Flexitarians in Brazil: Who are they, what do they eat, and why?

In this study, we conducted the first scientific investigation focusing on Brazilian flexitarians, aiming to characterize their socio-economic and demographic profiles, motivations for adopting flexitarianism, the frequency of animal-based meat consumption, and the primary meat substitutes they consume. To accomplish this, we distributed an online questionnaire with the assistance of university students and researchers from various regions of the country. Data were collected from 1029 individuals in Brazil who self-identified as flexitarians. Our findings reveal that the flexitarian dietary model is primarily adopted by women, constituting 76% of the sample (n = 786). Their motivations include concerns about the environmental impact of meat consumption (n = 361, 35%), personal health (n = 344, 33%), and animal welfare (n = 219, 21%). Flexitarians exhibit varying consumption patterns, which can be categorized into three groups: light flexitarians (consuming meat 36 times a week), medium flexitarians (consuming meat 7 times a week), and heavy flexitarians (consuming meat 4 times a week). The flexitarian dietary pattern is characterized by reduced beef consumption (less than 2 times per week) and higher consumption of chicken (3 times per week). It is complemented by plant-based protein sources and eggs as the primary meat substitutes. The recognition of legumes as the principal meat substitutes opens avenues for an expanded discussion on sustainable food systems and alternative meat products in Brazil. This provides opportunities to enhance the availability and accessibility of these foods and to develop nutritional interventions that prioritize plant-based proteins.

ß-Lapachone Increases Survival of Septic Mice by Regulating Inflammatory and Oxidative Response.

Sepsis is characterized by a dysregulated immune response to infection characterized by an early hyperinflammatory and oxidative response followed by a subsequent immunosuppression phase. Although there have been some advances in the treatment of sepsis, mortality rates remain high, urging for the search of new therapies. ß-Lapachone (ß-Lap) is a natural compound obtained from Tabebuia avellanedae Lorentz ex Griseb. with several pharmacological properties including bactericidal, anti-inflammatory, and antioxidant activity. Thus, the aim of this study was to evaluate the effects of ß-Lap in a mouse sepsis model. To this, we tested two therapeutic protocols in mice submitted to cecal ligation and puncture- (CLP-) induced sepsis. First, we found that in pretreated animals, ß-Lap reduced the systemic inflammatory response and improved bacterial clearance and mouse survival. Moreover, ß-Lap also decreased lipid peroxidation and increased the total antioxidant capacity in the serum and peritoneal cavity of septic animals. In the model of severe sepsis, the posttreatment with ß-Lap was able to increase the survival of animals and maintain the antioxidant defense function. In conclusion, the ß-Lap was able to increase the survival of septic animals by a mechanism involving immunomodulatory and antioxidant protective effects.

Phytostabilization of Pb and Cd polluted soils using Helianthus petiolaris as pioneer aromatic plant species.

The area of soils polluted with heavy metals is increasing due to industrialization and globalization. Aromatic plant species can be a suitable alternative way for agricultural valorization and phytomanagement of such soils by the commercialization of essential oils avoiding risks for the food chain. The potential of growing Helianthus petiolaris in heavy metal polluted soils was assessed in pot experiments using spiked soils and soils from a shooting range. In terms of phytostabilization, H. petiolaris could grow in soils containing 1000 mg/kg Pb2+, 50 mg/kg Cd2+, accumulating more than three times the soil Cd content in the aerial parts and translocating significant amounts of Pb to the aerial parts when growing in soils polluted with up to 500 mg/kg Pb. When phytostabilization is considered, phytotoxicity of heavy metals strongly depends on the rhizospheric microbial communities, either by mitigating trace element phytotoxicity or promoting plant growth via phytohormone production. So, the effects of heavy metals on the diversity of the rhizospheric bacterial community were assessed using DNA-fingerprinting.

Aerobic Physical Exercise as a Neuroprotector Strategy for Ethanol Binge-Drinking Effects in the Hippocampus and Systemic Redox Status in Rats.

