Liudmila Korkina

Xenobiotic sensor- and metabolism-related gene variants in environmental sensitivity-related illnesses: a survey on the Italian population.

In the environmental sensitivity-related illnesses (SRIs), multiple chemical sensitivity (MCS), chronic fatigue syndrome (FCS), and fibromyalgia (FM), the search for genetic polymorphisms of phase I/II xenobiotic-metabolizing enzymes as suitable diagnostic biomarkers produced so far inconclusive results, due to patient heterogeneity, geographic/ethnic differences in genetic backgrounds, and different methodological approaches. Here, we compared the frequency of gene polymorphisms of selected cytochrome P450 (CYP) metabolizing enzymes and, for the first time, the frequency of the xenobiotic sensor Aryl hydrocarbon receptor (AHR) in the three cohorts of 156 diagnosed MCS, 94 suspected MCS, and 80u2009FM/FCS patients versus 113 healthy controls. We found significantly higher frequency of polymorphisms CYP2C9∗2, CYP2C9∗3, CYP2C19∗2, CYP2D6∗4 and CYP2D6∗41 in patients compared with controls. This confirms that these genetic variants represent a genetic risk factor for SRI. Moreover, the compound heterozygosity for CYP2C9∗2 and ∗3 variants was useful to discriminate between either MCS or FM/CFS versus SMCS, while the PM ∗41/∗41 genotype discriminated between MCS and either SMCS or FM/CFS. The compound heterozygosity for CYP2C9 ∗1/∗3 and CYP2D6 ∗1/∗4 differentiated MCS and SMCS cases from FM/CFS ones. Interestingly, despite the distribution of the AHR Arg554Lys variant did not result significantly different between SRI cases and controls, it resulted useful for the discrimination between MCS and SMCS cases when considered within haplotypes in combination with CYP2C19 ∗1/∗2 and CYP2D6 ∗1/∗4. Results allowed us to propose the genotyping for these specific CYP variants, together with the AHR Arg554Lys variant, as reliable, cost-effective genetic parameters to be included in the still undefined biomarkers panel for laboratory diagnosis of the main types of environmental-borne SRI.

Integrated Haematological Profiles of Redox Status, Lipid, and Inflammatory Protein Biomarkers in Benign Obesity and Unhealthy Obesity with Metabolic Syndrome

The pathogenesis of obesity (OB) and metabolic syndrome (MetS) implies free radical-, oxidized lipid- (LOOH-), and inflammatory cytokine-mediated altered pathways in target organs. Key elements of the transition from benign OB to unhealthy OB+MetS remain unclear. Here, we measured a panel of redox, antioxidant, and inflammation markers in the groups of OB patients (67 with, 45 without MetS) and 90 controls. Both OB groups displayed elevated levels of adipokines and heavy oxidative stress (OS) evidenced by reduced levels of glutathione, downregulated glutathione-S-transferase, increased 4-hydroxynonenal-protein adducts, reactive oxygen species, and membrane-bound monounsaturated fatty acids (MUFA). Exclusively in OB+MetS, higher-than-normal glutathione peroxidase activity, tumor necrosis factor-α, and other proinflammatory cytokines/chemokines/growth factors were observed; a combination of high adipokine plasminogen activator inhibitor-1 and MUFA was consistent with increased cardiovascular risk. The uncomplicated OB group showed features of adaptation to OS such as decreased levels of vitamin E, activated superoxide dismutase, and inhibited catalase, suggesting H2O2 hyperproduction. Proinflammatory cytokine pattern was normal, except few markers like RANTES, a suitable candidate for therapeutic approaches to prevent a setting of MetS by inhibition of LOOH-primed leukocyte chemotaxis/recruitment to target tissues.

Metabolic and Genetic Screening of Electromagnetic Hypersensitive Subjects as a Feasible Tool for Diagnostics and Intervention

