Rat Red Blood Cells Research Articles

Effect of ozonation on resistance of ovine and human erythrocytes to hypothermic storage

Long-term hypothermic storage of animal blood can lead to the loss of its quality and can cause complications in recipient animals after transfusion, so the search for new methods of increasing the preservation of erythrocytes after hypothermic storage continues. The article presents the data of the ozonation effect on the preservation rate of ovine and human erythrocytes during hypothermic storage with Alsever’s solution and mannitol medium. Hemolysis, osmotic fragility and distribution density of ovine and human erythrocytes by the sphericity index were determined at different stages of hypothermic storage. The ovine erythrocytes in the control had a lower osmotic resistance compared to human erythrocytes; however, their osmotic fragility did not change significantly after hypothermic storage for 8 weeks, and for human erythrocytes, it significantly increased. Storage of ovine and human erythrocytes longer than 8 weeks led to a sharp hemolysis, while the level of hemolysis of ovine erythrocytes was lower than that of human erythrocytes. Preservation of ozonated erythrocytes is higher than non-ozonated ones during prolonged hypothermic storage. The effect of ozonation on the preservation rate of red blood cells depended on the composition of the preservation media. Hypothermal storage of human erythrocytes in Alsever’s solution for up to 8 weeks led to a shift in the density of distribution according to the sphericity index towards spheroidization of cells; in a medium with mannitol, the number of flattened cell forms increased. After 8 weeks of hypothermic storage of ovine erythrocytes, most of the cells had high sphericity indices. Pretreatment of human and sheep erythrocytes with ozone allows the distribution of cells to be kept closer to the control during long-term storage, which is especially pronounced in mannitol medium. Ovine erythrocytes retained the ability to form rosettes with human T-lymphocytes after hypothermic storage for up to 12 weeks. Thus, ozone pretreatment and the use of mannitol as part of hypothermic storage medium could be an approach to improve the quality of preserved ovine erythrocytes.

Evaluation of the non-clinical toxicity of an antiparasitic agent: diminazene aceturate

The diminazene aceturate (C14H15N7.2C4H7NO3) is a chemotherapeutic agent with more than six decades of use, however more studies regarding its toxicity still need to be performed. Thus, the present study determined the acute toxicity (14 days) of diminazene acetate (DIZE) in male and female swiss mice by changes in body mass, food consumption, biochemical and hematological parameters, locomotor activity and motor coordination. DIZE was administered at a single dose (1000 and 2000 mg/kg) orally. In addition, in vitro antioxidant capacity, hemolytic activity, toxicity in Artemia salina and in silico evaluation were also performed. The results obtained include several signs of toxicity (hypoactivity, loss of the straightening reflex and tachycardia), reduction of behavioral activity (locomotor activity and motor coordination) and significant changes (p < 0.05) in biochemical and hematological parameters. According to the in silico study, the DIZE can be classified based on the mean lethal dose (LD50) in category 4 (300 mg/kg < LD50 ≤ 2000 mg/kg, ProTox-II) or 3 (50 mg/kg < LD50 ≤ 300 mg/kg, AdmetSAR 1.0). Additionally, DIZE (30.3–969.9 nM) was not toxic to A. salina in the first 48 hours of treatment and was not cytotoxic to rat red blood cells after induced hemolysis. In vitro results indicated low antioxidant capacity against DPPH• and ABTS•+ radicals. Therefore, DIZE induces several adverse effects with influence on the central nervous system, changes in hematological and biochemical parameters and even mortality at the highest dose. However, absence of toxicity was observed in A. salina and rats red blood cells.

Investigation of the Antimicrobial Activity and &amp;lt;i&amp;gt;in Vivo &amp;lt;/i&amp;gt; Cytotoxicity of &amp;lt;i&amp;gt;Diospyros malabarica &amp;lt;/i&amp;gt; (Desr.) Kostel. Fruit Extracts

