Nanoemulsion containing Jatropha gossypiifolia leaf extract reduces dermonecrosis induced by Bothrops erythromelas venom and accelerates wound closure.

ETHNOPHARMACOLOGICAL RELEVANCE: The species Jatropha gossypiifolia, popularly known as "pinhão-roxo", is distributed throughout Brazil, is commonly employed for topical or oral administration in treating wounds, inflammations, and snake bites. Given the significant impact of snakebites on public health and the limitations of antivenom, coupled with the diverse molecular composition of this plant species, investigating its healing and antidermonecrotic capacities is relevant. AIM OF THE STUDY: This study aimed to develop a topical nanoemulsion incorporating the hydroethanolic extract of J. gossypiifolia leaves, to evaluate its therapeutic potential, particularly in terms of its efficacy in wound healing and inhibition of dermonecrosis induced by B. erythromelas venom (BeV). MATERIAL AND METHODS: The extract of J. gossypiifolia (JgE) leaves was obtained by maceration and remaceration. The phytochemical analysis was conducted and J. gossypiifolia nanoemulsion (JgNe) was obtained, characterized and assessed for stability. The cytotoxicity was determined in normal cells (erythrocytes and 3T3) using hemolytic assay and cell viability assay using crystal violet staining. The antioxidant activity was evaluated by the reduction of ABTS and DPPH radicals. The evaluation of wound healing was conducted in vivo following treatment with JgNe, wherein the percentage of wound closure and inflammatory mediators. The skin irritation test was assessed in vivo by applying JgNe directly to the animal's skin. In vitro, the antivenom capacity was evaluated through enzymatic inhibition assays (phospholipase A2 and hyaluronidase) of BeV. Additionally, the in vivo antidermonecrotic activity of JgNe was evaluated by measuring the reduction of the dermonecrotic halo. RESULTS: The HPLC-DAD analysis identified flavonoids, specifically vitexin, luteolin derivatives and apigenin derivatives. In addition, 95.08 ± 5.46 mg of gallic acid/g of extract and 137.92 ± 0.99 mg quercetin/g extract, was quantified. JgNe maintained stability over a 4-week period. Moreover, JgE and JgNe demonstrated no cytotoxicity in human erythrocytes and murine fibroblasts at tested concentrations (32.25-250 µg/mL). Additionally, exhibited significant antioxidant activity by reducing ABTS and DPPH radicals. The treatment with JgNe did not induce skin irritation and accelerated wound healing, with significant wound closure observed from 5th day and reduction in nitrite levels, myeloperoxidase activity, and cytokine. Both JgE and JgNe demonstrated in vitro inhibition of the phospholipase and hyaluronidase enzymes of BeV. Moreover, JgNe exhibited antidermonecrotic activity by reducing the dermonecrotic halo caused by BeV after 24 h. CONCLUSIONS: JgNe and JgE exhibited no cytotoxicity at the tested concentrations. Additionally, our findings demonstrate that JgNe has the ability to accelerate wound closure and reduce dermonecrosis caused by BeV, indicating to be promising formulation for complementary therapy to antivenom treatment.

Comparative analysis of the biocompatibility of endothelial cells on surfaces treated by thermal plasma and cold atmospheric plasma.

In recent years, cold atmospheric plasma (CAP) is used for surface disinfection. However, little is known about its ability to improve biocompatibility of metallic surfaces when compared to thermal plasma methods. In this context, the study aimed to evaluate the response of human endothelial cells (Ea.hy926) on titanium surfaces treated by non-thermal plasma method and thermal plasma method under nitriding atmosphere. The wettability was characterized by the sessile drop method, the topography and roughness were evaluated by atomic force microscopy (AFM), and the microstructure by grazing angle X-ray diffraction (GIXRD). Endothelial cells were cultured and evaluated for morphology by scanning electron microscopy and viability by an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. CAP treatment reduced the contact angle of the Ti surface (13.43° ± 1.48; p<0.05), increasing hydrophilicity. Rz roughness was higher on the nitrided surface (220.44±20.30; p< 0.001) compared to the CAP treated surfaces (83.29 ± 11.61; p< 0.001) and polished (75.98 ±34.21a); p<0.001). The different applied plasma treatments created different titanium surfaces improving the biocompatibility of endothelial cells, however CAP results demonstrate its potential for biomedical applications, considering the low cost and ease of use of the technique, allowing surface treatments before clinical procedures.

