Human Erythrocyte Membrane Research Articles

Homologues Phospholipases A2 isolated from Naja naja atra snake venom exhibit different activity against intact human erythrocytes

Phospholipases A2 (PLA2) catalyze the hydrolysis of fatty acid esters in the 2‐position of 3‐snphospholipids and are found in intracellular and secreted forms. Secretory PLA2s (sPLA2s) are small proteins (13‐15 kDa) classified into five groups based on primary structure differences. Despite their structural similarity, sPLA2s show a wide range of enzymatic and pharmacological activities. Most sPLA2s have high activity toward anionic membranes due to cationic residue presence on their binding recognition site (BRS). Within the same snake venom, several PLA2s can be found, which present differences in their ability to hydrolyze phospholipids in biological bilayers.In this study, Chinese cobra, Naja naja atra (N. n. atra) venom was purified by Size Exclusion Chromatography using a Superdex 75 and cation exchange using a column packed with Carboxymethyl Cellulose (CM‐Cellulose) to pre‐separate protein components from the venom. Subsequently, fractions displaying PLA2 activity were pooled, concentrated, and applied to a GE mini‐CM‐Cellulose column coupled to the AKTA Fast Protein Liquid Chromatography (FPLC) system. The final purification presents four peaks but only two present PLA2 activity (Band D and E). Peak purity was verified using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE).We have shown that hydrophobic residue presence on the PLA2 BRS is crucial for binding and hydrolytic activity toward human erythrocyte membranes. PLA2 activity was assayed against human erythrocytes and monomeric substrate to determine differences in hydrolytic activity. Primary sequence alignment shows 94% homology, however Band E presented 40% less activity against human erythrocytes, despite having 100% active site homology. Molecular modeling of both sPLA2s revealed differences at the Cys‐19 and Trp‐19 position and spatial orientation differences at the Trp‐61, Tyr‐63 Phe‐64, and Lys‐65 positions. Due to amino acid differences at the BRS, differences in hydrolytic activity may be linked to the anchorage of sPLA2 to the erythrocyte surface.

In vitro evaluation of the protective effect of crocin on human erythrocytes

The interactions and the protective effect of the carotenoid crocin (CRO) on human erythrocytes (RBC) and molecular models of its membrane were investigated. The latter consisted of bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representative of phospholipid classes located in the outer and inner monolayers of the RBC membrane, respectively. X-ray diffraction, differential scanning calorimetry (DSC) and electronic paramagnetic resonance spectroscopy (EPR) showed that CRO produced structural perturbations in DMPC bilayers and in isolated unsealed human erythrocyte membranes. On the other hand, scanning electron microscopy (SEM) showed that CRO induced shape changes in the RBC from their normal discoid form to echinocytes. This result indicates that the CRO molecules were mainly localized in the outer monolayer of the RBC membrane. The assessment of the protective capacity of CRO was revealed by the carotenoid inhibition of the morphological alterations caused by hypochlorous acid (HOCl) to RBC.

Structural organization of erythrocyte membrane microdomains and their relation with malaria susceptibility

Cholesterol-rich microdomains are membrane compartments characterized by specific lipid and protein composition. These dynamic assemblies are involved in several biological processes, including infection by intracellular pathogens. This work provides a comprehensive analysis of the composition of human erythrocyte membrane microdomains. Based on their floating properties, we also categorized the microdomain-associated proteins into clusters. Interestingly, erythrocyte microdomains include the vast majority of the proteins known to be involved in invasion by the malaria parasite Plasmodium falciparum. We show here that the Ecto-ADP-ribosyltransferase 4 (ART4) and Aquaporin 1 (AQP1), found within one specific cluster, containing the essential host determinant CD55, are recruited to the site of parasite entry and then internalized to the newly formed parasitophorous vacuole membrane. By generating null erythroid cell lines, we showed that one of these proteins, ART4, plays a role in P. falciparum invasion. We also found that genetic variants in both ART4 and AQP1 are associated with susceptibility to the disease in a malaria-endemic population.

The ratio of ATP11C/PLSCR1 mRNA transcripts has clinical significance in sickle cell anemia.