Growing numbers of “electromagnetic hypersensitive” (EHS) people worldwide self-report severely disabling, multiorgan, non-specific symptoms when exposed to low-dose electromagnetic radiations, often associated with symptoms of multiple chemical sensitivity (MCS) and/or other environmental “sensitivity-related illnesses” (SRI). This cluster of chronic inflammatory disorders still lacks validated pathogenetic mechanism, diagnostic biomarkers, and management guidelines. We hypothesized that SRI, not being merely psychogenic, may share organic determinants of impaired detoxification of common physic-chemical stressors. Based on our previous MCS studies, we tested a panel of 12 metabolic blood redox-related parameters and of selected drug-metabolizing-enzyme gene polymorphisms, on 153 EHS, 147 MCS, and 132 control Italians, confirming MCS altered (P < 0.05–0.0001) glutathione-(GSH), GSH-peroxidase/S-transferase, and catalase erythrocyte activities. We first described comparable—though milder—metabolic pro-oxidant/proinflammatory alterations in EHS with distinctively increased plasma coenzyme-Q10 oxidation ratio. Severe depletion of erythrocyte membrane polyunsaturated fatty acids with increased ω6/ω3 ratio was confirmed in MCS, but not in EHS. We also identified significantly (P = 0.003) altered distribution-versus-control of the CYP2C19∗1/∗2 SNP variants in EHS, and a 9.7-fold increased risk (OR: 95% C.I. = 1.3–74.5) of developing EHS for the haplotype (null)GSTT1 + (null)GSTM1 variants. Altogether, results on MCS and EHS strengthen our proposal to adopt this blood metabolic/genetic biomarkers panel as suitable diagnostic tool for SRI.

Redox Control of Multidrug Resistance and Its Possible Modulation by Antioxidants.

Clinical efficacy of anticancer chemotherapies is dramatically hampered by multidrug resistance (MDR) dependent on inherited traits, acquired defence against toxins, and adaptive mechanisms mounting in tumours. There is overwhelming evidence that molecular events leading to MDR are regulated by redox mechanisms. For example, chemotherapeutics which overrun the first obstacle of redox-regulated cellular uptake channels (MDR1, MDR2, and MDR3) induce a concerted action of phase I/II metabolic enzymes with a temporal redox-regulated axis. This results in rapid metabolic transformation and elimination of a toxin. This metabolic axis is tightly interconnected with the inducible Nrf2-linked pathway, a key switch-on mechanism for upregulation of endogenous antioxidant enzymes and detoxifying systems. As a result, chemotherapeutics and cytotoxic by-products of their metabolism (ROS, hydroperoxides, and aldehydes) are inactivated and MDR occurs. On the other hand, tumour cells are capable of mounting an adaptive antioxidant response against ROS produced by chemotherapeutics and host immune cells. The multiple redox-dependent mechanisms involved in MDR prompted suggesting redox-active drugs (antioxidants and prooxidants) or inhibitors of inducible antioxidant defence as a novel approach to diminish MDR. Pitfalls and progress in this direction are discussed.

Skin Antiageing and Systemic Redox Effects of Supplementation with Marine Collagen Peptides and Plant-Derived Antioxidants: A Single-Blind Case-Control Clinical Study

Recently, development and research of nutraceuticals based on marine collagen peptides (MCPs) have been growing due to their high homology with human collagens, safety, bioavailability through gut, and numerous bioactivities. The major concern regarding safety of MCPs intake relates to increased risk of oxidative stress connected with collagen synthesis (likewise in fibrosis) and to ROS production by MCPs-stimulated phagocytes. In this clinical-laboratory study, fish skin MCPs combined with plant-derived skin-targeting antioxidants (AO) (coenzyme Q10 + grape-skin extract + luteolin + selenium) were administered to volunteers (n = 41). Skin properties (moisture, elasticity, sebum production, and biological age) and ultrasonic markers (epidermal/dermal thickness and acoustic density) were measured thrice (2 months before treatment and before and after cessation of 2-month oral intake). The supplementation remarkably improved skin elasticity, sebum production, and dermal ultrasonic markers. Metabolic data showed significant increase of plasma hydroxyproline and ATP storage in erythrocytes. Redox parameters, GSH/coenzyme Q10 content, and GPx/GST activities were unchanged, while NO and MDA were moderately increased within, however, normal range of values. Conclusions. A combination of MCPs with skin-targeting AOs could be effective and safe supplement to improve skin properties without risk of oxidative damage.

Meristem Plant Cells as a Sustainable Source of Redox Actives for Skin Rejuvenation

Recently, aggressive advertisement claimed a “magic role” for plant stem cells in human skin rejuvenation. This review aims to shed light on the scientific background suggesting feasibility of using plant cells as a basis of anti-age cosmetics. When meristem cell cultures obtained from medicinal plants are exposed to appropriate elicitors/stressors (ultraviolet, ultrasound ultraviolet (UV), ultrasonic waves, microbial/insect metabolites, heavy metals, organic toxins, nutrient deprivation, etc.), a protective/adaptive response initiates the biosynthesis of secondary metabolites. Highly bioavailable and biocompatible to human cells, low-molecular weight plant secondary metabolites share structural/functional similarities with human non-protein regulatory hormones, neurotransmitters, pigments, polyamines, amino-/fatty acids. Their redox-regulated biosynthesis triggers in turn plant cell antioxidant and detoxification molecular mechanisms resembling human cell pathways. Easily isolated in relatively large quantities from contaminant-free cell cultures, plant metabolites target skin ageing mechanisms, above all redox imbalance. Perfect modulators of cutaneous oxidative state via direct/indirect antioxidant action, free radical scavenging, UV protection, and transition-metal chelation, they are ideal candidates to restore photochemical/redox/immune/metabolic barriers, gradually deteriorating in the ageing skin. The industrial production of plant meristem cell metabolites is toxicologically and ecologically sustainable for fully “biological” anti-age cosmetics.

