Beneficial effects of mate-herb, Ilex paraguariensis St. Hil. against potassium dichromate-induced oxidative stress and nephrotoxicity.

Chimarrão is a typical beverage made from the infusion of dried and ground leaves and stems of Ilex paraguariensis (popularly known as Yerba mate or mate herb) which is widely consumed in parts of South America. The aim of this study was to examine the effects of the chimarrão against nephrotoxicity and oxidative stress induced by the potassium dichromate (PD) salt in male Wistar rats. The experiment lasted 17 days, and in the first 15 days animals ingested a chimarrão infusion or control drinking water and then submitted to an intraperitoneal injection (15 mg/kg) of PD (or saline solution) and euthanized after 48 hr at which time animals still received infusion or drinking water. Blood plasma and 24 hr-urine samples were collected to measure creatinine levels as an estimate of glomerular filtration rate (GFR). Concomitantly oxidative stress was determined in the kidneys as evidenced by levels of carbonyl groups, malondialdehyde (MDA) and antioxidant capacity against peroxyl radicals. Potassium dichromate induced oxidative stress in the kidneys and reduced GFR. Treatment with chimarrão during the 15 days prior to PD injection reduced PD salt-mediated oxidative stress. Further, treatment with post-injection chimarrão to PD-administered rats improved the GFR. Our findings support that the use of the chimarrão beverage may be considered as an important nephroprotective substance.

Single and combined toxicity of amino-functionalized polystyrene nanoparticles with potassium dichromate and copper sulfate on brine shrimp Artemia franciscana larvae.

The increasing use and disposal of plastics has become a persistent problem in the marine environment, calling for studies that refer to realistic scenarios to understand their effects on biota. Particularly, the understanding about the effects of co-exposure with nanoplastic particles and metals on aquatic organisms is still limited. The present work aimed to investigate the acute toxicity of amino-functionalized polystyrene nanoparticles (PS-NH2; 50 nm) as proxy for nanoplastics on brine shrimp Artemia franciscana larvae under different culture conditions and at different stages of development, as well as the combined effect with two reference toxicants - potassium dichromate (K2Cr2O7) and copper sulfate (CuSO4). Nauplii (instar II or III larval stages) were exposed to different concentrations of PS-NH2 (0.005 to 5 µg mL-1) for up to 48 h, with or without agitation in order to mimic a more realistic environmental scenario. Larval mobility and PS-NH2 accumulation were monitored under microscopy. PS-NH2 alone showed toxicity only at the highest concentration tested (5 µg mL-1) regardless the incubation method used (61.2 + 3.1% and 65.0 + 4.5% with and without agitation, respectively). Moreover, instar III stage was the most sensitive to PS-NH2 exposure (38.2% immobility in 24 h of exposure; 5 µg mL-1). Evidence of PS-NH2 retention in the gastrointestinal tract in a concentration- and time-dependent manner was also obtained. Mixtures of PS-NH2 (0.005 and 5 µg mL-1) with different concentrations of K2Cr2O7 increased the immobilization rate of the larvae after 48 h of exposure, when compared to the K2Cr2O7 alone. Similar results were observed for CuSO4 in the co-exposure conditions at different concentrations. However, exposing nauplii to a mixture of PS-NH2 (0.005 µg mL-1) and CuSO4 decreased immobilization rate, in comparison to the group exposed to CuSO4 alone. The present work highlights the potential risk posed by nanoplastics to zooplanktonic species through their interaction with other toxicants.

Probiotic mitigates the toxic effects of potassium dichromate in a preclinical study: a randomized controlled trial.