One of the physiologic mechanisms responsible to maintain asymmetric phospholipid distribution (in particular phosphatidylserine, PS) in human erythrocyte membranes is orchestrated by the balance between enzymes responsible for active transport of PS from the outer to the inner leaflet (ATP11C) and those whose counteracts these activities (PLSCR1). Using quantitative real-time polymerase chain reaction and standard flow cytometry procedures, we hypothesized that the aberrant expression of either or both ATP11C and PLSCR1 transcripts may disrupt the PS internalization/externalization process and become clinically relevant for patients with sickle cell anemia (SCA). Overall, neither ATP11C/PLSCR1 ratio or ATP11C and PLSCR1 (if analyzed separately) had impact on risk to present acute or chronic organ damage in 178 patients with SCA. By collecting a new set of samples from SCA patients during a vaso-occlusive crisis (VOC, crisis state, 13 patients) and comparing with new samples of patients in steady state (15 patients), we noticed that patients in steady state exhibited mean values of ATP11C/PLSCR1 ratio significantly higher (mean value: 18.2, range, 0.3-53) than those who were in crisis (mean value: 3.7, range, 0.5-9) (P = 0.013). Most importantly, there was a strong inverse correlation between PS exposure and ATP11C/PLSCR1 ratio in sickle erythrocytes (Pearson correlation coefficient, r: - 0.78). Based on these findings, it is conceivable that the ATP11C/PLSCR1 ratio may switch from high to low during a VOC, although the underlying reasons require further investigations.

STUDY OF ANTI-INFLAMMATORY POTENTIAL OF WHOLE CELL EXRACTS OF CYANOBACTERIA BY MEMBRANE STABILIZATION & TRYPSIN INHIBITION ASSAY

Inflammation is a complex mechanism in response to any infection, injury, or irritation. The prolonged inflammation leads to tissue damage and loss of function result in various disease conditions like osteoarthritis, and autoimmune diseases like lupus, rheumatoid arthritis, asthma and Crohn’s disease. Anti-inflammatory drugs are used to control inflammatory response and prevent tissue damage .Cyanobacteria are rich sources of phytochemicals like phenolics, flavonoids are known to have anti-inflammatory activity. Because of ease of cultivation and faster growth rate than plants, they are preferred candidates over plants. This study focuses on screening of cyanobacterial isolates for their anti-inflammatory activity. The human erythrocytes (HRBC) membrane stabilization assay indicated the potential of whole cell extracts of cyanobacteria to stabilize lysosomal membrane and thereby prevent tissue damage by lysosomal chemokines and enzymes. The trypsin inhibition assay is an indicator for potential to inhibit proteinases and decelerate tissue damage. The whole cell extracts of 10 cyanobacterial isolates of different genus namely Weistellopsis, Pseudophormidium, Oscillatoria, Nostoc, Phormidium, Chlorella, Hapalosiphon under study showed 85%-94% membrane stabilization in hypotonicity induced hemolysis and 92% to 97% membrane stabilization in heat induced hemolysis. The test extracts also showed 48% to 52% inhibition of trypsin. Thus, the isolates under study have application as anti-inflammatory agent.

Protective Role of a Donepezil-Huprine Hybrid against the β-Amyloid (1-42) Effect on Human Erythrocytes.

Aβ(1-42) peptide is a neurotoxic agent strongly associated with the etiology of Alzheimer’s disease (AD). Current treatments are still of very low effectiveness, and deaths from AD are increasing worldwide. Huprine-derived molecules have a high affinity towards the enzyme acetylcholinesterase (AChE), act as potent Aβ(1-42) peptide aggregation inhibitors, and improve the behavior of experimental animals. AVCRI104P4 is a multitarget donepezil-huprine hybrid that improves short-term memory in a mouse model of AD and exerts protective effects in transgenic Caenorhabditis elegans that express Aβ(1-42) peptide. At present, there is no information about the effects of this compound on human erythrocytes. Thus, we considered it important to study its effects on the cell membrane and erythrocyte models, and to examine its protective effect against the toxic insult induced by Aβ(1-42) peptide in this cell and models. This research was developed using X-ray diffraction and differential scanning calorimetry (DSC) on molecular models of the human erythrocyte membrane constituted by lipid bilayers built of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE). They correspond to phospholipids representative of those present in the external and internal monolayers, respectively, of most plasma and neuronal membranes. The effect of AVCRI104P4 on human erythrocyte morphology was studied by scanning electron microscopy (SEM). The experimental results showed a protective effect of AVCRI104P4 against the toxicity induced by Aβ(1-42) peptide in human erythrocytes and molecular models.

