Human Red Cell Membrane Research Articles

Abstract LB-156: A diet-derived sialic acid promotes inflammation and hepatocellular cancer

Abstract N-glycolylneuraminic acid (Neu5Gc) is a non-human sialic acid derived from the diet (primarily red meat) that can be metabolically incorporated into human tissues despite being an antigen. Since this incorporation occurs in the face of circulating anti-Neu5Gc antibodies, we hypothesized that this generates an antibody-antigen reaction and leads to inflammation termed “xenosialitis”. Although red meat consumption is prominently associated with cancer development, pathological mechanisms behind this link are yet to be conclusively proven. The purpose of our research is to investigate the relationship between “xenosialitis”, inflammation and cancer. We used a Cmah null mouse model (mimicking the human lack of Neu5Gc) to provide evidence for such inflammation and cancer promotion. Anti-Neu5Gc antibodies were generated by immunizing Cmah null mice, with chimpanzee red blood cell membranes, or with human red blood cell membranes as controls. Pooled immune or control sera were repeatedly adsorbed with human red blood cells, and the resulting polyclonal antisera passively transferred into additional Cmah null mice that were on a diet with or without Neu5Gc. Mice fed with Neu5Gc and injected with anti-Neu5Gc antibodies showed dose-dependent elevation in acute phase proteins (Serum Amyloid A and Haptoglobin) in the serum as compared to controls. Such C57BL/6 mice are prone to developing hepatic adenomas and occasional carcinomas. Cmah null but not wild-type C57BL/6 mice immunized with chimpanzee red blood cell membranes and fed with Neu5Gc developed a higher frequency of hepatocellular cancer and liver histology showed Neu5Gc accumulation and foci of inflammation. In conclusion, Neu5Gc that has metabolically incorporated into tissues from the diet interacts with anti-Neu5Gc antibodies, generating xenosialitis. Potential correlations of human anti-Neu5Gc antibody levels with red meat consumption and cancer risk are being investigated. Methods to flush out the xenogenic Neu5Gc are being pursued. Similar mechanisms may be operative in other chronic inflammatory processes in diseases epidemiologically associated with red meat consumption, such as atherosclerosis. Citation Format: Annie N. Samraj, Heinz Laubli, Oliver Pearce, Patrick Secrest, Andrea E. Garcia-Bingman, Nissi Varki, Ajit Varki. A diet-derived sialic acid promotes inflammation and hepatocellular cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-156. doi:10.1158/1538-7445.AM2014-LB-156

Localization of the Plasmodium Falciparum K+ Channel, Pfkch1

The causative agent of malaria is the unicellular protozoan Plasmodium. The parasite has a complex life cycle, involving asexual replication in human red blood cells (RBCs) as well as sexual replication, forming egg-like cells called oocysts in the mosquito vector. In endemic areas it is estimated that 250 million people get infected with malaria annually, resulting in 500.000-1.000.000 deaths. Increasing resistance towards known antimalarial drugs poses a significant problem in the fight against malaria. Therefore, the development of novel drugs that target vital proteins encoded by the parasite has attracted major attention. Plasmodium falciparum, the species responsible for the majority of malaria- associated fatalities, encodes two putative K+ channels, PfKch1 and PfKch2, which have been cloned in our laboratories. Although viable in all intraerythrocytic stages, Kch1-null P. berghei parasites exhibit a total inhibition of oocyst development in the mosquito midgut. Thus, Kch1 might serve as a potential target in novel parasite transmission-blocking strategies. However, earlier published immunofluorescence microscopy images have suggested that Kch1 is located in the infected human red blood cell membrane. In the present study, polyclonal antibodies were raised against the PfKch1 channel and our results demonstrate that Kch1 is located in the parasites plasma membrane in all blood stages of malaria. This finding is in accordance with functional data previously published from our lab. Thus, Kch1 may be a major K+ transporter in the parasite plasma membrane and play an important role for regulation of the membrane potential of the Plasmodium parasite.