Mankind is facing an unprecedented threat of existence due to the antibiotic resistance developed by bacteria. The unripe fruits of Diospyros malabarica (Desr.) Kostel. (family: Ebenaceae) can be considered as one of the natural sources to tackle this issue. The present study is designed to assess the antimicrobial activity of D. malabarica seed and flesh ex-tracts. Herein, D. malabarica extracts were prepared using polar solvents (i.e., water and 70% ethanol) and their antimicrobial activity as well as in vivo toxicity was investigated. Their antibacterial activity was investigated against gram positive (Bacillus subtilis) and gram negative (Escherichia coli DH5α, and Salmonella typhi) bacteria at different time points. All the extracts showed the highest antibacterial activity after 2 hours of incubation. The aqueous seed extract showed the maximum zone of inhibition (i.e., ~13 mm) against Bacillus subtilis with a minimum inhibitory concentration (MIC) value of 2 μg/μl. The an-tibacterial propensity was also confirmed through trypan blue dye exclusion assay, CellToxTM Green assay, and lipid peroxidation (LPO) assay. On the other hand, the etha-nolic seed extract demonstrated higher antifungal activity through inhibition of mycelial growth. All the extracts showed excellent hemocompatibility against both human and rat red blood cells (RBCs). They also did not show any toxicity to rat liver and kidneys. Taken together, this study demonstrates that the aqueous and ethanolic extracts of D. malabarica seed and flesh could be an effective source of natural antimicrobial agents with no cytotox-ic activity.

A Randomized Phase 2 Study of Pevonedistat, Venetoclax, and Azacitidine Versus Venetoclax Plus Azacitidine in Adults with Newly Diagnosed Acute Myeloid Leukemia (AML) Who Are Unfit for Intensive Chemotherapy

A Randomized Phase 2 Study of Pevonedistat, Venetoclax, and Azacitidine Versus Venetoclax Plus Azacitidine in Adults with Newly Diagnosed Acute Myeloid Leukemia (AML) Who Are Unfit for Intensive Chemotherapy

Rapid determination of erythrocyte sedimentation rate (ESR) by an electrically driven blood droplet biosensor.

In healthcare practice, the sedimentation rate of red blood cells (erythrocytes) is a widely used clinical parameter for screening of several ailments such as stroke, infectious diseases, and malignancy. In a traditional pathological setting, the total time taken for evaluating this parameter varies typically from 1 to 2 h. Furthermore, the volume of human blood to be drawn for each test, following a gold standard laboratory technique (alternatively known as the Westergren method), varies from 4 to 5 ml. Circumventing the above constraints, here we propose a rapid (∼1 min) and highly energy efficient method for the simultaneous determination of hematocrit and erythrocyte sedimentation rate (ESR) on a microfluidic chip, deploying electrically driven spreading of a tiny drop of blood sample (∼8 μl). Our unique approach estimates these parameters by correlating the same with the time taken by the droplet to spread over a given radius, reproducing the results from more elaborate laboratory settings to a satisfactory extent. Our novel methodology is equally applicable for determining higher ranges of ESR such as high concentration of bilirubin and samples corresponding to patients with anemia and patients with some severe inflammation. Furthermore, the minimal fabrication steps involved in the process, along with the rapidity and inexpensiveness of the test, render the suitability of the strategy in extreme point-of-care settings.

Development of Self-Associating SN-38-Conjugated Poly(ethylene oxide)-Poly(ester) Micelles for Colorectal Cancer Therapy.