The heavy and episodic EtOH drinking pattern, equivalent to weekend consumption, characterizes the binge-drinking pattern and promotes a misbalance of encephalic metabolic functions, concurring to neurodegeneration and cerebral dysfunction. And for being a legal drug, it has global public health and social relevance. In this way, we aimed to investigate the effects of physical training, in a treadmill, on the deleterious effects of EtOH on hippocampal functions, related to memory and learning. For this, we used 40 Wistar rats, divided into four groups: Control group, Trained group (trained animals with doses of distilled water), EtOH group (nontrained animals with doses of 3 g/kg/day of EtOH, 20% w/v), and Trained+EtOH group (trained animals exposed to EtOH). The physical exercise was performed by running on a treadmill for 5 days a week for 4 weeks, and all doses of EtOH were administered through intragastric gavage in four repeated cycles of EtOH in binge. After the experimental period, the animals were submitted to the object recognition task and Morris water maze test, and after being euthanized, the blood and hippocampus were collected for Trolox Equivalent Antioxidant Capacity (TEAC), Reduced Glutathione Content (GSH), and Nitrite and Lipid Peroxidation (LPO) level measurements. Our results showed that EtOH caused marked oxidative stress and mnemonic damage, and the physical exercise promoted neuroprotective effects, among them, the modulation of oxidative biochemistry in plasma (by restoring GSH levels) and in the hippocampus (by reducing LPO levels and increasing antioxidant parameters) and cognitive function improvement. Therefore, physical exercise can be an important prophylactic and therapeutic tool in order to ameliorate and even prevent the deleterious effects of EtOH on cognitive functions.

Physical Exercise Attenuates Oxidative Stress and Morphofunctional Cerebellar Damages Induced by the Ethanol Binge Drinking Paradigm from Adolescence to Adulthood in Rats.

Ethanol (EtOH) binge drinking is characterized by high EtOH intake during few hours followed by withdrawal. Protection strategies against the damages generated by this binge are poorly explored. Thus, this study is aimed at investigating the protective role of treadmill physical exercise (PE) on the damage caused after repeated cycles of binge-like EtOH exposure in the oxidative biochemistry, morphology, and cerebellar function of rats from adolescence to adulthood. For this, animals were divided into four groups: control group (sedentary animals with doses of distilled water), exercised group (exercised animals with doses of distilled water), EtOH group (sedentary animals with doses of 3 g/kg/day of EtOH, 20% w/v), and exercised+EtOH group (exercised animals with previous mentioned doses of EtOH). The PE occurred on a running treadmill for 5 days a week for 4 weeks, and all doses of EtOH were administered through intragastric gavage in four repeated cycles of EtOH in a binge-like manner. After the EtOH protocol and PE, animals were submitted to open field and beam walking tests. In sequence, the cerebellums were collected for the biochemical and morphological analyses. Biochemical changes were analyzed by measurement of Trolox equivalent antioxidant capacity (TEAC), reduced glutathione content measurements (GSH), and measurement of nitrite and lipid peroxidation (LPO). In morphological analyses, Purkinje cell density evaluation and immunohistochemistry evaluation were measured by antimyelin basic protein (MBP) and antisynaptophysin (SYP). The present findings demonstrate that the binge drinking protocol induced oxidative biochemistry misbalance, from the decrease of TEAC levels and higher LPO related to tissue damage and motor impairment. In addition, we have shown for the first time that treadmill physical exercise reduced tissue and functional alterations displayed by EtOH exposure.

Hyperthermia-mediated drug delivery induces biological effects at the tumor and molecular levels that improve cisplatin efficacy in triple negative breast cancer.