Engineering Antimicrobial Peptides with Improved Antimicrobial and Hemolytic Activities

The rapid rise of antibiotic resistance in pathogens becomes a serious and growing threat to medicine and public health. Naturally occurring antimicrobial peptides (AMPs) are an important line of defense in the immune system against invading bacteria and microbial infection. In this work, we present a combined computational and experimental study of the biological activity and membrane interaction of the computationally designed Bac2A-based peptide library. We used the MARTINI coarse-grained molecular dynamics with adaptive biasing force method and the umbrella sampling technique to investigate the translocation of a total of 91 peptides with different amino acid substitutions through a mixed anionic POPE/POPG (3:1) bilayer and a neutral POPC bilayer, which mimic the bacterial inner membrane and the human red blood cell (hRBC) membrane, respectively. Potential of mean force (PMF, free energy profile) was obtained to measure the free energy barrier required to transfer the peptides from the bulk water phase to the water-membrane interface and to the bilayer interior. Different PMF profiles can indeed identify different membrane insertion scenarios by mapping out peptide-lipid energy landscapes, which are correlated with antimicrobial activity and hemolytic activity. Computationally designed peptides were further tested experimentally for their antimicrobial and hemolytic activities using bacteria growth inhibition assay and hemolysis assay. Comparison of PMF data with cell assay results reveals a good correlation of the peptides between predictive transmembrane activity and antimicrobial/hemolytic activity. Moreover, the most active mutants with the balanced substitutions of positively charged Arg and hydrophobic Trp residues at specific positions were discovered to achieve the improved antimicrobial activity while minimizing red blood cell lysis. Such substitutions provide more effective and cooperative interactions to distinguish the peptide interaction with different lipid bilayers. This work provides a useful computational tool to better understand the mechanism and energetics of membrane insertion of AMPs and to rationally design more effective AMPs.

Does quercetin protect human red blood cell membranes against γ-irradiation?

ObjectivesRadioprotective potential of quercetin, a powerful free radical scavenger, was investigated in human red blood cells (RBCs) and in isolated RBC membranes exposed to γ-irradiation-induced oxidative stress.MethodsRBCs and RBC membrane suspensions were irradiated (50 Gy) in the presence of quercetin (2–50 µM). Oxidative damage of the membranes was analysed by protein carbonyl measurement (enzyme-linked immunosorbent assay). In RBCs, the concentration of glutathione (GSH) was determined. Lipid peroxidation in RBCs, and for comparison in plasma and peripheral lymphocytes, was quantified by the amount of thiobarbituric acid-reactive substances (TBARS). Radiation-induced damage of the RBC membrane integrity was evaluated by the degree of haemolysis.ResultsQuercetin (50 µM) brought back the level of carbonyls to normal in γ-irradiated RBC membrane proteins and inhibited radiation-induced lipid peroxidation in plasma and lymphocytes, by 75 and 96%, respectively. However, it moderately decreased reduced/oxidized glutathione (GSH/GSSG) ratio and significantly increased TBARS concentrations, by 60 and 28% in irradiated and non-irradiated RBCs, respectively. Haemolysis rate was much higher in RBCs irradiated in the presence of quercetin vs. non antioxidant.DiscussionIn non-cellular systems (RBC membranes or plasma) and in lymphocytes, quercetin shows antioxidative/radioprotective activity but in whole RBCs it acts as a pro-oxidant and a cytotoxic substance. The possible mechanisms of such action are discussed.

ANTIARTHRITIC ACTIVITY OF DESMODIUM GANGETICUM ROOT

The present study is aimed to evaluate the in - vitro anti - arthritic activity of aqueous extract of Desmodium gangeticum root using inhibition of protein denaturation model and human red blood cell Membrane stabilization model. Diclofenac sodium was used as a standard drug. Resu lts revea led that the aqueous extract of Desmodium gangeticum root at different concentrations possessed significant anti - arthritic activity as compared to standard drug used as Diclofenac sodium. The results obtained in the present investigation Indicate that aque ous extract of Desmodium gangeticum root showed anti - arthritic activity.

