Microcystins (MC) are hepatotoxic for organisms. Liver MC accumulation and structural change are intensely studied, but the functional hepatic enzymes and energy metabolism have received little ...attention. This study investigated the liver and hepatocyte structures and the activity of key hepatic functional enzymes with emphasis on energetic metabolism changes after subchronic fish exposure to cyanobacterial crude extract (CE) containing MC. The Neotropical erythrinid fish, Hoplias malabaricus, were exposed intraperitoneally to CE containing 100 μg MC‐LR eq kg−1 for 30 days and, thereafter, the plasma, liver, and white muscle was sampled for analyses. Liver tissue lost cellular structure organization showing round hepatocytes, hyperemia, and biliary duct obstruction. At the ultrastructural level, the mitochondria and the endoplasmic reticulum exhibited disorganization. Direct and total bilirubin increased in plasma. In the liver, the activity of acid phosphatase (ACP) increased, and the aspartate aminotransferase (AST) decreased; AST increased in plasma. Alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were unchanged in the liver, muscle, and plasma. Glycogen stores and the energetic metabolites as glucose, lactate, and pyruvate decrease in the liver; pyruvate decreased in plasma and lactate decreased in muscle. Ammonia levels increased and protein concentration decreased in plasma. CE alters liver morphology by causing hepatocyte intracellular disorder, obstructive cholestasis, and dysfunction in the activity of key liver enzymes. The increasing energy demand implies glucose mobilization and metabolic adjustments maintaining protein preservation and lipid recruitment to supply the needs for detoxification allowing fish survival.
Cyanobacterial proliferation in river and lakes is the result of eutrophication. The cyanobacterium
Radiocystis fernandoi
strain R28 produces mostly two MC variants MC-RR and MC-YR and small amounts ...of other oligopeptides, but does not produce MC-LR. The present study investigated the hepatotoxic potential of the crude extract of the
R. fernandoi
strain R28 on the Neotropical fish,
Piaractus mesopotamicus
, at 3, 6, and 24 h after intraperitoneal injection (100 μg MC-LR equivalent per kg
−1
body mass) using biochemical and morphological biomarkers of liver damage. Although the protein phosphatases PP1 and PP2A were not inhibited during the 24-h treatment, liver parenchyma and hepatocyte structure were disrupted. Alkaline phosphatase increased at 3 h post-injection and decreased after 24 h; alanine aminotransferase and aspartate aminotransferase increased in a time-dependent manner up to 24 h indicating impaired liver function. Progressive histopathological changes were consistent with biochemical results demonstrating alterations in liver structure and function. In conclusion, the crude extract of
R. fernandoi
strain R28 has high hepatotoxic potential and can severely compromise fish health.
Our search for candidates for photosynthesis inhibitors is allowing us to report the effect of two acetogenins identified in Annona coriacea Mart. leaves, ACG−A and ACG−B, a non‐adjacent bis‐THF and ...a mono‐THF types, respectively. This is an important class of natural products which presents biological properties such as anticancer, neurotoxic, larvicidal and insecticidal. However, this is only the second report associated to its herbicidal activity. Their mechanisms of action on the light reactions of the photosynthesis were elucidated by polarographic techniques. Compounds inhibited the noncyclic electron transport on basal, phosphorylating, and uncoupled conditions from H2O to methyl viologen (MV); therefore, they act as Hill reaction inhibitors. Studies on fluorescence of chlorophyll a (ChL a) indicated that they inhibited the acceptor side of PSII between P680 and PQ‐pool, exactly as the commercial herbicide DCMU does.
