Use of erythrocytes in cytotoxicity and toxicity assays of medicinal plant extracts: analysis of their application and bibliometric study / Utilización de eritrocitos en ensayos de citotoxicidad y toxidez de extractos de plantas medicinales: análisis de su aplicación y estudio bibliométrico

Plant species have been used for therapeutic purposes since ancient times and are still in use today since these products represent a source of raw material for the production of phytotherapeutic formulations. Screening and investigation of plants with pharmacological potential require the evaluation of characteristics related to their action, efficacy and safety in different steps. Among these steps, pre- clinical trials are used to evaluate the properties of the test product in in vitro experiments, such as cytotoxicity assays. Within this context, this study consists of a bibliometric analysis of some in vitro cytotoxicity and toxicity assays in erythrocytes used during bioprospecting of medicinal plants. The results demonstrated the wide application of erythrocytes to evaluate the biological effects of medicinal plant extracts. The methods were found to be valid and effective for the preliminary investigation of the in vitro cytotoxicity and toxicity of plant products.

El uso de especies vegetales para fines terapéuticos es una práctica histórica y todavía bastante actual, ya que estos productos pueden representar una fuente de materia prima para la producción de formulaciones fitoterápicas. En investigación de plantas con potencial farmacológico requiere la evaluación de su acción, eficacia y seguridad, a través de diferentes etapas. Entre estas, en los ensayos preclínicos se evalúan las propiedades del producto-prueba en experimentos in vitro, tales como ensayos de citotoxicidad, entre otros. En este aspecto, el presente estudio consiste en un análisis bibliométrico acerca de algunas pruebas de citotoxicidad y toxicidad in vitro en eritrocitos realizados en los ensayos de bioprospección de plantas medicinales. Los resultados evidencian la amplia utilización de eritrocitos para la evaluación de los efectos biológicos de extractos de plantas medicinales, apuntándolos como métodos válidos y eficaces para la investigación preliminar de la citotoxicidad y toxicidad in vitro de productos vegetales.

Black and white teas as potential agents to combine with amphotericin B and protect red blood cells from amphotericin B-mediated toxicity / Chá preto e branco de Camellia sinensis como potenciais agentes para associar com anfotericina B

Abstract Amphotericin B is a fungicidal substance that is treatment of choice for most systemic fungal infections affecting immunocompromised patients. However, severe side effects have limited the utility of this drug. The aim of this study was to evaluate the antifungal effect of the combination of amphotericin B with black tea or white tea and protective of citotoxic effect. The present study shows that white and black teas have additive effects with amphotericin B against some species Candida. In addition, the combination of white and black tea with amphotericin B may reduce the toxicity of amphotericin B to red blood cells. Our results suggest that white and black tea is a potential agent to combine with amphotericin for antifungal efficacy and to reduce the amphotericin dose to lessen side effects.

Resumo A anfotericina B é o tratamento de escolha para a maioria das infecções fúngicas sistémicas que afetam os doentes imunocomprometidos. No entanto, efeitos secundários graves têm limitado a utilidade desta droga. O objetivo deste estudo foi avaliar o efeito antifúngico da combinação de anfotericina B com chá preto ou chá branco, bem como o efeito citotóxico desta combinação sobre hemáceas. O presente estudo demonstra que o chá branco e preto de Camellia sinensis têm efeitos aditivos com anfotericina B contra algumas espécies de Candida sp. Além disso, a combinação de chá branco e preto com anfotericina B pode reduzir a toxicidade da anfotericina B em hemáceas. Nossos resultados sugerem que o chá branco e preto são agentes potenciais para associação com anfotericina B contribuindo para eficácia antifúngica, bem como redução de toxicidade.

Mentha pulegium crude extracts induce thiol oxidation and potentiate hemolysis when associated to t-butyl hydroperoxide in human's erythrocytes

ABSTRACT Mentha pulegium (Lamiaceae) tea has been used as a traditional medicine; however, the modulatory effect of M. pulegium extracts on damage to human erythrocytes associated to t-butyl hydroperoxide (t-BHP) exposure remains to be investigated. Accordingly, we perform this study in order to test the hypothesis that aqueous and ethanolic extracts of M. pulegium could modulate the hemolysis associated to t-BHP exposure, non-protein thiol (NPSH) oxidation and lipid peroxidation (measured as thiobarbituric acid reactive substances - TBARS) in human erythrocytes. Samples were co-incubated with t-BHP (4 mmol/L) and/or aqueous or ethanolic extracts (10-1000 mg/mL) during 120 min to further analysis. We found that both extracts, when associated to t-BHP, potentiate NPSH oxidation and hemolysis. Moreover, both extracts significantly prevents against t-BHP-induced TBARS production. A significant correlation among hemolysis and NPSH levels was found. Taking together, our data points that the association of M. pulegium extracts with t-BHP culminates in toxic effect to exposed erythrocytes, besides its protective effect against t-BHP-induced TBARS production. So, we infer that the use of this extract may exert negative effect during painful crisis in sickle cell anemia. However, more studies are still necessary to better investigate/understand the mechanism(s) involved in the toxic effect resultant from this association.