Triple negative breast cancer is an aggressive disease that accounts for at least 15% of breast cancer diagnoses, and a disproportionately high percentage of breast cancer related morbidity. Intensive research efforts are focused on the development of more efficacious treatments for this disease, for which therapeutic options remain limited. The high incidence of mutations in key DNA repair pathways in triple negative breast cancer results in increased sensitivity to DNA damaging agents, such as platinum-based chemotherapies. Hyperthermia has been successfully used in breast cancer treatment to sensitize tumors to radiation therapy and chemotherapy. It has also been used as a mechanism to trigger drug release from thermosensitive liposomes. In this study, mild hyperthermia is used to trigger release of cisplatin from thermosensitive liposomes in the vasculature of human triple negative breast cancer tumors implanted orthotopically in mice. This heat-triggered liposomal formulation of cisplatin resulted in significantly delayed tumor growth and improved overall survival compared to treatment with either non-thermosensitive liposomes containing cisplatin or free cisplatin, as was observed in two independent tumor models (i.e. MDA-MB-231 and MDA-MB-436). The in vitro sensitivity of the cell lines to cisplatin and hyperthermia alone and in combination was characterized extensively using enzymatic assays, clonogenic assays, and spheroid growth assays. Evaluation of correlations between the in vitro and in vivo results served to identify the in vitro approach that is most predictive of the effects of hyperthermia in vivo. Relative expression of several heat shock proteins and the DNA damage repair protein BRCA1 were assayed at baseline and in response to hyperthermia both in vitro and in vivo. Interestingly, delivery of cisplatin in thermosensitive liposomes in combination with hyperthermia resulted in the most significant tumor growth delay, relative to free cisplatin, in the less cisplatin-sensitive cell line (i.e. MDA-MB-231). This work demonstrates that thermosensitive cisplatin liposomes used in combination with hyperthermia offer a novel method for effective treatment of triple negative breast cancer.

Sub-additive effects of photodynamic therapy combined with erlotinib for the treatment of epidermoid carcinoma: An in vitro study.

BACKGROUND: Photodynamic therapy (PDT) is an antitumour treatment that employs the combination of a photosensitive compound, oxygen and visible light. To improve the antitumour activity of PDT, the present study used the strategy of combining PDT with erlotinib (ERL), a drug frequently used in the treatment of epidermoid carcinoma. METHODS: An MTT cell viability assay was used to evaluate the cytotoxicity of PDT combined with ERL on A431 epidermoid carcinoma cells in vitro. This study evaluated the cytotoxicity of the following treatments: red laser irradiation (660nm) at different power densities (1.25-180J/cm2), the photosensitizer methylene blue (MB) at concentrations of 0.39-100µM, PDT (12.5µM MB and laser power densities from 1.25 to 180J/cm2), and PDT (12.5µM MB and a laser density of 120J/cm2) plus ERL (1µM). RESULTS: The laser power densities that were tested showed no cytotoxicity in A431 cells. MB showed a dose-dependent cytotoxicity. In PDT, an increase in the dose of light resulted in an increase in the cytotoxicity of MB. In addition, there was a sub-additive effect between PDT and ERL compared to the effect of each therapy alone. CONCLUSIONS: The sub-additive effect between PDT and ERL suggests that their combination may be an important strategy in the treatment of epidermoid carcinoma.

Nanofibers containing tetracycline/ß-cyclodextrin: Physico-chemical characterization and antimicrobial evaluation.

This study aimed to compare two nanofiber drug delivery systems that were prepared with an electrospun process and have the potential to serve as adjuvants for the treatment of periodontal disease. The first system was composed of polycaprolactone loaded with tetracycline (TCN) and the second was composed of polycaprolactone loaded with tetracycline/ß-cyclodextrin (TCN:BCD). An antimicrobial diffusion test was performed for each of these sets of nanofibers with the microorganisms, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, both of which contribute to periodontal disease. In vitro release profiles were also obtained, and the nanofibers were characterized by thermal analysis, x-ray powder diffraction, infrared absorption spectroscopy, and scanning electron microscopy. Profiles of the TCN and TCN:BCD nanofibers showed that drug release occurred for up to 14days. However, the TCN:BCD nanofibers appeared to better protect and enhance the biological absorption of TCN due to the formation of a TCN:BCD inclusion complex.

