Exploring viral reservoir: The combining approach of cell sorting and droplet digital PCR.

Combined antiretroviral therapy (cART) blocks different steps of HIV replication and maintains plasma viral RNA at undetectable levels. The virus can remain in long-living cells and create a reservoir where HIV can restart replicating after cART discontinuation. A persistent viral production triggers and maintains a persistent immune activation, which is a well-known feature of chronic HIV infection, and contributes either to precocious aging, or to the increased incidence of morbidity and mortality of HIV positive patients. The new frontier of the treatment of HIV infection is nowadays eradication of the virus from all host cells and tissues. For this reason, it is crucial to have a clear and precise idea of where the virus hides, and which are the cells that keep it silent. Important efforts have been made to improve the detection of viral reservoirs, and new techniques are now giving the opportunity to characterize viral reservoirs. Among these techniques, a strategic approach based upon cell sorting and droplet digital PCR (ddPCR) is opening new horizons and opportunities of research. This review provides an overview of the methods that combine cell sorting and ddPCR for the quantification of HIV DNA in different cell types, and for the detection of its maintenance.

Emerging role of Lon protease as a master regulator of mitochondrial functions.

Lon protease is a nuclear-encoded, mitochondrial ATP-dependent protease highly conserved throughout the evolution, crucial for the maintenance of mitochondrial homeostasis. Lon acts as a chaperone of misfolded proteins, and is necessary for maintaining mitochondrial DNA. The impairment of these functions has a deep impact on mitochondrial functionality and morphology. An altered expression of Lon leads to a profound reprogramming of cell metabolism, with a switch from respiration to glycolysis, which is often observed in cancer cells. Mutations of Lon, which likely impair its chaperone properties, are at the basis of a genetic inherited disease named of the cerebral, ocular, dental, auricular, skeletal (CODAS) syndrome. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.

Ovarian cancer: can proteomics give new insights for therapy and diagnosis?

The study of the ovarian proteomic profile represents a new frontier in ovarian cancer research, since this approach is able to enlighten the wide variety of post-translational events (such as glycosylation and phosphorylation). Due to the possibility of analyzing thousands of proteins, which could be simultaneously altered, comparative proteomics represent a promising model of possible biomarker discovery for ovarian cancer detection and monitoring. Moreover, defining signaling pathways in ovarian cancer cells through proteomic analysis offers the opportunity to design novel drugs and to optimize the use of molecularly targeted agents against crucial and biologically active pathways. Proteomic techniques provide more information about different histological types of ovarian cancer, cell growth and progression, genes related to tumor microenvironment and specific molecular targets predictive of response to chemotherapy than sequencing or microarrays. Estimates of specificity with proteomics are less consistent, but suggest a new role for combinations of biomarkers in early ovarian cancer diagnosis, such as the OVA1 test. Finally, the definition of the proteomic profiles in ovarian cancer would be accurate and effective in identifying which pathways are differentially altered, defining the most effective therapeutic regimen and eventually improving health outcomes.

Tooth Germ Autotransplantation With 24 Months of Follow-up: A Case Report.

The autotransplantation of a third molar represents an alternative treatment solution for filling an edentulous space that may exist because of traumatic avulsion, agenesis, large carious processes, or other reasons, particularly in young patients. Autotransplantation can offer many benefits, including maintenance of a normally functioning periodontium, preservation of pulp vitality, and completion of root formation. This case report describes a successful autotransplantation of an open-apex maxillary third molar germ to replace a hopeless mandibular first molar in a growing patient. After 24 months of follow-up, the donor tooth showed physiological mobility, absence of infection and ankylosis, positive pulp vitality, and fully formed periodontal integration. Radiographic examination confirmed a remarkable radicular edification.

Molecular Pathways of Breast Cancer in Systemic Sclerosis: Exploratory Immunohistochemical Analysis from the Sclero-Breast Study.

Several authors reported an increased risk of cancer in SSc patients, including breast cancer (BC). Nevertheless, the mechanisms underlying this association have not yet been clarified. SSc and BC share several molecular pathways, which seem to play a common etiopathogenetic role. The previously published Sclero-Breast study demonstrated the development of BC with a good prognosis among these patients, which could be explained by an autoimmune background as a possible mechanism for limiting tumor extension. Here, we report the results of an IHC analysis of molecular pathways known to be common drivers for both diseases, with the aim to better define the mechanisms underlying a good prognosis of BC in patients affected by SSc. The analysis demonstrated higher TILs rates in all BC subgroups, with a high rate of PD-L1 expression especially in TNBC and HER2-positive BC, suggesting a less aggressive behavior in these patients compared to the general population. These results support a possible de-escalation strategy of cancer therapies in these fragile patients. These data could represent a starting point for future prospective studies based on the clinical application of these biomarkers with a larger sample size to promote a personalized and targeted oncological treatment for this specific subset of patients.

