Influence of ovarian stimulation for IVF/ICSI on the antioxidant defence system and relationship to outcome.

Ovarian stimulation is used with IVF/intracytoplasmic sperm injection (ICSI) cycles to obtain multiple oocytes and improve pregnancy rates; however, it also induces perturbation in the oxidant-antioxidant balance leading to oxidation stress. The present study monitored the plasma antioxidant status in women undergoing a long agonist protocol of ovarian stimulation at three different time points: at baseline (T0), after pituitary suppression (T1) and on the day of oocyte retrieval (T2). The antioxidant composition of follicular fluid samples collected on T2 was also evaluated. Significant decreases (P < 0.05) of plasma vitamin C, vitamin E and carotenoids were found between T1 and T2 but not between T0 and T1. At T2, high plasma vitamin E was associated with high numbers of total and mature oocytes retrieved per patient, which, in turn, were favourable for achieving pregnancy. Accordingly, women who became pregnant presented higher vitamin E concentrations both in plasma and FF than those who did not. In conclusion, this study confirmed the occurrence of significant modifications of the plasma antioxidant profile during ovarian stimulation with gonadotrophins; at the same time, it was found that both systemic and follicular antioxidant status may be related to IVF/ICSI outcome.

Validation of a patented method to determine the antioxidant capacity of human saliva based on the reduction of iron: the SAT test.

BACKGROUND: The defense against damaging attack at mouth level caused by reactive species, in particular reactive oxygen species (ROS), is guaranteed by saliva, the main constituent of the antioxidant barrier. The aim of the performed tests was to establish the precision, linearity, and accuracy of the new patented test, SAT, on saliva samples taken from healthy volunteers. The analysis also provided useful information on storage conditions of the sample at low temperatures and on the normality range and defined the influences of interferences (in particular phosphates) in the determination. METHODS: Sixty apparently healthy volunteers were selected to verify the antioxidant capacity of the oral cavity using the new patented SAT method. RESULTS: SAT performed on 70 saliva samples demonstrated that the test was precise, linear (R = 0.9994), accurate, and reproducible (CV 4.39%). The SAT values in the saliva samples analyzed had a normal distribution with a control range for healthy subjects of 947-1459 micromol/L. The fundamental presence of a particular salt in the SAT solutions allowed avoidance of phosphate interference and eliminated false positives. CONCLUSIONS: SAT can be considered an important predictive test not only for periodontal disease, caries, gingivitis, and general pathologies related to oral cavity, but also for systemic diseases such as: cardiovascular diseases, diabetes, Alzheimer's disease, and others.

Performance evaluation of the innovative PAT test, comparison with the common BAP test and influence of interferences on the evaluation of the plasma antioxidant capacity.

BACKGROUND: Antioxidants (AOs) represent the main barrier of defense against damaging aggression due to reactive species, in particular by reactive oxygen species (ROS). The plasma AO capacity is a measure of physiological, environmental, and nutritional factors (exposure to ROS and antioxidant supplementation) determining the redox status in humans and can underline the oxidative stress (OS) conditions in the progression/development of many diseases. Moreover, changes in AO plasma content after supplementation may provide information on the absorption and bioavailability of nutritional compounds and efficacy of AO therapy. AIM: The aim of the study was a comparison between the common BAP (Biological Antioxidant Potential) test, used for the evaluation of the antioxidant capacity, and the innovative PAT (Plasma Antioxidant Test) and to assess both the in vitro interferences of phosphates on the iron reduction and the interference of the plasmatic concentration of phosphates in relation to the plasma antioxidant capacity measured with the two methods. METHODS: Thirty-six apparently healthy volunteers were involved in the study for the comparison of the two methods. RESULTS: BAP test and PAT performed on 36 plasma samples demonstrated that plasma antioxidant capacity dosage using the BAP test resulted in overestimated levels in relation to plasma phosphate. Increased BAP values due to phosphates correspond to increased differences between BAP and PAT value (correlation coefficient R = 0.812, p = 0.001). CONCLUSIONS: PAT can be considered an innovative and predictable method for the measure of the antioxidant power of plasma.

Differences in blood and semen oxidative status in fertile and infertile men, and their relationship with sperm quality.