The clinical use of 7-ethyl-10-hydroxy-camptothecin (SN-38), which is the active metabolite of irinotecan, has been hampered because of its practical water-insolubility. In this study, we successfully synthesized two self-associating SN-38-polymer drug conjugates to improve the water-solubility of SN-38, while retaining its anticancer activity. The polymeric micellar SN-38 conjugates were composed of either methoxy-poly(ethylene oxide)-block-poly(α-benzyl carboxylate-ε-caprolactone) conjugated to SN-38 at the PBCL end (mPEO-b-PBCL/SN-38) or mPEO-block-poly(α-carboxyl-ε-caprolactone) attached to SN-38 from the pendent-free carboxyl site (mPEO-b-PCCL/SN-38). The chemical structure of block copolymers was confirmed by 1H NMR. The physicochemical characterizations of their self-assembled structures including size, surface charge, polydispersity, critical micellar concentration, conjugation content and efficiency, morphology, kinetic stability, and in vitro release of SN-38 were compared between the two formulations. In vitro anticancer activities were evaluated by measuring cellular cytotoxicity and caspase activation by MTS and Caspase-Glo 3/7 assays, respectively. The hemolytic activity of both micellar structures against rat red blood cells was also measured. The results showed the formation of SN-38-polymeric micellar conjugates at diameters < 50 nm with a narrow size distribution and sustained release of SN-38 for both structures. The loading content of SN-38 in mPEO-b-PBCL and mPEO-b-PCCL were 11.47 ± 0.10 and 12.03 ± 0.17 (% w/w), respectively. The mPEO-b-PBCL/SN-38, end-capped micelles were kinetically more stable than mPEO-b-PCCL/SN-38. The self-assembled mPEO-b-PBCL/SN-38 and mPEO-b-PCCL/SN-38 micelles resulted in significantly higher cytotoxic effects than irinotecan against human colorectal cancer cell lines HCT116, HT-29, and SW20. The CRC cells were found to be 70-fold to 330-fold more sensitive to micellar SN-38 than irinotecan, on average. Both SN-38-incorporated micelles showed two-fold higher caspase-3/7 activation levels than irinotecan. The mPEO-b-PBCL/SN-38 micelles were not hemolytic, but mPEO-b-PCCL/SN-38 showed some hemolysis. The overall results from this study uphold mPEO-b-PBCL/SN-38 over mPEO-b-PCCL/SN-38 micellar formulation as an effective delivery system of SN-38 that warrants further preclinical investigation.

Impact of Preoperative Platelet Count on Bleeding Risk and Allogeneic Transfusion in Multilevel Spine Surgery.

This was an observational cohort study of patients receiving multilevel thoracic and lumbar spine surgery. The aim of this study was to identify which patients are at high risk for allogeneic transfusion which may allow for better preoperative planning and employment of specific blood management strategies. Multilevel posterior spine surgery is associated with a significant risk for major blood loss, and allogeneic blood transfusion is common in spine surgery. A univariate logistic regression model was used to identify variables that were significantly associated with intraoperative allogeneic transfusion. A multivariate forward stepwise logistic regression model was then used to measure the adjusted association of these variables with intraoperative transfusion. Multilevel thoracic and lumbar spine surgery was performed in 921 patients. When stratifying patients by preoperative platelet count, patients with pre-operative thrombocytopenia and severe thrombocytopenia had a significantly higher rate of transfusion than those who were not thrombocytopenic. Furthermore, those with severe thrombocytopenia had a higher rate of red blood cells, fresh frozen plasma, and platelet transfusion than those with higher platelet counts. Multivariate logistic regression found that preoperative platelet count was the most significant contributor to transfusion, with a platelet count ≤100 having an adjusted odds ratio (OR) of transfusion of 4.88 (95% confidence interval [CI] 1.58-15.02, P = 0.006). Similarly, a platelet count between 101and 150 also doubled the risk of transfusion with an adjusted OR of 2.02 (95% CI 1.01-4.04, P = 0.047). The American Society of Anesthesiologists classification score increased the OR of transfusion by 2.5 times (OR = 2.52, 95% CI 1.54-4.13), whereas preoperative prothrombin time and age minimally increased the risk. Preoperative thrombocytopenia significantly contributes to intraoperative transfusion in multilevel thoracic lumbar spine surgery. Identifying factors that may increase the risk for transfusion could be of great benefit in better preoperative counseling of patients and in reducing overall cost and postoperative complications by implementing strategies and techniques to reduce blood loss and blood transfusions. 2.

A 3D printed three-dimensional centrifugal fluidic system for blood separation

This paper reports a miniature microfluidic system based on centrifugal and gravity actuations for separation of blood cells. The fluidic platform is driven with a motor and controlled using a single-chip micyoco (SCM). Centrifugal force was used both for delivering the blood sample and realizing density gradient centrifugation for separation of red blood cells from plasma. By utilizing the centrifugal force, Coriolis force, Euler’s force, and gravity force in actuation of blood sample, a compact design of three-dimensional fluidic system for flow control was achieved. The centrifugal microfluidic platform was fabricated using 3D printing technology with polymers as structural materials. Because of the strong adhesion of leukocyte and the larger sizes of the blood cells, silica electrospun fiber was used as filter for white cells. In the experiments, the average removal rate of red blood cells is controllable by changing the working parameters. The instrument can separate 20–50 μl plasma at a time. No white cells were found in the plasma after separation.

