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1.
Toxicon ; 242: 107708, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38574827

RESUMO

Hepatocellular carcinoma and bacterial resistance are major health burdens nowadays. Thus, providing new therapies that overcome that resistance is of great interest, particularly those derived from nature rather than chemotherapeutics to avoid cytotoxicity on normal cells. Venomous animals are among the natural sources that assisted in the discovery of novel therapeutic regimens. L-amino acid oxidase Nh-LAAO (140 kDa), purified from Egyptian Naja haje venom by a successive two-step chromatography protocol, has an optimal pH and temperature of 8 and 37 °C. Under standard assay conditions, Nh-LAAO exhibited the highest specificity toward L-Arg, L-Met and L-Leu, with Km and Vmax values of 3.5 mM and 10.4 µmol/min/ml, respectively. Among the metal ions, Ca+2, Na+, and K+ ions are activators, whereas Fe+2 inhibited LAAO activity. PMSF and EDTA slightly inhibited the Nh-LAAO activity. In addition, Nh-LAAO showed antibacterial and antifungal activities, particularly against Gentamicin-resistant P. aeruginosa and E. coli strains with MIC of 18 ± 2 µg/ml, as well as F. proliferatum and A. parasiticus among the selected human pathogenic strains. Furthermore, Nh-LAAO exhibited anti-proliferative activity against cancer HepG2 and Huh7 cells with IC50 of 79.37 and 60.11 µg/ml, respectively, with no detectable effect on normal WI-38 cells. Consequently, the apoptosis % of the HepG2 and Huh7 cells were 12 ± 1 and 34.5 ± 2.5 %, respectively, upon Nh-LAAO treatment. Further, the Nh-LAAO arrested the HepG2 and Huh7 cell cycles in the G0/G1 phase. Thus, the powerful selective cytotoxicity of L-amino acid oxidase opens up the possibility as a good candidate for clinical cancer therapy.


Assuntos
Antineoplásicos , Venenos Elapídicos , L-Aminoácido Oxidase , L-Aminoácido Oxidase/farmacologia , L-Aminoácido Oxidase/química , Animais , Humanos , Antineoplásicos/farmacologia , Venenos Elapídicos/farmacologia , Venenos Elapídicos/química , Células Hep G2 , Naja naja , Linhagem Celular Tumoral , Testes de Sensibilidade Microbiana , Anti-Infecciosos/farmacologia , Egito , Antibacterianos/farmacologia , Apoptose/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos
2.
Plant Physiol Biochem ; 207: 108406, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38309182

RESUMO

Chrysanthemum is one of the most attractive flowering plants widely grown commercially worldwide. Having a good source of organic fertilizers plays an important role in meeting the increasing demand for these plants, which requires high-quality flowers and a high survival time for the longest period. The effect of nitrogen (N) coupled with spent coffee ground (SCG) at various levels (0.0, 2.5, 5.0, 7.5, 10.0°% w/w) was evaluated on growth performance and chemical components of the Chrysanthemum over two years in a pot scale. Overall, total dry matter (TDM) was significantly enhanced with N+ by 125 and 97°% over N- in the first and second years, respectively. SCG also enhanced TDM up to the highest level of application in the range of 27-98°% and 18-81°% over SCG (0.0°%) in the same years, respectively. The interaction effect between N and SCG was perfect on TDM, flower number, and flower dry weight. Similarly, total antioxidant activities when N and SCG were coupled together gave respective increments ranging from 11.8 to 45.9 U/g DW and from 2.1 to 15.9 U/g DW compared to N alone (5.8 and 0.9 U/g DW) in both leaves and flowers, respectively. Extracts of plant treated with N and 10°% SCG exhibited a higher content of rosmarinic, caffeic, chlorogenic, vanillic acids, and rutin in the leaves. SCG as a natural organic source is easy to obtain and is a practical and cost-effective solution to plant nutrition, which can be valuable for ornamental plants, especially when combined with nitrogen.


