105 resultados para Enzymatic Activities
Resumo:
The present study was designed to evaluate the possible effect of the consumption of blackberry juices (BJ) prepared with water (BJW) and defatted milk (BJM) on the plasma antioxidant capacity and the. enzymatic and nonenzymatic antioxidants. A significant (p < 0.05) increase in the ascorbic acid content in the plasma was observed after intake of both BJs. However, no changes were observed in the plasma urate and a-tocopherol levels. An increase on the plasma antioxidant capacity, by ORAC assay, was observed only after consumption of BJW but not statistically significant. Plasma antioxidant capacity had a good positive correlation with ascorbic acid (r = 0.93) and a negative correlation with urate level (r = -0.79). No correlation was observed between antioxidant capacity and total cyanidin or total ellagic acid contents. Further, it was observed that plasma catalase increased following intake of BJ`s. No change was observed on the plasma and erythrocyte CAT and glutathione peroxidase activities. A significant decrease (p < 0.05) in the urinary antioxidant capacity between 1 and 4 h after intake of both BJs was observed. A good correlation was observed between total antioxidant capacity and urate and total cyanidin levels. These results suggested association between anthocyanin levels and CAT and a good correlation between antioxidant capacity and ascorbic acid in the human plasma after intake of BJs. Follow-up studies investigating the antioxidant properties and health benefits are necessary to demonstrate the health benefits of polyphenols.
Resumo:
The effects of myotoxin III (MT-III), a phospholipase A(2) (sPLA(2)) from Bothrops asper snake venom, and crotoxin B (CB), a neurotoxic and myotoxic sPLA2 from the venom of Crotalus durissus terrificus, on cyclooxygenases (COXs) expression and biosynthesis of prostaglandins (PGs) were evaluated, together with the mechanisms involved in these effects. Upon intraperitoneal injection in mice, both sPLA(2)s promoted the synthesis of PGD(2) and PGE(2), with a different time-course. MT-III, but not CB, induced COX-2 expression by peritoneal leukocytes without modification on COX-1 constitutive expression, whereas CB increased the constitutive activity of COX-1. MT-III increased the enzymatic activity of COX-1 and COX-2. Similar effects were observed when these sPLA(2)s were incubated with isolated macrophages, evidencing a direct effect on these inflammatory cells. Moreover, both toxins elicited the release of arachidonic acid from macrophages in vitro. inhibition of cPLA(2) by AACOCF(3), but not of iPLA(2) by PACOCF(3) or BEL, significantly reduced PGD2, PGE2 and arachidonic acid (AA) release promoted by MT-III. These inhibitors did not affect MT-III-induced COX-2 expression. In contrast, cPLA2 inhibition did not modify the effects of CB, whereas iPLA2 inhibition reduced PGD2 and AA production induced by CB. These findings imply that distinct regulatory mechanisms leading to PGs` synthesis are triggered by these snake venom sPLA(2)s. Such differences are likely to explain the dissimilar patterns of inflammatory reaction elicited by these sPLA(2)s in vivo. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
Paraquat is a broad-spectrum contact herbicide that has been encountered worldwide in several cases of accidental, homicidal, and suicidal poisonings. The pulmonary toxicity of this compound is related to the depletion of NADPH in the pneumocytes, which is continuously consumed by the reduction/oxidation of paraquat and reductase enzyme systems in the presence of O(2) (redox cycling). Based on this mechanism, an enzymatic-spectrophotometric method was developed for the determination of paraquat in urine samples. The velocity of NADPH consumption was monitored at 340 nm, every 10 s during 15 min. The velocity of NADPH oxidation correlated with the paraquat levels found in samples. The enzymatic-spectrophotometric method showed to be sensitive, making possible the detection of paraquat in urine samples at concentrations as low as 0.05 mg/L.
Resumo:
To understand the role of peptidases in seminal physiology of Crotalus durissus terrificus, intra- and inter-seasonal activity levels of acid (APA), basic (APB), puromycin-sensitive (APN-PS) and puromycin-insensitive neutral (APN-PI), cystyl (CAP), dipeptidyl-IV (DPPIV), type-1 pyroglutamyl (PAP-I) and prolyl-imino (PIP) aminopeptidases as well as prolyl endopeptidase (POP) were evaluated in soluble (SF) and/or membrane-bound (MF) fractions of semen collected from the ductus deferens of the male reproductive tract and from the posterior portion of the uterus. Seminal APB, PIP and POP were detected in SF, while other peptidases were detected in SF and MF. Only the convoluted posterior uterus in winter and autumn had semen. Relative to other examined peptidases, in general, APN-PI, APN-PS and APB activities were predominant in the semen from the uterus and throughout the year in the semen from the ductus deferens, suggesting their great relevance in the seminal physiology of C. d. terrificus. The levels of peptidase activities in the ductus deferens semen varied seasonally and were different from those of semen in the uterus, suggesting that their modulatory actions on susceptible peptides are integrated to the male reproductive cycle events and spermatozoa viability of this snake.