Revealing the toxicity of dimethyl phthalate (DMP) to the oxygen-carrying function of red blood cells (RBCs): The iron release mechanism

Phthalic acid esters (PAEs), as typical hormone pollutants, do harms to human health after enrichment over a long term exposure, causing the loss of oxygen-carrying function of red blood cells (RBCs). This study has investigated the mechanism for the toxicity of dimethyl phthalate (DMP) on the oxygen-carrying function of RBCs by measuring the iron release content of hemoglobin (Hb) in vivo and in vitro. The hematologic examination showed that the high dose of DMP at 1000 mg/kg significantly reduced the Hb content and increased the granulocyte content, whereas such toxicity was not relatively observed at a low (50 mg/kg) or a medium (250 mg/kg) dose of DMP. The in vitro experiments showed that DMP, incubated with RBCs, increased the iron release content as a function of DMP concentration. Interestingly, such a phenomenon was not observed when DMP was incubated with Hb alone, indicating that the release of hemoglobin iron could not directly caused by the combination of DMP and hemoglobin. The in vivo experiments indicated that DMP induced iron release and oxidative stress for rat RBCs. Moreover, vitamin C and E was found to reduce the level of iron release by recovering erythrocytes from the oxidative stress induced by DMP. This work has revealed that the oxidative stress induced by DMP, causing the release of Hb iron from RBCs, is the reason for the toxicity of DMP to the oxygen-carrying function.

CD59-deficient bone marrow erythroid cells from rats treated with procarbazine and propyl-nitrosourea have mutations in the Pig-a gene.

Procarbazine (PCZ) and N-propyl-N-nitrosourea (PNU) are rodent mutagens and carcinogens. Both induce GPI-anchored marker-deficient mutant-phenotype red blood cells (RBCs) in the flow cytometry-based rat RBC Pig-a assay. In the present study, we traced the origin of the RBC mutant phenotype by analyzing Pig-a mutations in the precursors of RBCs, bone marrow erythroid cells (BMEs). Rats were exposed to a total of 450 mg/kg PCZ hydrochloride or 300 mg/kg PNU, and bone marrow was collected 2, 7, and 10 weeks later. Using a flow cell sorter, we isolated CD59-deficient mutant-phenotype BMEs from PCZ- and PNU-treated rats and examined their endogenous X-linked Pig-a gene by next generation sequencing. Pig-a mutations consistent with the properties of PCZ and PNU were found in sorted mutant-phenotype BMEs. PCZ induced mainly A > T transversions with the mutated A on the nontranscribed strand of the Pig-a gene, while PNU induced mainly T > A transversions with the mutated T on the nontranscribed strand. The treatment-induced mutations were distributed across the protein coding sequence of the Pig-a gene. The causal relationship between BMEs and RBCs and the agent-specific mutational spectra in CD59-deicient BMEs indicate that the rat RBC Pig-a assay, scoring CD59-deficient mutant-phenotype RBCs in peripheral blood, detects Pig-a gene mutation.

Food poisoning caused by sunfish Masturus lanceolatus in Taiwan

Attempts was made to clarify the toxicity and species of causative sunfish fillet concerning with a food poisoning. The frozen causative sunfish fillet was collected to determine its toxicity after two people eating it found poisoned. Tetrodotoxin (TTX) was not detected, however, the butanol extract of remained causative muscle showed ichthyotoxicity to gold carp and caused human, rat and tilapia red blood cells haemolysis. Patients and rats showed some symptoms similar to those caused by palytoxin. Hence, it is possible that this food poisoning is caused by a palytoxin-like compound. Moreover, fish species of the sunfish fillet was identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A PCR primer set (L14735/H15149) was used to amplify the partial fragment of the cytochrome b gene. Endonucleases Stu I was used in RFLP. The species of the causative sample was identified as Masturus lamceolatus.

Immediate effects of systemic administration of normal and high O2-affinity haemoglobin vesicles as a transfusion alternative in a rat pneumonectomy model

BackgroundHaemoglobin vesicles (HbVs) are red blood cell (RBC) substitutes with a phospholipid bilayer membrane and a polyethylene modified surface (diameter=250 nm; P50=28 Torr). They can be preserved for years and...

