Gastroprotective mechanisms of the chloroform and ethyl acetate phases of Praxelis clematidea (Griseb.) R.M.King & H.Robinson (Asteraceae)

Flavonoid-rich Praxelis clematidea (Griseb.) R.M.King & H.Robinson (Asteraceae) is a native plant of South America. This study evaluates the gastroprotective activity and possible mechanisms for both the chloroform (CHCl3P) and ethyl acetate phases (AcOEtP) obtained from aerial parts of the plant. The activity was investigated using acute models of gastric ulcer. Gastric secretion biochemical parameters were determined after pylorus ligature. The participation of cytoprotective factors such as mucus, nitric oxide (NO), sulfhydryl (SH) groups, prostaglandin E2 (PGE 2), reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), reduction of lipid peroxidation (malondialdehyde level), and polymorphonuclear infiltration (myeloperoxidase activity), was also investigated. CHCl3P (125, 250, and 500 mg/kg) and AcOEtP (62.5, 125, and 250 mg/kg) showed significant gastroprotective activity, reducing the ulcerative index by 75, 83, 88 % and 66, 66, 81 % for ethanol; 67, 67, 56 % and 56, 53, 58 % for a non-steroidal anti-inflammatory drug (NSAID); and 74, 58, 59 % and 64, 65, 61 % for stress-induced gastric ulcer, respectively. CHCl3P (125 mg/kg) and AcOEtP (62.5 mg/kg) significantly reduced the ulcerative area by 78 and 83 %, respectively, for the ischemia-reperfusion model. They also did not alter the biochemical parameters of gastric secretion, the GSH level or the activities of SOD, GPx or GR. They increased the quantity of gastric mucus, not dependent on NO, yet dependent on SH groups, and maintained PGE2 levels. The P. clematidea phases demonstrated gastroprotective activity related to cytoprotective factors. © 2012 The Japanese Society of Pharmacognosy and Springer.

Experimental and theoretical approach of nanocrystalline TiO2 with antifungal activity

Using a solvothermal method for this research we synthesized nanocrystalline titanium dioxide (nc-TiO2) anatase particles with a mean diameter of 5.4 nm and evaluated their potential antifungal effect against planktonic cells of Candida albicans without UV radiation. To complement experimental data, we analyzed structural and electronic properties of both the bulk and the (1 0 1) surface of anatase by first-principles calculations. Based on experimental and theoretical results, a reactive O2H- and OH- species formation mechanism was proposed to explain the key factor which facilitates the antifungal activity. © 2013 Published by Elsevier B.V.

Antimicrobial Brazilian propolis (EPP-AF) containing biocellulose membranes as promising biomaterial for skin wound healing

Among remarkable discoveries concerning propolis, such as antifungal, antiviral, and antioxidant activities, its anti-inflammatory, and mainly its antibacterial, properties deserve special attention when skin wound healing is concerned. Based on this and knowing the distinctive performance of bacterial (BC) membranes on wound healing, in this work it is proposed to demonstrate the potent antimicrobial activity and wound healing properties of a novel propolis containing biocellulose membrane. The obtained propolis/BC membrane was able to adsorb propolis not only on the surface, but also in its interstices demonstrated by scanning electron microscopy, X-ray diffraction, Fourier transform infrared (FT-IR) spectroscopy, and thermogravidimetric assays. Additionally, the polyphenolic compounds determination and the prominent antibacterial activity in the membrane are demonstrated to be dose dependent, supporting the possibility of obtaining propolis/BC membranes at the desired concentrations, taking into consideration its application and its skin residence time. Finally, it could be suggested that propolis/BC membrane may favor tissue repair in less time and more effectively in contaminated wounds. © 2013 Hernane da Silva Barud et al.

Evaluation of estrogenic, antiestrogenic and genotoxic activity of nemorosone, the major compound found in brown Cuban propolis

Background: Brown propolis is the major type of propolis found in Cuba; its principal component is nemorosone, the major constituent of Clusia rosea floral resins. Nemorosone has received increasing attention due to its strong in vitro anti-cancer action. The citotoxicity of nemorosone in several human cancer cell lines has been reported and correlated to the direct action it has on the estrogen receptor (ER). Breast cancer can be treated with agents that target estrogen-mediated signaling, such as antiestrogens. Phytoestrogen can mimic or modulate the actions of endogenous estrogens and the treatment of breast cancer with phytoestrogens may be a valid strategy, since they have shown anti-cancer activity.Methods: The aim of the present investigation was to assess the capacity of nemorosone to interact with ERs, by Recombinant Yeast Assay (RYA) and E-screen assays, and to determine by comet assay, if the compound causes DNA-damaging in tumoral and non-tumoral breast cells.Results: Nemorosone did not present estrogenic activity, however, it inhibited the 17-β-estradiol (E2) action when either of both methods was used, showing their antiestrogenicity. The DNA damage induced by the benzophenone in cancer and normal breast cells presented negative results.Conclusion: These findings suggest that nemorosone may have therapeutic application in the treatment of breast cancer. © 2013 Camargo et al.; licensee BioMed Central Ltd.

