Bioactive endophytic fungi isolated from Caesalpinia echinata Lam. (Brazilwood) and identification of beauvericin as a trypanocidal metabolite from Fusarium sp.

Aiming to identify new sources of bioactive secondary metabolites, we isolated 82 endophytic fungi from stems and barks of the native Brazilian tree Caesalpinia echinata Lam. (Fabaceae). We tested their ethyl acetate extracts in several in vitro assays. The organic extracts from three isolates showed antibacterial activity against Staphylococcus aureus and Escherichia coli [minimal inhibitory concentration (MIC) 32-64 μg/mL]. One isolate inhibited the growth of Salmonella typhimurium (MIC 64 μg/mL) and two isolates inhibited the growth of Klebsiella oxytoca (MIC 64 μg/mL), Candida albicans and Candida tropicalis (MIC 64-128 μg/mL). Fourteen extracts at a concentration of 20 μg/mL showed antitumour activities against human breast cancer and human renal cancer cells, while two isolates showed anti-tumour activities against human melanoma cancer cells. Six extracts were able to reduce the proliferation of human peripheral blood mononuclear cells, indicating some degree of selective toxicity. Four isolates were able to inhibit Leishmania (Leishmania) amazonensis and one isolate inhibited Trypanosoma cruzi by at least 40% at 20 μg/mL. The trypanocidal extract obtained from Fusarium sp. [KF611679] culture was subjected to bioguided fractionation, which revealed beauvericin as the compound responsible for the observed toxicity of Fusarium sp. to T. cruzi. This depsipeptide showed a half maximal inhibitory concentration of 1.9 μg/mL (2.43 μM) in a T. cruzi cellular culture assay.

Bats and zoonotic viruses: can we confidently link bats with emerging deadly viruses?

An increasingly asked question is 'can we confidently link bats with emerging viruses?'. No, or not yet, is the qualified answer based on the evidence available. Although more than 200 viruses - some of them deadly zoonotic viruses - have been isolated from or otherwise detected in bats, the supposed connections between bats, bat viruses and human diseases have been raised more on speculation than on evidence supporting their direct or indirect roles in the epidemiology of diseases (except for rabies). However, we are convinced that the evidence points in that direction and that at some point it will be proved that bats are competent hosts for at least a few zoonotic viruses. In this review, we cover aspects of bat biology, ecology and evolution that might be relevant in medical investigations and we provide a historical synthesis of some disease outbreaks causally linked to bats. We provide evolutionary-based hypotheses to tentatively explain the viral transmission route through mammalian intermediate hosts and to explain the geographic concentration of most outbreaks, but both are no more than speculations that still require formal assessment.

Adverse reaction to the sulphite additives

Sulphites are widely used as preservative and antioxidant additives in the food and pharmaceutical industries. Exposure to sulphites has been reported to induce a range of adverse clinical effects in sensitive individuals, ranging from dermatitis, urticaria, flushing, hypotension, abdominal pain and diarrhea to life-threatening anaphylactic and asthmatic reactions. Exposure to the sulphites arises mainly from the consumption of foods and drinks that contain these additives; however exposure may also occur through the use of pharmaceutical products, as well as in occupational settings. Most studies report a prevalence of sulphite sensitivity of 3 to 10% among asthmatic subjects who ingest these additives. However, the severity of these reactions varies, and steroid-dependent asthmatics, those with marked airway hyperresponsiveness, and children with chronic asthma, appear to be at greater risk. Although a number of potential mechanisms have been proposed, the precise mechanisms underlying sulphite sensitivity remain unclear

[Effect of nisin on decreasing concentration of chemical preservatives]

Because of widespread interests to biopreservatives, several studies have been conducted within last decades that show the nisin has been used as a preservative to control food borne spoilage microorganisms. The aim of this study was to evaluate anti-bacterial activity of nisin and its effect on decreasing concentration of current chemical preservatives. In this experimental study, anti-bacterial activity of nisisn and its effect on decreasing concentration of usual chemical preservatives against Staphylococcus aureus [PTCC 1112] and Listeria monocytogenes [PTCC 1301] were studied. The study was performed in two steps. First, MIC [minimum inhibitory concentration] and MBC [minimal bactericidal concentration] of preservatives, including sodium nitrite, benzoic acid and nisin, were measured in optimum ph [5.5] by serial dilution method. Second, MIC of sodium nitrite and benzoic acid were determined in combination with nisin. Sodium nitrite, benzoic acid and nisin had antibacterial activities against Staphylococcus aureus and Listeria monocytogenes; MIC was 500, 200 and 25 ppm for Staphylococcus aureus, and 100, 200 and 10 ppm for Listeria monocytogenes, respectively. Niacin reduced MIC of sodium nitrite and benzoic acid to 200 and 50 ppm for Staphylococcus aureus, and 25 and 25 ppm for Listeria monocytogenes, respectively. The nisin reduces chemical preservatives concentration required, and it could be used as a safe preservative in food microbiology

Biochemical and biological studies on the interaction of some food colorants and preservatives