Assuntos
Chrysanthemum , Café , Antioxidantes/química , Chrysanthemum/química , Nitrogênio/análise , Folhas de Planta , Flores
3.
Arch Microbiol ; 204(8): 526, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35895237

RESUMO

Viral infections are linked to a variety of human diseases. Despite the achievements made in drug and vaccine development, several viruses still lack preventive vaccines and efficient antiviral compounds. Thus, developing novel antiviral agents is of great concern, particularly the natural products that are promising candidates for such discoveries. In this study, we have purified an approximately 15 kDa basic phospholipase A2 (PLA2) enzyme from the Egyptian cobra Naja haje haje venom. The purified N. haje PLA2 showed a specific activity of 22 units/mg protein against 6 units/mg protein for the whole crude venom with 3.67-fold purification. The antiviral activity of purified N. haje PLA2 has been investigated in vitro against bovine coronavirus (BCoV) and simian rotavirus (RV SA-11). Our results showed that the CC50 of PLA2 were 33.6 and 29 µg/ml against MDBK and MA104 cell lines, respectively. Antiviral analysis of N. haje PLA2 showed an inhibition of BCoV and RV SA-11 infections with a therapeutic index equal to 33.6 and 16, respectively. Moreover, N. haje PLA2 decreased the BCoV and RV SA-11 titers by 4.25 log10 TCID50 and 2.5 log10 TCID50, respectively. Thus, this research suggests the potential antiviral activity of purified N. haje PLA2 against BCoV and RV SA-11 infections in vitro.


Assuntos
Antivirais , Coronavirus Bovino , Venenos Elapídicos , Fosfolipases A2 , Rotavirus , Animais , Antivirais/farmacologia , Coronavirus Bovino/efeitos dos fármacos , Venenos Elapídicos/farmacologia , Naja haje , Fosfolipases A2/farmacologia , Rotavirus/efeitos dos fármacos
4.
J Food Biochem ; 45(1): e13526, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33140461

RESUMO

The study aims to evaluate the relation between peroxidases of day-6 garden cress sprouts and phenolic compounds. Three cationic, three anionic, and two unbounded peroxidases were separated from day-6 garden cress sprouts. Cationic (GCP1) and anionic (GCP2) peroxidases were purified with molecular masses of 25 and 40 kDa, respectively. The Km values of GCP1 toward H2 O2 and guaiacol were lower than GCP2. The anionic GCP2 exhibited high affinity toward some lignin monomers, sinapyl alcohol, coniferyl alcohol, cinnamic and ferulic acids. Therefore, GCP2 is considered as a lignin peroxidase and contributed in lignin synthesis. The activity of GCP1 and GCP2 was stable at a wide pH range 5.5-8.0 and 6.0-7.5, respectively. Both peroxidases showed the same thermal stability range 20-50°C. GCP2 was more resistant against the effect of metal ions than GCP1. GCP2 showed high ability to remove of phenol and p-chlorophenol from effluent compared to GCP1. PRACTICAL APPLICATIONS: Generally, garden cress is used as a test plant to conduct biomonitoring of pollution in urban soil on a wide scale because of its simplicity, sensitivity, and cost-effectiveness. Peroxidase is an important antioxidant enzyme, which elevated when plant subjected to pollution. Recently, we reported that the increase of peroxidase activity was strongly correlated with high phenolic content and antioxidant activity during the germination of garden cress. In the present study, anionic peroxidase GCP2 may play an important role in lignification process and removal of phenol and p-chlorophenol from polluted soil/wastewater as well as resisted the harmful effect of heavy metals. Cationic peroxidase GCP1, as a natural scavenger, had high affinity toward H2 O2 coupled to oxidation of some plant phenolic compounds suggesting its role in consuming of excess H2 O2 .


