Neuroprotective potential of Myrciaria plinioides D. Legrand extract in an in vitro human neuroblastoma model.

Neurodegenerative diseases are multifactorial debilitating disorders of the nervous system affecting approximately 30 million individuals worldwide. Mitochondrial dysfunction and oxidative stress have also been implicated in causing neurodegeneration. As life expectancy is increasing, neurodegenerative disorders are becoming a major social issue. None of the drugs currently available for treatment are capable of healing the patient. This means that new molecules should be explored. Plants have been used for treatment of countless medical conditions and extensive research is being carried out on species of the Myrtaceae family, widely used in traditional medicine. To date, Myrciaria plinioides D. Legrand has not been studied for its therapeutic use. To evaluate the neuroprotective effect of aqueous and ethanol extracts of this plant, we investigated the protective effects in human neuroblastoma cells (SH-SY5Y). High-performance liquid chromatography fingerprinting of extracts revealed the presence of phenolic compounds and flavonoids. Extracts showed antioxidant activity in the ORAC, DPPH, FRAP and GAE methods. Ethanol extract presented a strong inhibitory activity toward p38 and JNK3 MAPKs and AChE activity and also toward TNF-α release in human whole blood. None of the extracts significantly affected cell viability; the ethanol extract, however, reversed 6-OHDA-induced toxicity. Particularly the ethanol extract suggests neuroprotective effects by preventing membrane depolarization and by significantly decreasing H2O2 production and caspase-3 activity. The present results indicate that the ethanol extract protects SH-SY5Y cells against oxidative damage and apoptosis, as shown by the antioxidative activity of the extract as well as by the inhibition of important proteins such as caspase-3, p38 and JNK3 and the cytokine TNF-α.

Guaraná, a Highly Caffeinated Food, Presents in vitro Antitumor Activity in Colorectal and Breast Cancer Cell Lines by Inhibiting AKT/mTOR/S6K and MAPKs Pathways.

The mammalian target of rapamycin (mTOR) and mitogen-activated protein kinases (MAPKs) pathways are frequently upregulated in cancer. Some authors have reported that some antioxidant molecules could be potential inhibitors of these pathways. Therefore, we investigated the in vitro antitumor effect of guaraná by inhibiting the AKT/mTOR/S6K and MAPKs pathways. Colorectal and breast cancer cell lineages, HT-29 and MCF-7 cells, respectively, were exposed to different guaraná concentrations (0.1, 1, 10, and 100 µg/mL) as well as its main bioactive molecule, caffeine, in proportional concentrations to those found in the extract. Western blot, clonogenic assay, and growth curve were performed. Moreover, we investigated the potential cytotoxic effect of guaraná in normal cells. The results revealed that guaraná and caffeine inhibited some MAPKs proteins (p-p38 and p-HSP27) in MCF-7 cells. However, they did not affect this pathway in HT-29 cells. Furthermore, guaraná inhibited mTORC1 (p-S6K) and mTORC2 (p-AKT) in MCF-7 cells, but only mTORC1 in HT-29 cells. Caffeine only inhibited the mTOR pathway in MCF-7 cells. Guaraná decreased the colony formation and cell growth in MCF-7 and HT-29 cells. Guaraná did not affect normal cells. In conclusion, guaraná could be an important agent in antitumor pharmacologic therapies by inhibiting the mTOR and MAPKs pathways.

Perfil de inaptidão na triagem clínica e sorológica de candidatos à doação de sangue / Profile of inability in the clinic and serological screening of candidates for blood donation

Objetivo: Caracterizar os candidatos quanto ao gênero e analisar a prevalência dos critérios de inaptidão adotados às doações de sangue, realizadas no Banco de Sangue Santa Maria, em Santa Maria, RS. Métodos: Dados retrospectivos arquivados foram avaliados, analisando-se os critérios de exclusão na triagem clínica e sorológica, no período de janeiro de 2005 até dezembro de 2010. Foram analisados 20.264 doadores. O estudo foi aprovado pelo Comitê de Ética e Pesquisa da Universidade Federal do Rio Grande do Sul-UFRGS, sob número de protocolo 18147. Resultados: Novecentos e setenta e seis (5%) candidatos foram considerados inaptos pela triagem clínica e 19.288 (95%) foram considerados aptos para prosseguirem com os testes laboratoriais. Dos doadores aptos, 941 (5%) foram excluídos na triagem sorológica, totalizando 18.347 bolsas de sangue disponíveis para uso. Predominaram os doadores do sexo masculino (62%) e a principal causa de exclusão, na triagem clínica, foi hipertensão (0,7%). Para a triagem sorológica, a principal causa de exclusão foi a Doença de Chagas (1,5%). Conclusão: Ressaltou-se a importância da triagem clínica, tendo em vista que ela excluiu 5% dos candidatos à doação e a relevância da triagem sorológica ser feita corretamente, evitando que resultados falso-negativos sejam liberados.

