more The study aimed at in vitro effects evaluation of vegetal antioxidants (quercetin -Q and epigallocatechin gallate -EGCG) on plasma membrane properties of peripheral blood mononuclear cells (PBMC) isolated from diabetes patients. A number 13 type II diabetes mellitus (T2DM) and 8 type I diabetes mellitus (T1DM) patients were selected and compared them 21 healthy control subjects. The protocol was approved by the local ethics committee and the informed consent of the patients was obtained. The PBMCs were separated from à jeun blood samples drawn from the subjects, treated with the above mentioned antioxidants at room temperature for 20 minutes, and evaluated for their membrane incorporated TMA-DPH fluorescence anisotropy (r) and the fluidity (f) using data gathered in steady state fluorescence polarization measurements.
Journal of Drug Targeting, 2002
It is generally accepted that the rate of entry into and distribution of drugs and other xenobiot... more It is generally accepted that the rate of entry into and distribution of drugs and other xenobiotics within the central nervous system (CNS) depends on the particular anatomy of the brain microvessels forming the blood-brain barrier (BBB), and of the choroid plexus forming the blood-cerebrospinal fluid barrier (CSF), which possess tight junctions preventing the passage of most polar substances. Drug entry to the CNS also depends on the physicochemical properties of the substances, which can be metabolised during this transport to pharmacologically inactive, non-penetrating polar products. Finally, the entry of drugs may be prevented by multiple complex specialized carriers, which are able to catalyse the active transport of numerous drugs and xenobiotics out of the CNS. Nasal delivery is currently considered as an efficient tool for systemic administration of drugs that are poorly absorbed via the oral route, and increasing evidence suggests that numerous drugs and potentially toxic xenobiotics can reach the CNS by this route. This short review summarizes recent knowledge on factors controlling the nasal pathway, focusing on drug metabolising enzymes in olfactory mucosa, olfactory bulb and brain, which should constitute a CNS metabolic barrier.
Clinical and Experimental Medical Journal, 2009
ATP/ADP = adenosine-triphosphate/adenosine-diphosphate; ESP = erythrocytes' susceptibility to lip... more ATP/ADP = adenosine-triphosphate/adenosine-diphosphate; ESP = erythrocytes' susceptibility to lipid peroxidation; FPG = fasting plasma glucose; G6PDH = glucose-6-phosphate dehydrogenase; HbA1c = glycated hemoglobin; IDDM = insulin dependent diabetes mellitus; LDL = low density lipoproteins; MDA = malondialdehyde; NADP + /NADPH = nicotinamide adenine dinucleotide phosphate oxidized/reduced; NIDDM = non-insulin dependent diabetes mellitus; NO = nitric oxide; NOS = nitric oxide synthase; PBMC = peripheral blood mononuclear cell; PBS = phosphate-buffered saline; PMS = phenazine methosulfate; RBC = red blood cell; ROS = reactive oxygen species; SOD = superoxide dismutase; TC = total cholesterol; TG = triglycerides; TMA-DPH = 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene ptoluensulfonate The present study aims at finding correlations between certain biochemical and biophysical blood parameters for diabetes patients, focusing on the antioxidant status of the red blood cells and the membrane fluidity of peripheral blood mononuclear cells (PBMC), the endothelial function and the risk of stable interaction between the leucocytes and the endothelium. For that purpose we evaluated blood samples from 32 diabetes patients compared to a control group of 10 subjects for erythrocytes' enzymatic activity of glucose-6phosphate dehydrogenase and of superoxide dismutase, their susceptibility to lipid peroxidation, the plasma nitric oxide stable end products level and the PBMC membrane fluidity. Our results showed that the erythrocytes' antioxidant mechanisms and the PBMC membrane fluidity are impaired under chronic hyperglycemic conditions. Since microvascular complications of diabetes are mainly determined by redox mechanisms, the evaluation of these parameters might help in characterizing the risk of vascular complication for diabetes patients.
Quantification of lipophilic vitamins in clinical or biological samples is very important from th... more Quantification of lipophilic vitamins in clinical or biological samples is very important from the medical, epidemiological and informational points of view. Adequate dietary intake of nutrients such as vitamin A (retinol) and vitamin E (tocopherol) is essential for normal ...