Oxidative stress plays a fundamental role in the aetiology of male infertility by negatively affecting sperm quality and function. Assessment of blood and seminal plasma oxidative profiles might be a valuable tool to improve evaluation of sperm reproductive capacity and functional competence. This study examined the lipid-soluble antioxidant profile and levels of lipid peroxidation both in blood and seminal plasma samples of infertile and fertile males, in relation to semen parameters. Total antioxidant capacity (TAC) and vitamin E concentrations were significantly (P<0.05) lower in seminal plasma of infertile men compared with fertile subjects; concurrently, a significant accumulation of malondialdehyde was found in infertile patients (P=0.032 compared with controls), which was negatively correlated with sperm motility and morphology. In blood samples, infertile men presented lower concentrations of TAC, carotenoids and vitamin E than fertile subjects; TAC and carotenoids were positively correlated with sperm motility, morphology and concentration. Finally, blood TAC and vitamin E concentrations were positively correlated with the corresponding seminal values, confirming the close relationship between blood and semen antioxidants. All these results indicated the possibility of using not only seminal antioxidants but also blood antioxidants as biochemical markers to support sperm quality evaluation. Oxidative stress induced by reactive oxygen species (ROS) has been widely recognized as one of the major causes of male infertility; indeed, excessive ROS production can negatively impact sperm quality and function. The assessment of blood and seminal plasma oxidative profiles has been suggested as a valuable tool to improve the evaluation of sperm reproductive capacity and functional competence in infertile men. With this in mind, in the present study we examined the lipid soluble antioxidant profile (carotenoids and vitamins A and E) and the levels of lipid peroxidation (malondialdehyde; MDA) both in blood and seminal plasma samples of infertile and fertile males, in correlation with semen parameters namely motility, morphology and concentration. As a result, we obtained evidence that the total antioxidant capacity (TAC) and the concentrations of vitamin E of seminal plasma samples were significantly lower in infertile men than in fertile subjects; at the same time, a significant accumulation of MDA was found in infertile patients. MDA, in turn, negatively correlated with sperm motility and morphology, thus confirming that oxidative damage to lipids impairs sperm quality. In blood samples, infertile men presented lower TAC and lower concentrations of carotenoids and vitamin E than fertile subjects; interestingly, TAC and carotenoid concentrations were positively correlated with sperm motility, morphology, and concentration, confirming the close relationship between blood antioxidants and sperm quality. In conclusion, all these results suggested that the examination of blood and semen oxidative profiles might furnish useful information on sperm quality and function in infertile men.

Effect of a 2-month treatment with Klamin, a Klamath algae extract, on the general well-being, antioxidant profile and oxidative status of postmenopausal women.

BACKGROUND AND AIM: Because of a growing demand for alternative treatments of the psychological and somatic/vasomotor symptoms related to menopausal transition, in this study we aimed to investigate the effect of a 2-month supplementation period with the Klamath algae extract (Klamin, Nutratec Srl, Urbino, Italy) on the general and psychological well-being of a group of 21 menopausal women not treated with hormonal therapy, as well as on their oxidative stress status and level of antioxidants. Klamin is an extract naturally rich in powerful algal antioxidant molecules (AFA-phycocyanins) and concentrated with Klamath algae's natural neuromodulators (phenylethylamine as well as natural selective MAO-B inhibitors). CONCLUSIONS: At the end of the Klamin supplementation period, plasma lipid peroxidation significantly decreased (as proven by a significant lowering of plasma MDA levels), while the overall antioxidant system improved thanks to the significant increase in the plasma levels of carotenoids, tocopherols and retinol. Furthermore, the average Green Scale score, which evaluates menopausal symptoms and thus by contrast the overall and psychological well-being of menopausal women, was significantly reduced. As it did not show the steroid-like effects on the hormonal parameters, Klamin could be proposed both as a valid natural remedy for women seeking an alternative to hormonal therapy, as well as as a complementary treatment for many climacteric symptoms.

Effect of a Klamath algae product ("AFA-B12") on blood levels of vitamin B12 and homocysteine in vegan subjects: a pilot study.

Vitamin B12 is a critical nutrient that is often inadequate in a plant-based (vegan) diet, thus the inclusion of a reliable vitamin B12 source in a vegan diet is recommended as essential. Unfortunately, many natural sources of vitamin B12 have been proven to contain biologically inactive vitamin B12 analogues, inadequate for human supplementation. The aim of this non-randomized open trial was to determine whether supplementation with a natural Klamath algae-based product ("AFA-B12", Aphanizomenon flos-aquae algae plus a proprietary mix of enzymes) could favorably affect the vitamin B12 status of a group of 15 vegan subjects. By assessing blood concentration of vitamin B12, folate, and more importantly homocysteine (Hcy, a reliable marker in vegans of their B12 absorption), the vitamin B12 status of the participants at the end of the 3-month intervention period, while receiving the Klamath-algae supplement (T2), was compared with their vitamin B12 status at the end of the 3-month control period (T1), when they were not receiving any supplement, having stopped taking their usual vitamin B12 supplement at the beginning of the study (T0). Compared to the control period, in the intervention period participants improved their vitamin B12 status, significantly reducing Hcy blood concentration (p=0.003). In conclusion, the Klamath algae product AFA-B12 appears to be, in a preliminary study, an adequate and reliable source of vitamin B12 in humans.

