RESUMO

Paclitaxel (PTX) is a potent anticancer drug. In the present study, PTX was loaded in poly-3-hydroxybutyrate-co-3-hydroxyvalarate (PHBV) to fabricate the PTX/PHBV (drug-loaded) nanoparticles via the nanoprecipitation method. Blank PHBV nanoparticles were also prepared. The drug-encapsulation efficiency of PTX/PHBV nanoparticles was 45±0.4%. The PTX/PHBV nanoparticles exhibited a pH-sensitive release profile and followed a quasi-Fickian diffusion mechanism. Cytotoxic properties of PHBV and PTX/PHBV nanoparticles were checked against the MCF-7 and Caco-2 cell lines. The PHBV nanoparticle did not inhibit the proliferation of MCF-7 and Caco-2 cell lines, thus depicting their non-toxic and biocompatible nature. On the other hand, the PTX/PHBV nanoparticles demonstrated 1.03-fold higher cytotoxicity and 1.61-fold enhanced apoptosis after treatment with the PTX/PHBV nanoparticles versus free PTX. In summary, the PHBV nanoparticles could be a potential candidate for the delivery of PTX for cancer treatment.

Assuntos

RESUMO

Abstract Citrus fruit production occupies a place of considerable importance in the economy of the world including Pakistan. Tristeza disease caused by Citrus Tristeza Virus (CTV) exists in various forms that may or may not cause symptoms in the plants. The bioactive compounds and antioxidants are naturally present in plants and provide a defense mechanism that is generally accelerated in response to a stress. The objective of the present study was to target and analyze the citrus plants that were CTV positive to observe the changes in the enzymatic and non-enzymatic antioxidants of citrus (Sweet Oranges only). It was observed that in response to CTV infection, both the non-enzymatic antioxidants (total flavonoid, ascorbic acid, phenolic acid) and enzymatic antioxidants (catalase, superoxide dismutase and peroxidase) activities showed an increasing trend overall. The profiling of antioxidants in response to a viral infection may help in the discovery of new biomarkers that can be used as a monitoring tool in disease management.

Resumo As frutas cítricas ocupam um lugar de considerável importância na economia do Paquistão, assim como o resto do mundo. A doença da tristeza causada pelo Vírus da Tristeza dos Citros (CTV) existe em várias formas que podem ou não apresentar sintomas nas plantas. Os compostos bioativos e antioxidantes estão naturalmente presentes nas plantas e fornecem um mecanismo de defesa que é geralmente acelerado em resposta a um estresse. O objetivo do presente estudo foi analisar as alterações causadas pelo CTV nos antioxidantes enzimáticos e não enzimáticos de laranjas doces. Foi observado que, em resposta ao ataque de CTV, os antioxidantes não enzimáticos como flavonoides totais, ácido ascórbico, ácido fenólico e antioxidantes enzimáticos, como as atividades de catalase, superóxido dismutase e peroxidase, geralmente mostram uma tendência crescente. O perfil de antioxidantes em resposta a um ataque viral pode ajudar na descoberta de novos biomarcadores que podem ser usados ​​como uma ferramenta de monitoramento no gerenciamento de doenças.

Assuntos

RESUMO

Citrus fruit production occupies a place of considerable importance in the economy of the world including Pakistan. Tristeza disease caused by Citrus Tristeza Virus (CTV) exists in various forms that may or may not cause symptoms in the plants. The bioactive compounds and antioxidants are naturally present in plants and provide a defense mechanism that is generally accelerated in response to a stress. The objective of the present study was to target and analyze the citrus plants that were CTV positive to observe the changes in the enzymatic and non-enzymatic antioxidants of citrus (Sweet Oranges only). It was observed that in response to CTV infection, both the non-enzymatic antioxidants (total flavonoid, ascorbic acid, phenolic acid) and enzymatic antioxidants (catalase, superoxide dismutase and peroxidase) activities showed an increasing trend overall. The profiling of antioxidants in response to a viral infection may help in the discovery of new biomarkers that can be used as a monitoring tool in disease management.

Assuntos

RESUMO

Citrus fruit production occupies a place of considerable importance in the economy of the world including Pakistan. Tristeza disease caused by Citrus Tristeza Virus (CTV) exists in various forms that may or may not cause symptoms in the plants. The bioactive compounds and antioxidants are naturally present in plants and provide a defense mechanism that is generally accelerated in response to a stress. The objective of the present study was to target and analyze the citrus plants that were CTV positive to observe the changes in the enzymatic and non-enzymatic antioxidants of citrus (Sweet Oranges only). It was observed that in response to CTV infection, both the non-enzymatic antioxidants (total flavonoid, ascorbic acid, phenolic acid) and enzymatic antioxidants (catalase, superoxide dismutase and peroxidase) activities showed an increasing trend overall. The profiling of antioxidants in response to a viral infection may help in the discovery of new biomarkers that can be used as a monitoring tool in disease management.(AU)