Effects of Standardised Fermented Papaya Gel on Clinical Symptoms, Inflammatory Cytokines, and Nitric Oxide Metabolites in Patients with Chronic Periodontitis: An Open Randomised Clinical Study.

The clinical efficacy of topical administration of standardised fermented papaya gel (SFPG), known to have antioxidant and anti-inflammatory properties, versus conventional therapy was evaluated in a group of 84 patients with moderate-to-severe periodontitis, randomly assigned to control group (n = 45) undergoing traditional pharmacologic/surgical protocols or to experimental group (n = 39), additionally treated with intragingival pocket SFPG (7u2009g) applications (15u2009min daily for 10 days). Patients undergoing SFPG treatment showed significant (P < 0.05), durable improvement of three major clinical indices of disease severity: reduced bleeding (day 7), plaque and gingival conditions (day 14), and consistent gingival pocket depth reduction (day 45). Proinflammatory nitric oxide metabolites reached normal values in plasma (day 14) and gingival crevicular fluid (GCF) at day 45 with SFPG applications compared to controls that did not reach normalisation. Levels of highly increased proinflammatory (IL-1B, IL-6) and suppressed anti-inflammatory (IL-10) cytokines normalised in the SFPG group by days 14 (plasma) and 45 (GCF), but never in the control group. Although not acting directly as antibiotic, SFPG acted in synergy with human granulocytes blocking adaptive catalase induction in S. aureus in response to granulocyte-derived oxidative stress, thus enhancing intracellular bacterial killing.

Is There a Role for Antioxidants in the Prevention of Infection-Associated Carcinogenesis and in the Treatment of Infection-Driven Tumors?

Causative connections between infections and cancer are ascertained for several types of viruses, bacteria, and parasites. The mechanisms of cancer induction in chronically infected inflamed tissues strongly implicate oxygen- and nitrogen-centered reactive species, and an impairment of redox-sensitive molecular pathways involved in the tumorigenic transformation, tumor growth, altered immune defense, and in the mechanisms of tumor cell death and survival. Here, we briefly reviewed mechanistic data on carcinogenesis and tumor progression of three major infection-associated tumors, human papillomavirus-induced cervical cancer, hepatitis B virus-positive hepatocarcinoma, and Helicobacter pylori-positive gastric cancer. Notwithstanding the contradictory results of clinical studies on cancer chemoprevention with long-term, high dosage antioxidant vitamin/micronutrient supplementation, natural and synthetic agents with proven capacity to affect redox-dependent molecular pathways still hold the promise for preventing/delaying carcinogenesis initiation, as well as the overt malignancy evolution from dysplastic/aplastic stages. Novel directions for a targeted antioxidant-based approach to the reduction of persistent infection-driven cancer risk stems from the current knowledge of critical factors in the host-microbe interaction leading to oncogenesis. An emerging role of redox active substances in the chemotherapy of tumors relies on their stimulating effects towards TRAIL-related apoptosis and the induction of intracellular oxidative stress.

Clinical and Laboratory Assessment of Supplementation with Marine Collagen Peptides and Selected Antioxidants in Men with Mild-to-Moderate Erectile Dysfunction