Projeto pingo de luz: um relato de experiência com pacientes em cuidados paliativos / "Pingo de luz": an assistance for patients in palliative care

O estudo e desenvolvimento de cuidados paliativos no Brasil, especialmente quando articulado com o sistema de saúde, ainda carece de muitos avanços, frequentemente estando ausente este serviço em grande parte do país. Nesse sentido, o Centro de Orientação Sobre a Morte e O Ser (COSMOS) desenvolve um trabalho de assistência em Cuidados Paliativos a pacientes com baixa expectativa de vida. O projeto Pingo de Luz é uma atividade na qual estudantes de psicologia acompanham semanalmente os pacientes atendidos pelo Serviço de Terapia da Dor e Cuidados Paliativos com o objetivo de auxiliar não somente a psicóloga responsável, como também toda equipe envolvida no tratamento. Os serviços oferecidos pelo referido Projeto se mostraram significativos na melhora do quadro em que o paciente estava quando se iniciaram os acompanhamentos, não somente na forma de lidar com o sofrimento psíquico, para além disso, uma melhora no aspecto fisiológico. Vale ressaltar também que esse prejuízo causado pela doença afeta o paciente e seu convívio. Portanto, o Projeto Pingo de Luz, com base nos estudos em tanatologia, acompanha o paciente e seus familiares a fim de trabalhar as demandas mais emergentes e atuar conjuntamente com a equipe de cuidados paliativos na identificação de informações relevantes para o tratamento.

The study and development of palliative cares in Brazil, especially when articulated with the health system, yet lack many advances, this kind of service has been used in the most part of the country. In that matter the Centro de OrientaçãoSobre a Morte e O Ser (COSMOS) has been developing a work of palliative cares with patients who has low life expectancy. The ProjetoPingo de Luz is an activity which psychology students accompany weekly patients of Serviço de Terapia da Dor e CuidadosPaliativos, working not only with the responsible psychologist but also trying to talk to the whole multidisciplinary team involved in the treatment. Our services shows relevant in the improvement of the patient's situation, there is an improvement in both the psychic situation as under physiological. Worth mentioning as well that the prejudice caused by the disease progress affects the patient and his social environment. Therefore, the ProjetoPingo de Luz, based in thanatology studies, accompanies the patient and his Family in order to work the emerging demands and act together with the team of palliative care, identifying relevant situations for the treatment.

Projeto Pingo de Luz: um relato de experiência com pacientes em cuidados paliativos / “Pingo de Luz”: an assistance for patients in palliative care

O estudo e desenvolvimento de cuidados paliativos no Brasil, especialmente quando articulado com o sistema de saúde, ainda carece de muitos avanços, frequentemente estando ausente este serviço em grande parte do país. Nesse sentido, o Centro de Orientação Sobre a Morte e O Ser (COSMOS) desenvolve um trabalho de assistência em Cuidados Paliativos a pacientes com baixa expectativa de vida. O projeto Pingo de Luz é uma atividade na qual estudantes de psicologia acompanham semanalmente os pacientes atendidos pelo Serviço de Terapia da Dor e Cuidados Paliativos com o objetivo de auxiliar não somente a psicóloga responsável, como também toda equipe envolvida no tratamento. Os serviços oferecidos pelo referido Projeto se mostraram significativos na melhora do quadro em que o paciente estava quando se iniciaram os acompanhamentos, não somente na forma de lidar com o sofrimento psíquico, para além disso, uma melhora no aspecto fisiológico. Vale ressaltar também que esse prejuízo causado pela doença afeta o paciente e seu convívio.(AU)

PLGA nanofibers improves the antitumoral effect of daunorubicin.

The objective of this study was to evaluate the in vivo anti-inflammatory angiogenesis activity and in vitro cytotoxicity on normal and cancer cell models of a drug delivery system consisting of poly(lactic-co-glycolic acid) nanofibers loaded with daunorubicin (PLGA-DNR) that were fabricated using an electrospinning process. The PLGA-DNR nanofibers were also characterized by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and confocal fluorescence microscopy. In vitro release of DNR from the nanofibers and its corresponding mechanism were also evaluated. Sixty-five percent of the DNR was released in an initial burst over 8h, and by 1224 h, eighty-five percent of the DNR had been released. The Higuchi model yielded the best fit to the DNR release profile over the first 8h, and the corresponding data from 24 to 1224 h could be modeled using zero-order kinetics. The PLGA-DNR nanofibers exhibited a higher cytotoxicity to A431 cells than free DNR but a cytotoxicity similar to free DNR against fibroblast cells. A higher antiangiogenic effect of PLGA nanofibers was observed in the in vivo data when compared to free DNR, and no inflammatory potential was observed for the nanofibers.