Tephrosia toxicaria (Sw.) Pers. extracts: Screening by examining aedicidal action under laboratory and field conditions along with its antioxidant, antileishmanial, and antimicrobial activities.

An increase in the incidence of arboviral, microbial and parasitic infections, and to disorders related to oxidative stress has encouraged the development of adjuvant therapies based on natural formulations, such as those involving plant extracts. Thus, to expand the repertoire of the available therapeutic options, this study aimed to describe the versatility of Tephrosia toxicaria (Sw.) (Pers., 1807) extracts for the control of arbovirus vectors, as well as their antioxidant, antileishmanial, and antimicrobial potential. Among the aqueous and hydroethanolic extracts obtained, the hydroethanolic extract from roots (RHA) was identified as the most active larvicide extract demonstrating, respectively, the lowest lethal concentration (mg/mL) for 50%, 90% and 99% of Aedes aegypti (L., 1762) and Aedes albopictus (S., 1894) larvae, observed at 24 h (0.33, 0.84 and 1.80; 0.32, 0.70 and 1.32) and 48 h (0.17, 0.51 and 1.22; 0.26, 0.47 and 0.78) post-exposure. Field assays revealed that RHA (0.84 mg/mL) is a potential oviposition deterrent, reducing egg-laying by approximately 90%. RHA (0.1 mg/mL) also exhibited antioxidant activity for the following tests: total antioxidant capacity (286.86 mg AAE/g), iron (87.16%) and copper (25.64%) chelation, and superoxide scavenging (10%). In the cell culture assays, RHA (0.1 mg/mL) promoted regeneration of metabolic activity (92% cell viability) in cells exposed to oxidative stress. Furthermore, RHA displayed weak antileishmanial activity (IC50 = 3.53 mg/mL) against Leishmania amazonensis and not exhibit antimicrobial activity. The extraction favored the concentration of carbohydrates in RHA, in addition to lectins and protease inhibitors, with molecular masses estimated between 10 and 24 kDa. Cytotoxicity and phytotoxicity analyses of RHA suggested its biosecurity. Thus, RHA is a multivalent extract with insecticide and antioxidant properties at low and safe concentrations. However, others studies on its indirect toxic effects are ongoing to ensure the complete safety of RHA.

Cationic PLGA Nanoparticle Formulations as Biocompatible Immunoadjuvant for Serum Production and Immune Response against Bothrops jararaca Venom.

Snakebite envenoming represents a worldwide public health issue. Suitable technologies have been investigated for encapsulated recombinant or native proteins capable of inducing an effective and long-lasting adaptive immune response. Nanoparticles are colloidal dispersions that have been used as drug delivery systems for bioactive biological compounds. Venom-loaded nanoparticles modulate the protein release and activate the immune response to produce specific antibodies. In this study, biocompatible cationic nanoparticles with Bothrops jararaca venom were prepared to be used as a novel immunoadjuvant that shows a similar or improved immune response in antibody production when compared to a conventional immunoadjuvant (aluminum hydroxide). We prepared stable, small-sized and spherical particles with high Bothrops jararaca venom protein association efficiency. The high protein loading efficiency, electrophoresis, and zeta potential results demonstrated that Bothrops jararaca venom is adsorbed on the particle surface, which remained as a stable colloidal dispersion over 6 weeks. The slow protein release occurred and followed parabolic diffusion release kinetics. The in vivo studies demonstrated that venom-loaded nanoparticles were able to produce an immune response similar to that of aluminum hydroxide. The cationic nanoparticles (CNp) as carriers of bioactive molecules, were successfully developed and demonstrated to be a promising immunoadjuvant.

Role of sulfated polysaccharides from seaweeds in bone regeneration: A systematic review.