This study aims to investigate the effect of some food colorants and preservatives on Sprague-Dawley albino rats. The study was conducted on six equal groups fed on either basal control diet [group 1] or experimental diets [groups 2-6] as following: groups 2, 3 and 4 received a standard diet containing beta-carotene, tartrazine or benzoic acid, respectively at a dose of 200 mg/kg diet, while groups Sand 6 received a standard diet containing benzoic acid [200mg/ kg diet] incorporated with beta-carotene or tartrazine [200mg/ kg diet], respectively. Animals were fed ad libitum for 45 days. Body weight, food intake, feed efficiency and some biochemical analyses were measured, also histopathological examination of liver was performed. Our results showed a significant increase in blood urea, serum creatinine, ALT, AST, ALP and bilirubin in all groups except that received beta-carotene. Liver glycogen showed a significant decrease in rats fed on tartrazine alone or in combination with beuzoic acid. The histopathological results showed no significant toxic effects of beta-carotene alone while when combined with benzoic acid, moderate congestion and necrotic degeneration occurred. Tartrazine also induced slight mononuclear infiltration and benzoic alone showed marked vaculation, while in combination showed marked congestion, vascular infiltration and vaculation. In conclusion, the present study showed that even the permitted doses of colorants [e.g. beta-carotene and tartrazine] and food preservatives [e.g. benzoic acid] when taken together or if taken in excessive quantity may be harmful

Inhibition of aflatoxins and ochratoxin a production in corn [Zea mays] by certain food preservatives

The effect of propionic acid, ammonia and methionine on aflatoxins and ochratoxin A production by Aspergillus parasiticus and Penicillium verrucosum in autoclaved and non-autoclaved corn was investigated. The tested mycotoxins were determined by HPLC using fluorescence detector. The results indicated that the inhibition of toxins production vary between the three tested preservatives and the concentration of each as well. The higher inhibition of toxins production was obtained using a mixture which consists of equal volumes of propionic acid [65%], ammonia [2%] and methionine [0.2%]. In non-autoclaved corn, the inhibition of aflatoxin B1 and aflatoxin G1 production was 99.6% and 99.7% respectively, while aflatoxin B2, aflatoxin G2 and ochratoxin A production were completely inhibited. Meanwhile, in autoclaved corn, the inhibition of aflatoxins B1, B2, G1, G2 and ochratoxin A reached 83.0%, 83.6%, 85.7%, 83.1% and 86.4%, respectively

Peligros de los colorantes y aditivos / Risk of coloring and food additives

Las reacciones adversa a aditivos es un tema de especial interés en la práctica clínica. Hasta la fecha, no se dispone de estudios de calidad que permitan aportar datos sólidos sobre los efectos de los aditivos a largo plazo. La evidencia actualmente disponible no demuestra, sin embargo, una asociación clara, que justifique el retiro de alguno de los aditivos en uso. La legislación chilena sobre aditivos se basa en los estudios descritos y es acorde con los estándares internacionales actuales. Nuestro rol como médicos, es mantenernos informados al respecto, utilizando evidencia sólida. A la vez, como promotores de la salud, fomentar el consumo familiar de alimentos naturales.

Erupción fija pigmentaria por jugos artificiales / Fixed pigmentary drug eruption due to artificial juices

Se presentan tres pacientes entre siete y once años de edad, que desarrollaron una erupción fija pigmentaria tras al ingesta durante más de tres años de jugos artificiales dietéticos. Se realizó estudio histológico, que fue de compatibilidad en el primer y segundo caso, mostrando un patrón liquenoide en el tercero. Se discute el rol de los edulcorantes contenidos en estos jugos artificiales, como así su asociación con las sulfas

Incidencia de reacciones adversas a metabisulfitos en niños con asma bronquial: rol de la hiperreactividad / Incidence of adverse reactions to metabisulfites in children with bronchial asthma: roll of the hyperreactivity

Los metabisulfitos son capaces de desencadenar reaciones asmáticas en adultos y niños, con frecuencia variable según distintos autores. Estudiamos 30 niños asmáticos de grado leve a moderado, atópicos: 17 femeninos y 13 masculinos, a los que se les suspendía la terapéutica de su asma y le realizábamos prueba con metabisulfitos de potasio en cápsulas de 5 -10 -25 y 50mg. A los 7 días se realizaba una prueba nebulizable con metabisulfito de potasio en solución de 0.05 -0.5 y 5 mg/ml. 24 horas previas y posteriores a cada prueba con metabisulfitos realizábamos prueba de metacolina con la técnica de Chai, midiendo los pesos de cada paciente. Además, realizábamos pruebas cutáneas por Prick e introdermo, entre otras cosas, con metabisulfito de potasio. Como resultado 3 niños reaccionaron con cápsulas (2 a 25mg - 1 a 50mg); 3 niños reaccionaron con las nebuluzaciones (1 a 0.5 - 2 a 5mg/ml). El paciente N-19 reaccionó con cápsulas y soluciones, es decir, que el 16.66% de los niños reaccionó con metabisulfitos. Todos los niños reactores en cápsulas y soluciones tenían gran hiperreactividad bronquial a metacolina, pero no todos los que tenían gran hiperreactividad a metacolina eran sensibles a metabisulfitos. Las pruebas con metabisulfitos no produjeron cambios significativos en la hiperreactividad bronquial. Para cápsulas, P=0.3; para soluciones nebulizables, P=0.2. Las pruebas cutáneas con metabisulfitos fueron negativas en todos los pacientes