Radiosensitivity in lymphoblastoid cell lines derived from Shwachman-Diamond syndrome patients.

Shwachman-Diamond syndrome is an autosomal-recessive disorder characterised by bone marrow failure and a cumulative risk of progression to acute myeloid leukaemia. The Shwachman-Bodian-Diamond syndrome (SBDS) gene, the only gene known to be causative of the pathology, is involved in ribosomal biogenesis, stress responses and DNA repair, and the lack of SBDS sensitises cells to many stressors and leads to mitotic spindle destabilisation. The effect of ionising radiation on SBDS-deficient cells was investigated using immortalised lymphocytes from SDS patients in comparison with positive and negative controls in order to test whether, in response to ionising radiation exposure, any impairment in the DNA repair machinery could be observed. After irradiating cells with different doses of X-rays or gamma-rays, DNA repair kinetics and the residual damages using the alkaline COMET assay and the γ-H2AX assay were assessed, respectively. In this work, preliminary data about the comparison between ionising radiation effects in different patients-derived cells and healthy control cells are presented.

Development of a calcium phosphate nanocomposite for fast fluorogenic detection of bacteria.

Current procedures for the detection and identification of bacterial infections are laborious, time-consuming, and require a high workload and well-equipped laboratories. Therefore the work presented herein developed a simple, fast, and low cost method for bacterial detection based on hydroxyapatite nanoparticles with a nutritive mixture and the fluorogenic substrate. Calcium phosphate ceramic nanoparticles were characterized and integrated with a nutritive mixture for the early detection of bacteria by visual as well as fluorescence spectroscopy techniques. The composite was obtained by combining calcium phosphate nanoparticles (Ca:P ratio, 1.33:1) with a nutritive mixture of protein hydrolysates and carbon sources, which promote fast bacterial multiplication, and the fluorogenic substrate 4-methylumbellipheryl-ß-D-glucuronide (MUG). The composite had an average particle size of 173.2 nm and did not show antibacterial activity against Gram-negative or Gram-positive bacteria. After an Escherichia coli suspension was in contact with the composite for 60-90 min, fluorescence detected under UV light or by fluorescence spectrophotometer indicated the presence of bacteria. Intense fluorescence was observed after incubation for a maximum of 90 min. Thus, this calcium phosphate nanocomposite system may be useful as a model for the development of other nanoparticle composites for detection of early bacterial adhesion.

Structural and thermodynamic characterization of doxycycline/ß-cyclodextrin supramolecular complex and its bacterial membrane interactions.

Doxycycline is a semi-synthetic antibiotic commonly used for the treatment of many aerobic and anaerobic bacteria. It inhibits the activity of matrix metalloproteinases (MMPs) and affects cell proliferation. In this study, the structural and thermodynamic parameters of free DOX and a DOX/ßCD complex were investigated, as well as their interactions and effects on Staphylococcus aureus cells and cellular cytotoxicity. Complexation of DOX and ßCD was confirmed to be an enthalpy- and entropy-driven process, and a low equilibrium constant was obtained. Treatment of S. aureus with higher concentrations of DOX or DOX/ßCD resulted in an exponential decrease in S. aureus cell size, as well as a gradual neutralization of zeta potential. These thermodynamic profiles suggest that ion-pairing and hydrogen bonding interactions occur between DOX and the membrane of S. aureus. In addition, the adhesion of ßCD to the cell membrane via hydrogen bonding is hypothesized to mediate a synergistic effect which accounts for the higher activity of DOX/ßCD against S. aureus compared to pure DOX. Lower cytotoxicity and induction of osteoblast proliferation was also associated with DOX/ßCD compared with free DOX. These promising findings demonstrate the potential for DOX/ßCD to mediate antimicrobial activity at lower concentrations, and provides a strategy for the development of other antimicrobial formulations.