Cancer of the head and neck is a group of upper aerodigestive tract neoplasms in which aggressive treatments may cause harmful side effects to the patient. In the last decade, investigations on ...natural compounds have been particularly successful in the field of anticancer drug research. Our aim is to evaluate the antitumor effect of
Aubl. extracts on a panel of head and neck squamous cell carcinoma (HNSCC) cell lines. Analysis of secondary metabolites classes in fractions of
was performed using Nuclear Magnetic Resonance (NMR). Mutagenicity effect was evaluated by Ames mutagenicity assay. The cytotoxic effect, and migration and invasion inhibition were measured. Additionally, the expression level of apoptosis-related molecules (PARP, Caspases 3, and Fas) and MMP-2 was detected using Western blot. Heterogeneous cytotoxicity response was observed for all fractions, which showed migration inhibition, reduced matrix degradation, and decreased cell invasion ability. Expression levels of MMP-2 decreased in all fractions, and particularly in the hexane fraction. Furthermore, overexpression of FAS and caspase-3, and increase of cleaved PARP indicates possible apoptosis extrinsic pathway activation. Antiproliferative activity of
extract in HNSCC cells lines suggests the possibility of developing an anticancer agent or an additive with synergic activities associated with conventional anticancer therapy.
Pequi (Caryocar spp.) is a fruit native to the Brazilian Savannah (Cerrado), and Caryocar brasilienseCamb. is one of the most prevalent species in this biome. The consumption of the pequi pulp has ...been associated with health benefits, such as antioxidant, anti-inflammatory, hypolipidemic, hepatoprotective, and anticarcinogenic effects. These benefits have been attributed to its high density in nutrients and bioactive compounds. However, there is evidence about considerable variation in the nutritional profile among pequi pulps of different species, and among pulps of the same species, but from different areas of the Cerrado. In addition, there is no information in literature regarding the polyphenols profile of C. brasiliense pulp, neither about the influence of the native area of the fruit on the composition of these phytochemicals. So, this study analyzed the nutrient composition and identified the phenolic compounds in the pulp of C. brasiliense fruits native to four different areas of the Cerrado. There was a remarkable variation in the contents of energy (176.3-387.2 kcal/100 g) and lipids (13.0-37.5 g/100 g) among samples. In contrast, no difference was observed in the polyphenols composition, since gallic acid, protocatechuic acid, catechin, epicatechin, p-coumaric acid, and ellagic acid were identified in all pequi pulps. C. brasiliense pulp shows potential to be used as a functional ingredient rich in bioactive compounds, but with different contents of energy and lipids according to the fruit’s native area to attempt distinct health allegations of the product.
RESUMO: O pequi (Caryocar spp.) é um fruto nativo do cerrado brasileiro e Caryocar brasiliense Camb. é uma das espécies mais prevalentes neste bioma. O consumo da polpa de pequi tem sido associado a benefícios à saúde, como efeitos antioxidantes, anti-inflamatórios, hipolipidêmicos, hepatoprotetores e anticarcinogênicos. Esses benefícios têm sido atribuídos à sua alta densidade em nutrientes e compostos bioativos. No entanto, há evidências de considerável variação no perfil nutricional entre polpas de pequi de diferentes espécies, e entre polpas da mesma espécie, mas de diferentes áreas do cerrado. Além disso, não há informações na literatura sobre o perfil de polifenóis da polpa de C. brasiliense, tampouco sobre a influência da área nativa do fruto na composição desses fitoquímicos. Assim, este estudo analisou a composição de nutrientes e identificou os compostos fenólicos na polpa de frutos de C. brasiliense nativos de quatro diferentes áreas do Cerrado. Houve notável variação nos teores de energia (176,3-387,2 kcal/100 g) e lipídios (13,0-37,5 g/100 g) entre as amostras. Em contrapartida, não foi encontrada diferença na composição em polifenóis, uma vez que ácido gálico, ácido protocatecuico, catequina, epicatequina, ácido p-cumárico e ácido elágico foram identificados em todas as polpas de pequi analisadas. A polpa de C. brasiliense tem potencial para ser utilizada como ingrediente funcional rico em compostos bioativos, porém com diferentes teores de energia e lipídios de acordo com a área nativa do fruto para atender a distintas alegações de saúde do produto.