Protein expression patterns associated with advanced stage ovarian cancer.

This is a comparative proteomic study on biopsies from patients with ovarian cancer to identify potential diagnostic/prognostic biomarkers in both healthy and tumor tissue, interstitial fluid (normal interstitial fluid and tumoral interstitial fluid and peritoneal effusion. Protein expression/identification was evaluated by 2-DE and MS analysis: six proteins showed differential expression in tumoral interstitial fluid and tumor tissue compared to normal interstitial fluid and healthy tissue: five were found to be downregulated and identified as galectin 3, glutathione S-transferase A-2, retinol binding protein 1, phosphatidylethanolamine-binding protein and annexin 5, while the calgranulin, was significantly upregulated in all pathological samples, including the ascitic fluid. Validation of S100A8 overexpression in carcinoma tissue was obtained by immunohistochemistry. To our knowledge, this is the first study to report an over-expression of calgranulin by 2-DE associated with MS/MS analysis on surgical biopsy. The reduced expression of galectin 3 and retinol binding protein 1 in cystic fluid and serum of patients with early stage disease is confirmed in this study. The results highlight alterations in proteins that control cell-cycle progression and apoptosis, as well as factors that modulate the activity of signal transduction pathways. Moreover, this study suggests that calgranulin expression may be used as a diagnostic and/or prognostic biomarker.

The Burden of Cardio-Cerebrovascular Risk Factors: Differences Between Individual Risk and Population Risk.

INTRODUCTION: Cardio-cerebrovascular (CCV) disease contributes significantly to the global burden of disease, with dramatic consequences in terms of mortality and general health. Mitigate CCV risk factors is the key to reduce individual and population risk of CCV events. Evidence-based medicine and epidemiological investigations of risk factors are essential to optimize actions. AIM: To contribute to the knowledge of the burden of risk factors in determining CCV events in the individual patient and in the community. METHODS: Clinical data and risk factors were collected through a longitudinal survey (1999) as part of a larger epidemiology and cardiovascular prevention project, namely the "VIP (Valle dell'Irno Prevention) Project". We assessed the incidence of major cardiovascular events (MACE) and for each risk factor we calculated: prevalence, absolute risk, odds ratio (OR), additional risk (AR) = risk of exposed to the risk factor - risk of non-exposed, population attributable risk (PAR) = additional risk * prevalence, population attributable risk fraction (PAF) = PAR/total incidence of the disease. RESULTS: Comparing the MACE group with the non-MACE group, a statistically significant difference was found for the following: glomerular filtration rate (GFR), glucose and systolic blood pressure (SBP), BMI, diastolic blood pressure (DBP), cholesterol, triglycerides, creatinine and uric acid. GFR, glucose and SBP showed the highest OR. Age, creatinine, glycemia, SBP and uric acid were independent predictor of MACE. When calculating the PAF, the CCV risk factors with the greatest impact on MACE were: SBP (29.6%), triglyceridemia (19.4%) and metabolic syndrome (18.3%). CONCLUSION: The burden of risk factors on MACE changes substantially according to whether it is calculated in the single patient or in the population. It is crucial for physicians to take these differences into account when applying their own intervention to reduce CCV events.

Obesity in Postmenopausal Breast Cancer Patients: It Is Time to Improve Actions for a Healthier Lifestyle. The Results of a Comparison Between Two Italian Regions With Different "Presumed" Lifestyles.