Molecular Brain Research, 2002
Archives of Toxicology, 2009
The presence of drug metabolizing enzymes in extrahepatic tissues such as the choroid plexus (CP)... more The presence of drug metabolizing enzymes in extrahepatic tissues such as the choroid plexus (CP) suggests that the CP, like the blood-brain barrier, aVords a metabolic protection to the brain against xenobiotics. The CP, which is the principal site of formation of the cerebrospinal Xuid (CSF), controls the exchange of many endogenous compounds and exogenous molecules between brain tissue and CSF. We present the changes in mRNA expression and enzymatic activities of UDP-glucuronosyltransferase, UGT1A6 isoform and NADPH-cytochrome P450 reductase, after in vitro treatment with xenobiotic molecules known to act in the liver as inducers or inhibitors of these drug metabolizing enzymes. Five study groups of male Sprague-Dawley rats were treated separately with 3-methylcholantrene (3-MC), phenobarbital (PB), dexamethasone (DEX), cyclosporine (CsA) or paraquat (PQ). Choroidal 1-naphthol glucuronidation activities were signiWcantly induced by 3-MC and PQ administration (354 § 85 and 257 § 49 vs. 115 § 24 nmol/h per mg protein, in control group), whereas the other molecules were without eVect. Accordingly, UGT1A6 mRNA expression, measured by RT-PCR, was 2.3-fold higher after 3-MC treatment and 2.1-fold higher after PQ administration. By contrast, reductase activities and mRNA expression remained unchanged in the isolated choroids plexus in these experimental conditions. We present for the Wrst time evidences that the choroids plexus express transcripts for both UGT1A6 and NADPH-cytochrome P450 reductase, and their mRNA expression can be diVerently regulated by exogenous factors. These results emphasize that xenobiotics could modulate the biotransformation of exogenous and/or endogenous compounds in the choroids plexus, and underline the role of UGTs in the maintenance of brain homeostasis.
Redox Biology, 2015
Protein carbonyls are widely analysed as a measure of protein oxidation. Several different method... more Protein carbonyls are widely analysed as a measure of protein oxidation. Several different methods exist for their determination. A previous study had described orders of magnitude variance that existed when protein carbonyls were analysed in a single laboratory by ELISA using different commercial kits. We have further explored the potential causes of variance in carbonyl analysis in a ring study. A soluble protein fraction was prepared from rat liver and exposed to 0, 5 and 15 min of UV irradiation. Lyophilised preparations were distributed to six different laboratories that routinely undertook protein carbonyl analysis across Europe. ELISA and Western blotting techniques detected an increase in protein carbonyl formation between 0 and 5 min of UV irradiation irrespective of method used. After irradiation for 15 min, less oxidation was detected by half of the laboratories than after 5 min irradiation. Three of the four ELISA carbonyl results fell within 95% confidence intervals. Likely errors in calculating absolute carbonyl values may be attributed to differences in standardisation. Out of up to 88 proteins identified as containing carbonyl groups after tryptic cleavage of irradiated and control liver proteins, only seven were common in all three liver preparations. Lysine and arginine residues modified by carbonyls are likely to be resistant to tryptic proteolysis. Use of a cocktail of proteases may increase the recovery of oxidised peptides. In conclusion, standardisation is critical for carbonyl analysis and heavily oxidised proteins may not be effectively analysed by any existing technique.
Mechanisms of ageing and development, Jan 21, 2015
Oxidized LDL (oxLDL) and nitric oxide (NO) exert contradictory actions within the vascular endoth... more Oxidized LDL (oxLDL) and nitric oxide (NO) exert contradictory actions within the vascular endothelium microenvironment influencing key events in atherogenesis. OxLDL and NO are so far regarded as representative parameters of oxidative stress and endothelial dysfunction, new targets in prevention, diagnosis and therapy of cardiovascular diseases, and also as candidate biomarkers in evaluating the human biological age. The aim of this review is to explore recent literature on molecular mechanisms and pathophysiological relationships between LDL oxidation, NO synthesis and vascular endothelium function/dysfunction in ageing, focusing on the following aspects: (1) the impact of metabolic status on both LDL oxidation and NO synthesis in relation with oxidative stress, (2) the use of oxidized LDL and NO activity as biomarkers in human studies reporting on cardiovascular outcomes, and (3) evidences supporting the importance of oxidized LDL and NO activity as relevant biomarkers in vascula...