Acarbose Mitigates Age-Dependent Alterations in Erythrocyte Membrane Transporters During Aging in Rats.

Acarbose (ACA), a well-studied and effective inhibitor of α-amylase and α-glucosidase, is a postprandial-acting antidiabetic medicine. The membrane of the erythrocyte is an excellent tool for analyzing different physiological and biochemical activities since it experiences a range of metabolic alterations throughout aging. It is uncertain if ACA modulates erythrocyte membrane activities in an age-dependent manner. As a result, the current study was conducted to explore the influence of ACA on age-dependent deteriorated functions of transporters/exchangers, disrupted levels of various biomarkers such as lipid hydroperoxides (LHs), protein carbonyl (PCO), sialic acid (SA), total thiol (-SH), and erythrocyte membrane osmotic fragility. In addition to a concurrent increase in Na+/H+ exchanger activity and concentration of LH, PCO, and osmotic fragility, we also detected a considerable decrease in membrane-linked activities of Ca2+-ATPase (PMCA) and Na+/K+-ATPase (NKA), as well as concentrations of SA and -SH in old-aged rats. The aging-induced impairment of the activities of membrane-bound ATPases and the changed levels of redox biomarkers were shown to be effectively restored by ACA treatment.

Appraisal of Anti-Arthritic and Anti-Inflammatory Potential of Folkloric Medicinal Plant Peganum harmala.

BACKGROUND & OBJECTIVE: Peganum harmala has been traditionally used to manage rheumatoid arthritis (RA) and other inflammatory conditions. However, its use against RA has not been scientifically evaluated. The current study was designed to assess the anti-arthritic and anti-inflammatory activities of the methanolic extract of P. harmala leaves by in vitro and in vivo methods. METHODS: The in vitro assays were carried out to determine the effect of plant extract on inhibition of egg albumin denaturation and human red blood cell membrane (HRBC) stabilization. Moreover, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity was performed to determine the antioxidant potential. In vivo anti-arthritic activity was performed by determining the curative effect against Complete Freund's adjuvant (0.1 ml). The plant extract was administered to rats orally at 200, 400 and 600 mg/kg/day for 21 days. RESULTS: The values of IC50 of plant extract in protein denaturation, stabilization of HRBC and DPPH assays were 77.54 mg/ml, 23.90 mg/ml and 58.09 µg/ml, respectively. Moreover, the plant extract significantly attenuated the poly-arthritis and weight loss, anemia and paw edema. The plant extract restored the level of C-reactive protein, rheumatoid factor, alanine transaminase, aspartate transaminase and alkaline phosphatase in poly-arthritic rats. Moreover, the plant extract restored the immune organs' weight in treated rats. Treatment with P. harmala also significantly subdued the oxidative stress by reinstating superoxide dismutase, reduced glutathione, catalase and malondialdehyde in poly-arthritic rats. The plant extract notably restored the prostaglandin-E2 and tumor necrosis factor (TNF)-α in the serum of poly-arthritic rats. CONCLUSION: It was concluded that P. harmala extract had potential antioxidant, anti-inflammatory and antiarthritic activities, which primarily might be attributed to alkaloids, flavonoids and phenols.

Therapeutic appraisal of ephedrine against rheumatoid arthritis: A new indication.

Ephedra, natural flora has been used traditionally to treat rheumatism since decades. The scientific evidence of anti-rheumatic effect of this plant has also been reported. But the anti-rheumatic activity of major constituent of this plant (ephedrine) has not been evaluated. Based on this, the current study was aimed to assess anti-arthritic activity of ephedrine by using in vitro and in vivo approaches. Correspondingly, enzyme linked immunosorbent assay was performed for the estimation of prostaglandins E2 (PGE2) and tumor necrosis factor-α (TNF-α) in serum of formaldehyde-induced arthritic animals. The results elaborated significant reduction in albumin denaturation and remarkable progress on stabilization of red blood cells outer membrane at higher concentration during in vitro experiments. The ephedrine (40mg/kg) revealed noteworthy (p<0.001) inhibition in paw swelling in animals intoxicated with albumin as well as formaldehyde as compared to animals of control group by in vivo results. In this assay, ephedrine (20 & 40 mg/kg orally) significantly suppressed the level of these inflammatory markers (PGE2 & TNF-α). Ephedrine exhibited anti-arthritic effect by decreasing pro-inflammatory cytokines (PGE2 & TNF-α). This experimental work pharmacologically supports the use of ephedrine as anti-rheumatic drug but limited to evaluate in immunological arthritic model.