BACKGROUND: Adult body fatness is a convincing risk factor for postmenopausal breast cancer. With the aim to compare the different breast cancer (BC) features in Northern and Southern Italy, we investigated the relationship between BMI and BC characteristic in two groups of patients referred in the Modena and Lecce breast units. MATERIALS AND METHODS: A retrospective analysis of a continuous series of BC patients referred to the Città di Lecce Hospital and the Modena Cancer Center, from January 2019 to December 2020 was performed. We identified four groups of BMI at BC diagnosis: underweight, BMI <18.5 kg/m2; normal weight, BMI ≥ 18.5-24.9 kg/m2; overweight, BMI ≥ 25.0-29.9 kg/m2; obese, BMI ≥30.0 kg/m2. BC characteristics and clinical outcomes were analyzed by the Kolmogorov-Smirnov test and Mann-Whitney U test; categorical data were compared using Pearson's chi-square test, and dicotomic data were compared by odds ratio. RESULTS: Nine hundred seventy-seven BC patients were included in the analysis. Overall, 470 were from Modena and 507 from Lecce. No differences were observed in the mean age of BC patients of Modena (61,42) and Lecce (62,08). No statistical differences between the two populations were shown in terms of tumor characteristics and pathological stage. Conversely, a statistical difference of BMI between the BC patients coming from Modena and Lecce (25.87 and 27.81, respectively; p = 0.000001) was found. BC patients diagnosed in Lecce at age ≥70 years had higher median BMI compared with the ones from Modena (p = 0.000002). The increased BMI in this aged population was also associated to larger tumor size (p = 0.040). CONCLUSION: The rate of overweight and obesity was higher in BC women living in Southern Italy, despite the presumed nutrition according to the so-called Mediterranean type dietary pattern. Unexpectedly, an increased BMI rate and a relationship with larger tumor size were found in Southern BC patients aged ≥70 years. Our findings strongly support the need for promoting a healthier lifestyle model in Italy, with the aim of reducing the rate of the obesity and, consequently, the increased risk of BC.

Clinical and Pathological Features of Breast Cancer in Systemic Sclerosis: Results from the Sclero-Breast Study.

Systemic Sclerosis (SSc) is a chronic disease associated with a 1.5-fold increase in cancer risk, including lung cancer, hematological malignancies, and breast cancer (BC). This is a retrospective study aiming to explore the clinical and pathological features of BC developed by SSc patients. A total of 54.5% of patients developed BC before SSc (median interval: 5 years), whereas 45.5% of patients developed BC after SSc (median delay: 8 years). A total of 93.1% of patients were diagnosed with an early stage tumor. Among invasive carcinomas, 70.8% presented with a low Mib1, 8.3% with a tubular histotype, and 42.8% with a Luminal A-like phenotype. A total of 66.6% of patients underwent breast-conserving surgery and 55.5% RT. A total of 40% of patients developed interstitial lung disease after RT and 20% diffuse cutaneous SSc. The cause of death of the six deceased patients was PAH. A significant association was observed between the use of immunosuppressive therapy and diffuse skin extension, negative ACA, positive Anti-Scl-70, and interstitial lung disease, but not BC status. SSc patients developed BC at a good prognosis, suggesting a de-escalation strategy of cancer therapies. In particular, ionizing radiation and chemotherapeuticals should be limited to higher-risk cases. Finally, proper screening is mandatory in order to allow for early cancer detection in SSc patients.

Epidemiologic Data of Vitamin D Deficiency and Its Implication in Cardio-Cerebrovascular Risk in a Southern Italian Population.

BACKGROUND: Vitamin D (25(OH)D) deficiency is a prevalent condition worldwide. However, the highest prevalence rates of 25(OH)D deficiency have been attributed to regions with higher latitude. A close association between 25(OH)D and cardio-cerebrovascular (CCV) risk factors and major health problems has been identified. AIM: To establish the prevalence of 25(OH)D deficiency and to investigate the relationship between 25(OH)D levels and CCV risk factors (blood cholesterol, triglycerides, glucose concentrations, body mass index, and systolic and diastolic blood pressure) in a cohort representative of Southern Italy. METHODS: The prevalence of 25(OH)D levels was evaluated in 1200 subjects aged 25-74 years (600 males and 600 females), enrolled in the "VIP" (from Italian for Irno Valley Prevention) Project, whereas multiple linear regression analysis was used to determine the relationship between 25(OH)D levels and CCV risk factors. RESULTS: Only 13.3% of females and 11.1% of males showed adequate serum concentrations of 25(OH)D (≥30 ng/ml), while 59.3% of females and 55.1% of males showed 25(OH)D deficient levels (<20 ng/ml). We observed an independent association between 25(OH)D concentrations and metabolic syndrome score, LDL cholesterol, HDL cholesterol, and corrected QT (cQT). CONCLUSIONS: We report a high prevalence of 25(OH)D deficiency across the largest Italian adult population studied so far and, in particular, the first across Southern Italy; furthermore, we provide data on the association between 25(OH)D deficiency and higher CCV risk factors.

Endogenous control of inflammation characterizes pregnant women with asymptomatic or paucisymptomatic SARS-CoV-2 infection.