&lt;p&gt;Cordycepin Nanoencapsulated in Poly(Lactic-Co-Glycolic Acid) Exhibits Better Cytotoxicity and Lower Hemotoxicity Than Free Drug&lt;/p&gt;

PurposeCordycepin, a natural product isolated from the fungus Cordyceps militaris, is a potential candidate for breast cancer therapy. However, due to its structural similarity with adenosine, cordycepin is rapidly metabolized into an inactive form in the body, hindering its development as a therapeutic agent. In the present study, we have prepared cordycepin as nanoparticles in poly(lactic-co-glycolic acid) (PLGA) and compared their cellular uptake, cytotoxicity and hemolytic potential with free cordycepin.Materials and MethodsCordycepin-loaded PLGA nanoparticles (CPNPs) were prepared by the double-emulsion solvent evaporation method. Physico-chemical characterization of the nanoparticles was done by zetasizer, transmission electron microscopy (TEM) and reverse-phase high-pressure liquid chromatography (RP-HPLC) analyses. Cellular uptake and cytotoxicity of CPNPs and free drug were tested in human breast cancer cells (MCF7). Hemolytic potential of both of these forms was evaluated in rat red blood cells (RBCs).ResultsPhysico-chemical characterization revealed that CPNPs were spherical in shape, possessed a size range of 179–246 nm, and released the encapsulated drug sustainably over a period of 10 days. CPNPs exhibited a high level of cellular uptake and cytotoxicity than the free drug in MCF-7 cells. While CPNPs were not toxic to rat RBCs even at high concentrations, free cordycepin induced hemolysis of these cells at relatively low concentration.ConclusionOur results reveal that delivery as CPNPs could enhance the clinical efficacy of cordycepin substantially.

The effect of NaFeEDTA-fortified soy milk on the red blood cell counts of male Sprague Dawley rats (Rattus norvegicus L.)

This study explored the effect of NaFeEDTA-fortified soy milk on red blood cell counts of male Sprague-Dawley rats (Rattus norvegicus L.). Using a completely randomized design (CRD), 25 rats were divided into five groups: the normal control group, which received standard food and water without the addition of soy milk or fortificant; treatment control group, which received extra soy milk without fortificant; and three treatment groups, which received extra soy milk containing NaFeEDTA as a fortificant at 2.7 (treatment group 1), 5.4 (treatment group 2) and 10.8 mg Fe/kg bodyweight (treatment group 3). All the five groups were treated for 21 consecutive days. Rat red blood cell counts were measured using a hematology analyzer. Oneway ANOVA and the least significant difference post hoc test showed that after 21 days of consecutive treatment, there was a significant effect on the red blood cell count in all the treatment groups compared with the normal control and treatment control groups. The highest increase in the red blood cell count was detected in treatment group 2 at t21, with a 19.70 % increase compared with the normal control group and 17.27 % compared with the treatment control group.

Transfusion of Anaerobically or Conventionally Stored Blood After Hemorrhagic Shock.

ABSTRACTBackground:Resuscitation from hemorrhagic shock (HS) by blood transfusion restores oxygen (O2) delivery and provides hemodynamic stability. Current regulations allow red blood cells (RBCs) to be stored and used for up to 42 days. During storage, RBCs undergo many structural and functional changes. These storage lesions have been associated with adverse events and increased mortality after transfusion, increasing the need for improved RBC storage protocols. This study evaluates the efficacy of anaerobically stored RBCs to resuscitate rats from severe HS compared with conventionally stored RBCs.Methods and results:Rat RBCs were stored under anaerobic, anaerobic/hypercapnic, or conventional conditions for a period of 3 weeks. Hemorrhage was induced by controlled bleeding, shock was maintained for 30 min, and RBCs were transfused to restore and maintain blood pressure near the prhemorrhage level. All storage conditions met current regulatory 24-h posttransfusion recovery requirements. Transfusion of anaerobically stored RBCs required significantly less RBC volume to restore and maintain hemodynamics. Anaerobic or anaerobic/hypercapnic RBCs restored hemodynamics better than conventionally stored RBCs. Resuscitation with conventionally stored RBCs impaired indices of left ventricular cardiac function, increased hypoxic tissue staining and inflammatory markers, and affected organ function compared with anaerobically stored RBCs.Conclusions:Resuscitation from HS via transfusion of anaerobically stored RBCs recovered cardiac function, restored hemodynamic stability, and improved outcomes.