Seasonal variation of peptidase activities in the reproductive tract of Crotalus durissus terrificus
Resumo:
Seasonal quantitative patterns of acid (APA), basic (APB), puromycin-sensitive (APN-PS) and puromycin-insensitive neutral (APN-PI), cystyl (CAP), dipeptidyl IV (DPPIV), type-1 pyroglutamyl (PAP-I) and prolylimino (PIP) aminopeptidases and prolyl oligopeptidase (POP) activities in soluble (SF) and solubilized membrane-bound (MF) fractions from ductus deferens, vagina and uterus were studied to evaluate their relationships with the reproductive cycle and the extensive long-term spermatozoa storage (LTSS) of the Neotropical rattlesnake Crotalus durissus terrificus. APB, PIP and POP were detected only in SF, while other peptidases were detected in SF and MF. APB, APN-PI and APN-PS were predominant in most tissues in all seasons. Peptidase activities had a common pattern of increment during the dry season (winter/autumn), which coincides with the mating period (autumn) and LTSS in the female (winter), as well as the reduction of spermatozoa motility and maintenance of fertilization capacity of spermatozoa. The high CAP activity in the soluble fraction of the vagina during winter, compared to summer (time of parturition) and spring, coincides with the relaxation of this tissue. In the soluble fraction, the low PAP-1 activity of the ductus deferens coincided with its high activity in the vagina during the winter; and the inverse occurred in summer, which is consistent with the physiological process of preserving spermatozoon viability. In conclusion, the studied peptidase activities had seasonal and tissue-specific characteristics, which suggest a relevant role in the reproductive physiology of C. d. terrificus. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
To understand the role of peptidases in seminal physiology of Crotalus durissus terrificus, activity levels of representative enzymes in semen and their sensitivities to inhibitors, cofactors, and peptide hormones were evaluated. The existence of seminal fractions and the association of peptidases with these fractions were also characterized for the first time in snakes. The prominent inhibitors of aminopeptidases (APs) were amastatin for acid, basic, and neutral; bestatin for basic; and diprotin A for dipeptidyl-IV. Cystyl and prolylimino AN were similarly susceptible to the majority of these inhibitors. The basic and neutral were characterized as metallo-peptidases, acid AP was activated by MnCl(2), and cystyl, prolyl-imino, and type I pyroglutamyl were characterized as sulphydryl-dependent APs. Angiotensin II, vasotocin, bradykinin, fertilization-promoting peptide, and TRH altered the majority of these peptidase activities; these peptides are possible substrates and/or modulators of these peptidases. Peptidase activities were found in all seminal fractions: seminal plasma (SP), prostasome-like (PR) structures, and soluble (S-) and membrane-bound fractions (MFs) of spermatozoa. The levels of activity of each peptidase varied among different seminal fractions. In SP, the higher activities were puromycin-insensitive neutral and basic APs. in PR, the higher activity was puromycin-insensitive neutral AP. In spermatozoa, the higher activity in subcellular SF was puromycin-sensitive neutral, while in MF both puromycin-sensitive and -insensitive neutral AN were equally higher than the other examined peptidases. Data suggested that these peptidases, mainly basic and neutral, have a high relevance in regulating seminal functions of C. d. terrificus.
Resumo:
The Suzuki-Miyaura cross-coupling reaction of a hydroxylated vinyl bromide obtained by a chemoenzymatic approach with a diverse range of potassium organotrifluoroborates has been accomplished catalyzed by Pd(PPh(3))(4) in satisfactory yields. A variety of functional groups are tolerated in the nucleophilic partner. (C) 2008 Elsevier B.V. All rights reserved.