SARS-CoV-2 infection can affect all human beings, including pregnant women. Thus, understanding the immunological changes induced by the virus during pregnancy is nowadays of pivotal importance. Here, using peripheral blood from 14 pregnant women with asymptomatic or mild SARS-CoV-2 infection, we investigate cell proliferation and cytokine production, measure plasma levels of 62 cytokines, and perform a 38-parameter mass cytometry analysis. Our results show an increase in low density neutrophils but no lymphopenia or gross alterations of white blood cells, which display normal levels of differentiation, activation or exhaustion markers and show well preserved functionality. Meanwhile, the plasma levels of anti-inflammatory cytokines such as interleukin (IL)-1RA, IL-10 and IL-19 are increased, those of IL-17, PD-L1 and D-dimer are decreased, but IL-6 and other inflammatory molecules remain unchanged. Our profiling of antiviral immune responses may thus help develop therapeutic strategies to avoid virus-induced damages during pregnancy.

Lifestyle Intervention on Body Weight and Physical Activity in Patients with Breast Cancer can reduce the Risk of Death in Obese Women: The EMILI Study.

: Background obesity and sedentary lifestyle have been shown to negatively affect survival in breast cancer (BC). The purpose of this study was to test the efficacy of a lifestyle intervention on body mass index (BMI) and physical activity (PA) levels among BC survivors in Modena, Italy, in order to show an outcome improvement in obese and overweight patients. METHODS: This study is a single-arm experimental design, conducted between November 2009 and May 2016 on 430 women affected by BC. Weight, BMI, and PA were assessed at baseline, at 12 months, and at the end of the study. Survival curves were estimated among normal, overweight, and obese patients. RESULTS: Mean BMI decreased from baseline to the end of the study was equal to 2.9% (p = 0.065) in overweight patients and 3.3% in obese patients (p = 0.048). Mean PA increase from baseline to the end of the study was equal to 125% (p < 0.001) in normal patients, 200% (p < 0.001) in overweight patients and 100% (p < 0.001) in obese patients. After 70 months of follow-up, the 5-year overall survival (OS) rate was 96%, 96%, and 93%, respectively in normal, obese, and overweight patients. Overweight patients had significantly worse OS than normal ones (HR = 3.69, 95%CI = 1.82-4.53 p = 0.027) whereas no statistically significant differences were seen between obese and normal patients (HR 2.45, 95%CI = 0.68-8.78, p = 0.169). CONCLUSIONS: A lifestyle intervention can lead to clinically meaningful weight loss and increase PA in patients with BC. These results could contribute to improving the OS in obese patients compared to overweight ones.

Increased plasma levels of mitochondrial DNA and pro-inflammatory cytokines in patients with progressive multiple sclerosis.

The role of damage-associated molecular patterns in multiple sclerosis (MS) is under investigation. Here, we studied the contribution of circulating high mobility group box protein 1 (HMGB1) and mitochondrial DNA (mtDNA) to neuroinflammation in progressive MS. We measured plasmatic mtDNA, HMGB1 and pro-inflammatory cytokines in 38 secondary progressive (SP) patients, 35 primary progressive (PP) patients and 42 controls. Free mtDNA was higher in SP than PP. Pro-inflammatory cytokines were increased in progressive patients. In PP, tumor necrosis factor-α correlated with MS Severity Score. Thus, in progressive patients, plasmatic mtDNA and pro-inflammatory cytokines likely contribute to the systemic inflammatory status.

Marked T cell activation, senescence, exhaustion and skewing towards TH17 in patients with COVID-19 pneumonia.

The immune system of patients infected by SARS-CoV-2 is severely impaired. Detailed investigation of T cells and cytokine production in patients affected by COVID-19 pneumonia are urgently required. Here we show that, compared with healthy controls, COVID-19 patients' T cell compartment displays several alterations involving naïve, central memory, effector memory and terminally differentiated cells, as well as regulatory T cells and PD1+CD57+ exhausted T cells. Significant alterations exist also in several lineage-specifying transcription factors and chemokine receptors. Terminally differentiated T cells from patients proliferate less than those from healthy controls, whereas their mitochondria functionality is similar in CD4+ T cells from both groups. Patients display significant increases of proinflammatory or anti-inflammatory cytokines, including T helper type-1 and type-2 cytokines, chemokines and galectins; their lymphocytes produce more tumor necrosis factor (TNF), interferon-γ, interleukin (IL)-2 and IL-17, with the last observation implying that blocking IL-17 could provide a novel therapeutic strategy for COVID-19.