GC-MS profiling and in vitro antioxidant, cytotoxic and antimicrobial activities of Trianthema triquetra Rottl. ex Willed.

Trianthema triquetra Rottl. ex Willed is being used as herbal remedy for chronic ulcer, wound healing, diabetes, skin and inflammatory diseases in India and Pakistan. Still, no scientific data is available about the therapeutic potential and phytochemistry of the plant. The aim of the current investigation is to perform GC-MS analysis, antioxidant (total phenolic and flavonoid content, DPPH assay), antimicrobial (disc diffusion assay) and cytotoxic (XTT and RBC's cellular membrane protection assay) studies. Whole plant material was dried and extracted with methanol to get crude methanolic extract and then it was fractionated with n-hexane, ethyl-acetate, chloroform, n-butanol and water. Results showed that n-butanol fraction exhibited a significant (p<0.05) antioxidant potential measured by DPPH assay (IC50=63.35±0.13µg/mL) and also possess highest phenolic content (177±4.36mg/g GAE). Whereas, n-hexane fraction showed highest flavonoid content (14.67±1.53mg/g QE). Two major components (2, 4-Ditert-butyl-6-nitrophenol (26.79%) and Squalene (25.64%) were detected in GC-MS analysis of chloroform fraction, eluted from column chromatography. Moreover, chloroform fraction also exhibited antibacterial activity towards all the tested strains of bacteria and fungi. Significant (p<0.05) dose dependent inhibition response on cell growth against CCRF-CEM cell lines was exhibited by methanolic extract. Furthermore, hemolytic potential of methanolic extract was found to be in safe range (2.23%-6.37%). So, it can be inferred that Trianthema triquetra can be exploited as an alternative remedy for cancer, oxidative stress related disorders and in various skin diseases.

The Impact of Short-Term Shark Liver Oil Supplementation on the Fatty Acid Composition of Erythrocyte Membranes.

Fatty acid (FA) balance is strictly related to human health. The composition of fatty acids in lipid membranes seems to be influenced by diet. Shark liver oil (SLO) supplementation has been widely used recently in the prevention and treatment of human diseases. We analyzed the impact of short-term SLO supplementation on certain biochemical parameters and erythrocyte FA composition in a group of young healthy women. Our results showed that 6 weeks of SLO supplementation led to a significant decrease in C-reactive protein levels in sera and intracellular cholesterol levels in peripheral blood mononuclear cells. SLO supplementation caused a significant increase in the content of the polyunsaturated omega-3 FAs: docosahexaenoic acid, docosapentaenoic acid and α-linolenic acid. In the group of omega-6 FAs, we observed a significant elevation of arachidonic and dihomo-gamma-linoleic acid content. Due to these alterations, the omega-3 index increased significantly from 3.6% (before) to 4.2% (after supplementation). We also observed the impact of SLO supplementation on the membrane fluidity index. The ratio between saturated and unsaturated FAs decreased significantly from 13.1 to 9.9. In conclusion, our results show that even short-term SLO supplementation can improve human erythrocyte fatty acid composition and other parameters that may have health-promoting consequences.

An In Vitro Comparative Study of the Effects of Tetrabromobisphenol A and Tetrabromobisphenol S on Human Erythrocyte Membranes-Changes in ATP Level, Perturbations in Membrane Fluidity, Alterations in Conformational State and Damage to Proteins.

Brominated flame retardants (BFRs) are substances used to reduce the flammability of plastics. Among this group, tetrabormobisphenol A (TBBPA) is currently produced and used on the greatest scale, but due to the emerging reports on its potential toxicity, tetrabromobisphenol S (TBBPS)-a compound with a very similar structure-is used as an alternative. Due to the fact that the compounds in question are found in the environment and in biological samples from living organisms, including humans, and due to the insufficient toxicological knowledge about them, it is necessary to assess their impacts on living organisms and verify the validity of TBBPA replacement by TBBPS. The RBC membrane was chosen as the research model. This is a widely accepted research model for assessing the toxicity of xenobiotics, and it is the first barrier to compounds entering circulation. It was found that TBBPA and TBBPS caused increases in the fluidity of the erythrocyte membrane in their hydrophilic layer, and conformational changes to membrane proteins. They also caused thiol group elevation, an increase in lipid peroxidation (TBBPS only) and decreases in the level of ATP in cells. They also caused changes in the size and shape of RBCs. TBBPA caused changes in the erythrocyte membrane at lower concentrations compared to TBBPS at an occupational exposure level.