Objectives: Notwithstanding great progress in the management of erectile dysfunction (ED) by phosphodiesterase inhibitors, safety concerns hinder their routine use in men with mild-to-moderate forms. Several plant-derived supplements have been proven acceptable substituents of conventional anti-ED drugs. Most anti-ED drugs/supplements act through nitric oxide (NO)-dependent molecular pathways, due to NO-induced smooth muscle relaxation of the local Corpus cavernosum vessels. A randomised single-blind self-controlled clinical investigation recently showed that dietary supplementation with marine collagen peptides (MCP) in combination with selected antioxidants remarkably enhanced nitrite/nitrate plasma levels along with skin rejuvenation and general energising (hormesis-like) effects. This pilot study was designed to reveal possible clinical action of this supplement towards ED and its mechanisms. nMethods: Fifteen otherwise healthy men (age range 55-61 years), free of sex organ diseases/malformations, diabetes or pre-diabetes, atherosclerosis, metabolic syndrome, cardio-vascular diseases or testosterone deficiency suffering from the mild-to-moderate erectile dysfunction diagnosed by the International Index of Erectile Function (IIEF-5 ≤ 20) were recruited for a pilot, clinical trial. The participants were given 2 capsules containing MCP +antioxidants a day for 30 consecutive days. Several functions of circulating phagocytes (granulocytes and monocytes), plasma levels of macrophage-targeting cytokines and nitrites/nitrates, expression of genes encoding inducible and endothelial nitric oxide synthase (iNOS and eNOS, respectively) and ATP content in phagocytes, and activity of glutathione peroxidase (GPX) in erythrocytes were recorded twice, at enrolment and at the cessation of the oral supplementation. Eighteen age-matched men without ED and 41 healthy subjects of both sexes (age range 20-65 years) served as controls. nResults: The supplementation was proven safe, not causing any adverse reaction. The IIEF-5 score was increased in 100% of participants, of 3-4 points on average. The MCP+antioxidants supplementation lead to activation of phagocyte defence functions (phagocytosis, intracellular bacterial killing, and reactive oxygen species production), to increased plasma levels of nitrites/nitrates, TNF-alpha and INF-gamma, to increased phagocyte levels of ATP, and to up-regulation of iNOS RNA. Although statistically significantly increased, these parameters remained within the normal range of values. There were no changes in the eNOS expression, GPX activity, and IL-10 levels. nDiscussion: We suggest a novel mechanism of possible regulation of penile erection through the initial selective stimulation of Toll-like receptors on circulating phagocytes, to convert them into defensive M1 cells producing enhanced quantities of TNF-alpha and INF-gamma, along with a hormesis-like moderate induction of iNOS. The measured increase of ATP levels might facilitate phagocyte NO release by the interaction with adenosine receptors. nConclusions: For the first time, marine collagen peptides combined with selected antioxidants are shown to have pro-erectile effects, through different mechanisms than those described previously. This oral supplementation could be considered as a safe and effective alternative to anti-ED drugs in the case of mild-to-moderate ED. More mechanistic studies are needed, along with larger-scale multi-centre placebo-controlled clinical trials.

Modulation of Oxidative Stress: Pharmaceutical and Pharmacological Aspects

Notwithstanding the fact that the multiple roles of oxidative stress in human biology and pathology have been intensely discussed over the last half century, the problem is still far beyond our full comprehension. Thus, in a comparatively short history of oxidative medicine, the roles of two major heroes, free radicals and antioxidants, have been entirely redefined. Free radicals and other reactive oxygen and nitrogen species, widely recognized two-three decades ago as absolute evils leading to and/or accompanying damage to biologically important molecules and structures, have been recently transformed into positive actors, in the appreciation of their essential impact in the intracellular signaling on the organisms defense against biotic and abiotic stresses. Several original research papers published in this special issue have been focused on this subject. The evidence for detrimental cross interaction of reactive oxygen and nitrogen species was shown in a single clinical case report of rare human disease (Lebers Hereditary Optic Neuropathy (M. Falabella et al.)). The chronic change in the NO homeostasis and enhanced superoxide availability contributed to dysfunction of peripheral blood mononuclear cells derived from a patient due to a cooperative action of nitrosative and oxidative stresses in driving on the genetically determined pathology. Relations between endothelial nitric oxide synthase genotypes and oxidative stress markers in patients with larynx cancer were studied in an original research (K. Yanar et al.). The results indicated a potential relationship among G894T polymorphism of NOS3 and impaired redox homeostasis that may influence the risk of laryngeal cancer. An interesting mechanism of adaptation to oxidative stress evolved in enterohemorrhagic Escherichia coli, consisting of upregulation of Shiga toxin production by prophages of the bacteria in response to H 2 O 2 excretion by infected human neutrophils, was described by K. Licznerska and coauthors. The intestinal haemorrhage induced by this type of bacteria depends mainly on Shiga toxin cytotoxicity. This way enterohemorrhagic Escherichia coli become tolerant to natural redox-based antibacterial defense of the host organism. One could assume that the modulation of hydrogen peroxide production by human neutrophils could be a promising strategy against this type of bacterial virulence/toxicity. The role of the exo-xis region of the bacterial genome in the induction of Shiga toxin-converting prophages is further elucidated by the same group of authors (K. Licznerska and coauthors). Unfortunately, the great hope that direct antioxidants could be the panacea resolving practically all health problems has vanished, due to the growing number of …