Studies on the effect of sulfated polysaccharides from seaweed on bone regeneration have increased in recent years. However, there is no consensus on how to use them and their real effectiveness in that process. Thereby, we carried out a systematic review to answer the question "Do the sulfated polysaccharides from seaweeds promote osteogenesis?". Searches were performed in Pubmed, Scopus, and Web of Knowledge databases. A total of 599 articles were selected, resulting in 14 eligible studies. Results showed that the sulfated polysaccharides from seaweeds increase the osteogenic markers evaluated. Nevertheless, due to the lack of standardization on protocols used, the results should be cautiously interpreted. In addition, studies using animal models are still scarce, and the results with cellular models cannot always be extrapolated to systems that are more complex. Despite the study limitations, the use of sulfated polysaccharides appears to promote in vitro osteogenesis and enhance bone regeneration.

NMR three-dimensional structure of the cationic peptide Stigmurin from Tityus stigmurus scorpion venom: In vitro antioxidant and in vivo antibacterial and healing activity.

Infectious diseases and the rapid development of pathogens resistant to conventional drugs are a serious global public health problem, which motivates the search for new pharmacological agents. In this context, cationic peptides without disulfide bridges from different species of scorpion venom have been the target of scientific studies due to their multifunctional activities. Stigmurin is a linear peptide composed of 17 amino acid residues (Phe-Phe-Ser-Leu-Ile-Pro-Ser-Leu-Val-Gly-Gly-Leu-Ile-Ser-Ala-Phe-Lys-NH2), which is present in the venom gland of the scorpion Tityus stigmurus. Here we present investigations of the in vitro antioxidant action of Stigmurin together with the in vivo antibacterial and healing activity of this peptide in a wound infection model induced by Staphylococcus aureus. In addition, we have reports for the first time of the three-dimensional structure determined by NMR spectroscopy of a peptide without disulfide bridges present in scorpion venom from the Tityus genus. Stigmurin showed hydroxyl radical scavenging above 70 % at 10 µM and antibiotic action in the skin wound, reducing the number of viable microorganisms by 67.2 % on the 7 day after infection. Stigmurin (1 µg / µL) increased the retraction rate of the lesion, with wound area reduction of 43 % on the second day after skin injury, which indicates its ability to induce tissue repair. Stigmurin in trifluoroethanol:water exhibited a random conformation at the N-terminus region (Phe1 to Pro6), with a helical structure from Ser7 to Phe16. This structural information, allied with the multifunctional activity of Stigmurin, makes it an attractive candidate for the design of novel therapeutic agents.

Low-level laser irradiation promotes proliferation of cryopreserved adipose-derived stem cells.

OBJECTIVE: To evaluate the effect of low-level laser irradiation on proliferation and viability of murine adipose-derived stem cells previously submitted to cryopreservation. METHODS: Adipose-derived stem cells were isolated from inguinal fat pads of three mice, submitted to cryopreservation in fetal bovine serum with 10% dimethylsulfoxide for 30 days and then thawed and maintained in normal culture conditions. Culture cells were either irradiated or not (control) with an InGaAIP diode laser at zero and 48 hours, using two different energy densities (0.5 and 1.0J/cm2). Cell proliferation was evaluated by trypan blue exclusion method and MTT assay at intervals of zero, 24, 48, and 72 hours after the first laser application. Cell viability and apoptosis of previously cryopreserved cells submitted to laser therapy were evaluated by flow cytometry. RESULTS: The Irradiated Groups (0.5 and 1.0J/cm2) showed an increased cell proliferation (p<0.05) when compared to the Control Group, however no significant difference between the two energy densities was observed. Flow cytometry revealed a percentage of viable cells higher than 99% in all groups. CONCLUSION: Low-level laser irradiation has stimulatory effects on the proliferation of adipose-derived stem cells previously submitted to cryopreservation.