ANTIARTHRITIC ACTIVITY OF MILK EXTRACT OF SEMECARPUS ANACARDIUM NUT

The present study is aimed to evaluate the anti - arthritic activity of milk extract of Semecarpus anacardium nut using inhibition of protein denaturation model and human red blood cell Membrane stabilization model. Diclofenac sodium was used as a standard drug. Results revealed that the milk extract of Semecarpus anacardium nut at different concentrations possessed significant anti - arthritic activity as compared to standard drug used as Diclofenac sodium. The results obtained in the present i nvestigation Indicate that milk extract of Semecarpus anacardium nut showed anti - arthritic activity.

DNA-Templated Silver Nanoclusters for Fluorescence Turn-on Assay of Acetylcholinesterase Activity

We have developed a fluorescence turn-on assay using DNA-templated silver nanoclusters (Ag NCs) (i.e., 12 polycytosine-templated silver nanoclusters, dC12-Ag NCs), which is amenable to rapid, ultrasensitive assay of acetylcholinesterase (AChE). The detection mechanism is based on the concept, that is, AChE hydrolyzes the acetylthiocholine (ATCh) chloride to produce thiocholine (TCh). Subsequently, TCh sensitively and rapidly reacts with dC12-Ag NCs via Ag-S bond forming and enhances the fluorescence of dC12-Ag NCs. Using dC12-Ag NCs, detection of TCh has a linear concentration range of 2.0 nM to 16.0 nM and a detection limit of 0.3 nM. Due to the sensitive and rapid fluorescence turn-on response of dC12-Ag NCs to TCh, AChE with activity as low as 0.5 × 10(-4) U/mL (signal/noise = 3) can be analyzed with a dynamic range of 0.1 to 1.25 × 10(-3) U/mL. The promising application of the proposed method in AChE inhibitor screening was demonstrated. AChE concentrations were determined in human blood red cell (RBC) membranes from clinical specimens using dC12-Ag NCs, and the quantitative results were validated with Ellman's method. Aside from the ease of manufacture, reduction of matrix effect, and low background noise, the continuous detection format and detection sensitivity can open up to wider applications to AChE activity assay in neurobiology, toxicology, and pharmacology, among other fields.

IN VITRO ANTIINFLAMMATORY ACTIVITY OF FICUS BENGHALENSIS BARK

To evaluate the anti - inflammatory property of the different extract of bark of Ficus benghalensis , family Moraceae is a very large , fast growing, evergreen tree up to 30 meters, with spreading branches and many aerial roots. Leaves stalked, ovate - cordate, 3 - nerved, entire, when young downy on both sides; petiole with a broad smooth greasy gland at the apex, compressed, downy; Fruit i n axillary pairs, the size of a cherry, round and downy. According to Ayurveda, it is astringent to bowels; useful in treatment of biliousness, ulcers, erysipelas, vomiting, vaginal complains, fever, inflammatio ns, leprosy. According to Unani system of med icine, its latex is aphrodisiac, tonic, vulernary, maturant, lessens inflammations; useful in piles etc. The present study aimed at the evaluation of anti - inflammatory property of the aqueous , chloroform and alcoholic extracts of the bark by in vitro metho ds. In vitro method was estimated by human red blood cell membrane stabilization (HRBC) method . Results showed significant anti - inflammatory property of the different extracts tested. The methanolic extract at a concentration of 2 00 mg/ml. showed potent ac tivity on comparing with the standard drug diclofenac sodium.

Transport of H2S and HS(-) across the human red blood cell membrane: rapid H2S diffusion and AE1-mediated Cl(-)/HS(-) exchange.