Estrogenic and mutagenic activities of crotalaria pallida measured by recombinant yeast assay and ames test

Background: Crotalaria pallida Ailton is a plant belonging to the Fabaceae family, popularly known as rattle or rattlesnake and used in traditional medicine to treat swelling of the joints and as a vermifuge. Previous pharmacological studies have also reported anti-inflammatory, antimicrobial and antifungal activities. Nevertheless, scientific information regarding this species is scarce, and there are no reports related to its possible estrogenic and mutagenic effects. Thus, the purpose of the present study was to investigate the estrogenic potential of C. pallida leaves by means of the Recombinant Yeast Assay (RYA), seeking an alternative for estrogen replacement therapy during menopause; and to reflect on the safe use of natural products to assess the mutagenic activity of the crude extract from C. pallida leaves, the dichloromethane fraction and stigmasterol by means of the Ames test.Methods: The recombinant yeast assay with the strain BY4741 of Saccharomyces cerevisiae, was performed with the ethanolic extract, dichloromethane fraction and stigmasterol isolated from the leaves of C. pallida. Mutagenic activity was evaluated by the Salmonella/microsome assay (Ames test), using the Salmonella typhimurium tester strains TA100, TA98, TA97 and TA102, with (+S9) and without (-S9) metabolization, by the preincubation method.Results: All samples showed estrogenic activity, mainly stigmasterol. The ethanolic extract from C. pallida leaves showed mutagenic activity in the TA98 strain (-S9), whereas dichloromethane fraction and stigmasterol were found devoid of activity.Conclusion: Considering the excellent estrogenic activity performed by stigmasterol in the RYA associated with the absence of mutagenic activity when evaluated by the Ames test, stigmasterol becomes a strong candidate to be used in hormone replacement therapy during menopause. © 2013 Boldrin et al.; licensee BioMed Central Ltd.

The role of cytokines in inflammatory bone loss

Chronic inflammatory processes close to bone often lead to loss of bone in diseases such as rheumatoid arthritis, periodontitis, loosened joint prosthesis and tooth implants. This is mainly due to local formation of bone resorbing osteoclasts which degrade bone without any subsequent coupling to new bone formation. Crucial for osteoclastogenesis is stimulation of mononuclear osteoclast progenitors by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) which induces their differentiation along the osteoclastic lineage and the fusion to mature, multinucleated osteoclasts. M-CSF and RANKL are produced by osteoblasts/ osteocytes and by synovial and periodontal fibroblasts and the expression is regulated by pro- and anti-inflammatory cytokines. These cytokines also regulate osteoclastic differentiation by direct effects on the progenitor cells. In the present overview, we introduce the basic concepts of osteoclast progenitor cell differentiation and summarize the current knowledge on cytokines stimulating and inhibiting osteoclastogenesis by direct and indirect mechanisms. © Informa Healthcare USA, Inc.

Biochemical, functional, structural and phylogenetic studies on Intercro, a new isoform phospholipase A2 from Crotalus durissus terrificus snake venom

Crotoxin is a neurotoxin from Crotalus durissus terrificus venom that shows immunomodulatory, anti-inflammatory, antimicrobial, antitumor and analgesic activities. Structurally, this toxin is a heterodimeric complex composed by a toxic basic PLA2 (Crotoxin B or CB) non-covalently linked to an atoxic non-enzymatic and acidic component (Crotapotin, Crotoxin A or CA). Several CA and CB isoforms have been isolated and characterized, showing that the crotoxin venom fraction is, in fact, a mixture of different molecules derived from the combination of distinct subunit isoforms. Intercro (IC) is a protein from the same snake venom which presents high similarity in primary structure to CB, indicating that it could be an another isoform of this toxin. In this work, we compare IC to the crotoxin complex (CA/CB) and/or CB in order to understand its functional aspects. The experiments with IC revealed that it is a new toxin with different biological activities from CB, keeping its catalytic activity but presenting low myotoxicity and absence of neurotoxic activity. The results also indicated that IC is structurally similar to CB isoforms, but probably it is not able to form a neurotoxic active complex with crotoxin A as observed for CB. Moreover, structural and phylogenetic data suggest that IC is a new toxin with possible toxic effects not related to the typical CB neurotoxin. © 2013.

Efeito da silibinina sobre o metabolismo oxidativo e produção de citocinas por monócitos em gestantes portadores de pré-eclâmpsia

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do efeito do extrato hidroalcóolico de Myrcia bella cambess na dor aguda e na inflamação em modelos experimentais de roedores

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Compostos bioativos e atividade antioxidante em bananas (Musa sp.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atividade biológica de gel dentifrício e enxagüatório bucal contendo extratos vegetais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ingestão habitual do suco de laranja vermelha e fatores de risco para a síndrome metabólica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos endócrinos, anti-inflamatórios e na atividade pedométrica após as administrações de flunixin meglumine e de meloxicam no pós-operatório de laparotomias em bezerros

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)