CO2 permeability of the rat erythrocyte membrane and its inhibition.

We have studied the CO2 permeability of the erythrocyte membrane of the rat using a mass spectrometric method that employs 18 O-labelled CO2. The method yields, in addition, the intraerythrocytic carbonic anhydrase activity and the membrane HCO3- permeability. For normal rat erythrocytes, we find at 37 °C a CO2 permeability of 0.078 ± 0.015 cm/s, an intracellular carbonic anhydrase activity of 64,100, and a bicarbonate permeability of 2.1 × 10-3 cm/s. We studied whether the rat erythrocyte membrane possesses protein CO2 channels similar to the human red cell membrane by applying the potential CO2 channel inhibitors pCMBS, Dibac, phloretin, and DIDS. Phloretin and DIDS were able to reduce the CO2 permeability by up to 50%. Since these effects cannot be attributed to the lipid part of the membrane, we conclude that the rat erythrocyte membrane is equipped with protein CO2 channels that are responsible for at least 50% of its CO2 permeability.

Combined therapy of ruthenium dendrimers and anti-cancer drugs against human leukemic cells.

Carbosilane ruthenium(ii) dendrimers have been complexed with conventional anti-cancer drugs. Due to its features, the presence of ruthenium within a dendrimer structure improves the anti-cancer properties of nanocomplexes containing 5-flurouracyl, methotrexate and doxorubicin. These dendrimers could be promising carriers of anti-cancer medicines. Ruthenium dendrimers that are positively charged can also enhance the cytotoxicity to cancer cells; moreover, they can form stable complexes with drugs. Results indicate that ruthenium dendrimers combined with doxorubicin and methotrexate significantly reduced the viability of leukaemia 1301 and HL-60 cancer cells.

Inhibition of ABCC5-mediated cGMP transport by progesterone, testosterone and their analogues.

The biodynamics and biokinetics of sex hormones are complex. In addition to the classical steroid receptors (nuclear receptors), these hormones act through several non-genomic mechanisms. Modulation of ABC-transporters by progesterone represents a non-genomic mechanism. In the present study, we employed inside out vesicles from human erythrocytes to characterize high affinity cGMP transport by ABCC5 (member 5 of the ATP-Binding Cassette subfamily C). Progesterone and testosterone inhibited the transport with respective Ki of 1.2 ± 0.3 and 2.0 ± 0.6 µmol/L. We used virtual ligand screening (VLS) to identify analogues to progesterone and testosterone. A large number of substances were screened in silico and the 19 most promising candidates were screened in vitro. Each substance was tested for a concentration of 10 µmol/L. The range of cGMP transport reduction was 21.5% to 86.2% for progesterone analogues and 8.6% to 93.8 % for testosterone analogues. Three of the most potent test compounds (TC) of each analogue class, in addition to progesterone and testosterone, were characterized for concentrations from 1 nanomol/L to 1 mmol/L. The progesterone analogues showed following Ki-values (µmol/L): TC-08: 0.61, TC-16: 0.66 and TC-15: 9.3. The Ki-values (µmol/L) for the testosterone analogues were: TC-18: 0.10, TC-07: 0.67 andTC-05: 2.0. The present study shows that VLS may be a versatile tool in the development of membrane transport modulating agents (MTMAs).

Changes in Human Erythrocyte Membrane Exposed to Aqueous and Ethanolic Extracts from Uncaria tomentosa.