The rates of H2S and HS(-) transport across the human erythrocyte membrane were estimated by measuring rates of dissipation of pH gradients in media containing 250 μM H2S/HS(-). Net acid efflux is caused by H2S/HS(-) acting analogously to CO2/HCO3(-) in the Jacobs-Stewart cycle. The steps are as follows: 1) H2S efflux through the lipid bilayer and/or a gas channel, 2) extracellular H2S deprotonation, 3) HS(-) influx in exchange for Cl(-), catalyzed by the anion exchange protein AE1, and 4) intracellular HS(-) protonation. Net acid transport by the Cl(-)/HS(-)/H2S cycle is more efficient than by the Cl(-)/HCO3(-)/CO2 cycle because of the rapid H2S-HS(-) interconversion in cells and medium. The rates of acid transport were analyzed by solving the mass flow equations for the cycle to produce estimates of the HS(-) and H2S transport rates. The data indicate that HS(-) is a very good substrate for AE1; the Cl(-)/HS(-) exchange rate is about one-third as rapid as Cl(-)/HCO3(-) exchange. The H2S permeability coefficient must also be high (>10(-2) cm/s, half time <0.003 s) to account for the pH equilibration data. The results imply that H2S and HS(-) enter erythrocytes very rapidly in the microcirculation of H2S-producing tissues, thereby acting as a sink for H2S and lowering the local extracellular concentration, and the fact that HS(-) is a substrate for a Cl(-)/HCO3(-) exchanger indicates that some effects of exogenous H2S/HS(-) may not result from a regulatory role of H2S but, rather, from net acid flux by H2S and HS(-) transport in a Jacobs-Stewart cycle.

IN VITRO ANTIINFLAMMATORY ACTIVITY OF JUGLANS REGIA BARK

To evaluate the anti-inflammatory property of the different extract of bark of Juglans regia , family Juglandaceae is a deciduous tree. Its fruits are consumed as food, which are rich in unsaturated fatty acids. Walnut leaf has been widely used in traditional medicine for the treatment of skin inflammations and ulcers and for its antidiarrheic, antihelmintic, antiseptic and astringent properties. The present study aimed at the evaluation of anti-inflammatory property of the aqueous, chloroform and alcoholic extracts of the bark by in vitro methods. In vitro method was estimated by human red blood cell membrane stabilization (HRBC) method. Results showed significant anti-inflammatory property of the different extracts tested. The aqueous extract at a concentration of 200 mg/ml. showed potent activity on comparing with the standard drug diclofenac sodium. Key words: Juglans regia , HRBC, Inflammation and dicloenac.

Resolution of translation start site for the human Kell glycoprotein

The human Kell blood group system currently contains 35 antigens determined by allelic polymorphisms in the Kell glycoprotein, a single-pass Type II transmembrane protein. The Kell glycoprotein was initially cloned through screening of a cDNA library; however, direct amino acid sequencing of most of the Kell glycoprotein has not been reported. The N-terminus of the Kell glycoprotein contains two potential translational start sites, which result in differences in the cytoplasmic tail. Protein extracts were isolated from human red blood cell membranes and were digested with trypsin. The resulting peptides were subjected to liquid chromatography-tandem mass spectrometry, allowing resolution of peptides from the N-terminus of the Kell glycoprotein. Peptides were isolated and sequenced that correspond to the upstream methionine start site predicted by the full cDNA sequence. No evidence of internal translation initiation at Methionine 20 was detected. These findings identify the translational start site and define the full cytoplasmic tail of the human Kell glycoprotein.

Characterization of citrate capped gold nanoparticle-quercetin complex: Experimental and quantum chemical approach

Quercetin and several other bioflavonoids possess antioxidant property. These biomolecules can reduce the diabetic complications, but metabolize very easily in the body. Nanoparticle-mediated delivery of a flavonoid may further increase its efficacy. Gold nanoparticle is used by different groups as vehicle for drug delivery, as it is least toxic to human body. Prior to search for the enhanced efficacy, the gold nanoparticle-flavonoid complex should be prepared and well characterized. In this article, we report the interaction of gold nanoparticle with quercetin. The interaction is confirmed by different biophysical techniques, such as Scanning Electron Microscope (SEM), Circular Dichroism (CD), Fourier-Transform InfraRed (FT-IR) spectroscopy and Thermal Gravimetric Analysis (TGA) and cross checked by quantum chemical calculations. These studies indicate that gold clusters are covered by citrate groups, which are hydrogen bonded to the quercetin molecules in the complex. We have also provided evidences how capping is important in stabilizing the gold nanoparticle and further enhances its interaction with other molecules, such as drugs. Our finding also suggests that gold nanoparticle-quercetin complex can pass through the membranes of human red blood cells.