Identification of protein clusters predictive of response to chemotherapy in breast cancer patients.

An attempt for the identification of potential biomarkers predictive of response to chemotherapy (CHT) in breast cancer patients has been performed by the use of two-dimensional electrophoresis and mass spectrometry analysis. Since growth and progression of tumor cells depend also on stromal factors in the microenvironment, we choose to investigate the proteins secreted in Tumor Interstitial Fluid (TIF) and in Normal Interstitial Fluids (NIF). One-hundred and twenty-two proteins have been analyzed and a comparison was also made between the proteomic profile of responders versus nonresponders to CHT. At baseline, proteins isolated in TIF and NIF of all the 28 patients show significant differences in expression. Two clusters of proteins, differentially expressed in TIF with respect to NIF were found. Most significant is the decreased expression in TIF of CRYAB. In the protein metabolism group, also FIBB was found decreased. Some proteins involved in energy pathways were overexpressed (PGAM-1, ALDO A, PGK1, G3Pcn), while some other were down-regulated (CAH2, G3Pdx, PRDX6, TPIS). The same trend was observed for signal transduction proteins, with 14-3-3-Z overexpressed, and ANXA2 and PEBP 1 down-regulated. Moreover, an analysis has been conducted comparing protein expression in interstitial fluids of responders and nonresponders, irrespective of TIF or NIF source. This analysis lead us to identify two clusters of proteins with a modified expression, which might be predictive of response to CHT. In responders, an increase in expression of LDHA, G3Pdx, PGK1sx (energy pathways), VIME (cell growth and maintenance) and 14-3-3-Z (signal transduction), coupled with a decreased expression of TPIS, CAH 2, G3Psx, PGK 1dx (energy pathways), TBB5 (cell growth and maintenance), LDHB and FIBB (protein metabolism), was found. We observed that CHT modifies the expression of these cluster proteins since, after treatment, their expression in TIF of responder is generally decreased. Patients not responding to CHT show an unchanged expression pattern in TIF, with the exception of protein 14-3-3-Z, which is overexpressed, and a decreased expression in NIF of several cluster proteins. In conclusion, the identification of protein clusters associated with response to CHT might be important for predicting the efficacy of a specific antineoplastic drug and for the development of less empiric strategies in choosing the therapy to be prescribed to the single patient.

Genomic alterations at the basis of treatment resistance in metastatic breast cancer: clinical applications.

The standard of care for breast cancer has gradually evolved from empirical treatments based on clinical-pathological characteristics to the use of targeted approaches based on the molecular profile of the tumor. Consequently, an increasing number of molecularly targeted drugs have been developed. These drugs target specific alterations, called driver mutations, which confer a survival advantage to cancer cells. To date, the main challenge remains the identification of predictive biomarkers for the selection of the optimal treatment. On this basis, we evaluated a panel of 25 genes involved in the mechanisms of targeted treatment resistance, in 16 primary breast cancers and their matched recurrences, developed during treatment. Overall, we found a detection rate of mutations higher than that described in the literature. In particular, the most frequently mutated genes were ERBB2 and those involved in the PI3K/AKT/mTOR and the MAPK signaling pathways. The study revealed substantial discordances between primary tumors and metastases, stressing the need for analysis of metastatic tissues at recurrence. We observed that 85.7% of patients with an early-stage or locally advanced primary tumor showed at least one mutation in the primary tumor. This finding could explain the subsequent relapse and might therefore justify more targeted adjuvant treatments. Finally, the mutations detected in 50% of relapsed tissues could have guided subsequent treatment choices in a different way. This study demonstrates that mutation events may be present at diagnosis or arise during cancer treatment. As a result, profiling primary and metastatic tumor tissues may be a major step in defining optimal treatments.

LonP1 Differently Modulates Mitochondrial Function and Bioenergetics of Primary Versus Metastatic Colon Cancer Cells.