ABSTRACT Rice blast caused by the Magnaporthe oryzae pathogen is a major disease in this crop, and may cause devastating losses. This study aimed to investigate the profile of Waitea circinata ...mycorrhiza volatile compounds in antagonism to M. oryzae, under different growth periods and temperatures, using a completely randomized design. Volatile organic compounds were extracted by headspace solid phase microextraction and analyzed by gas chromatography mass spectrometry, while multidimensional scaling was used to compare the produced volatile organic compounds. The main compounds responsible by the antagonism to M. oryzae were longifolene, trans-β-farnesene, (Z)-α-bisabolene and δ-amorphene, which can be used as biofungicides and incorporated into rice blast management strategies.
RESUMO A brusone causada pelo patógeno Magnaporthe oryzae é a principal doença do arroz, e pode causar perdas devastadoras. Objetivou-se investigar o perfil de compostos voláteis da micorriza Waitea circinata no antagonismo a M. oryzae, em diferentes períodos e temperaturas, utilizando-se delineamento inteiramente casualizado. Compostos orgânicos voláteis foram extraídos por micro extração em fase sólida, no modo headspace, e analisados por cromatografia gasosa acoplada a espectrometria de massas, enquanto o escalonamento multidimensional foi usado para comparar os compostos orgânicos voláteis produzidos. Os principais compostos responsáveis pelo antagonismo a M. oryzae foram longifoleno, trans-β-farneseno, (Z)-α-bisaboleno e δ-amorfeno, que podem ser usados como biofungicidas e incorporados às estratégias de manejo da brusone do arroz.
•Cyanobacterium R. fernandoi crude extract (CE) causes osmoregulatory disorder in fish.•CE unchanged endogenous PP1 and PP2A activities in gills and decreased in the kidney.•Mitochondria-rich cell ...density and Na+/K+-ATPase activity changed in the gills.•Gill histopathology exhibited continuous increasing 24 h after CE injection.•Kidney function and glomeruli and tubules morphology unchanged.
Blooms of cyanobacteria, a common event in eutrophic environments, result in the release of potentially toxic substances into the water. The cyanobacterium Radiocystis fernandoi produces microcystin (MC) and other peptides that may disturb homeostasis. This study evaluated the effect of intraperitoneal injections containing the crude extract (CE) of R. fernandoi strain R28 on the gills and kidneys of neotropical fish, Piaractus mesopotamicus, 3, 6 and 24 h post-injection. CE contained MC-RR, MC-YR and minor other oligopeptides. Plasma ions and the activities of the enzymes PP1 and PP2A, Na+/K+-ATPase (NKA), H+-ATPase (HA) and carbonic anhydrase (CA) were determined and morphological changes in both the gills and kidneys were characterized. Compared to controls, the concentration of Na+ within the plasma of P. mesopotamicus decreased after treatment with CE 3 h post treatment and increased after 24 h; the concentration of K+ decreased after 6 h. The activity of the endogenous PP1 and PP2A was unchanged in the gills and was inhibited in the kidneys 6 h after i.p. injection. In the gills, NKA activity increased after 3 h and decreased 6 h post i.p. exposure. Further, NKA activity did not differ from the controls 24-h post injection. In the kidneys, NKA, HA and CA activities were unaffected by treatment. The mitochondria-rich cell (MRC) density in the gills decreased after 3 h in the filament and 3 and 6 h in the lamellae and was restored to the control levels 24 h post-exposure. Filament epithelial hyperplasia and hypertrophy, lamellar atrophy and rupture of the lamellar epithelium were the most common effects of treatment in the gills. No histopathological changes occurred in the kidneys. This study demonstrates that a single dose of toxic CE from R. fernandoi can cause a transitory ion imbalance in P. mesopotamicus which is related to the changes in MRC levels and NKA activity. Ionic balance was recovered 24 h post i.p. injection, however, morphological changes that occurred in the gills took a longer amount of time to return to normal. To conclude, the effects of components contained within the CE of R. fernandoi may be harmful to P. mesopotamicus. In particular, the recovery of ionic regulation depends on MRC responses and histopathological changes produced by CE may affect gas exchange and other gill functions.