Study of the effect of some drugs used in the clinic on the AQP1 activity of the human erythrocyte membrane

Using the stopped flow method and based on the study of the intensity of light scattering, the effect of pharmacological preparations used in the clinic on the water exchange of human erythrocytes, catalyzed by aquaporin AQP1, was studied. Pharmacological preparations used in therapeutic concentrations have a variable inhibitory effect on water permeability of the erythrocyte membrane. The obtained results broaden our understanding of the molecular action mechanism of the investigated drugs. In view of the wide distribution of AQP1 in various human tissues, these data should be taken into account when carrying out therapeutic measures aimed at normalizing the water exchange of organs and tissues.

Importance of Cholesterol Side Chain in the Membrane Stability of Human Erythrocytes.

Cholesterol suppresses the hemolysis and the detachment of cytoskeletal proteins from bilayer in the human erythrocyte membrane under stress conditions. However, there is little information on how cholesterol functions. So, examining the role of a short side chain of cholesterol, we used the plant sterols such as β-sitosterol and stigmasterol. Incorporation of sterols into the membrane using a sterol/methyl-β-cyclodextrin complex was confirmed by the mass spectrometry. Hemolysis of human erythrocytes under high hydrostatic pressure (200 MPa) or hypotonic conditions was suppressed by cholesterol, but not by β-sitosterol and stigmasterol. Moreover, the bilayer-cytoskeleton interaction was also strengthened by cholesterol, but not by β-sitosterol and stigmasterol. Taken together, we suggest that the short side chain of cholesterol plays an important role in the membrane stability of human erythrocytes.

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.

Erythrocyte membrane proteins involved in the immune response to Plasmodium falciparum and Plasmodium vivax infection

Invasion of Plasmodium into the red blood cell involves the interactions of a substantial number of proteins, with red cell membrane proteins as the most involved throughout the process from entry to exit. The objective of this work was to identify proteins of the human erythrocyte membrane capable of generating an antigenic response to P. falciparum and P. vivax infection, with the goal of searching for new molecular targets of interest with an immunological origin to prevent Plasmodium infection. To identify these proteins, an immunoproteomic technique was carried out in four stages: protein separation (electrophoresis), detection of antigenic proteins (western blotting), identification of proteins of interest (mass spectrometry), and interpretation of the data (bioinformatic analysis). Four proteins were identified from extracts of membrane proteins from erythrocytes infected with P. falciparum: Spectrin, Ankyrin-1, Band 3 and band 4.2, and a single protein was identified from erythrocytes infected with P. vivax: Band 3. These results demonstrate that modifications in the red blood cell membrane during infection with P. falciparum and P. vivax can generate an immune response, altering proteins of great structural and functional importance.

Sauropus androgynus (L.) leaf phytochemical activated biocompatible zinc oxide nanoparticles: An antineoplastic agent against human triple negative breast cancer and a potent nanocatalyst for dye degradation

The present study delineates the biosynthesis of ZnOSA NPs by availing S. androgynous (L.) aqueous leaf extract. The formation of ZnOSA NPs was substantiated by FT-IR and UV–visible spectroscopy which was further corroborated by the elemental composition study through EDS spectroscopy. The FE-SEM and HRTEM micrographs have revealed the formation of NPs with different shapes and sizes ranging from 12 to 23 nm. The BET isotherms obtained have manifested the mesoporous nature of ZnOSA NPs. The in-vitro cytotoxicity studies of ZnOSA NPs carried out on MDAMB468 human triple-negative breast cancer (TNBC) and NIH3T3 mouse fibroblast cells have evinced their potential cytotoxic effect (75.98 ± 1.07) on cancer cells sparing the normal cells. Further, the results of the AO-EB dual staining assay indicated early apoptosis in TNBC cells by displaying greenish yellow-fluorescence in the nuclei at a IC50 concentration of 53.79 µg/mL of NPs. Additionally; the human erythrocyte membrane stabilization assay has corroborated the haemocompatibility of ZnOSA NPs by exhibiting a % HRBCMS up to 89.15 ± 0.02%. Furthermore, the photocatalytic experiments performed on Methylene Blue dye have revealed the excellent degradation efficiencies of ZnOSA NPs up to 88.01% with high stability and reusability tested during 4 catalytic cycles. Thus, the obtained results have shown greater potential in the anticancer and photocatalytic dye degradation activities of bio-fabricated ZnOSA NPs.