Assuntos
Lepidium sativum , Fenol , Clorofenóis , Peroxidases , Fenóis
5.
Toxicon ; 188: 108-116, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33065201

RESUMO

Echis pyramidum (Epy) is a venomous snake belongs to Viperidae family; it causes fetal coagulopathy systemic effects and death. Searching for more effective and safe antivenom is mandatory for viper bites treatment. Proteases are the most lethal components in viper venom inducing hemorrhage, edema and coagulation problems. Thus, the study aims to evaluate the potency of the prepared antisera and their neutralizing properties against the biological activities induced by whole Epy venom individually. Echis pyramidum metalloprotease enzyme (60 kDa) was purified using size-exclusion followed by DEAE-ion exchange chromatography. The purified Epy metalloprotease enzyme (SVMP) was detoxified with 1.5 kGy gamma rays from cobalt60 gamma cell and used for immunization. 1.5 kGy irradiated Epy metalloprotease (SVMPi) showed less lethal activity (LD50) compared to the corresponding native immunogen. The prepared antisera boosted against whole Epy venom (WV), 1.5 kGy irradiated whole Epy venom (WVi), SVMP and SVMPi were tested for neutralization of lethality and biological activities induced by Epy venom. The antibodies elicited against WVi and SVMPi were 30,000 and 20,000 EU, respectively. The anti-SVMPi serum showed the highest neutralization of lethality (ED50) compared to the other prepared antisera. In addition, it prolonged the clotting time from 49.0 ± 2.5 to 176.2 ± 1.4 s. Furthermore, it demonstrated a highly neutralizing activity against edema induction and hemorrhage of Epy venom by 66.8% and 94.3%, respectively compared with the other prepared antisera. These findings would encourage further studies for using gamma irradiated purified fraction(s) from different snake venoms as safe antigen(s) to produce more effective antivenoms.


Assuntos
Raios gama , Metaloproteases/uso terapêutico , Mordeduras de Serpentes/terapia , Viperidae , Animais , Antivenenos , Radioisótopos de Cobalto , Endopeptidases , Soros Imunes/imunologia , Dose Letal Mediana , Metaloproteases/imunologia , Metaloproteases/efeitos da radiação , Venenos de Víboras
6.
Int J Biol Macromol ; 130: 695-704, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30826405

RESUMO

A hemorrhagic metalloprotease (CVHT1) was isolated from Cerastes vipera (CV) viper venom and characterized in a set of biochemical and immunological assays. A simple two-step purification procedure included gel filtration and ion-exchange increase the purity of enzyme 39-fold with specific activity of 20,200 Umg-1 compared to 520 Umg-1 for crude venom. CVHT1 is a dimer enzyme with two subunits of ~60 kDa. The LC-MS/MS analysis of CVHT1 revealed that the identified peptides show high homology to other P-III snake venom zinc-metalloproteases. The activity of CVHT1 showed stability at pH (6.5-8.5) and temperature (30-60 °C) with optima at pH 8.5 and 60 °C. Activators for CVHT1 included Mg+2, Zn+2, Ca+2, K+, Ba+2 and Na+, while the full inhibition was given by other tested ions, SH-group reagents and metalloproteinase inhibitors. The CVHT1 potentially digested gelatin, fibrinogen, fibronectin and inhibited the platelet aggregation. The hemorrhagic and proteolytic activities of medically important Egyptian viper venoms were highly cross-neutralized by anti-CVHT1. The anti-CVHT1 increased the survival time of mice injected with lethal dose of CV venom to 23 ±â€¯2.5 h compared to the mice injected with venom alone 0.52 ±â€¯0. 05 h. This study could be useful for production of safer and more efficient therapeutic anti-venom.


Assuntos
Metaloendopeptidases/química , Venenos de Víboras/enzimologia , Sequência de Aminoácidos , Animais , Cromatografia Líquida , Ativação Enzimática/efeitos dos fármacos , Masculino , Metaloendopeptidases/imunologia , Metaloendopeptidases/isolamento & purificação , Metais/química , Camundongos , Peso Molecular , Testes de Neutralização , Agregação Plaquetária/imunologia , Proteólise , Coelhos , Análise Espectral , Espectrometria de Massas em Tandem , Venenos de Víboras/imunologia , Viperidae
7.
J Biochem ; 165(2): 177-184, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30407509