Purification and characterization of phycocyanin from the blue-green alga Aphanizomenon flos-aquae.

Aphanizomenon flos-aquae (AFA) is a blue-green alga and represents a nutrient-dense food source. In this study the presence of phycocyanin (PC), a blue protein belonging to the photosynthetic apparatus, has been demonstrated in AFA. An efficient method for its separation has been set up: PC can be purified by a simple single step chromatographic run using a hydroxyapatite column (ratio A620/A280 of 4.78), allowing its usage for health-enhancing properties while eliminating other aspecific algal components. Proteomic investigation and HPLC analysis of purified AFA phycobilisomes revealed that, contrary to the well-characterized Synechocystis and Spirulina spp., only one type of biliprotein is present in phycobilisomes: phycocyanins with no allo-phycocyanins. Two subunit polypeptides of PC were also separated: the beta subunit containing two bilins as chromophore and the alpha subunit containing only one.

Oxidative stress and antioxidant status in patients undergoing prolonged exposure to hyperbaric oxygen.

OBJECTIVES: To evaluate the condition of oxidative stress in patients undergoing prolonged exposure to hyperbaric oxygen (HBO) and the possible modifications of the antioxidant defense systems in the absence of antioxidant supplementation. DESIGN AND METHODS: Twelve patients exposed to 15 HBO treatments for pathological conditions related to hypoxia were included in the study. Oxidative stress indices as well as plasma and erythrocyte antioxidant levels were measured in blood samples collected both at the 1st and 15th HBO session. RESULTS: The repeated exposures to HBO led to a significant accumulation of plasmatic reactive oxygen metabolites (ROM) and malondialdehyde (MDA). After 15 HBO sessions, no relevant differences were detected for reduced glutathione (GSH), alpha-tocopherol, and retinol plasma levels; however, a significant decrease in erythrocyte superoxide dismutase (SOD) and catalase (CAT) activity was observed when compared to the 1st HBO exposure; glutathione peroxidase (GPx) activity remained almost unchanged. CONCLUSIONS: In the absence of antioxidant supplementation, the prolonged HBO treatment leads to a condition of oxidative stress that seems to affect in particular the response of the enzymatic antioxidant defense system; the possible relationship between the chemical modifications of the enzymes caused by oxygen reactive species and the consequent inactivation of the proteins is under investigation.

Antioxidant properties of a novel phycocyanin extract from the blue-green alga Aphanizomenon flos-aquae.

Aphanizomenon flos-aquae (AFA) is a fresh water unicellular blue-green alga (cyanophyta) rich in phycocyanin (PC), a photosynthetic pigment with antioxidant and anti-inflammatory properties. The purpose of this study was to evaluate the ability of a novel natural extract from AFA enriched with PC to protect normal human erythrocytes and plasma samples against oxidative damage in vitro. In red blood cells, oxidative hemolysis and lipid peroxidation induced by the aqueous peroxyl radical generator [2,2'-Azobis (2-amidinopropane) dihydrochloride, AAPH] were significantly lowered by the AFA extract in a time- and dose-dependent manner; at the same time, the depletion of cytosolic glutathione was delayed. In plasma samples, the natural extract inhibited the extent of lipid oxidation induced by the pro-oxidant agent cupric chloride (CuCl2); a concomitant increase of plasma resistance to oxidation was observed as evaluated by conjugated diene formation. The involvement of PC in the antioxidant protection of the AFA extract against the oxidative damage was demonstrated by investigating the spectral changes of PC induced by AAPH or CuCl2. The incubation of the extract with the oxidizing agents led to a significant decrease in the absorption of PC at 620 nm accompanied with disappearance of its blue color, thus indicating a rapid oxidation of the protein. In the light of these in vitro results, the potential clinical applications of this natural compound are under investigation.

Gas chromatographic--mass spectrometric determination of phenylacetic acid in human blood.