Uncaria tomentosa (Willd.) DC is a woody climber species originating from South and Central America that has been used in the therapy of asthma, rheumatism, hypertension, and blood purification. Our previous study showed that U. tomentosa extracts altered human erythrocyte shape, which could be due to incorporation of the compounds contained in extracts into the erythrocyte membrane. The aim of the present study was to determine how the compounds contained in U. tomentosa extracts incorporate into the human erythrocyte membrane. The study has assessed the effect of aqueous and ethanolic extracts from leaves and bark of U. tomentosa on the osmotic resistance of the human erythrocyte, the viscosity of erythrocyte interior, and the fluidity of erythrocyte plasma membrane. Human erythrocytes were incubated with the studied extracts in the concentrations of 100, 250, and 500 µg/mL for 2, 5, and 24 h. All extracts tested caused a decrease in erythrocyte membrane fluidity and increased erythrocyte osmotic sensitivity. The ethanolic extracts from the bark and leaves increased viscosity of the erythrocytes. The largest changes in the studied parameters were observed in the cells incubated with bark ethanolic extract. We consider that the compounds from U. tomentosa extracts mainly build into the outer, hydrophilic monolayer of the erythrocyte membrane, thus protecting the erythrocytes against the adverse effects of oxidative stress.

RRx-001 Increases Erythrocyte Preferential Adhesion to the Tumor Vasculature.

Red blood cells (RBCs) serve a variety of functions beyond mere oxygen transport both in health and pathology. Notably, RRx-001, a minimally toxic pleiotropic anticancer agent with macrophage activating and vascular normalization properties currently in Phase III trials, induces modification to RBCs which could promote vascular adhesion similar to sickle cells. This study assessed whether RBCs exposed to RRx-001 adhere to the tumor microvasculature and whether this adhesion alters tumor viability. We next investigated the biomechanics of RBC adhesion in the context of local inflammatory cytokines after treatment with RRx-001 as a potential mechanism for preferential tumor aggregation. Human HEP-G2 and HT-29 tumor cells were subcutaneously implanted into nu/nu mice and were infused with RRx-001-treated and Technetium-99m (99mTc)-labeled blood. RBC adhesion was quantified in an in vitro human umbilical vein endothelial cell (HUVEC) assay under both normoxic and hypoxic conditions with administration of either lipopolysaccharide (LPS) or Tumor necrosis alpha (TNFα) to mimic the known inflammation in the tumor microenvironment. One hour following administration of 99mTc labeled RBCs treated with 10 mg/kg RRx-001, we observed an approximate 2.0-fold and 1.5-fold increase in 99mTc-labeled RBCs compared to vehicle control in HEPG2 and HT-29 tumor models, respectively. Furthermore, we observed an approximate 40% and 36% decrease in HEP-G2 and HT-29 tumor weight, respectively, following treatment with RRx-001. To quantify RBC adhesive potential, we determined τ50, or the shear stress required for 50% disassociation of RBCs from HUVECs. After administration of TNF-α under normoxia, τ50 was determined to be 4.5 dynes/cm2 (95% CI: 4.3-4.7 dynes/cm2) for RBCs treated with 10 µM RRx-001, which was significantly different (p < 0.05) from τ50 in the absence of treatment. Under hypoxic conditions, the difference of τ50 with (4.8 dynes/cm2; 95% CI: 4.6-5.1 dynes/cm2) and without (2.6 dynes/cm2; 95% CI: 2.4-2.8 dynes/cm2) 10 µM RRx-001 treatment was exacerbated (p = 0.05). In conclusion, we demonstrated that RBCs treated with RRx-001 preferentially aggregate in HEP-G2 and HT-29 tumors, likely due to interactions between RRx-001 and cysteine residues within RBCs. Furthermore, RRx-001 treated RBCs demonstrated increased adhesive potential to endothelial cells upon introduction of TNF-α and hypoxia suggesting that RRx-001 may induce preferential adhesion in the tumor but not in other tissues with endothelial dysfunction due to conditions prevalent in older cancer patients such as heart disease or diabetic vasculopathy.

Fluorescence lifetime imaging microscopy and time-resolved anisotropy of nanomaterial-induced changes to red blood cell membranes.