RESUMO

Xylan saccharification is a key step in many important biotechnological applications. Xylose is the main product of xylan degradation and is a major xylanase inhibitor in a bioreactor; however, xylose-binding site of xylanase is not discovered yet. Evolving of xylose-tolerant xylanase variants will reduce the cost of xylanases in industry. Glycoside hydrolase family-10 thermostable Geobacillus stearothermophilus xylanase XT6 is non-competitively inhibited by xylose with inhibition constant ki equals to 12.2 mM. In the absence of X-ray crystallography of xylanase-xylose complex, unbiased random mutagenesis of the whole xylanase gene was done by error-prone polymerase chain reaction constructing a huge library. Screening a part of the library revealed xylose-tolerant mutants having three mutations, M116I, L131P and L133V, clustered in the N-terminus of α-helix 3. The best xylose-tolerant mutant showed higher ki and catalytic capability than that of the parent by 3.5- and 3-fold, respectively. In addition, kcat increased 4.5-fold and KM decreased 2-fold. The molecular docking of xylose into xylanase XT6 structure showed that xylose binds into a small pocket between N-terminus of α-helices 3 and 4 and close to the three mutations. Mobility of α-helices 3 and 4, which controls catalysis rate, is restricted by xylose binding and increased by these mutations.


Assuntos
Evolução Molecular Direcionada , Endo-1,4-beta-Xilanases/química , Endo-1,4-beta-Xilanases/metabolismo , Geobacillus stearothermophilus/enzimologia , Xilose/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Endo-1,4-beta-Xilanases/genética , Geobacillus stearothermophilus/genética , Modelos Moleculares , Mutação , Relação Estrutura-Atividade , Xilose/química
8.
J Tradit Complement Med ; 8(4): 465-475, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30302327

RESUMO

The morbidity caused by viper bites is very dangerous and the anti-venom therapy couldn't treat the local injures such as hemorrhage, edema, necrosis and inflammation of bitten tissues. Searching for safe and effective anti-venom compounds from natural sources is very important. This study was designed to explore the neutralizing ability of Rosmarinus officinalis L. leaves aqueous extract (RMAE) against Egyptian Cerastes cerastes (Cc) viper venom toxicity. The RMAE contained a considerable amount of phenolic and flavonoid contents with 3,300 and 800 mg/100 g dry weight, respectively. The RMAE showed a considerable variation of phenolic acids by using HPLC technique. Rosmarinic acid is the major component of the RMAE which recorded 400 mg/100 g dry weight and 64% of all the identified compounds. In vitro, the RMAE neutralized the enzymatic activities of proteases, l-amino acid oxidases, and phospholipases A2 of the Cc venom dose-dependently. In addition, the RMAE effectively neutralized the gelatinolytic, fibrinogenolytic, hemolytic and procoagulant activities of Cc venom. In vivo, the RMAE markedly reduced lethality, hemorrhage, edema, muscle and liver toxicities induced by Cc venom. In conclusion, the venom neutralizing property of the RMAE gives a new prospect for efficient treatment of the lethal viper bites.

9.
Rev. bras. farmacogn ; 28(5): 594-601, Sept.-Oct. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-977737

RESUMO

Abstract In this study, mango seed kernels extract contained a considerable amount of phenolics and flavonoids (17,400 and 3325 mg/100 g seed, respectively). The HPLC profiling revealed that hesperidin was the major phenolic compound of the mango seed kernels extract. This is the first report find hesperidin in mango extracts. The phenolic compounds of mango seed kernels extract were effective in scavenging free radicals of DPPH and ABTS with IC50 values of 47.3 and 7.9 µg/ml, respectively. The total antioxidant activity of mango seed kernels extract based on the reduction of molybdenum was also measured. The phenolic compounds of mango seed kernels extract potentially inhibited the protease, fibrinogenase, phospholipase A2, l-amino acid oxidase, hyaluronidase, and hemolytic activities of the most dangerous Cerastes cerastes and Echis coloratus viper venoms. The phenolic compounds of mango seed kernels extract could completely neutralize the hemorrhage and lethality of both venoms in experimental animals. It could be concluded that the mango seed kernels extract phenolic compounds with potential antioxidant activity are considered as a new avenue in the viper bite treatment.