BACKGROUND: The present study aimed to evaluate the nutritional, physiological and biochemical effects of dietary supplementation of an association of probiotic bacteria in rats intoxicated with chromium (VI). Ninety-six male rats, recently weaned, were randomly divided into eight groups (n = 12): Control, DK12, DK24 and DK36 (0, 0.12, 0.24 and 0.36 g kg-1 of K2 Cr2 O7 incorporated in the basal feed, respectively) and groups Prob, DK12 + Prob, DK24 + Prob and DK36 + Prob received a progressive dose of 0, 0.12, 0.24 and 0.36 g kg-1 of K2 Cr2 O7 incorporated in the basal feed and supplemented with 0.02 g kg-1 of an association of probiotic bacteria (Lactobacillus acidophilus, Enterococcus faecium, Bifidobacterium thermophilum and Bifidobacterium longum). RESULTS: After 90 days, we observed significant (P < 0.05) and dose-dependent alterations from incorporation of increasing doses of chromium (VI) related to nutritional, physiological and biochemical parameters. These changes were attenuated (P < 0.05) with probiotic supplementation. CONCLUSION: Supplementation with probiotics in the diet beneficially modified the nutritional and physiological parameters, as well as hepatic, renal, glycemic and lipid profiles, of animals intoxicated with increasing doses of K2 Cr2 O7 . © 2018 Society of Chemical Industry.

Curcumin prevents potassium dichromate (K2Cr2O7)-induced renal hypoxia.

Curcumin exhibits several therapeutic properties. Potassium dichromate (K2Cr2O7)-induced nephropathy is associated with oxidative stress. Reactive oxygen species production affects renal oxygenation that may participate in the progression of renal damage. The aim of the present work was to elucidate whether K2Cr2O7-induced nephropathy is associated to partial O2 pressure (pO2) impairment and if curcumin is able to prevent it. Four groups of rats were studied: control group; K2Cr2O7 group (12.5 mg/kg, s.c.); curcumin + K2Cr2O7 group, in which animals were treated with curcumin (400 mg/kg/day, p.o.) for 10 days before K2Cr2O7 injection; and curcumin group. All animals were sacrificed 48 h after the end of the treatments. K2Cr2O7 administration increased renal function markers and decreased glomerular filtration rate, pO2 and renal perfusion. Concerning hemodynamic parameters, K2Cr2O7 increased mean arterial pressure and renal vascular resistance and reduced renal blood flow. The hemodynamic changes were attributed to decreased availability of nitric oxide and increased 3-nitrotyrosine levels. Moreover, increased superoxide anion production and vascular endothelial growth factor levels were observed after K2Cr2O7 administration. Curcumin attenuated all the above-described alterations. Our results suggest that the protective effects of curcumin in K2Cr2O7-induced nephropathy are associated with its ability to prevent O2 supply reduction.

Mutagenic and histopathological effects of hexavalent chromium in tadpoles of Lithobates catesbeianus (Shaw, 1802) (Anura, Ranidae).

The potential mutagenic and histopathological effects of the hexavalent chromium were investigated in Lithobates catesbeianus tadpoles. These larvae (GS 25-31) were exposed to three nominal concentrations of potassium dichromate (4, 12, and 36 mg L-1) and 5 mg L-1 of Cyclophosphamide as a positive control (PC), for 24 h. A negative control (NC) was also added to the experiment. Our results showed that, in general, the micronuclei (MN) were less frequent than the erythrocyte nuclear abnormalities (ENA); there was a significant difference in the frequency of MN between the NC and all treated groups (p < 0.05) in a concentration-dependent curve, in addition the PC did not differ from the chromium treatments. Also, only PC and the group treated with potassium dichromate at 36 mg L-1 showed significantly higher frequencies of ENA than NC (p < 0.05). Chromium treatments promoted cell retention in the Sub-G1 phase and a decrease of cells in the S and G2/M phases indicating inhibition of the cell cycle. All treatments with chromium led to liver and kidney histopathological lesions, especially with 36 mg L-1 (greater number of lesions). In conclusion, hexavalent chromium was mutagenic to L. catesbeianus tadpoles and its toxic effects also resulted in anti-mitotic activity, besides inducing histopathological alterations in liver and kidney. Amphibians have been proven to be useful bioindicators, and we suggest that tadpoles of different species can be used to represent the environmental impacts in aquatic ecosystems.

Mutagenic Effects of Potassium Dichromate as Evaluated by Means of Animal and Plant Bioindicators.