Gallic acid and MiADMSA reversed arsenic induced oxidative/nitrosative damage in rat red blood cells

Arsenic (As) is naturally occurring toxic metalloid which is considered as a serious environmental and health concern. Red blood cells are the prime target for any toxicants as their population is higher in systemic circulation. High prevalence of anaemia too has been reported from arsenic contaminated area, suggesting possible linkage between arsenic and the damaging effects on RBCs. The exact mechanism for these effects is still not clear, however, oxidative/nitrosative stress might be one of the causative factors to play a key role. The present study was planned to evaluate the protective effects of a metal chelator, MiADMSA either alone or in combination with a natural antioxidant (gallic acid) for the reversal of arsenic induced oxidative damage in red blood cells. We collected rat RBCs and cultured them in appropriate medium. They were incubated with MiADMSA and gallic acid and then treated with sodium arsenite at 37 °C. Hemolysates were prepared and assayed for various biochemical parameters such as oxidative/nitrosative variables, osmotic fragility, acetylcholinesterase activity, and cellular metal accumulation. We found there was reversibility of oxidative/nitrosative stress variables, elevated cellular antioxidant power, and decreased osmotic fragility of red blood cells both in MiADMSA alone as well as in combination with gallic acid treated group compared with arsenic treated group. In conclusion, MiADMSA efficiently participated in the reversal of arsenic induced oxidative/nitrosative damage in red blood cells where as Gallic acid improved its reversal when given in combination with MiADMSA.

Hydroxyapatite/silk fibroin composite biomimetic scaffold for dental pulp repair

Dental pulp repair is a difficult clinical problem. In the present study, the authors aimed to mimic the extracellular matrix of dental pulp tissue structurally and compositionally. Nanofibrous silk fibroin (SF) scaffolds containing hydroxyapatite (HAp) nanoparticles were fabricated by using the freeze-drying approach. Rod-shaped HAp was successfully embedded in the composite scaffold, the diameter of which was about 100–200 nm as shown by transmission electron microscopy analysis. The three-dimensional microstructure of the composite scaffold prepared in various ratios of HAp to SF was observed by scanning electron microscopy and the pore size of the optimal scaffold was about 30–120 μm. Meanwhile, the hemocompatibility of the composite scaffolds was evaluated based on their impact on the clotting function by way of activated partial thromboplastin time, prothrombin time and thromboelastographic assays. The scaffolds possessed a low hemolysis rate of red blood cells. Furthermore, cell culture tests using dental pulp stem cells found that the scaffolds had good biocompatibility. There biomimetic HAp/SF composite scaffolds may serve as a promising biomaterial for dental pulp repair.

Three-Dimensional Shapes and Cell Deformability of Rat Red Blood Cells during and after Asphyxial Cardiac Arrest.

Changes in microcirculation are believed to perform an important role after cardiac arrest. In particular, rheological changes in red blood cells (RBCs) have been observed during and after ischemic-reperfusion injury. Employing three-dimensional laser interferometric microscopy, we investigated three-dimensional shapes and deformability of RBCs during and after asphyxial cardiac arrest in rats at the individual cell level. Rat cardiac arrest was induced by asphyxia. Five rats were maintained for 7 min of no-flow time, and then, cardiopulmonary resuscitation (CPR) was started. Blood samples were obtained before cardiac arrest, during CPR, and 60 min after return of spontaneous circulation (ROSC). Quantitative phase imaging (QPI) techniques based on laser interferometry were used to measure the three-dimensional refractive index (RI) tomograms of the RBC, from which structural and biochemical properties were retrieved. Dynamic membrane fluctuations in the cell membrane were also quantitatively and sensitively measured in order to investigate cell deformability. Mean corpuscular hemoglobin, mean cell volume, mean corpuscular hemoglobin concentration, and red blood cell distribution width remained unchanged during CPR and after ROSC compared with those before cardiac arrest. QPI results revealed that RBC membrane fluctuations, sphericity, and surface area did not change significantly during CPR or after ROSC compared with initial values. In conclusion, no three-dimensional shapes and cell deformability changes in RBCs were detected.