With the use of engineered nano-materials (ENM) becoming more prevalent, it is essential to determine potential human health impacts. Specifically, the effects on biological lipid membranes will be important for determining molecular events that may contribute to both toxicity and suitable biomedical applications. To better understand the mechanisms of ENM-induced hemolysis and membrane permeability, fluorescence lifetime imaging microscopy (FLIM) was performed on human red blood cells (RBC) exposed to titanium dioxide ENM, zinc oxide ENM, or micron-sized crystalline silica. In the FLIM images, changes in the intensity-weighted fluorescence lifetime of the lipophilic fluorescence probe Di-4-ANEPPDHQ were used to identify localized changes to membrane. Time-resolved fluorescence anisotropy and FLIM of RBC treated with methyl-ß-cyclodextrin was performed to aid in interpreting how changes to membrane order influence changes in the fluorescence lifetime of the probe. Treatment of RBC with methyl-ß-cyclodextrin caused an increase in the wobble-in-a-cone angle and shorter fluorescence lifetimes of di-4-ANEPPDHQ. Treatment of RBC with titanium dioxide caused a significant increase in fluorescence lifetime compared to non-treated samples, indicating increased membrane order. Crystalline silica also increased the fluorescence lifetime compared to control levels. In contrast, zinc oxide decreased the fluorescence lifetime, representing decreased membrane order. However, treatment with soluble zinc sulfate resulted in no significant change in fluorescence lifetime, indicating that the decrease in order of the RBC membranes caused by zinc oxide ENM was not due to zinc ions formed during potential dissolution of the nanoparticles. These results give insight into mechanisms for how these three materials might disrupt RBC membranes and membranes of other cells. The results also provide evidence for a direct correlation between the size, interaction-available surface area of the nano-material and cell membrane disruption.

Spectroscopic Signature of Red Blood Cells in a D-Galactose-Induced Accelerated Aging Model.

This work presents a semi-quantitative spectroscopic approach, including FTIR-ATR and Raman spectroscopies, for the biochemical analysis of red blood cells (RBCs) supported by the biochemical, morphological and rheological reference techniques. This multi-modal approach provided the description of the RBC alterations at the molecular level in a model of accelerated aging induced by administration of D-galactose (D-gal), in comparison to natural aging. Such an approach allowed to conclude that most age-related biochemical RBC membrane changes (a decrease in lipid unsaturation and the level of phospholipids, or an increase in acyl chain shortening) as well as alterations in the morphological parameters and RBC deformability are well reflected in the D-gal model of accelerated aging. Similarly, as in natural aging, a decrease in LDL level in blood plasma and no changes in the fraction of glucose, creatinine, total cholesterol, HDL, iron, or triglycerides were observed during the course of accelerated aging. Contrary to natural aging, the D-gal model led to an increase in cholesterol esters and the fraction of total esterified lipids in RBC membranes, and evoked significant changes in the secondary structure of the membrane proteins. Moreover, a significant decrease in the phosphorous level of blood plasma was specific for the D-gal model. On the other hand, natural aging induced stronger changes in the secondary structures of the proteins of the RBCs' interior. This work proves that research on the aging mechanism, especially in circulation-related diseases, should employ the D-gal model with caution. Nonetheless, the D-gal model enables to imitate age-related rheological alterations in RBCs, although they are partially derived from different changes observed in the RBC membrane at the molecular level.

In vitro alteration on erythrocytes mechanical properties by propofol, remifentanil and vecuronium.

Several studies report flow disturbance and microcirculation disorders upon anesthesia treatment. These alterations are often related to blood rheology changes. In this work, it was attempted to make a detailed description of the alterations in erythrocyte mechanical properties by the action of propofol, remifentanil, and vecuronium. For this, an in vitro study was performed on red blood cell samples from healthy donors incubated with solutions of propofol (4 µg/mL whole blood), remifentanil (10 ng/mL plasma), and vecuronium (0.15 µg/mL plasma). Erythrocyte viscoelastic parameters were determined by octuplicate using a Reómetro Eritrocitario. Also, a Wilcoxon signed rank-test with Yates correction for continuity was performed to analyze the overall alteration in the mechanical properties of erythrocytes. Statistical analysis showed that the three studied anesthetics changed the erythrocyte mechanical properties at different parts of the membrane. These results would imply an interaction of these anesthetics with the erythrocyte membrane. Finally, this could conduce to alterations in microcirculation.

Usage of atomic force microscopy for detection of the damaging effect of CdCl2 on red blood cells membrane.