10.
Toxicon ; 150: 270-279, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29898379

RESUMO

A homodimeric l-amino acid oxidase enzyme (Cv-LAAOI) was isolated from the venom of Cerastes vipera (Egyptian Sand viper) using gel filtration followed by anion exchange chromatography. The molecular mass of Cv-LAAO is 120 kDa in its native form and 60 kDa in its monomeric form. The optimum enzyme activity was achieved on l-Leucine as a substrate in 50 mM buffer pH 7.5 at 50 °C. The Cv-LAAOI activity was significantly reduced by increasing the temperature over 40 °C, lost 75% of its activity at 60 °C and inhibited completely at 80 °C. The Cv-LAAOI attains the highest substrate specificity towards L-Met. The results have also indicated that Mn2+ enhances the enzyme activity by 10%, while Cu2+, Hg2+, Ni2+, Co2+ have suppressive effects on the Cv-LAAOI activity. On the other hand, EDTA has no significant effect on the enzyme activity. The kinetic parameters of Cv-LAAOI activity (Km, Kcat and Vmax) estimated on l-Leucine at pH 8 and 37 °C were found to be 2 mM, 12 S-1 and 16.7 µmol/min/ml, respectively. In addition, the results have shown that Cv-LAAOI exhibits a significant bactericidal activity against gram-positive and gram-negative bacteria, particularly Staphylococcus aureus and Escherichia coli with MIC values of 20 µg/ml. Moreover, Cv-LAAOI has exhibited a considerable cytotoxic activity against breast cancer cell line (MCF-7) with IC50 value 2.75 ±â€¯0.38 µg/ml compared with different tumor cell lines (liver HepG2, lung A549, colon HCT116 and prostate PC3). Furthermore, Cv-LAAOI has triggered antiproliferative activity via extensive H2O2 generation as indicated by the increase in H2O2 and TBARS levels accompanied by the depletion in the catalase activity (CAT) in MCF-7 treated cells compared to the untreated ones. Thus, these findings clearly indicate that Cv-LAAOI has a selective cytotoxic effect on breast cancer cell line, demonstrating a great prospective for future use in cancer therapy.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Bactérias/efeitos dos fármacos , L-Aminoácido Oxidase/metabolismo , Venenos de Víboras/enzimologia , Viperidae/metabolismo , Animais , Antibacterianos/química , Antineoplásicos/química , Linhagem Celular Tumoral , Humanos , Concentração de Íons de Hidrogênio , L-Aminoácido Oxidase/química , Testes de Sensibilidade Microbiana , Especificidade por Substrato , Temperatura , Venenos de Víboras/química
11.
Toxicon ; 60(8): 1380-9, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-23000079

RESUMO

Novel Hyaluronidase CcHaseII (33 kDa) of the most dangerous horned viper Cerastes cerastes (Cc) was purified and partial characterized in a set of biochemical assays. CcHaseII was purified by applying a protocol of two successive chromatographic steps; gel filtration on a Sephacryl S-200 and cation exchange chromatography on CM-Sepharose columns. It has specific activity 4000 units/mg protein against 154 units/mg protein for the whole venom with 26-purification fold. The enzymatic activity of the purified Hyaluronidase stimulated by Na(+) and inhibited by entire tested cations, metalloproteinase inhibitors and heparin. CcHaseII (5-10 µg) enhanced one hundred percent of hemorrhagic activity of the potent purified hemorrhagic SVMP of corresponding venom (CcHTI) and enhanced edema-inducing activity of Cc venom in a dose-dependent manner. Furthermore, the described purification procedure allows simple preparation of appreciable quantities of the CcHaseII for further studies. Eventually, exploration of snake venom antigenic parts is the most crucial factor for establishing good immunogens and specific diagnostic reagents.


Assuntos
Hialuronoglucosaminidase/isolamento & purificação , Venenos de Víboras/enzimologia , Animais , Western Blotting , Cromatografia em Gel , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Hialuronoglucosaminidase/química , Hialuronoglucosaminidase/metabolismo , Cinética , Peso Molecular , Especificidade por Substrato
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