BACKGROUND: Chromium typically occurs in two oxidation states in the natural environment, Cr(3+) [Cr(III)] and Cr(6+) [Cr(VI)]. Out of the two chromium species, Cr(VI) is the most mobile, labile and toxic. Hexavalent chromium [Cr(VI)] compounds are classified by the International Agency for Research on Cancer (IARC) as carcinogenic agents to humans. The main source of release of chromium in aquatic ecosystems is related to the industrial application of this metal in metallurgies, tanneries, and in the manufacturing of paints and dyes. The ecotoxicology of Cr(VI) is linked to its environmental persistence and the ability to induce adverse effects in biological systems. In the present study, we evaluated mutagenic effects of Cr(VI) in animal and plant bioindicators. MATERIALS AND METHODS: We evaluated primary DNA damage and frequencies of micronuclei (MN) and morphological nuclear abnormalities (NA) in erythrocytes in peripheral blood of the fish Oreochromis niloticus exposed to potassium dichromate at 12 mg l(-1). The genotoxicity and cytotoxicity of Cr(VI) in the onion (Allium cepa) test were also assessed. RESULTS: The comet assay showed a significant increase of tailed nucleoids in the erythrocytes of fish treated with K2Cr2O7; MN frequency was also increased in the treatments; cytotoxicity of a low concentration of potassium dichromate, however, was not confirmed. CONCLUSION: The combination of both systems - animal and plant - is adequate and advantageous for mutagenicity evaluation. The findings indicate that at the concentration tested, the chromium compound is a clastogenic as well as an aneugenic.

Oxidative Stress Markers and Histological Analysis in Diverse Organs from Rats Treated with a Hepatotoxic Dose of Cr(VI): Effect of Curcumin.

Hexavalent chromium [Cr(VI)] compounds are extremely toxic and carcinogenic. Despite the vast quantity of reports about Cr(VI) toxicity, the information regarding its effects when it is intraperitoneally (i.p.) administered is still limited. In contrast, it has been shown that curcumin prevents hepatotoxicity induced by a single intraperitoneal injection of 15 mg/kg body weight (b.w.) of potassium dichromate (K2Cr2O7). This study aims to evaluate oxidative stress markers, the activity of antioxidant enzymes, and the potential histological injury in brain, heart, lung, kidney, spleen, pancreas, stomach, and intestine from rats treated with a hepatotoxic dose of K2Cr2O7 (15 mg/kg b.w.), and the effect of curcumin pretreatment. Rats were divided into four groups: control, curcumin, K2Cr2O7, and curcumin+K2Cr2O7. At the end of the treatment, plasma and ascites fluid were collected and target organs were dissected out for biochemical and histological analysis. K2Cr2O7 induced hepatotoxicity but failed to induce in all the other studied organs either oxidative or histological injury, since levels of malondialdehyde (MDA), glutathione (GSH), and the activity of superoxide dismutase (SOD), catalase (CAT), and related GSH enzymes were unchanged. As expected, curcumin was safe. Lack of K2Cr2O7-induced toxicity in those target organs could be due to the following: (1) route of administration, (2) absorption through the portal circulation, (3) lower dose than needed, (4) short time of exposure, or (5) repeated doses are required to produce damage. Thus, the intraperitoneal injection of 15 mg/kg of K2Cr2O7, that is able to induce hepatotoxicity, was unable to induce histological and oxidative damage in other target organs.

Curcumin attenuates Cr(VI)-induced ascites and changes in the activity of aconitase and F(1)F(0) ATPase and the ATP content in rat liver mitochondria.

Occupational and environmental exposure to potassium dichromate (K2Cr2O7), a hexavalent chromium compound, can result in liver damage associated with oxidative stress and mitochondrial dysfunction. The purpose of this study was to evaluate the effect of the antioxidant curcumin (400 mg/kg b.w.) on the K2Cr2O7-induced injury, with special emphasis on ascitic fluid accumulation and oxidative phosphorylation mitochondrial enzymes and the adenosine triphosphate (ATP) levels in isolated mitochondria from livers of rats treated with K2Cr2O7 (15 mg/kg b.w.). Thus, curcumin attenuated the ascites generation, prevented the decrease in the activities of aconitase and F1F0 ATPase, and maintained the ATP levels. The activity of complex II was not completely reestablished by curcumin, whereas complexes III and IV activities were unchanged.