Low-level laser irradiation promotes proliferation of cryopreserved adipose-derived stem cells / Laser de baixa intensidade promove proliferação de células-tronco derivadas de tecido adiposo criopreservadas

ABSTRACT Objective To evaluate the effect of low-level laser irradiation on proliferation and viability of murine adipose-derived stem cells previously submitted to cryopreservation. Methods Adipose-derived stem cells were isolated from inguinal fat pads of three mice, submitted to cryopreservation in fetal bovine serum with 10% dimethylsulfoxide for 30 days and then thawed and maintained in normal culture conditions. Culture cells were either irradiated or not (control) with an InGaAIP diode laser at zero and 48 hours, using two different energy densities (0.5 and 1.0J/cm2). Cell proliferation was evaluated by trypan blue exclusion method and MTT assay at intervals of zero, 24, 48, and 72 hours after the first laser application. Cell viability and apoptosis of previously cryopreserved cells submitted to laser therapy were evaluated by flow cytometry. Results The Irradiated Groups (0.5 and 1.0J/cm2) showed an increased cell proliferation (p<0.05) when compared to the Control Group, however no significant difference between the two energy densities was observed. Flow cytometry revealed a percentage of viable cells higher than 99% in all groups. Conclusion Low-level laser irradiation has stimulatory effects on the proliferation of adipose-derived stem cells previously submitted to cryopreservation.

RESUMO Objetivo Avaliar o efeito do laser de baixa intensidade na proliferação e na viabilidade de células-tronco derivadas de tecido adiposo murinas previamente submetidas à criopreservação. Métodos Células-tronco derivadas de tecido adiposo foram isoladas da região inguinal de três camundongos, submetidas à criopreservação em soro fetal bovino com 10% de dimetilsulfóxido por 30 dias e, depois, descongeladas e mantidas em condições normais de cultivo. As células cultivadas foram irradiadas ou não (controle) com um laser de diodo InGaAIP nos intervalos de zero e 48 horas, utilizando duas densidades de energia diferentes (0,5 e 1,0J/cm2). A proliferação celular foi avaliada pelo método de exclusão de azul de tripan e ensaio MTT, nos intervalos de zero, 24, 48 e 72 horas após a primeira aplicação do laser. A viabilidade celular e a apoptose das células previamente criopreservadas submetidas à laserterapia foram avaliadas por citometria de fluxo. Resultados Os Grupos Irradiados (0,5 e 1,0J/cm2) apresentaram aumento da proliferação celular (p<0,05) quando comparados ao Grupos Controle, porém não foi observada diferença significativa entre as duas densidades de energia. A citometria de fluxo revelou percentagem de células viáveis superior a 99% em todos os grupos. Conclusão O laser de baixa intensidade tem efeitos estimuladores sobre a proliferação de células-tronco derivadas de tecido adiposo previamente submetidas à criopreservação.

Libidibia ferrea presents antiproliferative, apoptotic and antioxidant effects in a colorectal cancer cell line.

Colorectal cancer is noted for being one of the most frequent of tumors, with expressive morbidity and mortality rates. In new drug discovery, plants stand out as a source capable of yielding safe and high-efficiency products. Well known in Brazilian popular medicine, Libidibia ferrea (Mart. Ex Tul.) L.P. Queiroz var. ferrea (better known as "ironwood" or "jucá"), has been used to treat a wide spectrum of conditions and to prevent cancer. Using methodologies that involved flow cytometry, spectrophotometry and RT-qPCR assays, crude extracts of the fruits of L. ferrea (20T, 40T, 60T and 80T) were evaluated at 24h and/or 48h for: their ability to inhibit cell proliferation; induce apoptosis through Bcl-2, caspase-3 and Apaf-1; their antioxidant activity and effects on important targets related to cell proliferation (EGFR and AKT) in the HT-29 human colorectal cancer lineage. The results revealed high antiproliferative potential as compared to the controls, induction of apoptosis through the intrinsic pathway, and probable tumor inhibition activity under the mediation of important targets in tumorigenesis. In addition, L. ferrea revealed antioxidant, lipid peroxidation and chemoprotective effects in healthy cells. Thus, L. ferrea derivatives have important anticancer effects, and may be considered promising candidate for colorectal cancer therapy.