The resveratrol analogue 4,4'-dihydroxy-trans-stilbene inhibits cell proliferation with higher efficiency but different mechanism from resveratrol.

Resveratrol (3,4',5-trihydroxy-trans-stilbene) is a natural phytoalexin found in grapes and wine, which shows antiproliferative activity. We previously found that 4-hydroxy group in the trans conformation was absolutely required for the inhibition of cell proliferation. In the present work we have synthesized the resveratrol analogue 4,4'-dihydroxy-trans-stilbene, which contains two OH in 4' and 4 positions, with the aim of developing a compound with an antiproliferative potential higher than that of resveratrol, on the basis of the correlation between structure and activity previously observed. In comparison with resveratrol, 4,4'-dihydroxy-trans-stilbene inhibited cell clonogenic efficiency of fibroblasts nine times more although with a different mechanism. First, 4,4'-dihydroxy-trans-stilbene induced predominantly an accumulation of cells in G1 phase, whereas resveratrol perturbed the G1/S phase transition. Second, although both compounds were able to inhibit DNA polymerase (pol) delta in an in vitro assay, 4, 4'-dihydroxy-trans-stilbene did not affect pol alpha activity. Finally, 4,4'-dihydroxy-trans-stilbene increased p21(CDKN1A) and p53 protein levels, whereas resveratrol led to phosphorylation of the S-phase checkpoint protein Chk1. Taken together, our results demonstrated for the first time that the two hydroxyl groups on 4- and 4'- positions of the stilbenic backbone enhance the antiproliferative effect and introduce additional targets in the mechanism of action of resveratrol. In conclusion, 4,4'-dihydroxy-trans-stilbene has potent antiproliferative activities that differ from the effect of resveratrol shown in this system, suggesting that it warrants further development as a potential chemopreventive or therapeutic agent.

Posterior fossa abnormalities in hereditary spastic paraparesis with spastin mutations.

BACKGROUND: Hereditary spastic paraparesis (HPS) linked to mutations in the spastin gene (SPG4) is considered to be a pure form of spastic hereditary paraparesis. However, in this disease also other signs of central nervous system involvement are frequently found. METHODS: Clinical, genetical and neuroradiological investigations were carried out in a large family with autosomal dominant spastic paraparesis and in a sporadic case with spastic paraparesis. RESULTS: Additional clinical and molecular data are provided, studying other members of the same pedigree, as already described, with a five-base deletion in exon 9 of the SPG4 gene (1215-1219delTATAA) whose members show MRI anomalies that fall within the Dandy-Walker continuum. Furthermore, an unrelated female patient with hypoplasia of the cerebellar vermis is indicated, carrying a de novo previously reported mutation of the SPG4 gene (c.1741C>T p.R581X). CONCLUSIONS: Spastin may play an important role in the development of the central nervous system and in particular in the development of the structures of posterior fossa.

COP1D, an alternatively spliced constitutive photomorphogenic-1 (COP1) product, stabilizes UV stress-induced c-Jun through inhibition of full-length COP1.

COP1 is an evolutionarily conserved RING-finger ubiquitin ligase acting within a Cullin-RING ligase (CRL) complex that promotes polyubiquitination of c-Jun and p53. Stability of the above substrates is affected by post-translational changes priming the proteins for polyubiquitination and proteasome-dependent degradation. However, degradation of both substrates is controlled indirectly by signaling pathways affecting the E3 ligases involved in their polyubiquitination. Here, we report the identification of COP1D, a ubiquitously expressed splice variant of COP1 lacking a portion of a coiled-coil region involved in intermolecular associations. While being unable to associate with other components of the CRL complex, COP1D exerts a dominant-negative function over the full-length protein, due to its ability to heterodimerize with COP1 and sequester it from the enzymatically active complex. Ectopic expression of COP1D antagonizes the function of COP1, while its selective downregulation by RNA interference promotes more efficient degradation of c-Jun and p53 by the full-length protein. The COP1/COP1D mRNA ratio is modulated by UV stress and a decreased COP1/COP1D ratio correlates with elevated c-Jun, but not p53 protein levels in invasive ductal breast cancer. Thus, dynamic changes of the COP1/COP1D ratio provide an additional level of regulation of the half-life of the substrates of this E3 ligase under homeostatic or pathological conditions.