Efeito do probiótico após toxicidade hepática do dicromato de potássio em ratos / Effect of probiotic after hepatic toxicity of potassium dichromate in rats

O objetivo do presente trabalho foi o de avaliar as alterações dependentes da dose de dicromato de potássio (0, 12, 24 e 36 mg.kg-1 ) no tecido hepático, após suplementação com probiótico em dosagens 0 ou 0,2%, em 80 ratos machos. A ingestão oral por 90 dias de doses crescentes de dicromato de potássio produziu sinais clínicos de toxicidade frente à análise histopatológica (p< 0,05) e atividades séricas enzimáticas (p< 0,05), dos marcadores de função hepática. A inclusão do probiótico na dieta mitigou os efeitos nos parâmetros estudados.

This work aims to evaluate the alterations, depending on the dose of potassium dichromate (0, 12, 24 and 36 mg.kg-¹), in liver tissue after supplementation with probiotic at dosages 0 or 0.2% in 80 male rats. Oral ingestion done for 90 days of increasing amounts of potassium dichromate produced clinical signs of toxicity compared to histopathological analysis (p˂0.05), and seric enzymatic activities (p˂0.05), markers of hepatic function. The inclusion of probiotics to the diet mitigated the effects on the studied parameters.

Efeito do probiótico após toxicidade hepática do dicromato de potássio em ratos / Effect of probiotic after hepatic toxicity of potassium dichromate in rats

O objetivo do presente trabalho foi o de avaliar as alterações dependentes da dose de dicromato de potássio (0, 12, 24 e 36 mg.kg-1 ) no tecido hepático, após suplementação com probiótico em dosagens 0 ou 0,2%, em 80 ratos machos. A ingestão oral por 90 dias de doses crescentes de dicromato de potássio produziu sinais clínicos de toxicidade frente à análise histopatológica (p< 0,05) e atividades séricas enzimáticas (p< 0,05), dos marcadores de função hepática. A inclusão do probiótico na dieta mitigou os efeitos nos parâmetros estudados.(AU)

This work aims to evaluate the alterations, depending on the dose of potassium dichromate (0, 12, 24 and 36 mg.kg-¹), in liver tissue after supplementation with probiotic at dosages 0 or 0.2% in 80 male rats. Oral ingestion done for 90 days of increasing amounts of potassium dichromate produced clinical signs of toxicity compared to histopathological analysis (p˂0.05), and seric enzymatic activities (p˂0.05), markers of hepatic function. The inclusion of probiotics to the diet mitigated the effects on the studied parameters.(AU)

Acute toxicity by water containing hexavalent or trivalent chromium in native Brazilian fish, Piaractus mesopotamicus: anatomopathological alterations and mortality.

This study evaluated the toxicity of hexavalent and trivalent compounds of chromium to the pacu, Piaractus mesopotamicus, in acute exposures of 96 h through mortality and histopathological responses. Hexavalent potassium dichromate was more toxic than trivalent compounds of chromium chloride, chromium oxide and chromium carbochelate. Sufficient mortalities occurred only with potassium dichromate to yield an LC50 value at 124.2 mg L(-1). Hexavalent chromium caused reversible and irreversible lesions, which may affect organ functionality. Histopathological evaluation showed that trivalent chromium caused lesions of lower severity. Pacu subjected to different concentrations of chromium carbochelate showed no histopathological changes in the kidneys, liver, skin and gills, being similar to those of the control fish. Among the three sources of Cr(3+), only chromium chloride at 200 mg L(-1) resulted in mortality, which reached 100 % within the first 18 h. These findings confirm that trivalent chromium, when administered within recommended levels, may be used safely in aquaculture.

Use of the microalgae Thalassiosira weissflogii to assess water toxicity in the Suape industrial-port complex of Pernambuco, Brazil.