Membrane stabilization – A possible mechanism of action for the anti-inflammatory activity of a Bangladeshi medicinal plant: Erioglossum rubiginosum (Bara Harina)

AimsThe present study aimed at assessing the effect of methanol extract of Erioglossum rubiginosum, a widely used shrub like plant in folkloric medicine, in experimentally induced inflammation, using human red blood cell (HRBC) membrane stabilization as study method. MethodsThe methanol extract of leaves of E. rubiginosum and its pet-ether, carbon tetrachloride, chloroform and aqueous soluble partitionates were subjected to assays for lysis of erythrocytes and % of inhibition in hypotonic solution and heat induced lysis, using acetyl salicylic acid as standard drug, in an in vitro model. ResultsAt the concentration of 1 mg/ml, methanol extract and its pet-ether, carbon tetrachloride, chloroform and aqueous soluble partitionates significantly inhibited hypotonic solution induced lysis of the human red blood cell membrane with values of 0.428 ± 0.005, 0.204 ± 0.003, 0.233 ± 0.002, 0.411 ± 0.003, 0.439 ± 0.003% respectively; which were comparable to the standard drug acetyl salicylic acid (0.1 mg/ml), 0.166 ± 0.003. In case of heat induced HRBC heamolysis, the plant extracts also showed significant activity where the values of inhibitory actions were 14.46 ± 0.344, 28.23 ± 0.315, 25.18 ± 0.303, 17.09 ± 0.365, 13.44 ± 0.470% for methanol extract, pet-ether, carbon tetrachloride, chloroform and aqueous soluble partitionates respectively. ConclusionIt can be postulated from the observed results that the membrane stabilizing action and inhibition of erythrocyte lysis property of E. rubiginosum may be the possible mechanism of action of its anti-inflammatory activity. So, further studies are suggested to evaluate the anti-inflammatory and analgesic activities of the plant.

IN VITRO ANTI-ARTHRITIC ACTIVITY OF ETHANOLIC EXTRACT OF CALLICARPA MACROPHYLLA FLOWER

The prese nt study is aimed to evaluate the in - vitro anti - arthritic activity of ethanolic extract of Callicarpa macrophylla flower using inhibition of protein denaturation model and human red blood cell Membrane stabilization model. Diclofenac sodium was used as a s tandard drug. Results revealed that the ethanolic extract of Callicarpa macrophylla at different concentrations possessed significant anti - arthritic activity as compared to standard drug used as Diclofenac sodium. The results obtained in the present invest igation Indicate that ethanolic extract of Callicarpa macrophylla flower showed anti - arthritic activity.

Proteomic analysis of ERK1/2-mediated human sickle red blood cell membrane protein phosphorylation