Phenyl acetic acid, a metabolite of 2-phenyl ethylamine, acts as a neuromodulator in the nigrostriatal dopaminergic pathway stimulating the release of dopamine. The evaluation of phenyl acetic acid concentration in the biological fluid reflects phenyl ethylamine levels thus allowing the assessment of the modulatory role of this endogenous substance. Changes in biological fluids levels of 2-phenylethylamine and/or in its metabolite have been reported in affective disorders, such as depression and schizophrenia. Recently, the occurrence of the "attention deficit hyperactivity syndrome" has been frequently reported in childhood population and involvement of dopaminergic dysfunction in this disease has been suspected. A fast, reliable and reproducible method for the determination of phenyl acetic acid in human blood, is therefore needed in order to have a screening tool for monitoring both healthy childhood population and suspected "attention deficit hyperactivity syndrome" patients. The gas chromatographic-mass spectrometric method here described makes use of a deuterated internal standard in order to overcome problems related to the lack of reproducibility often encountered when a derivatization step is performed.

CELLFOOD™ induces apoptosis in human mesothelioma and colorectal cancer cells by modulating p53, c-myc and pAkt signaling pathways.

BACKGROUND: CELLFOOD™ (CF) is a nutraceutical non-addictive, non-invasive, and completely non-toxic unique proprietary colloidal-ionic formula. Little is known about its effect on cancer cells in solid tumors. The aim of this study was to evaluate the effect that CF has on different cancer cell lines and the mechanism by which the nutraceutical works. METHODS: The effect of CF on HFF (normal fibroblasts), Met5A (mesothelium), MSTO-211H, NCI-2452, Ist-Mes1, MPP89, Ist-Mes2 (mesothelioma), M14 (melanoma), H1650, H1975 (lung cancer), SKRB3 (breast cancer), and HCT-116 (colorectal cancer) cell growth was tested by cell proliferation and clonogenic assay. Among all of them, MSTO-211 and HCT-116 were analyzed for cell cycle by flow cytometry and western blot. RESULTS: All human cancer lines were suppressed on cell growth upon 1:200 CF treatment for 24 and 48 hours. Death was not observed in HFF and Met5A cell lines. Cell cycle analysis showed an increased sub-G1 with reduction of G1 in MSTO-211 and a cell cycle arrest of in G1 in HCT116. Activation of caspase-3 and cleavage of PARP confirmed an apoptotic death for both cell lines. Increased expression levels of p53, p21, and p27, downregulation of c-myc and Bcl-2, and inhibition of Akt activation were also found in CF-treated MSTO-211 and HCT-116 cells. CONCLUSIONS: These findings ascertained an interaction between p53, c-myc, p21, p27, Bcl-2, PI3K/Akt pathway, and CF-induced apoptosis in MSTO-211H and HCT-116 cells, suggesting that CF acts as an important regulator of cell growth in human cancer cell lines. CF could be a useful nutraceutical intervention for prevention in colon cancer and mesothelioma.

Selective monoamine oxidase B inhibition by an Aphanizomenon flos-aquae extract and by its constitutive active principles phycocyanin and mycosporine-like amino acids.

Aphanizomenon flos-aquae (AFA) is a fresh water unicellular blue-green alga that has been traditionally used for over 25 years for its health-enhancing properties. Recent studies have shown the ability of a proprietary AFA extract (Klamin(®)) to improve mood, counteract anxiety, and enhance attention and learning. Aim of this study was to test the monoamine oxidase (MAO) inhibition activity of the same AFA extract and of its constituents phycocyanin (AFA-PC) and mycosporine-like aminoacids (AFA-MAAs). All compounds showed a dose-dependent selective inhibition of MAO-B activity as compared to MAO-A. The IC50 values of the AFA extract (concentration 10 mg/ml), AFA-PC and AFA-MAAs were 6.4 µl/ml, 1.33 µM and 1.98 µM, respectively, evidencing a mixed-type of inhibition for the AFA extract (Ki 0.99 µl/ml), a non-competitive inhibition for AFA-PC (Ki 1.06 µM) and a competitive inhibition for AFA-MAAs (Ki 0.585 µM). These results are important to explain the neuromodulating properties of the AFA extract Klamin(®), which is rich in phenylethylamine, a general neuromodulator, that would nevertheless rapidly destroyed by MAO-B enzymes without the inhibitory activity of the synergic active principles AFA-PC and AFA-MAAs. The present investigation thus proposes the extract as potentially relevant in clinical areas such as mood disorders and neurodegenerative diseases.