The possibility of detecting the damaging effect of cadmium salts on red blood cells (RBC) membrane by atomic force microscopy and light microscopy was studied. White wistar rats RBC were incubated with cadmium chloride in concentrations of 1 µg/l, 10 µg/l, 100 µg/l, and 1000 µg/l for the research. A comparison of sample preparation methods proposed by other authors in previous studies is made. The optimal method that does not significantly affect the change in the morphological features of the cell is selected. The quantitative assessment of damaged and destroyed RBC depending on the concentration of cadmium was performed by optical microscopy. The study showed that CdCl2 has a damaging effect on the RBC membrane, which leads to the formation of non-specific cell forms. A comparative assessment was made between the methods of optical microscopy and atomic force microscopy for the suitability of studying the morphological characteristics of abnormal forms of the RBC. It is shown that the method of atomic force microscopy allows registering morphological changes in the RBC that cannot be registered by optical microscopy. It is pointed that CdCl2 has effect on destruction of the RBC and the formation of specific bulges on the RBC membrane. Influence of CdCl2 on the RBC mechanical properties was studied using atomic force microscopy. The possibility of using atomic force microscopy in studies of morphology and mechanical properties of the RBC under toxicity effect of cadmium is shown.

Mechanism of CuSO4 cytotoxicity in goat erythrocytes after high-level in vitro exposure to isotonic media.

Copper (Cu) is a common environmental pollutant in nature. Cu-poisoning can cause liver damage and erythrocytes hemolysis. To evaluate the effect of CuSO4 poisoning on the morphological and functional characteristics of goat red blood cells. Five 10-14-month-old goats were selected for jugular vein blood sampling to obtain erythrocytes, and then the erythrocytes were processed with different concentrations (0, 10, 20, 30, 40 and 50 µmol/L) of CuSO4 for 48 h, and 40 µmol/L doses CuSO4 incubated for different time (12, 24, 36, 48 and 60 h) to process erythrocytes. We observed the changes in erythrocyte morphology through scanning electron microscopy, and detected the antioxidant function and activities of three ATPases. Additionally, biological properties were examined from the perspectives of phospholipids and membrane protein components, permeability fragility, and fluidity in erythrocytes. We found that after CuSO4 treatment, the antioxidant capacity of erythrocytes decreased, which was manifested as increased MDA content and decreased CuZn-SOD and GSH-Px activities (p < 0.05). In addition, we also found that erythrocyte fluidity decreased, osmotic fragility increased, membrane phospholipid percentage and protein composition changes abnormally, and Na+/K+-ATPase, Mg2+-ATPase and Ca2+-ATPase activities decreased (p < 0.05). From the results, it can be concluded that CuSO4 exposure causes hemolysis of goat erythrocytes through oxidative stress to the structure and function of erythrocytes, showing a dose-time effect.

Correlated flickering of erythrocytes membrane observed with dual time resolved membrane fluctuation spectroscopy under different D-glucose concentrations.

A correlated human red blood cell membrane fluctuation dependent on D-glucose concentration was found with dual time resolved membrane fluctuation spectroscopy (D-TRMFS). This new technique is a modified version of the dual optical tweezers method that has been adapted to measure the mechanical properties of red blood cells (RBCs) at distant membrane points simultaneously, enabling correlation analysis. Mechanical parameters under different D-glucose concentrations were obtained from direct membrane flickering measurements, complemented with membrane fluidity measurements using Laurdan Generalized Polarization (GP) Microscopy. Our results show an increase in the fluctuation amplitude of the lipid bilayer, and a decline in tension value, bending modulus and fluidity as D-glucose concentration increases. Metabolic mechanisms are proposed as explanations for the results.

Demonstration of intracellular trafficking, cytosolic bioavailability, and target manipulation of an antibody delivery platform.

Intracellular antibody delivery into live cells has significant implications for research and therapeutic applications. However, many delivery systems lack potency due to low uptake and/or endosomal entrapment and understanding of intracellular delivery processes is lacking. Herein, we studied the cellular uptake, intracellular trafficking and targeting of antibodies using our previously developed Hex antibody nanocarrier. We demonstrated Hex-antibodies were internalized through multiple endocytic routes into lysosomes and provide evidence of endo/lysosomal disruption and Hex-antibody release to the cytosol. Cytosolic antibodies retained their bioactivity for at least 24 h. Functional effect of Hex delivered anti-STAT3 antibodies was evidenced by inhibition of nuclear translocation of cytosolic transcription factor STAT3. This study has generated understanding of key steps in the Hex intracellular antibody delivery system and will facilitate the development of effective cytosolic antibody delivery and applications in both the therapeutic and research domains.