BackgroundIn sickle cell disease (SCD), the mitogen-activated protein kinase (MAPK) ERK1/2 is constitutively active and can be inducible by agonist-stimulation only in sickle but not in normal human red blood cells (RBCs). ERK1/2 is involved in activation of ICAM-4-mediated sickle RBC adhesion to the endothelium. However, other effects of the ERK1/2 activation in sickle RBCs leading to the complex SCD pathophysiology, such as alteration of RBC hemorheology are unknown.ResultsTo further characterize global ERK1/2-induced changes in membrane protein phosphorylation within human RBCs, a label-free quantitative phosphoproteomic analysis was applied to sickle and normal RBC membrane ghosts pre-treated with U0126, a specific inhibitor of MEK1/2, the upstream kinase of ERK1/2, in the presence or absence of recombinant active ERK2. Across eight unique treatment groups, 375 phosphopeptides from 155 phosphoproteins were quantified with an average technical coefficient of variation in peak intensity of 19.8%. Sickle RBC treatment with U0126 decreased thirty-six phosphopeptides from twenty-one phosphoproteins involved in regulation of not only RBC shape, flexibility, cell morphology maintenance and adhesion, but also glucose and glutamate transport, cAMP production, degradation of misfolded proteins and receptor ubiquitination. Glycophorin A was the most affected protein in sickle RBCs by this ERK1/2 pathway, which contained 12 unique phosphorylated peptides, suggesting that in addition to its effect on sickle RBC adhesion, increased glycophorin A phosphorylation via the ERK1/2 pathway may also affect glycophorin A interactions with band 3, which could result in decreases in both anion transport by band 3 and band 3 trafficking. The abundance of twelve of the thirty-six phosphopeptides were subsequently increased in normal RBCs co-incubated with recombinant ERK2 and therefore represent specific MEK1/2 phospho-inhibitory targets mediated via ERK2.ConclusionsThese findings expand upon the current model for the involvement of ERK1/2 signaling in RBCs. These findings also identify additional protein targets of this pathway other than the RBC adhesion molecule ICAM-4 and enhance the understanding of the mechanism of small molecule inhibitors of MEK/1/2/ERK1/2, which could be effective in ameliorating RBC hemorheology and adhesion, the hallmarks of SCD.

High-efficiency localization of Na+–K+ ATPases on the cytoplasmic side by direct stochastic optical reconstruction microscopy

We describe a concise and effective strategy towards precisely mapping Na(+)-K(+) ATPases on the cytoplasmic side of cell membranes by direct stochastic optical reconstruction microscopy (dSTORM). We found that most Na(+)-K(+) ATPases are localized in different sizes of clusters on human red blood cell (hRBC) membranes, revealed by Ripley's K-function analysis. Further evidence that cholesterol depletion causes the dispersion of Na(+)-K(+) ATPase clusters indicates that such clusters could be localized in cholesterol-enriched domains. Our results suggest that Na(+)-K(+) ATPases might aggregate within the lipid rafts to fulfill their functions.

In vitro and in vivo antiinflammatory activity of Clerodendrum paniculatum linn. leaves

Preliminary phytochemical screening showed the presence of terpenes, flavonoids, tannins, alkaloids, phenolic acid, sterols, and glycosides. This study was intended to evaluate the antiinflammatory activity of various extracts of fresh leaves of Clerodendrum paniculatum Linn experimentally by in vitro (human red blood cell membrane stabilization method) and in vivo methods (0.1 ml of 1% w/v carrageenan-induced rat paw oedema model). Petroleum ether, chloroform, ethyl acetate, alcohol, and aqueous extracts were screened for in vitro antiinflammatory activity. Petroleum ether and chloroform extracts which showed, best in vitro antiinflammatory activity was screened for in vivo antiinflammatory activity at the dose level of 200 and 400 mg/kg. Indomethacin at the dose level of 10 mg/kg was used as reference standard drug. Both the extracts showed a dose dependent significant (P<0.001) reduction in paw edema when compared to the control, at all the time intervals and comparable to indomethacin (reference standard) treated group. The results of the present study demonstrate that petroleum ether and chloroform extracts possess significant (P<0.001) antiinflammatory potential which provide scientific basis for the traditional claims of Clerodendrum paniculatum Linn leaves as an antiinflammatory drug.