Investigation of the Antibacterial Activity and in vivo Cytotoxicity of Biogenic Silver Nanoparticles as Potent Therapeutics.

Biogenic nanoparticles are the smartest weapons to deal with the multidrug-resistant “superbugs” because of their broad-spectrum antibacterial propensity as well as excellent biocompatibility. The aqueous biogenic silver nanoparticles (Aq-bAgNPs) and ethanolic biogenic silver nanoparticles (Et-bAgNPs) were synthesized using aqueous and ethanolic extracts of Andrographis paniculata stem, respectively, as reducing agents. Electron microscopic images confirmed the synthesis of almost spherical shaped biogenic silver nanoparticles (bAgNPs). The zeta potentials of the nanoparticles were negative and were −22 and −26 mV for Aq-bAgNPs and Et-bAgNPs, respectively. The antibacterial activity of bAgNPs was investigated against seven pathogenic (i.e., enteropathogenic Escherichia coli, Salmonella typhi, Staphylococcus aureus, Vibrio cholerae, Enterococcus faecalis, Hafnia alvei, Acinetobacter baumannii) and three nonpathogenic (i.e., E. coli DH5α, E. coli K12, and Bacillus subtilis) bacteria at different time points (i.e., 12, 16, 20, and 24 h) in a dose-dependent manner (i.e., 20, 40, and 60 μg) through broth dilution assay, disk diffusion assay, CellToxTM Green uptake assay, and trypan blue dye exclusion assay. The lowest minimum inhibitory concentration value for both the bAgNPs was 0.125 μg. Et-bAgNPs showed the highest antibacterial activity against S. aureus at 60 μg after 16 h and the diameter of inhibited zone was 28 mm. Lipid peroxidation assay using all the bacterial strains revealed the formation of malondialdehyde–thiobarbituric acid adduct due to the oxidation of cell membrane fatty acids by bAgNPs. The bAgNPs showed excellent hemocompatibility against human as well as rat red blood cells. Furthermore, there was no significant toxicity observed when the levels of rat serum ALT, AST, γ-GT (i.e., liver function biomarkers), and creatinine (i.e., kidney function biomarker) were determined.

Acute and Subacute Toxicity of Oxalis barrelieri (Oxalidaceae) Aqueous Aerial Parts Extract

Aims: The present study was carried out to investigate the toxic effects of the Oxalis barrelieri aqueous aerial parts extract.&#x0D; Place and Duration of Study: Department of Biological Sciences (Animal Physiology Laboratory), Higher Teachers’ Training College, University of Yaoundé I. Between April 2017 and June 2018.&#x0D; Materials and Methods: Acute toxicity using a single dose of 2000 mg/kg was administered to mice and effects were observed for 14 days. In sub-acute toxicity, the experimental rats (males and females) received aqueous extract of Oxalis barrelieri at doses of 200 mg/kg, 400 mg/kg and 800 mg/kg daily for 28 days while the control and satellite control groups received distilled water and satellite test group received extract at the dose of 800 mg/kg. The physical parameters were evaluated throughout the treatment, while the haematological, biochemical and histological parameters were evaluated at the end of the treatment.&#x0D; Results: In acute toxicity, the results obtained show no death and no significant variation (p&gt;0.05) in behavioral and morphological parameters. In sub-acute toxicity assay, few modifications were observed in haematological and biochemical parameters. At the higher dose of extract (800 mg/kg),the rate of red blood cells decreased significantly (p&lt;0.05) two weeks after treatment in male rats , there were a significant increase (P˂0.001) in ASAT activity in male and female rats two weeks after extract administration, and a reversible significant increase (P˂0.05) in triglyceride level in male rats only. Histopathology showed a reversible slight dose dependent structural alteration of the kidney and reversible vascular congestion in liver.&#x0D; Conclusion: The aqueous aerial parts extract of Oxalis barrelieri could possess moderate toxicity at high doses and adequate caution should be exercised in its use in ethnomedicine.