Evaluation of Biological Activity of Derivatives of 1,3,4-Thiadiazole, 1,3,4-Oxadiazole and 1,2,4-Triazole.

OBJECTIVE: 1,3,4-thiadiazole (A), 1,3,4-oxadiazole (B) and 1,2,4-triazole (C) derivatives have been known for their immense pharmacotherapeutic potential. The current research article attempts to further explore and understand the probable biochemical mechanism related to antiinflammatory activity of derivatives. METHODS: The screened A, B and C derivatives were investigated for both in-vitro (Erythrocyte Membrane stabilization activity, Proteinase enzyme inhibitory activities) and in-vivo correlation using acute and chronic anti-inflammatory potential by carrageenan induced rats paw edema and cotton pellet granuloma methods, respectively. The activity was studied after interpreting acute toxicity studies results. RESULTS: In vitro studies in the case of Erythrocyte Membrane stability and Proteinase enzyme inhibitory activities exhibited by A, B, and C at 100 ppm were found to be 48.89%, 51.08% and 50.08% and 66.78%, 76.91% and 57.41%, respectively. The maximum toxic dose was found to be 2000 mg/kg. The derivatives were studied for two-dose levels viz; Lower (100 mg/kg) and higher dose (200 mg/kg). In rat paw edema, maximum decrease was obtained for A (50.05%), B (50.05%) and C (51.06%) at lower and higher dose at 68.76%, 55.61%, and 65.26%, respectively for effect up to 24 h. In the chronic model of cotton pellet granuloma viz; higher and lower doses of A, B and C exhibited 38.15%, 33.19% and 30.25 % and 19.45%, 18.55% and 17.55 %, respectively. CONCLUSION: The studied models depicted that derivatives A, B and C have the probable potential as anti-inflammatory agents. Further studies need to be undertaken to explore their potential in the different therapeutic areas.

Folic Acid-Modified Erythrocyte Membrane Loading Dual Drug for Targeted and Chemo-Photothermal Synergistic Cancer Therapy.

To overcome the challenges of systemic toxicity and weak tumor selectivity caused by traditional antitumor drugs, numerous nanocarrier systems have been developed in recent decades, and their therapeutic effect has been improved to varying degrees. However, because of the drug resistance effect and metastasis involved in tumor recurrence, a single chemotherapy can no longer satisfy the diversified treatment needs. Recently, the application of chemotherapy in combination with thermotherapy as a synergistic approach has been proven to be more effective, and it provides a new strategy for cancer therapy. In this work, by utilizing the unique properties of erythrocytes, a surface-modified erythrocyte membrane was constructed as a novel nanocarrier system (DOX and ICG-PLGA@RBC nanoparticles, DIRNPs for short) for the simultaneous transportation of chemotherapeutic drugs (doxorubicin, DOX) and photothermal agents (indocyanine green, ICG) to achieve the effects of long-term circulation, active tumor targeting, and triggered drug release. The results indicated that DIRNPs have a nanoscale particle size of 158.4 nm with a narrow size distribution and a negative surface charge of -5.79 mV. No particle aggregation or remarkable drug leakage was observed during the 30 day storage test, and because of the excellent photothermal conversion ability of ICG, the local temperature of DIRNPs could dramatically increase from 33.7 to 49.8 °C in 10 min under near-infrared (NIR) laser irradiation. The in vitro drug dissolution data demonstrated that the DOX release from the DIRNPs was pH-dependent and NIR-triggered. Folic acid modifications of the erythrocyte membrane effectively facilitated the intracellular uptake of DIRNPs by HepG2 cells and, as a result, it significantly inhibited tumor cell growth, promoted reactive oxygen species levels, induced cell apoptosis, and restricted cell recovery and migration. In vivo pharmacokinetics and biodistribution studies indicated that the DIRNPs prolonged the half-life of DOX from 6.03 to 17.6 h and remarkably reduced the DOX level in the heart to avoid drug-related cardiotoxicity. More importantly, the DIRNPs exerted excellent in vivo antitumor efficacy against H22 tumors with superior safety. In conclusion, utilizing the advantageous properties of erythrocytes to construct a tumor-targeted biomimetic nanocarrier for codelivery of chemotherapeutics and photothermal agents to produce synergistic effects is considered an effective method for cancer therapy.