Microalgae are among the organisms that are most frequently recommended to assess water toxicity levels. They provide qualitative and quantitative population changes and have become important in environmental monitoring. The aim of the present study was to assess the sensitivity of the microalgae Thalassiosira weissflogii to water toxicity in the Suape industrial-port complex, and to potassium dichromate in the months of July, September and November of 2010 and January and September of 2011, as well as to compare the microalgae results to those obtained in tests with the sea urchin Lytechinus variegatus. The chronic toxicity tests with both species followed standardized methods. Once the exposure period was completed, the population increase of the algae was assessed using cell density and growth rate data and the percentage of L. variegatus pluteus larvae revealing normal and aberrant development was determined. The algal growth and percentage of pluteus results demonstrated that toxicity in the studied area varied according to the month. The present study confirmed that the best timeframe to conclude tests with the microalgae T. weissflogii was 72 h. The microalgae cell density results after 72 h were sufficient to assess the toxicity of surface water samples and were more sensible than the growth rates. The microalgae T. weissflogii was a sensitive test-organism for seawater toxicity.

Deferoxamine pretreatment prevents Cr(VI)-induced nephrotoxicity and oxidant stress: role of Cr(VI) chelation.

Deferoxamine (DFO) is a recognized iron chelator which has been shown to exert nephroprotection in models of toxic nephropathies. In the present work the potential protective effects of DFO against Cr(VI)-induced nephrotoxicity and oxidant stress were evaluated. Rats were injected with a single injection (15mg/kg, s.c.) of potassium dichromate (K(2)Cr(2)O(7)). DFO was given as a single i.p. injection 30min before K(2)Cr(2)O(7) administration at three different doses (100, 200 and 400mg/kg). It was found that DFO pretreatment attenuated, in a dose-dependent way, K(2)Cr(2)O(7)-induced renal dysfunction and structural alterations evaluated by serum creatinine, blood urea nitrogen, creatinine clearance, proteinuria, plasma glutathione peroxidase activity, urinary excretion of N-acetyl-ß-d-glucosaminidase and histological analyses. Furthermore, DFO prevented the K(2)Cr(2)O(7)-induced renal oxidant stress and the decrease in the activity of the antioxidant enzymes superoxide dismutase, glutathione reductase, glutathione peroxidase, glutathione-S-transferase and catalase. Finally it was found that DFO, at 400mg/kg, decreases renal Cr(VI) content which prompted us to evaluate the potential Cr(VI) chelating properties of this compound. Indeed was found in an in vitro assay that DFO was an effective Cr(VI) chelator with an IC(50) of 800µg. In additional groups of rats was found that DFO posttreatment was ineffective to attenuate K(2)Cr(2)O(7)-induced nephrotoxicity and renal oxidant stress. Furthermore, DFO was unable to modify urinary excretion of total chromium. The nephroprotective effect of DFO against Cr(VI)-induced nephrotoxicity and oxidant stress may be explained, at least partially, by the ability of DFO to chelate Cr(VI) and to attenuate renal Cr(VI) content. However, it cannot be excluded that the ability of DFO to chelate iron may also be involved in the protection observed in our study.

Microcrustaceans escape behavior as an early bioindicator of copper, chromium and endosulfan toxicity.

The purpose of this work was to experimentally analyze the impact of copper, chromium and a commercial pesticide with endosulfan on the escape behavior of two copepods (Notodiaptomus conifer, Argyrodiaptomus falcifer) and three cladocerans (Daphnia magna, Pseudosida variabilis and Ceriodaphnia dubia). The experimental assays were carried out using a novel hydraulic devise designed to mimic three-speed predator capture behavior. Two concentrations, one "high" and one "low", were employed and the exposure time was 15 (±5) minutes. With two exceptions, the species exposed to heavy metals manifested higher ability to escape than controls. Both concentrations of the pesticide reduced the escape ability of cladocerans but copepods responded, in general, in a similar manner as for heavy metals. The immediate apparent advantage of low and early toxic effects is discussed and the high sensitivity of the escape behavior suggests that it could be a complementary endpoint to be used in future ecotoxicological tests.

Exposure to sublethal chromium and endosulfan alter the diel vertical migration (DVM) in freshwater zooplankton crustaceans.

