Cytotoxicity In Human Blood Cells Research Articles

Peroxidase of Cedrela fissilis leaves: Biochemical characterization and toxicity of enzymatically decolored solution of textile dye Brilliant Sky-Blue G

This work aimed at studying an alternative source of peroxidase for application in textile dye decoloration. Cedar leaf peroxidase (Cedrela fissilis) was characterized. The enzyme showed maximum activity conditions in the temperature range of 50 °C-62 °C and pH 5, using guaiacol as a substrate. For gallic acid as substrate, the maximum activity conditions were in the temperature range from 45 °C to 50 °C and in the pH range from 6.0 to 6.4. The KM, values, when used guaiacol and gallic acid as substrates, were 18.7 mM and 31 mM, respectively. The inactivation temperature was 85 °C. The enzymatic activity was not influenced by the presence of Na+, K+, Mg2+, Ca2+ and Zn2+ metal ions, but decreased in the presence of Cu2+ ion. Partial purification using acetone 65% (v.v−1) showed a purification factor of 18.7. The specific activity of crude and partially purified enzymatic extract was 6.78 U.mg−1 and 126.69 U.mg−1, respectively. The enzyme maintained about 90% of relative activity after one month when stored in an ultrafreezer. In the conventional freezer, relative activity decreased to approximately 50% in three weeks. Application of the partially purified extract on Brilliant Sky-Blue G textile dye removed 82.65% of the color when subjected to optimal reaction conditions. The treated dye solutions showed no phytotoxicity in L. sativa seeds, and there was a decrease in cytotoxicity in human blood cells. Cedar leaf peroxidase may be an alternative for the treatment of wastewater containing textile dyes.

Rational design of novel amphipathic antimicrobial peptides focused on the distribution of cationic amino acid residues.

Antimicrobial peptides (AMPs) have garnered much attention as novel therapeutic agents against infectious diseases. They exhibit antimicrobial activity through microbial membrane disruption based on their amphipathic properties. In this study, we rationally designed and synthesized a series of novel AMPs Block, Stripe, and Random, and revealed that Stripe exhibits potent antimicrobial activity against Gram-positive and Gram-negative microbes. Moreover, we also demonstrated that Stripe disrupts both Gram-positive and Gram-negative mimetic bacterial membranes. Finally, we investigated the hemolytic activity and cytotoxicity in human blood cells and human cell lines, and found that Stripe exhibited neither. These data indicated that Stripe is a promising antimicrobial reagent that does not display significant cytotoxicity.

Cytotoxicity and genotoxicity of iron oxide nanoparticles: An in vitro biosafety study

With the development of nanotechnology and the wide use of iron oxide nanoparticles, it has become necessary to assess the potential adverse biological effects of magnetite. This study investigated the cytotoxicity, genotoxicity and oxidative damage of different concentrations of magnetite (0 to 1000 mg/L) in human whole blood cultures. After supplementation of magnetite, the blood samples were incubated for 72 h. Cell viability was assessed by the 3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release assays. The total antioxidant capacity (TAC) and total oxidant status (TOS) were determined to evaluate the dose-dependent effects of magnetite on the oxidant/antioxidant balance and to evaluate the potential oxidative injury due to increased oxidative stress. Genotoxicity was estimated by by the sister chromatid exchange (SCE), micronuclei (MN) and chromosome aberration (CA) assays and determination of 8-oxo-2-deoxyguanosine (8-OH-dG) levels. The results of MTT and LDH assays showed that the higher concentrations of magnetite (100, 150, 300, 500 and 1000 mg/L) decreased cell viability. Concentrations of magnetite higher than 10 mg/L increased TOS levels and decreased TAC levels in human blood cells. Increasing concentrations of magnetite caused significant increases in MN, SCE and CA rates and 8-OH-dG levels. The obtained results showed that magnetite exerted dose-dependent effects on oxidative damage, genotoxicity and cytotoxicity in human blood cells.

Evaluation of cytotoxic, oxidative stress and genotoxic responses of hydroxyapatite nanoparticles on human blood cells

The present study was designed to investigate genotoxic and cytotoxic effects and oxidative damage of increasing concentrations of nano-hydroxyapatite (5, 10, 20, 50, 75, 100, 150, 300, 500 and 1000 ppm) in primary human blood cell cultures. Cell viability was detected by [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide] assay and lactate dehydrogenase release, while total antioxidant capacity and total oxidative stress levels were determined to evaluate the oxidative injury. The DNA damage was also analyzed by sister chromatid exchange, micronuclei, chromosome aberration assays and 8-oxo-2-deoxyguanosine level as indicators of genotoxicity. The results of [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide] and lactate dehydrogenase assays showed that the higher concentrations (150, 300, 500 and 1000 ppm) of hydroxyapatite nanoparticles (HAP NPs) decreased cell viability. HAP NPs led to increases of total oxidative stress (300, 500 and 1000 ppm) levels and decreased total antioxidant capacity (150, 300, 500 and 1000 ppm) levels in cultured human blood cells. On the basis of increasing concentrations, HAP NPs caused significant increases of sister chromatid exchange, micronuclei, chromosome aberration rates and 8-oxo-2-deoxyguanosine levels as compared to untreated culture. In conclusion, the obtained in vitro results showed that HAP NPs had dose-dependent effects on inducing oxidative damage, genotoxicity and cytotoxicity in human blood cells.