Composition and significance of glycosaminoglycans in the uterus and placenta of mammals

Glycosaminoglycans (GAGs) are heteropolysaccharides in mammalian tissue and consist of repeated disaccharide units with mono-sulfated or non-sulfated monosaccharides. GAGs are important components of the Extracellular Matrix (ECM) with several physiological roles, in the recognition, migration, adhesion, proliferation and differentiation processes. They are also important in angiogenesis, blood homeostasis, immune reactions, follicule development and also in the development of pathologies such as infertility, tumors and metastases. It has been shown that the profile of glycosaminoglycans in the uterine and placental tissues is highly variable throughout the reproductive cycle and during pregnancy. It may be directly related to their physiological or pathological functions in the tissue. The latter has recently triggered special clinical interest. Current review collaborates for a deeper knowledge on the profile and importance of GAGs in uterine and placental tissues throughout the reproductive cycle and pregnancy. It also covers information on the involvement of these molecules in pathological processes.

Influência da composição dos gases durante a modificação da superfície por plasma na adesão de células primárias da polpa dental / Influence of the composition of gases during plasma surface modification on adhesion of primary cells from dental pulp

Amostras de titânio foram nitretadas por plasma usando duas composições gasosas: 80%H2-20%N2 e 20%H2-80%N2 e as propriedades físicas químicas desse tratamento foram estudas, bem como sua resposta biológica quando submetidas à cultura de células primárias da polpa dentária. Análise por difração de raios X indicam a formação de TiN nas duas amostras nitretadas ao contrário da superfície não nitretada que continha apenas a fase Ti-α. Verificaram-se modificações na dureza, topografia e molhabilidade dessas amostras quando comparadas às amostras não nitretadas. A adesão celular nessas amostras indica que o tratamento aumenta seu valor sendo superior para amostras tratadas em maior concentração de hidrogênio.

Samples of titanium were nitrided using plasma and a composition of two gases: 80% H2-20% N2 and 20% H2-80% N2. The influence of these treatments on their physical chemical properties and biological response when subjected to the primary cell culture of dental pulp were studied. Analyses by X-ray diffraction indicate the formation of TiN in both nitrided samples in contrast to the non-nitrided surface samples that contained only the Ti-α phase. Changes in hardness, topography and wettability of these samples compared to non-nitrided samples were found as well. Finally, the analysis of cell’s adhesion in these samples indicate that treatment increases its value being higher for samples treated at higher hydrogen concentration.

Stem cells behavior on titanium surfaces modified by plasma / Análise do comportamento de células-tronco em superfícies de titânio modificadas por plasma

Over the last decade, a considerable development of new technologies to the modification of dental implants has been observed contributing to reduce the healing process and their use in areas with low bone density. Among the new techniques, plasma nitriding has showed excellent results. In this study, a superficial modification of commercial pure titanium (Degree II), by using two different plasma treatments (planar and hollow cathode nitriding) was accomplished aiming at an optimization of the surface for biomedical applications. An evaluation of the chemical composition in all samples was carried out, in addition to a study of their roughness and texture. Then, stem cells were deposited onto these surfaces and a comparison among their properties and their biological behavior was accomplished. The results showed that the nitriding techniques produced significant changes in the superficial texture of the Ti samples. The roughness test presented better results in samples nitrided by hollow cathode technique. Statistically significant differences were found in the cell proliferation of samples nitrided by hollow cathode nitriding when compared to samples without treatment. The used techniques were, therefore, effective and directly influenced the characteristics of the titanium surface and consequently, the stem cell behavior.