Among zooplankton behaviors, diel migrations constitute one of the most effective predator avoidance strategy and confer metabolic and demographic advantages. We aim to examine whether sublethal concentrations of two widespread pollutants (a pesticide with endosulfan and chromium as potassium dichromate) alter the depth selection, vertical migration and grouping of five freshwater species: Argyrodiaptomus falcifer, Notodiaptomus conifer, Pseudosida variabilis, Ceriodaphnia dubia and Daphnia magna. In a series of experimental assays, performed with 150 cm length transparent tubes, we analyzed the ascents and descents movements through periods of 24 h. Among controls, the copepods showed a tendency to remain closest to the surface, however, N. conifer registered a downward movement of 18.14 cm between 06:00 and 12:00. The cladoceran P. variabilis occupied the deeper position (85 cm), C. dubia showed a tendency to hike to the surface at 06:00 (57.7 cm) descending to lower levels at 18:00. D. magna showed a constant movement of ascent between 00:00 and 18:00, making an average travel of 29.4 cm. When subjected to pollutants, these behaviors were altered. It is hypothesized that a reduction in swimming activity and disorientation would be the main cause of such alterations. The high sensitivity of this endpoint sugests it to be adecuate as a complement in future standard toxicity tests.

Acute toxicity tests with the tropical cladoceran Pseudosida ramosa: The importance of using native species as test organisms.

Cladocerans have long been used for toxicological assessments of a diverse range of substances. The use of cladocerans in toxicity tests has many advantages, such as their short life cycle, parthenogenetic reproduction (clones), and high sensitivity to toxicants, as well as the easy laboratory maintenance of cultures. The most commonly used cladoceran in ecotoxicological studies of aquatic environments is undoubtedly Daphnia magna. Standard methods using cladocerans as test organisms have been documented and adopted by major international organizations and regulatory agencies of many countries. However, today there is a growing need for improving test organisms and protocols to better reflect local species sensitivity or site-specific conditions. The present study aimed to assess the tropical species Pseudosida ramosa as a potential test organism for ecotoxicological purposes, by carrying out standard acute tests with six reference compounds. Based on the results obtained in the present study and in comparison with other cladocerans, it was found that P. ramosa was more sensitive than Daphnia magna, had a sensitivity similar to that of Daphnia similis, and was less sensitive compared to Ceriodaphnia dubia and C. silvestrii (Neotropical species), except for the salts, sodium chloride and potassium chloride. Also, when P. ramosa was compared with test organisms of other taxonomic groups, we observed that it was more sensitive than most of the others, from simple coelenterates to complex fish. Considering these results and the wide distribution of the cladoceran P. ramosa in tropical and subtropical regions, we suggest that this species can be adopted as a test organism, being a good substitute for the exotic daphnid D. magna, for monitoring of toxicants in freshwaters.

Validation test with embryonic and larval stages of Chordodes nobilii (Gordiida, Nematomorpha): sensitivity to three reference toxicants.

Chordodes nobilii is a parasite whose pre- and postparasitic stages are found in different types of freshwater bodies. Due to the peculiarities of its life cycle, it acts as a link between freshwater bodies and terrestrial ecosystems. There is little toxicological information on the group Gordiida. It is only known that embryos and larvae of C. nobilii are sensitive to glyphosate and malathion at relevant concentrations in the environment. On this basis, the aims of this study were to characterize the sensitivity of the pre-parasitic stages of C. nobilii to three reference toxicants: sodium dodecyl sulfate (SDS), cadmium chloride and potassium dichromate (Cr(6+)), and to validate a previous experimental protocol for ecotoxicological risk assessment. The protocol involved acute exposure of early embryonic stages and larvae to the three toxicants for 96 h and 48 h, respectively. Embryo development was inhibited only by Cr(6+) which presented a IC(50) of 0.71 mg Cr(6+)L(-1). The development of the eggs exposed to SDS and those exposed to cadmium chloride showed no differences as compared to that of controls. However, the infective capacity of larvae derived from the eggs exposed to the three toxicants was lower than that of controls. Larval survival was affected even at the lowest concentration of the three toxicants assayed. In relation to other freshwater organisms, C. nobilii can be characterized as an organism medium to highly sensitive to the toxicants tested.

Assessment of the potential toxicity of a linear alkylbenzene sulfonate (LAS) to freshwater animal life by means of cladoceran bioassays.