Piperine protects oxidative modifications in human erythrocytes.

Piperine (1-piperoyl piperidine), a major alkaloid constituent of Piper nigrum L. and Piper longum L. has pleiotropic biological effects, but the mechanism(s) involved remain to be elucidated. The current study was conducted to examine the efficacy of antioxidant ability of piperine on t-BHP induced markers of oxidative stress in human erythrocytes. Healthy human erythrocytes and erythrocytes membrane was stressed with free radical inducer chemical; t-BHP (10-5M), and the effects of piperine was measured against free radical mediated modification in lipid and protein content,-SH and GSH value with antioxidant potential. The results demonstrate that treatment of erythrocytes with piperine (10-5 to 10-7M) significantly (p<0.05) ameliorated the adverse consequences of oxidative stress as evidenced by prevention of oxidation of erythrocyte reduced glutathione, membrane thiols, proteins, and peroxidation of lipids; the effects were in correlation with ferric reducing and radical scavenging abilities of piperine. The study concludes that piperine possesses potent anti-oxidant potential which may explain many of its observed biological effects.

Influence of the dimensionality of the periodic boundary conditions on the transport of a drug–peptide complex across model cell membranes

Many research efforts are devoted to improving the efficiency of chemotherapy. One of the aspects is to facilitate the transport of drugs across the cell membranes by attaching the therapeutics to a carrier molecule. The current study focuses on computational investigation of such a system with doxorubicin as the model drug, which is covalently bound to a cell-penetrating peptide. The correct description of its membrane translocation at the molecular level requires proper choice of the model membrane and of the simulation parameters. For the purpose, two phospholipid bilayers are built, one containing solely DPPC and another with mixed lipid content mimicking the composition of a human erythrocyte membrane. Atomistic molecular dynamics simulations are carried out in two types of periodic boundary conditions (2D and 3D PBC), in order to assess the effect of the periodicity dimensionality on the intermolecular interactions. The evolution of some basic characteristics of the bilayers and of the drug–peptide complex is tracked: mass density profiles, electrostatic potentials, lateral diffusion coefficients and areas per lipid, lipid-complex radial distribution functions, secondary structure of the peptide and orientation of the drug relative to the membrane. Thus, the influence of the periodic boundary conditions is quantified and it shows that the mixed system in 3D PBC is the most suitable for analysis of the translocation of the transporting moiety across cell membranes.

Ultrasound-assisted fabrication of acoustically active, erythrocyte membrane “bubbles”

In this communication, we report an ultrasound-assisted method, utilising human red blood cell (RBC) or erythrocyte membranes, to produce acoustically active “bubbles”, intended for vasculature imaging. The resulting RBC membrane bubbles have an average size of 1.5 μm with a generally spherical morphology, altered internal aqueous compartment contents, and small gas-containing protrusions or “pockets” in between the membrane bilayer. We also found that this method produced some nanobubbles (200–400 nm diameter), due to the shedding of lipid components from the RBC membranes to compensate for the membrane structural changes. In vitro ultrasound imaging showed that RBC membrane bubbles had comparable ultrasound contrast enhancement as the standard DEFINTYTM microbubble preparation (~13% v/v) and lower concentrations of this standard contrast agent. This current technology demonstrate a new and important application of ultrasound and of RBC membranes, having inherent biocompatibility, as potential material for the development of new types of ultrasound imaging agents, without the use of additional lipid components and pre-made microbubbles.