Nos últimos anos tem-se observado um grande crescimento em tecnologias para modificação de superfícies de implantes dentais visando reduzir o tempo de espera pela cicatrização, assim como possibilitar seu uso com sucesso em áreas de baixa densidade óssea. Dentre esses métodos de modificação, a nitretação por plasma tem apresentado ótimos resultados. No presente trabalho, estudou-se superfícies de titânio comercialmente puro (Grau II) modificadas através de dois tratamentos por plasma diferentes (nitretação planar e nitretação em cátodo oco), com o objetivo de obter uma otimização da superfície para aplicações biomédicas. Uma avaliação da composição química e um estudo da rugosidade e textura destas amostras foram realizados. Em seguida, depositou-se células-tronco sobre essas superfícies e uma comparação entre as novas propriedades obtidas e a proliferação celular foi feita. Os resultados mostraram que a nitretação por plasma produziu mudanças significativas na textura superficial das amostras de titânio. A rugosidade foi superior nas amostras nitretadas em cátodo oco. Encontrou-se diferença estatisticamente significante na proliferação celular das amostras nitretadas em cátodo oco quando comparadas com as amostras sem tratamento. Essas técnicas de modificação são, portanto, efetivas e possuem influência direta nas características da superfície e no comportamento de células-tronco.

Morphological features and vascularization study of caprine cyclic corpus luteum / Características morfológicas e estudo da vascularização do corpo lúteo cíclico de cabras ao longo do ciclo estral

Corpus luteum is a temporary endocrine gland that regulates either the estrous cycle and pregnancy. It presents extreme dependency on the adequate blood supply. This work aims to evaluate goat corpus luteum (CL) vascular density (VD) over the estrous cycle. For that purpose, 20 females were submitted to estrus synchronization/ovulation treatment using a medroxyprogesterone intra-vaginal sponge as well as intramuscular (IM) application of cloprostenol and equine chorionic gonadotrophine (eCG). After sponge removal, estrus was identified at about 72hs. Once treatment was over, female goats were then subdivided into 4 groups (n=5 each) and slaughtered on days 2, 12, 16 and 22 after ovulation (p.o). Ovaries were collected, withdrawn and weighted. CL and ovaries had size and area recorded. Blood samples were collected and the plasma progesterone (P4) was measured through RIA commercial kits. The VD was 24.42±6.66, 36.26±5.61, 8.59±2.2 and 3.97±1.12 vessels/mm² for days 2, 12, 16 and 22 p.o, respectively. Progesterone plasma concentrations were 0.49±0.08, 2.63±0.66, 0.61±0.14 and 0.22±0.04ng/ml for days 2, 12, 16 e 22 p.o, respectively. Studied parameters were affected by the estrous cycle phase. Values greater than 12 p.o were observed. In the present work we observed that ovulation occurred predominantly in the right ovary (70 percent of the animals), which in turn presented bigger measures than the contra lateral one. There is a meaningful relationship between the weight and size of the ovary and these of CL (r=0.87, r=0.70, respectively, p<0.05). It is possible to conclude that morphology of goat's ovaries and plasma progesterone concentration changed according to estrous cycle stages. We propose these parameters can be used as indicators of CL functional activity.

O corpo lúteo é uma glândula endócrina temporária que regula tanto o ciclo estral quanto a prenhez, apresentando extrema dependência de aporte sanguíneo adequado. Objetivaram-se avaliar mudanças morfométricas dos ovários e densidade vascular (DV) dos corpos lúteos (CL) de cabras ao longo do ciclo estral (AOLC). Vinte animais foram submetidos ao tratamento para indução/sincronização do estro, usando esponjas intravaginais commedroxiprogesterona, associadas a aplicações intramusculares de cloprostenol e gonadotrofina coriônica eqüina. Após remoção das esponjas, o estro foi identificado em aproximadamente de 72h. Concluído o tratamento, as cabras foram subdivididas em 4 grupos (n=5 cada) para abate nos dias 2, 12, 16 e 22 após ovulação (p.o.). Posteriormente, foram retirados os ovários e realizadas as mensurações de peso, tamanho e área do órgão e dos CL. Amostras de sangue foram coletadas e a progesterona sérica (P4) mensurada utilizando-se RIA convencional. A DV média dos CL AOLC foi 24,42±6,66; 36,26±5,61; 8,59±2,2 e 3,97±1,12 vasos/mm2 para os dias 2, 12, 16 e 22 p.o., respectivamente. A concentração média de P4 foi de 0,49±0,08; 2,63±0,66; 0,61±0,14 e 0,22±0,04ng/ml para os dias 2, 12, 16 e 22 p.o., respectivamente. Os parâmetros em estudo também se mostraram afetados pela fase do ciclo estral, sendo observados os maiores (p < 0,05) valores no dia 12 p.o. Neste experimento, a ovulação ocorreu predominantemente no ovário direito (70 por cento dos animais), o qual apresentou medidas maiores que o contralateral. Observou-se ainda alta correlação significativa entre o peso do ovário e o do CL (r=0,87; p<0,05) e entre o tamanho destes órgãos (r=0,70; p<0,05). Conclui-se que, a morfologia dos ovários de cabras e a concentração sérica de progesterona variam em função da fase do ciclo estral e podem ser utilizadas como parâmetro na avaliação funcional do órgão.