The acute and chronic toxic effects of LAS on the cladocerans Daphnia similis, Ceriodaphnia dubia and Ceriodaphnia silvestrii were tested. Both types of toxicity bioassays and the methods of culture and stock maintenance of the test organisms conformed to the recommendations of ABNT (Brazilian Society of Technical Standards), which closely follow the standard methods of USEPA. The results obtained for EC(50) (48 h) were: 14.17 mg L(-1) for D. similis, 11.84 mg L(-1) for C. dubia and 13.52 mg L(-1) for C. silvestrii. In the chronic toxicity tests performed on C. dubia and C. silvestrii, there was a significant decrease in the fecundity of the exposed animals; the value of NOEC for C. dubia and C. silvestrii were 1.00 mg L(-1) and 2.50 mg L(-1), respectively. Cladoceran bioassays provided evidence that LAS concentration as low as 1.00 mg L(-1) can damage invertebrate animal life in freshwaters, concentrations that can be found in many eutrophic rivers and reservoirs.

Levaduras autóctonas con capacidad fermentativa en la producción de etanol a partir de pulpa de excedentes de plátano musa (AAB Simmonds) en el departamento de Córdoba, Colombia / Autoctonous yeasts having fermentation ability in producing ethanol from Musa (AAB Simmonds) plantain surplus pulp in the Córdoba department of Colombia

Se evaluó la capacidad fermentativa de levaduras nativas de la zona costanera del departamento de Córdoba, Colombia, para la obtención de etanol a partir de la pulpa de excedentes de plátano Musa (AAB Simmonds), con el objetivo de encontrar cepas eficientes. Los microorganismos utilizados correspondieron a las especies: Kloeckera sp, Candida guillliermondii 14AD, Candida albicans y Candida guillliermondii 13AD (nativas), y una cepa comercial de referencia, Saccharomyces cerevisiae T73. La fermentación se realizó a diferentes concentraciones de sustrato, siendo la concentración del 40% la mejor; se evaluó la producción de etanol mediante el método colorimétrico del dicromato de potasio utilizando un equipo espectrofotómetro Lambda 11. Se observó que la levadura Candida guilliermondii 14AD nativa fue la más eficiente con una producción promedio de 3,45% v/v de etanol a las 72 horas de fermentación; no se encontraron diferencias estadísticamente significativas con la producción de etanol a partir de la cepa de referencia, la cual produjo 3,59% v/v. Estos resultados sugieren la existencia de levaduras nativas con capacidad para ser utilizadas en la obtención de etanol a partir de material residuo de plátano.

Native yeasts™ (Cordoba, Colombia) fermentation ability for producing ethanol from plantain (Musa AAB Simmonds) surplus pulp was evaluated; the object was to find efficient yeasts. The microorganisms used here came from the Kloeckera sp, Candida guillliermondii (14AD), Candida albicans and Candida guilllier-mondii 13AD strains (native) and Saccharomyces cerevisiae T73 (a commercial reference yeast). Fermentation was carried out on different substrate concentrations, the 40% one giving the best result; ethanol production was evaluated by the potassium dichromate colorimetric method using a Lambda 11 spectrophotometer. It was observed that the Candida guilliermondii 14AD native yeast was the most efficient, having an average 3.45% v/v ethanol production after 72 hours’ fermentation. There were no statistically significant differences compared to reference yeast strain ethanol production (3.59% v/v). These results suggest that native yeasts can be used in obtaining ethanol from residual plantain matter.

The flavonoid quercetin protects and prevents against potassium dichromate-induced systemic peroxidation of lipids and diminution in renal clearance of para-aminohippuric acid and inulin in the rat.

It is well known that exposure to chromium (Cr) can lead to nephrotoxicity. Quercetin is a flavonoid of interest because of its proposed health-promoting effects. The aim of this work was to elucidate the role of quercetin against the nephrotoxicity caused by Cr in rats. Quercetin may have positive effects in combating, or helping to prevent, nephrotoxicity. It was observed that a single dose of potassium dichromate resulted in both an increase of systemic peroxidation of lipids and a decrease of the renal clearance of para-aminohippuric acid and inulin. Our results show that treatment with quercetin protected and prevented against these damaging effects.