Metabolism modifications and apoptosis induction after Cellfood™ administration to leukemia cell lines.

BACKGROUND: Cellfood™ (CF) is a nutritional supplement containing deuterium sulphate, minerals, amino acids, and enzymes, with well documented antioxidant properties. Its organic and inorganic components are extracted from the red algae Lithothamnion calcareum, whose mineral extract has shown growth-inhibitory effect both on in vitro and in vivo models. The purpose of this study was to evaluate the antiproliferative effects of CF on leukemic cells. In fact, according to its capacity to modulate O2 availability and to improve mitochondrial respiratory metabolism, we wondered if CF could affect cancer cell metabolism making cells susceptible to apoptosis. METHODS: Three leukemic cell lines, Jurkat, U937, and K562, were treated with CF 5 µl/ml up to 72 hours. Cell viability, apoptosis (i.e. caspase-3 activity and DNA fragmentation), hypoxia inducible factor 1 alpha (HIF-1α) concentration, glucose transporter 1 (GLUT-1) expression, lactate dehydrogenase (LDH) activity and lactate release in the culture medium were detected and compared with untreated cells. RESULTS: CF significantly inhibited leukemic cell viability by promoting cell apoptosis, as revealed by caspase-3 activation and DNA laddering. In particular, CF treated cells showed lower HIF-1α levels and lower GLUT-1 expression as compared to untreated cells. At the same time, CF was able to reduce LDH activity and, consequently, the amount of lactate released in the extracellular environment. CONCLUSIONS: We supplied evidence for an antiproliferative effect of CF on leukemia cell lines by inducing cell death through an apoptotic mechanism and by altering cancer cell metabolism through HIF-1α and GLUT-1 regulation. Thanks to its antioxidative and proapoptotic properties, CF might be a good candidate for cancer prevention.

Counteraction of oxidative damage in the rat liver by an ancient grain (Kamut brand khorasan wheat).

OBJECTIVE: We previously demonstrated in rat plasma the antioxidant protective effect of whole-grain bread, particularly when made from Kamut brand khorasan wheat. In the present study, we investigated the effects of the same experimental breads in rat liver using two different bread-making procedures (baker's yeast and sourdough fermentation). METHODS: Rats were examined in the basal condition and after the administration of doxorubicin, a pro-oxidative agent. The following parameters were measured in liver homogenates: glutathione peroxidase and thioredoxin reductase activities, as antioxidant enzymes containing selenium; glutathione, α-tocopherol and ß-carotene, as major non-enzymatic cell antioxidants; malondialdehyde and advanced oxidation protein products, as markers of oxidative damage to lipids and proteins, respectively. A histologic evaluation of liver tissue was also conducted. RESULTS: In agreement with our previous work, we observed a lower oxidative status and a different activity of glutathione peroxidase and thioredoxin reductase in rats fed the whole-grain Kamut khorasan bread than in rats fed the modern whole-grain durum wheat bread. Histologic evaluation of the hepatic tissue showed the onset of inflammation in response to doxorubicin only in rats fed the modern durum wheat bread. CONCLUSION: Our data confirm that bread made from whole-grain Kamut khorasan protects rats from oxidative stress better than bread made from whole-grain durum wheat. This is consistent with their different antioxidant profiles. The type of wheat used for bread-making appeared to be the main determinant of the observed protective effect.

The antioxidant protection of CELLFOOD against oxidative damage in vitro.

CELLFOOD (CF) is an innovative nutritional supplement containing 78 ionic/colloidal trace elements and minerals combined with 34 enzymes and 17 amino acids, all suspended in a solution of deuterium sulfate. The aim of this study was to investigate, for the first time, the antioxidant properties of CF in vitro in different model systems. Three pathophysiologically relevant oxidants were chosen to evaluate CF protection against oxidative stress: hydrogen peroxide, peroxyl radicals, and hypochlorous acid. Both biomolecules (GSH and plasmid DNA) and circulating cells (erythrocytes and lymphocytes) were used as targets of oxidation. CF protected, in a dose-dependent manner, both GSH and DNA from oxidation by preserving reduced GSH thiol groups and supercoiled DNA integrity, respectively. At the same time, CF protected erythrocytes from oxidative damage by reducing cell lysis and GSH intracellular depletion after exposure to the oxidant agents. In lymphocytes, CF reduced the intracellular oxidative stress induced by the three oxidants in a dose-dependent manner. The overall in vitro protection of biomolecules and cells against free radical attacks suggests that CF might be a valuable coadjuvant in the prevention and treatment of various physiological and pathological conditions related to oxidative stress, from aging to atherosclerosis, from neurodegeneration to cancer.