The toxicological effect of cellular extract of cyanobacterium Radiocystis fernandoi strain R28 containing RR and YR microcystins was analyzed in the fish Hoplias malabaricus with emphasis on the ...liver structure and energetic metabolism, after short-term exposure. Fish were intraperitoneally (i.p.) injected with 100 μg of equivalent MC-LR kg−1 body mass containing in the cellular extract of R. fernandoi strain R28. Twelve and 96 h post-injection, the plasma, liver and white muscle were sampled for biochemical analyses and liver was also sampled for morphological analyses. After i.p. injection, the activity of acid phosphatase (ACP), alanine aminotransferase (ALT) and direct bilirubin increased in the plasma, while ALT and aspartate aminotransferase (AST) decreased in the liver. Glucose, lactate and pyruvate increased while protein decreased in the plasma; glycogen, pyruvate and lactate decreased in the liver; and glycogen and glucose increased in the muscle. Ammonia increased in the plasma, liver and muscle. The hepatocyte cell shape changed from polyhedral to round after cellular extract injection; there was loss of biliary canaliculus organization, but the biliary duct morphology was conserved in the liver parenchyma. In conclusion, microcystins present in the cellular extract of R. fernandoi strain R28 affect the liver structure of H. malabaricus, but the liver was able to continuously produce energy by adjusting its intermediate metabolism; glycogenolysis and gluconeogenesis maintained glucose homeostasis and energy supply.
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•Microcystins RR and YR are majority toxins produced by R. fernandoi strain R28.•Cyanobacterial cellular extract changes the plasma and liver enzyme activity in fish.•Biliary canaliculus is altered, but biliary duct integrity is maintained.•Glycogen depletion occurred in liver and increased in white muscles.•Energetic metabolic compounds are altered in liver, plasma and muscles.
The cyanobacterium Radiocystis fernandoi has been frequently identified in cyanobacterial blooms in Brazil. Recently, R. fernandoi strain R28, which produces microcystin (MC)-RR and MC-YR, was ...isolated from the Furnas reservoir, Minas Gerais, Brazil. The present study evaluated the hematological variables and erythrocyte antioxidant responses, lipid peroxidation (LPO), and genotoxicity in a neotropical fish (Hoplias malabaricus) after acute and subchronic exposure to a crude extract (CE) of R. fernandoi strain R28. Acute exposure (12 or 96 h) consisted of a single intraperitoneal (i.p.) CE injection, and subchronic exposure consisted of one i.p. CE injection every 72 h for 30 days. After acute exposure, fish exhibited macrocytic anemia (12 h post-injection) followed by normocytic anemia (96 h post-injection). The increased activity of superoxide dismutase, glutathione peroxidase, glutathione-S-transferase, and the glutathione level in the erythrocytes did not prevent oxidative stress, manifested as lipid peroxidation and elevated DNA damage after acute exposure. After subchronic exposure, the hematological variables recovered, and the absence of erythrocyte oxidative stress suggests possible modulation by other biological factors, including a possible decrease in MC uptake by the cells and/or increasing detoxification efficiency that precludes erythrocyte damage.
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•R. fernandoi strain 28 crude extract changes fish erythrocyte and antioxidant system.•Macrocytic anemia occurs after 12 h and normocytic anemia after 96 h exposure.•Erythrocyte antioxidant system responses increased after 12 and 96 h exposure.•Erythrocyte lipid peroxidation and DNA damage occurs after 12 and 96 h exposure.•After 30 days exposure blood variables and erythrocyte damages were recovered.
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