A xylogalactofucan from the brown seaweed Spatoglossum schröederi stimulates the synthesis of an antithrombotic heparan sulfate from endothelial cells.

The brown seaweed Spatoglossum schröederi (Dictyotaceae) contains three main fucans (fucans A, B and C) with different mobility in electrophoresis. The fucan with highest mobility (fucan C) was precipitated with 2.0 volumes of acetone, purified using a combination of ion exchange chromatography and electrophoresis. It showed an MW of 24 kDa determined by HPLC and Sephadex G-75 chromatography and migrates as a single band in three distinct electrophoretic systems. This fucan contains fucose, xylose, galactose and sulfate in a molar ratio 1 : 0.6 : 2:2.3. The fucan has neither anticoagulant (from 10 to 100 microg) nor hemorrhagic activities (100 microg/mL). In addition, fucan C is neither cytotoxic nor cytostatic. However, fucan C (100 microg/mL) stimulated the synthesis of an antithrombotic heparan sulfate from endothelial cells of rabbit aorta. The results suggest that fucan C might be used as an antithrombotic therapeutic compound.

Caracterizaçäo de uma fucana da alga Spatoglossum schröederi e análise de suas atividades anti-adesiva, antimigratória, antiproliferativa e antitrombótica / Characterization the fucan of patoglossum schröederi alga and analusis of this activity anti-aahesive, antimigratory, antiprolephetative and antitrombotic

Fucana é uma denominaçao utilizada para polissacarídeos sulfatados, lineares ou nao, que tem como característica estrutural mais marcante a presença de L-fucose sulfatada. A alga Spatoglossum schroederi produz três fucanas, denominadas de fucanas A, B e C. A Fuc B, com massa molecular de 21,5 kDa, constituída de fucose: xilose: galactose: sulfato (1: 0,5: 2: 2) e traços de ácido urônico, foi extraída da alga por hidrólise enzimática e purificada por precipitaçao diferencial com acetona e cromatografias de troca iônica e gel filtraçao. As análise químicas, estudos de metilaçao e espectroscopia de RMN de 113 e 213, indicaram as principais características estruturais da Fuc B. Ela é formada por um estrutura central de (3-D-1-galactose-3504-4, com aproximadamente 50 por cento dessas galactoses sendo substituídas em C2 por cadeia laterais formadas por a-L-1-fucose-4 ou a-L-fucose(1 -->4) (3D-xilose-, estando as (coses sulfatadas em C3, apresentando essas cadeias monômeros de xilose ou galactose na posiçao de açúcar terminal nao redutor. A Fuc B nao apresentou atividades anticoagulante e hemorrágica. Todavia, testes "in vivo" indicaram que ela possui atividade antitrombótica no estudo de ligadura de veia ficava, dependente do tempo, da dose e do seus grupamentos sulfato. Verificou-se, também, que a Fuc B foi duas vezes mais potente do que a heparina ou a fucana A (Fuc A) em estimular a síntese do heparam sulfato (HS) pelas células endoteliais de aorta de coelho. Esse efeito foi dose dependente e foi abolido com a dessulfataçao da Fuc B. Todavia, tanto Fuc B como Fuc A nao apresentaram atividades citotóxicas como citostáticas frente as células endoteliais. Esses dados levam a proposta de que a capacidade de estimular a síntese de HS pelas células endoteliais é que é responsável pela atividade antitrombótica da Fuc B...(au)