Mitochondrial Lon protease (LonP1) is a multi-function enzyme that regulates mitochondrial functions in several human malignancies, including colorectal cancer (CRC). The mechanism(s) by which LonP1 contributes to colorectal carcinogenesis is not fully understood. We found that silencing LonP1 leads to severe mitochondrial impairment and apoptosis in colon cancer cells. Here, we investigate the role of LonP1 in mitochondrial functions, metabolism, and epithelial-mesenchymal transition (EMT) in colon tumor cells and in metastasis. LonP1 was almost absent in normal mucosa, gradually increased from aberrant crypt foci to adenoma, and was most abundant in CRC. Moreover, LonP1 was preferentially upregulated in colorectal samples with mutated p53 or nuclear ß-catenin, and its overexpression led to increased levels of ß-catenin and decreased levels of E-cadherin, key proteins in EMT, in vitro. LonP1 upregulation also induced opposite changes in oxidative phosphorylation, glycolysis, and pentose pathway in SW480 primary colon tumor cells when compared to SW620 metastatic colon cancer cells. In conclusion, basal LonP1 expression is essential for normal mitochondrial function, and increased LonP1 levels in SW480 and SW620 cells induce a metabolic shift toward glycolysis, leading to EMT.

Hyperuricemia as an independent risk factor for major cardiovascular events: a 10-year cohort study from Southern Italy.

AIMS: To date, whether hyperuricemia may represent a marker or an independent risk factor for cardiovascular disease remains unclear. This study aimed at assessing the role of hyperuricemia in the onset of major cardiovascular events (MACE). METHODS: Baseline clinical data were collected through a 1998/1999 longitudinal survey as part of the larger Valle dell'Irno Prevenzione Project. Ten years later, MACE incidence was evaluated. RESULTS: A total of 1175 patients (50% men, aged 25-74 years) completed the study. At least one MACE was reported by 135 patients, whose mean uric acid values were significantly higher compared with patients without events (6.0 ±â€Š4.8 and 4.6 ±â€Š4.0 mg/dl, respectively; P < 0.01). Patients with uric acid values of at least 6 mg/dl (prevalence of 14.6%) had significantly lower levels of high-density lipoprotein cholesterol and increased values of BMI, blood pressure (BP), cholesterol, triglycerides, white blood cells, complement component 3 (C3) and creatinine. After subgrouping patients in tertiles and considering the first one as reference [odds ratio (OR): 1], the OR (95% confidence interval) was 1.44 (0.7-2.9) in the second and 2.2 (1.3-3.5) in the third tertile, respectively. Confounder-adjusted stepwise linear regression revealed uric acid, age, creatinine, glucose and systolic BP as independent predictors of MACE. Diastolic BP and creatinine were independently correlated with uric acid in the entire population, diastolic BP only in men and BMI, creatinine, age and C3 in women. CONCLUSION: Hyperuricemia was shown to be a strong independent risk factor for MACE and should be included in cardiovascular prevention strategies. Whether hypouricemic drugs can decrease cardiovascular disease risk warrants further studies.

Alpha-tocopherol amplifies benzoyl peroxide free radical decomposition in a chemical system.

Benzoyl peroxide is commonly used in the treatment of acne, even though some adverse effects have been reported, probably mediated by the formation of peroxide-derived free radicals and the depletion of antioxidants. In the present work we have studied, in a chemical system, the effect of alpha-tocopherol on benzoyl peroxide radical decomposition to analyse the presence of an interaction between these two compounds, leading to an enhanced peroxide-cytotoxicity, as we have previously reported. Under our experimental conditions alpha-tocopherol strongly amplified the peroxide free radical decomposition occurring either in the presence or in the absence of UV irradiation, and lead to the formation of an unknown radical species in addition to benzoyloxy, phenyl and tocopheroxyl free radicals. The results of this study show that the enhancement of benzoyl peroxide toxicity in cells exposed simultaneously to this peroxide and alpha-tocopherol, is likely due to the generation of the detected radical species.

Antioxidant effect of FeAOX-6 on free radical species produced during iron catalyzed breakdown of tert-butyl hydroperoxide.

There is a body of evidences demonstrating, in biological systems, a cooperative interaction between tocopherols and carotenoids. FeAOX-6 is a novel antioxidant that combines the chroman head of alpha-tocopherol and a fragment of the isoprenyl chain of lycopene. We have tested its antioxidant effect on different radical species generated in a chemical system, where peroxyl, alkoxyl and methyl radicals are generated by the ferrous ion-mediated decomposition of tert-butyl hydroperoxide. We found that FeAOX-6 has the same effectiveness of alpha-tocopherol in quenching peroxyl radical with no contribution by lycopene. The antioxidant activity of FeAOX-6 on alkoxyl and methyl radicals is comparable to that of the equimolar mixture of the parent compounds. Lycopene is able to quench alkoxyl radical, while it has no effect on peroxyl radical, showing a different antioxidant activity compared to other carotenoids, such as beta-carotene and lutein.