Interaction effects of mesoporous silica nanoparticles with different morphologies on human red blood cells

A series of MCM-41-type mesoporous silica nanoparticle (MSN) materials with different morphologies (spherical and tubular) and sizes but similar surface and pore properties were synthesized and characterized. The effect of particle morphology on human red blood cell (RBC) membrane integrity was evaluated using flow cytometry, UV-Vis spectroscopy, confocal fluorescence and electron microscopy. Although the hemolytic activity was miniscule at higher nanoparticle concentrations for MSN with spherical geometry (up to 500 μg mL−1), electron microscopy results showed significant occurrences of RBC spiculation, indicating damage to the plasma membrane. However, no evidence for particle embedment or internalization was found in all the geometries and particle concentrations tested. We envisage that complete hemocompatibility studies of varied nanoparticle morphologies would provide important guidelines when considering the overall toxicity of these nanodevices in vivo.

Mechanical characteristics of human red blood cell membrane change due to C60 nanoparticle infiltration

The mechanical characteristics of human red blood cell (RBC) membrane change due to C(60) nanoparticle (NP) infiltration have been investigated in the present work. Using experimental approaches, including optical tweezer (OT) stretching and atomic force microscopy (AFM) indentation, we found that RBCs in the presence of C(60) NPs are softer than normal RBCs. The strain-stress relations of both normal and C(60) infiltrated RBC membranes are extracted from the data of AFM indentation, from which we proved that C(60) NP infiltration can affect the mechanical properties of RBC membrane and tend to weaken the tensile resistance of lipids bilayers. In order to explain this experimental phenomenon, a mechanical model has been developed. Based on this model, the strain-stress relations of both normal and C(60) infiltrated lipid bilayers are calculated with consideration of intermolecular interactions. The theoretical results are in great agreement with the experimental results. The influence of C(60) NP concentration on the mechanical properties of RBC membrane is successfully predicted. Higher concentrations of C(60) NPs in the lipid bilayers will lead to increased damage to the cell membrane, implying that the dosage of C(60) NPs should be controlled in medical applications.

Membrane stabilization as a mechanism of the anti-inflammatory activity of methanol extract of garden egg (Solanum aethiopicum)

BackgroundSome observations and reports show that people with high consumption of Solanum aethiopicum (African garden egg) have relief in arthritic pains and swelling. We aimed at assessing the effect of methanol extract of Solanum aethiopicum in experimentally induced inflammation using leukocyte mobilization and vascular permeability tests in rats and human red blood cell (HRBC) membrane stabilization as studies.MethodsTwenty five (25) adult Wistar rats of either sex (120 g – 200 g) divided into five groups of five rats each were used for each of the animal models. Groups 2, 3 and 4 were administered varied doses of the extract (100, 200 and 400 mg/kg), while groups 1 (vehicle control) and 5 (treatment control) received normal saline and indomethacin (50 mg/kg) respectively. Vascular permeability was induced by the intra-peritoneal injection of 1 ml of acetic acid and monitored using 0.5 ml intravenous injection of 1% Evans blue solution. Leukocyte mobilization was induced by the intra-peritoneal injection of 0.5 ml of 3% agar suspension in normal saline. Heat and hypotonicity induced heamolysis of HRBC membrane was used to assess membrane stabilization.ResultsThe methanol extracts of garden egg significantly and dose dependently reduced (p≤0.05) the acetic acid induced vascular permeability and agar induced leukocyte mobilization in rats. The percentage inhibitions of induced vascular permeability were 21 ± 3.39, 25 ±1.92 and 60 ± 3.81 for the 100, 200 and 400 mg/kg of the extract while the inhibitions of the agar induced leucocyte migration were 23 ± 2.17, 26 ± 1.58 and 32 ± 1.58 for the 100, 200 and 400 mg/kg of the extract respectively. The extract also, at doses of 100, 200, 400, 600 and 800 μg/ml significantly inhibited heat induced lysis of the human red cell membrane with values of 66.46 ± 2.89, 65.14 ± 4.58, 46.53 ± 2.52, 61.88 ± 4.51and 86.67 ± 3.06 respectively.ConclusionsThese results show that methanol extract of Solanum aethiopicum has anti-inflammatory properties and can reduce inflammatory injury and tissue damage.