Resumo:
The main goal of the present research effort was to evaluate the physical-chemical properties of blends of lard and soybean oil following enzymatic interesterification catalyzed by an immobilized lipase from Thermomyces lanuginosa (Lipozyme (TM) TL IM). Lipase-catalyzed interesterification produced new tri-acylglycerols that changed the physical-chemical properties of the fat blends under study. Solid fat content (31.3 vs 31.5 g/100 g), consistency (104.7 vs 167.6 kPa), crystallized area (0.6 vs 11.8) and softening point (31.8 vs 32.2 degrees C) of lard increased after interesterification, and this was mostly due to the increase of SSS (saturated) + SSU (disaturated-monounsaturated) triacylglycerols. These contents (SSU + SSS) increased in lard after interesterification from 42.9 to 46.7 g/100 g. The interesterified blends exhibited lower values for the physical properties when compared with their counterparts before enzymatic interesterification. The interesterification of blends of lard with soybean oil increased the amounts of UUU (triunsaturated) and SSS triacylglycerols and reduced the amounts of UUS (diunsaturated-monosaturated) triacylglycerols. The interesterified blends of lard and soybean oil demonstrated physical properties and chemical composition similar to human milk fat and they could be used for the production of a human milk fat substitute. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
The Brazilian Network of Food Data Systems (BRASILFOODS) has been keeping the Brazilian Food Composition Database-USP (TBCA-USP) (http://www.fcf.usp.br/tabela) since 1998. Besides the constant compilation, analysis and update work in the database, the network tries to innovate through the introduction of food information that may contribute to decrease the risk for non-transmissible chronic diseases, such as the profile of carbohydrates and flavonoids in foods. In 2008, data on carbohydrates, individually analyzed, of 112 foods, and 41 data related to the glycemic response produced by foods widely consumed in the country were included in the TBCA-USP. Data (773) about the different flavonoid subclasses of 197 Brazilian foods were compiled and the quality of each data was evaluated according to the USDAs data quality evaluation system. In 2007, BRASILFOODS/USP and INFOODS/FAO organized the 7th International Food Data Conference ""Food Composition and Biodiversity"". This conference was a unique opportunity for interaction between renowned researchers and participants from several countries and it allowed the discussion of aspects that may improve the food composition area. During the period, the LATINFOODS Regional Technical Compilation Committee and BRASILFOODS disseminated to Latin America the Form and Manual for Data Compilation, version 2009, ministered a Food Composition Data Compilation course and developed many activities related to data production and compilation. (C) 2010 Elsevier Inc. All rights reserved.
Resumo:
Phospholipase A(2) (PLA(2), EC 3.1.1.4), a major component of snake venoms, specifically catalyzes the hydrolysis of fatty acid ester bonds at position 2 of 1,2-diacyl-sn-3-phosphoglycerides in the presence of calcium. This article reports the purification and biochemical/functional characterization of BmooTX-I, a new myotoxic acidic phospholipase A(2) from Bothrops moojeni snake venom. The purification of the enzyme was carried out through three chromatographic steps (ion-exchange on DEAE-Sepharose, molecular exclusion on Sephadex G-75 and hydrophobic chromatography on Phenyl-Sepharose). BmooTX-I was found to be a single-chain protein of 15,000 Da and pI 4.2. The N-terminal sequence revealed a high homology with other acidic Asp49 PLA(2)S from Bothrops snake venoms. It displayed a high phospholipase activity and platelet aggregation inhibition induced by collagen or ADP. Edema and myotoxicity in vivo were also induced by BmooTX-I. Analysis of myotoxic activity was carried out by optical and ultrastructural microscopy, demonstrating high levels of leukocytary infiltrate. Previous treatment of BmooTX-1 with BPB reduced its enzymatic and myotoxic activities, as well as the effect on platelet aggregation. Acidic myotoxic PLA(2)S from Bothrops snake venoms have been little explored and the knowledge of its structural and functional features will be able to contribute for a better understanding of their action mechanism regarding enzymatic and toxic activities. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
The trace element selenium (Se), once known only for its potential toxicity, is now a well-established essential micronutrient for mammals. The organoselenium compound diphenyl diselenide (DPDS) has shown interesting antioxidant and neuroprotective activities. On the other hand, this compound has also presented pro-oxidant and mutagenic effects. The compound 3`3-ditrifluoromethyldiphenyl diselenide (DFDD), a structural analog of diphenyl diselenide, has proven antipsychotic activity in mice. Nevertheless, as opposed to DPDS, little is known on the biological and toxicological properties of DFDD. In the present study, we report the genotoxic effects of the organoselenium compound DFDD on Salmonella typhimurium, Saccharomyces cerevisiae and Chinese hamster lung fibroblasts (V79 cells). DFDD protective effects against hydrogen peroxide (H(2)O(2))-induced DNA damage in vitro are demonstrated. DFDD did not cause mutagenic effects on S. typhimurium or S. cerevisiae strains; however, it induced DNA damage in V79 cells at doses higher than 25 mu M, as detected by comet assay. DFDD protected S. typhimurium and S. cerevisiae against H(2)O(2)-induced mutagenicity, and, at doses lower than 12.5 mu M, prevented H(2)O(2)-induced genotoxicity in V79 cells. The in vitro assays demonstrated that DFDD mimics catalase activity better than DPDS, but neither presents Superoxide dismutase action. The products of the reactions of DFDD or DPDS with H(2)O(2) were different. as determined by electrospray mass spectrometry analysis (ESI-MS). These results suggest that DFDD is not mutagenic for bacteria or yeast; however, it may induce weak genotoxic effects on mammalian cells. In addition, DFDD has a protective effect against H(2)O(2)-induced damage probably by mimicking catalase activity, and the distinct products of the reaction DFDD with H(2)O(2) probably have a fundamental role in the protective effects of DFDD. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
The aim of this work was to investigate the effects of drying parameters on the retention of the enzymatic activity and on the physical properties of spray-dried pineapple stem extract. A Box and Behnken experimental design was used to investigate the effects of the processing parameters on the product properties. The parameters studied were the inlet temperature of drying gas (Tgi), the feed flow rate of the pineapple extract relative to evaporative capacity of the system (Ws /Wmax), and the concentration of maltodextrin added to the extract (MD). Significant effects of the processing parameters on the retention of the proteolytic activity of the powdered extract were observed. High processing temperatures lead to a product with a smaller moisture content, particle size, and lower agglomerating tendency. A product with insignificant losses of the proteolytic activity ( 10%) and low moisture content (less than 6.5%) is obtained at selected conditions.