Bioassay-guided fractionation of pterocarpans from roots of Harpalyce brasiliana Benth.

Pterocarpans, a special kind of isoflavonoids possessing two contiguous benzofuran and benzopyran rings, have been reported as possessing several biological activities. In order to isolate and identify the active principles possibly responsible for the stronger activity of the EtOH extract from roots of Harpalyce brasiliana on the antimitotic assay using sea urchin egg development, a bioassay-guided fractionation was performed. Six bioactive pterocarpan derivatives: 4'-dehydroxycabenegrin A-I, leiocarpin, medicarpin, cabenegrins A-I and A-II, and maackiain were isolated from the chloroform fraction of H. brasiliana extract. Leiocarpin was the most active on the sea urchin egg assay with IC(50) values ranging from 0.1 to 1.2 microg/mL, followed by 4'-dehydroxycabenegrin A-I. The isolated compounds were also tested for cytotoxicity against tumor cell lines in cultures, where 4'-dehydroxycabenegrin A-I was the most active, followed by leiocarpin. Additionally, some studies on the structure-activity relationship of these pterocarpans are suggested.

Anthocyanins protect against DNA damage induced by tert-butyl-hydroperoxide in rat smooth muscle and hepatoma cells.

Anthocyanins are flavonoids present in a variety of pigmented food and, like other flavonoids, seem to play a role in preventing human pathologies related to oxidative stress. In fact, anthocyanins have been shown to exert antiproliferative effects in cell cultures and exhibit antiinflammatory and vasoprotective activities in animal models. Although these biological activities have been related to their antioxidant properties, little is known on the molecular mechanism of action of anthocyanins. The effects of pretreatment with the anthocyanins delphinidin, cyanidin, and their glycoside and rutinoside derivatives against induction of DNA damage induced by tert-butyl-hydroperoxide (TBHP) were evaluated in rat smooth muscle and in rat hepatoma cell lines using alkaline single cell gel electrophoresis (Comet test). In addition, a possible protection exerted by anthocyanins on cell killing, lipid peroxidation, and redox state alterations induced by TBHP was also investigated. It was found that the treatment with TBHP induces the formation of DNA single strand breaks (SSB) and oxidised bases, along with cell killing, lipid peroxidation and redox state alteration. Our data demonstrate that anthocyanins are effective against cytotoxicity, DNA SSB formation and lipid peroxidation induced by TBHP, but they do not have any detectable effect against impairment by TBHP of cellular redox state and on protection against DNA bases oxidation. The presence of a sugar moiety in anthocyanin derivatives reduced this protective effect, mainly in rat hepatoma cells. The different activity of anthocyanins and their derivatives may be explained taking into account a structure/function relationship that could also influence anthocyanin intracellular localisation.

Inter-individual differences in repair of DNA base oxidation, measured in vitro with the comet assay.

There is a need for a reliable, robust and sensitive assay for DNA repair, suitable for use with human lymphocyte samples in molecular epidemiological investigations. The comet assay (single cell alkaline gel electrophoresis) has been modified to measure the ability of a simple subcellular extract of lymphocytes to carry out the initial step of repair, i.e. incision, on a DNA substrate carrying specific lesions--namely, oxidized bases introduced by visible light in the presence of photosensitizer. The cell extract is free of non-specific nuclease activity, incising DNA only if the DNA has been treated with photosensitizer and light. The activity varies between individuals, but consistency is seen between samples from each individual taken on occasions several months apart. The lack of activity of extract from Ogg1(-) mouse cells (deficient in the glycosylase that excises 8-oxoguanine) in this assay confirms that the activity measured is predominantly excision repair of oxidized bases. This new DNA repair assay is simple, rapid and requires only small quantities of lymphocyte extract (obtainable from 10 ml blood).