Oxygen radical absorbance capacity of phycocyanin and phycocyanobilin from the food supplement Aphanizomenon flos-aquae.

The oxygen radical absorbance capacity (ORAC) assay has been widely used to quantify peroxyl radical scavenging capacity of pure antioxidant compounds and antioxidant plant/food extracts. However, it has never been applied to natural compounds derived from microalgae-based dietary supplements, namely, phycocyanin (PC) and phycocyanobilin (PCB), for which a strong radical scavenger activity has been documented. In this article, we applied the ORAC method to investigate the capacity of PC and PCB purified from the edible microalga Aphanizomenon flos-aquae to directly quench peroxyl radicals in comparison to well-known antioxidants molecules such as Trolox, ascorbic acid, and reduced glutathione. As a result, PCB was found to have the highest ORAC value (22.18 micromol of Trolox/micromol of compound), comparable to that of PC (20.33 micromol of Trolox/micromol of compound), hence confirming that PCB is mostly responsible for the scavenger activity of PC and making the protein a possible source of the antioxidant in vivo. Our data further corroborate the use of these natural compounds from A. flos-aquae as dietary antioxidant supplements in the treatment of clinical conditions related to oxidative stress.

Biomarkers of oxidation, inflammation and cartilage degradation in osteoarthritis patients undergoing sulfur-based spa therapies.

OBJECTIVES: To investigate the effects of sulfur-based spa therapies on oxidation, inflammation and cartilage degradation biomarkers in osteoarthritis (OA) patients. DESIGN AND METHODS: Analyses were performed before therapy (T0), after therapy (T1) and 1 month after its suspension (T2), in OA subjects undergoing mud bath treatments in combination (group A) or not (group B) with hydropinotherapy, and compared with those of patients not subjected to spa therapies (group C). RESULTS: No modifications in plasma/serum biomarker concentrations were observed throughout the study in non-treated patients, while a significant reduction in oxidation, inflammation and cartilage degradation parameters was evidenced in patients of group A. Group B presented a favorable biochemical profile at T1 but not at T2. CONCLUSIONS: To ensure the long term preservation of the chondroprotective effects of sulfur-based therapies, standard mud bath treatments should be associated with hydropinotherapy in order to maintain reduced oxidative, inflammatory and degradative stimuli longer.

Nutrients and nipple aspirate fluid composition: the breast microenvironment regulates protein expression and cancer aetiology.

The aetiology of breast cancer is complex and multifactorial, and may include diet and xenobiotic compounds. A change in diet affects nutrient levels in blood, but to what extent diet can affect micronutrient concentrations in the breast is not yet well established. Breast nipple aspirate fluids (NAF) can be non-invasively obtained from the breast in most women; it represents a biological tool to assess metabolic changes in the breast ductal microenvironment. A wide variation in biomolecular and hormonal composition of NAFs collected from healthy and breast cancer patient may be due to genetic and nutritional factors; however, micro- and macro-nutrients may influence the secretory status of these women, thus NAF composition and risk of breast carcinoma. The aim of this overview is to highlight the detrimental/beneficial role that diet-related compounds in nipple aspirate fluid can have in breast cancer risk.

Heparin affects matrix metalloproteinases and tissue inhibitors of metalloproteinases circulating in peripheral blood.

OBJECTIVES: Blood sampling/handling alters matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) expression. The aim of this study is to evaluate the effects of high molecular weight heparin on MMP and TIMP expression in blood. DESIGN AND METHODS: We analyzed by gelatin zymography and ELISA assays the effects of different heparin salts, dose- and time-dependence of MMP and TIMP concentrations in plasma and sera collected with and without clot-accelerator in plastic tubes from 50 healthy donors. RESULTS: The levels and zymography of MMP-2 did not show significant changes among all samples, and during time- and dose-dependent heparin treatments. MMP-9 and TIMP-2 expression were strongly affected by heparin, with significant increase of their content and gelatinolytic activity both in time- and in dose-dependent fashion. Addition of heparin allowed also the displacement of MMP-2 prodomain, favouring zymogen activation. CONCLUSIONS: Heparin has direct and indirect effects, altering MMP/TIMP complexes circulating in blood, and increasing the release of TIMP-2. To avoid misinterpretations due to MMP/TIMP complex alteration and MMP prodomain displacement, heparin should be cautiously used in blood collection procedures.