Resumo:
Seven tetrahydrofuran lignans, isolated from Nectandra megapotamica (Lauraceae), were evaluated for their in vitro antileishmanial and antimalarial activities. Among the evaluated compounds, machilin-G (1a) and veraguensin (2a) showed the highest antileishmanial activities, displaying for both compounds an IC(50) value of 18 mu g/mL and an IC(50) value of 36 mu g/mL, while galgravin (1b), nectandrin-A (1c), nectandrin-B (1d), calopeptin (2b) and ganshisandrine (3) were inactive against Leishmania donovani. In the antimalarial assay against Plasmodium falciparum, it was observed that calopeptin (2b) displayed moderate activity, with IC(50) values of 3800 ng/mL (136 clone) and 3900 ng/mL (W2 clone), while the lignans 1a-1d, 2a and 3 were inactive. In order to compare the effect on the parasites with toxicity to mammalian cells, the cytotoxic activity of the isolated compounds were evaluated against the Vero cells, showing that all evaluated tetrahydrofuran lignans exhibited no cytotoxicity at the maximum dose tested. Copyright (C) 2008 John Wiley & Sons, Ltd.
Resumo:
The dibenzylbutyrolactolic lignan (-)-cubebin was isolated from dry seeds of Piper cubeba L (Piperaceae). (-)-Cubebin possesses anti-inflammatory, analgesic and antimicrobial activities. Doxorubicin (DXR) is a topoisomerase-interactive agent that may induce single- and double-strand breaks, intercalate into the DNA and generate oxygen free radicals. Here, we examine the mutagenicity and recombinogenicity of different concentrations of (-)-cubebin alone or in combination with DXR using standard (ST) and high bioactivation (HB) crosses of the wing Somatic Mutation And Recombination Test in Drosophila melanogaster. The results from both crosses were rather similar. (-)-Cubebin alone did not induce mutation or recombination. At lower concentrations, (-)-cubebin statistically reduced the frequencies of DXR-induced mutant spots. At higher concentrations, however, (-)-cubebin was found to potentiate the effects of DXR, leading to either an increase in the production of mutant spots or a reduction, due to toxicity. These results suggest that depending on the concentration, (-)-cubebin may interact with the enzymatic system that catalyzes the metabolic detoxification of DXR, inhibiting the activity of mitochondria! complex 1 and thereby scavenging free radicals. Recombination was found to be the major effect of the treatments with DXR alone. The combined treatments reduced DXR mutagenicity but did not affect DXR recombinogenicity. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
The in vitro antileishmanial activity of Brazilian green propolis hydroalcoholic extract (BPE) were carried out on Leishmania (Viannia) braziliensis against both promastigote (doses ranging from 1 to 750 mu g mL(-1)) and amastigote (10, 100, and 250 mu g mL(-1)) assays in comparison with the positive (amphotericin B) and negative (dimethyl sulfoxide at 1% in physiologic solution) control groups. BPE displayed in vitro antileishmanial activities against promastigote forms of the parasite (p<0.05). However, it was inactive against its amastigote ones. In the in vitro cytotoxicity assay against Vero cells, BPE showed no cytotoxicity in the maximum doses tested. The high-performance liquid chromatography analysis allowed the identification of caffeic acid, p-coumaric acid, aromadendrine-4`-methyl-ether, 3-prenyl-p-coumaric acid (drupanin), and 3,5-diprenil-p-cumarico acid (artepillin C) as major compounds of BPE. In the in vivo assay, using a Balb/C lineage of Mus musculus male mice, groups of ten animals each were treated (1.5 mg kg day(-1)) with BPE orally (group 1), BPE topically (group 2), BPE orally and topically (group 3), and glucantime (group 4), using NaCl 0.9% (group 5) as the negative control group. Groups 1, 2, and 3 displayed a decrease on lesion development, after 90 days of treatment, by 78.6%, 84.3%, and 90.0%, respectively, while the glucantime-treated group showed 57.7% of decrease, all in comparison with the negative control group. It is the first time that the in vivo antileishmanial activity has been reported for Brazilian green propolis.