Degradation of Spectrin and band 3 protein

Oxygen free radicals generated during radiation injury damage human erythrocyte membrane proteins including spectrin and band 3 protein. Results show an appreciable degree of spectrin and band 3 protein loss of about 55-65% due to crosslinking, and proteolysis when sodium dodecyl sulphate polyacrylamide gel electrophoresis carried out on erythrocyte ghosts. Oxidative damage to membrane proteins lead to degradation of its cytoskeletal components. Keywords: Spectrin, Band 3 protein, Erythrocyte ghosts, Oxygen free radicals

Study on the Hemolytic and Anti-Hemolytic Activities of the Aerial Parts Extracts of Centaurea virgata and Centaurea solstitialis

In this study, we subjected Centaurea virgata and Centaurea solstitialis extracts to a qualitative chemical analysis to identify the most important chemical groups they contain, we also aimed to determine their total phenolic content. In addition to the phytochemical study, hemolysis test was conducted to investigate the toxic effects of the plant extracts on red blood cells membranes, and to evaluate the plants’ ability to prevent the oxidative hemolysis for normal and G6PD enzyme-deficient human erythrocytes. Qualitative Phytochemical analysis exposed that the aerial parts extracts contains phenolic compounds, tannins, flavonoids, saponins, and carbohydrates. Both extracts had good phenolic contents. The present study also showed that hydromethanolic extracts of the plants have no obvious toxic effects towards human erythrocytes membranes. The extracts proved their antioxidant activities through their excellent activities in protecting normal and G6PD enzyme-deficient human erythrocytes from oxidative damage induced by H2O2. Further studies are wanted for detecting biological and biochemical effects of these plants.

Interaction of the antimicrobial peptide ∆M3 with the Staphylococcus aureus membrane and molecular models

Staphylococcus aureus is one of the most pathogenic bacteria; infections with it are associated with significant morbidity and mortality in health care facilities. Antimicrobial peptides are a promising next generation antibiotic with great potential against bacterial infections. In this study, evidence is presented of the biological and biophysical properties of the novel synthetic peptide ΔM3. Its antimicrobial activity against the ATCC 25923 and methicillin-resistant S. aureus strains was evaluated. The results showed that ΔM3 has activity in the same μM range as vancomycin. Biophysical studies were performed with palmitoyloleoylphosphatidylglycerol and cardiolipin liposomes loaded with calcein and used to follow the lytic activity of the peptide by fluorescence spectroscopy. On the other hand, ΔM3 was induced to interact with molecular models of the erythrocyte membrane buil-up of dimiristoylphosphatidylcholine and dimyristoylphosphatidylethanolamine, representative lipids of the outer and inner monolayers of the human erythrocyte membrane, respectively. The capacity of ΔM3 to interact with the bacteria and erythrocyte model membranes was also evaluated by X-ray diffraction and differential scanning calorimetry. The morphological changes induced by the peptide to human erythrocytes were observed by scanning electron microscopy. Results with these techniques indicated that ΔM3 interacted with the inner monolayer of the erythrocyte membrane, which is rich in anionic lipids. Additionally, the cytotoxic effects of ΔM3 on red blood cells were evaluated by monitoring the hemoglobin release from erythrocytes. The results obtained from these different approaches showed ΔM3 to be a non-cytotoxic peptide with antibacterial activity.

The anti-inflammatory potential of Cinnamomum camphora (L.) J.Presl essential oil in vitro and in vivo