As frutas cítricas ocupam um lugar de considerável importância na economia do Paquistão, assim como o resto do mundo. A doença da tristeza causada pelo Vírus da Tristeza dos Citros (CTV) existe em várias formas que podem ou não apresentar sintomas nas plantas. Os compostos bioativos e antioxidantes estão naturalmente presentes nas plantas e fornecem um mecanismo de defesa que é geralmente acelerado em resposta a um estresse. O objetivo do presente estudo foi analisar as alterações causadas pelo CTV nos antioxidantes enzimáticos e não enzimáticos de laranjas doces. Foi observado que, em resposta ao ataque de CTV, os antioxidantes não enzimáticos como flavonoides totais, ácido ascórbico, ácido fenólico e antioxidantes enzimáticos, como as atividades de catalase, superóxido dismutase e peroxidase, geralmente mostram uma tendência crescente. O perfil de antioxidantes em resposta a um ataque viral pode ajudar na descoberta de novos biomarcadores que podem ser usados como uma ferramenta de monitoramento no gerenciamento de doenças.(AU)

RESUMO

Kinetics of a lipase isolated from Bacillus sp. was studied. The enzyme showed maximum activity at pH 9 and temperature 60ºC. The Michaelis constant (K M 0.31 µM) obtained from three different plots i.e., Lineweaver-Burk, Hanes-Wolf and Hofstee, was found to be lower than already reported lipases that confirmed higher affinity of the enzyme for its substrate p-NPL (p-nitrophenyl laurate). Vmax of the enzyme was found to be 7.6 µM/mL/min. Energy of activation calculated from Arrhenius plot was found to be 20.607 kJmol-1. Activation enthalpy (ΔH*) had negative trend and the value for the hydrolysis of p-NPL by the enzyme at optimum temperature was -2.748 kJmol-1 . Activation entropy (ΔS*) and free energy of activation (ΔG*) of the enzyme were found to be 1.468 Jmol-1K-1 and -3.237 kJmol-1, respectively at optimum temperature. Low value of Q10 (0.04788) shows high catalytic activity of the enzyme. Mn2+, Fe2+ and Mg2+ enhanced the lipase activity whereas Cu2+, Na+ and Co2+ inhibited the enzyme activity. However, the enzyme activity was not affected significantly by K+ ions. EDTA and SDS also significantly inhibited the lipase activity. Activity of the enzyme was increased in n-hexane while decreased with increase in concentration of acetone, chloroform, ethanol and isopropanol.

Assuntos

RESUMO

Kinetics of a lipase isolated from Bacillus sp. was studied. The enzyme showed maximum activity at pH 9 and temperature 60°C. The Michaelis constant (KM 0.31 mM) obtained from three different plots i.e., Lineweaver-Burk, Hanes-Wolf and Hofstee, was found to be lower than already reported lipases that confirmed higher affinity of the enzyme for its substrate p-NPL (p-nitrophenyl laurate). Vmax of the enzyme was found to be 7.6 µM/mL/min. Energy of activation calculated from Arrhenius plot was found to be 20.607 kJmol(-1). Activation enthalpy (ΔH*) had negative trend and the value for the hydrolysis of p-NPL by the enzyme at optimum temperature was -2.748 kJmol(-1). Activation entropy (ΔS*) and free energy of activation (ΔG*) of the enzyme were found to be 1.468 Jmol(-1)K(-1) and -3.237 kJmol(-1), respectively at optimum temperature. Low value of Q10 (0.04788) shows high catalytic activity of the enzyme. Mn(2+), Fe(2+) and Mg(2+) enhanced the lipase activity whereas Cu(2+), Na(+) and Co(2+) inhibited the enzyme activity. However, the enzyme activity was not affected significantly by K(+) ions. EDTA and SDS also significantly inhibited the lipase activity. Activity of the enzyme was increased in n-hexane while decreased with increase in concentration of acetone, chloroform, ethanol and isopropanol.

RESUMO

Kinetics of a lipase isolated from Bacillus sp. was studied. The enzyme showed maximum activity at pH 9 and temperature 60ºC. The Michaelis constant (K M 0.31 µM) obtained from three different plots i.e., Lineweaver-Burk, Hanes-Wolf and Hofstee, was found to be lower than already reported lipases that confirmed higher affinity of the enzyme for its substrate p-NPL (p-nitrophenyl laurate). Vmax of the enzyme was found to be 7.6 µM/mL/min. Energy of activation calculated from Arrhenius plot was found to be 20.607 kJmol-1. Activation enthalpy (H*) had negative trend and the value for the hydrolysis of p-NPL by the enzyme at optimum temperature was -2.748 kJmol-1 . Activation entropy (S*) and free energy of activation (G*) of the enzyme were found to be 1.468 Jmol-1K-1 and -3.237 kJmol-1, respectively at optimum temperature. Low value of Q10 (0.04788) shows high catalytic activity of the enzyme. Mn2+, Fe2+ and Mg2+ enhanced the lipase activity whereas Cu2+, Na+ and Co2+ inhibited the enzyme activity. However, the enzyme activity was not affected significantly by K+ ions. EDTA and SDS also significantly inhibited the lipase activity. Activity of the enzyme was increased in n-hexane while decreased with increase in concentration of acetone, chloroform, ethanol and isopropanol.