Objective: Characterize donors by gender and analyze theprevalence of the inability criteria of donations made at the SantaMaria Blood Bank, located at Santa Maria, Brazil. Methods: First,we searched historical data for exclusion criteria used in clinicaland serological screenings during the period from January, 2005 toJuly, 2010. We evaluated 20,264 blood donors' data for this study.The Ethical Committee of Rio Grande do Sul Federal UniversityUFRGSapproved this study under the protocol number 18147.Results: Nine hundred and seventy-six (5%) candidates wereconsidered unfit by the clinical screening and 19,288 (95%) wereconsidered fit. From the resulting fit population of the clinicalscreening, 941 (5%) were excluded from donating by the serologicalscreening, totaling 18.347 blood donations fit for use. The resultsshows that majority of the donors were male (62%) and the leadingcause of exclusion from donating in the clinical screening washypertension (0.7%). As for the serological screening, the leadingcause for exclusion was Chagas disease (1.5%). Conclusion: Thestudy stress the importance of the clinical screening process, giventhat it excluded 5% of blood donations, which were unfit for use. Wealso notice the relevance of a correctly done serological screening,thus avoiding that false-negative results are released.

Contribution of S6K1/MAPK signaling pathways in the response to oxidative stress: activation of RSK and MSK by hydrogen peroxide.

Cells respond to different kind of stress through the coordinated activation of signaling pathways such as MAPK or p53. To find which molecular mechanisms are involved, we need to understand their cell adaptation. The ribosomal protein, S6 kinase 1 (S6K1), is a common downstream target of signaling by hormonal or nutritional stress. Here, we investigated the initial contribution of S6K1/MAPK signaling pathways in the cell response to oxidative stress produced by hydrogen peroxide (H2O2). To analyze S6K1 activation, we used the commercial anti-phospho-Thr389-S6K1 antibody most frequently mentioned in the bibliography. We found that this antibody detected an 80-90 kDa protein that was rapidly phosphorylated in response to H2O2 in several human cells. Unexpectedly, this phosphorylation was insensitive to both mTOR and PI3K inhibitors, and knock-down experiments showed that this protein was not S6K1. RSK and MSK proteins were candidate targets of this phosphorylation. We demonstrated that H2O2 stimulated phosphorylation of RSK and MSK kinases at residues that are homologous to Thr389 in S6K1. This phosphorylation required the activity of either p38 or ERK MAP kinases. Kinase assays showed activation of RSK and MSK by H2O2. Experiments with mouse embryonic fibroblasts from p38 animals' knockout confirmed these observations. Altogether, these findings show that the S6K1 signaling pathway is not activated under these conditions, clarify previous observations probably misinterpreted by non-specific detection of proteins RSK and MSK by the anti-phospho-Thr389-S6K1 antibody, and demonstrate the specific activation of MAPK signaling pathways through ERK/p38/RSK/MSK by H2O2.

Antimicrobial activity of Amazonian oils against Paenibacillus species.

The Gram-positive, spore-forming bacterium Paenibacillus larvae is the primary bacterial pathogen of honeybee brood and the causative agent of American foulbrood disease (AFB). One of the feasible alternative treatments being used for their control of this disease is essential oils. In this study in vitro antimicrobial activity of Andiroba and Copaíba essential oils against Paenibacillus species, including P. larvae was evaluated. Minimal inhibitory concentration (MIC) in Mueller-Hinton broth by the microdilution method was assessed. Andiroba registered MIC values of 1.56-25%, while the MICs values obtained for Copaíba oil were of 1.56-12.5%. In order to determine the time-response effect of essential oils on P. larvae, this microorganism was exposed to the oils for up to 48 h. After 24 h treatment with Andiroba oil and after 48 h treatment with Copaíba oil no viable cells of P. larvae ATCC 9545 were observed. The possible toxic effect of essential oils were assessed by the spraying application method of the same concentrations of MICs. Bee mortality was evident only in treatment with Andiroba oil and the Copaíba oil shows no toxic effects after 10 days of observation. Taking together ours results showed for the first time that these oils presented a high activity against Paenibacillus species showing that Copaíba oil may be a candidate for the treatment or prevention of AFB.