Ethnopharmacological relevanceBorneol was widely used in traditional Chinese medicine formulas due to its pharmacological activities, e.g. sedative, anti-inflammatory, and anti-ischemic properties. Cinnamomum camphora (L.) J.Presl essential oil (BEO) is a by-product of natural crystalline borneol (NCB) production obtained by steam distillation of Cinnamomum camphora (L.) J.Presl leaves, and borneol was the main component of BEO. This study aims to investigate the anti-inflammatory effect of BEO and its corresponding mechanisms through in vitro and in vivo studies. Materials and methodsHuman erythrocyte membrane stability assay and the acute inflammation murine model (xylene-induced ear edema) were chosen to evaluate the anti-inflammatory effect of BEO. Expression of inflammatory mediators, including interleukin (IL)-1β, IL-6, and tumor necrosis factor α (TNF-α) was determined by real-time quantitative polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assays (ELISA). The functional compounds in the BEO were identified by using gas chromatography-mass spectrometry (GC-MS). The steady-state transdermal diffusion rates of BEO and BEO nano-emulsion with were also determined in this study. Cytotoxicity of BEO was analyzed by cell counting kit-8 (CCK-8) assay. ResultsThe BEO showed a high human erythrocyte membrane stabilization by inhibiting heat-induced hemolysis (IC50 = 5.29 mg/mL) and hypotonic solution-induced hemolysis (IC50 = 0.26 mg/mL) in vitro. The BEO was topically applied to mice auricles, both single and repeated administration significantly reduced xylene-induced auricle swelling (p < 0.0001). Expression of inflammatory mediators, including interleukin (IL)-1β, IL-6, and tumor necrosis factor α (TNF-α) in serum and tissue was significantly downregulated (p < 0.05), so as to the mRNA expression of IL-1β (p＜0.05) and TNF-α (p < 0.001). A total of 43 components were identified and quantified by GC-MS. The most abundant was borneol [178.3 mg/mL, 20.9% (m/v)], followed by β-caryophyllene (116.3 mg/mL), camphor (115.2 mg/mL), and limonene (89.4 mg/mL). For determining the skin permeability of BEO, the steady-state transdermal diffusion rates of BEO and BEO nano-emulsion were determined to be 6.7 and 8.9 mg/cm2·h, respectively. ConclusionIt is suspected that the anti-inflammatory effects in vivo and in vitro were derived from the above-mentioned components in the BEO. These findings will facilitate the development of BEO as a new and natural therapeutic agent for inflammatory skin conditions.

DARC, Glycophorin A, Band 3, and GLUT1 Diffusion in Erythrocytes: Insights into Membrane Complexes

Single-particle tracking offers a method to interrogate the organization of transmembrane proteins by measuring their mobilities within a cell’s plasma membrane. Using this technique, the diffusion characteristics of the Duffy antigen (DARC), glycophorin A, band 3, and GLUT1 were compared under analogous conditions on intact human erythrocyte membranes. Microscopic diffusion coefficients revealed that the vast majority of all four transmembrane proteins exhibit very restricted movement but are not completely immobile. In fact, only 12% of GLUT1 resolved into a highly mobile subpopulation. Macroscopic diffusion coefficients and compartment sizes were also similar for all four proteins, with movements confined to the approximate dimensions of the “corrals” of the cortical spectrin cytoskeleton. Taken together, these data suggest that almost the entire populations of all four transmembrane proteins are immobilized by either the incorporation within large multiprotein complexes or entrapment within the protein network of the cortical spectrin cytoskeleton.

Stem extract of Albizia richardiana exhibits potent antioxidant, cytotoxic, antimicrobial, anti-inflammatory and thrombolytic effects through in vitro approach

BackgroundAlbizia richardiana belongs Fabaceae family which different parts like fruits, flowers, barks, and roots are used medicinally. The study reports the in vitro anti-inflammatory, thrombolytic, cytotoxicity and antimicrobial activity of methanolic extract of A. richardiana stem and its different fractions.MethodThe methanolic extract of A. richardiana stem (MEAR) extracted with n-hexane (HXFAR), carbon tetrachloride (CTFAR), chloroform (CFAR), and aqueous (AQFAR) and subjected for DPPH scavenging activity and total phenol content (TPC). The cytotoxic activity evaluated by brine shrimp lethality bioassay, while the disk diffusion method used for the antimicrobial study. The anti-inflammatory and thrombolytic activities of the extracts evaluated by the hypotonic solution induced hemolysis, heat-induced hemolysis and human blood clot lysis, respectively.ResultsAll the extracts exhibited excellent antioxidant activity in the DPPH scavenging assay and maximum total phenol content observed by HXFAR. Secondly, the extract showed a moderate LC50 value in brine shrimp lethality bioassay, where the CTFAR extract exhibited potential antimicrobial activities against sixteen different microorganisms. In anti-inflammatory, all the extract exhibited a significant (P < 0.0001) protection against lysis of human erythrocyte membrane induced by heat and hypotonic solution, as compared to the standard acetyl salicylic acid. An extremely significant (P < 0.0001) clot lysis was found in MEAR (16.66%) while the standard drug streptokinase (70.94%).ConclusionAll the fractions revealed the significant free radical scavenging activity. Moreover, CTFAR showed wide spectrum of antimicrobial activity. Thus, the results of the present study provided scientific evidence for the use of Albizia richardiana as traditional medicine.