Scoring System for Detecting Spurious Hemolysis in Anticoagulated Blood Specimens

BACKGROUND: The identification of in vitro hemolysis (IVH) using a hematology analyzer is challenging because centrifugation of the specimens cannot be performed for cell counts. In the present study, we aimed to develop a scoring system to help identify the presence of hemolysis in anticoagulated blood specimens. METHODS: Thirty-seven potassium EDTA anticoagulated blood specimens were obtained, and each specimen was divided into 3 aliquots (A, B, and C). Aliquots B and C were mechanically hemolyzed by aspirating 2 and 5 times, respectively, using a 27-gauge needle and then tested; aliquot A was analyzed immediately without any hemolysis. After the cells were counted, aliquots B and C were centrifuged and the supernatants were tested for the hemolytic index and lactate dehydrogenase levels. RESULTS: The 4 hematologic parameters were selected and scored from 0 to 3 as follows: or =38.5 for mean cell hemoglobin concentration (MCHC, g/dL); or =0.04 for red blood cell ghosts (10(12)/L); or =1.31 for difference value (g/dL) of measured hemoglobin and calculated hemoglobin; and or =3.35 for difference value (g/dL) of MCHC and cell hemoglobin concentration mean. The hemolysis score was calculated by adding all the scores from the 4 parameters. At the cutoff hemolysis score of 3, the IVH of aliquots B and C were detected as 64.9% and 91.9%, respectively. CONCLUSIONS: The scoring system might provide effective screening for detecting spurious IVH.

G6PD deficiency in Latin America: systematic review on prevalence and variants

Plasmodium vivax radical cure requires the use of primaquine (PQ), a drug that induces haemolysis in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals, which further hampers malaria control efforts. The aim of this work was to study the G6PDd prevalence and variants in Latin America (LA) and the Caribbean region. A systematic search of the published literature was undertaken in August 2013. Bibliographies of manuscripts were also searched and additional references were identified. Low prevalence rates of G6PDd were documented in Argentina, Bolivia, Mexico, Peru and Uruguay, but studies from Curaçao, Ecuador, Jamaica, Saint Lucia, Suriname and Trinidad, as well as some surveys carried out in areas of Brazil, Colombia and Cuba, have shown a high prevalence (> 10%) of G6PDd. The G6PD A-202A mutation was the variant most broadly distributed across LA and was identified in 81.1% of the deficient individuals surveyed. G6PDd is a frequent phenomenon in LA, although certain Amerindian populations may not be affected, suggesting that PQ could be safely used in these specific populations. Population-wide use of PQ as part of malaria elimination strategies in LA cannot be supported unless a rapid, accurate and field-deployable G6PDd diagnostic test is made available.

Ultrastructural changes of erythrocytes in whole blood after exposure to prospective in silico-designed anticancer agents: a qualitative case study

BACKGROUND: Novel, in silico-designed anticancer compounds were synthesized in our laboratory namely, 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10),15-tetraen-17-ol (ESE-15-ol) and 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (ESE-16). These compounds were designed to have improved bioavailability when compared to their source compound, 2-methoxyestradiol. This theoretically would be due to their increased binding affinity to carbonic anhydrase II, present in erythrocytes. Since the novel compounds under investigation are proposed to be transported within erythrocytes bound to carbonic anhydrase II, the morphological effect which they may exert on whole blood and erythrocytes is of great significance. A secondary outcome included revision of previously reported procedures for the handling of the whole blood sample. The purpose of this study was twofold. Firstly, the ultrastructural morphology of a healthy female's erythrocytes was examined via scanning electron microscopy (SEM) after exposure to the newly in silico-designed compounds. Morphology of erythrocytes following exposure to ESE-15-ol and ESE-16 for 3 minutes and 24 hours at 22°C were described with the use of SEM. The haemolytic activity of the compounds after 24 hours exposure were also determined with the ex vivo haemolysis assay. Secondly, storage conditions of the whole blood sample were investigated by determining morphological changes after a 24 hour storage period at 22°C and 37°C. RESULTS: No significant morphological changes were observed in the erythrocyte morphology after exposure to the novel anticancer compounds. Storage of the whole blood samples at 37°C for 24 hours resulted in visible morphological stress in the erythrocytes. Erythrocytes incubated at 22°C for 24 hours showed no structural deformity or distress. CONCLUSIONS: From this research the optimal temperature for ex vivo exposure of whole blood samples to ESE-15-ol and ESE-16 for 24 hours was determined to be 22°C. Data from this study revealed the potential of these compounds to be applied to ex vivo study techniques, since no damage occurred to erythrocytes ultrastructure under these conditions. As no structural changes were observed in erythrocytes exposed to ESE-15-ol and ESE-16, further ex vivo experiments will be conducted into the potential effects of these compounds on whole blood. Optimal incubation conditions up to 24 hours for whole blood were established as a secondary outcome.

Evaluación del efecto citotóxico y del daño genético de extractos estandarizados de Solanum nudumcon actividad anti- Plasmodium / Evaluation of cytotoxic effect and genetic damage of standardized extracts of Solanum nudum with antiplasmodial activity

Introducción. La planta Solanum nudum es ampliamente usada en la medicina tradicional del Pacífico colombiano para tratar las fiebres y la malaria, o paludismo, y se ha convertido en una fuente de nuevas moléculas promisorias. Objetivo. Evaluar el efecto citotóxico y daño genético de extractos estandarizados de S. nudum en diferentes modelos celulares. Materiales y métodos. A 66 extractos estandarizados de S. nudum se les evaluó la actividad anti- Plasmodiumin vitro en dos cepas de Plasmodium falciparum, una sensible (NF54) y otra resistente (FCB2) a la cloroquina, y la citotoxicidad en células U937 y HepG2. Se seleccionaron los extractos que presentaron actividad anti- Plasmodium y baja toxicidad, y se les estimó su efecto hemolítico en eritrocitos sanos O + , el efecto mutagénico en las cepas TA98 y TA100 de Salmonella Typhimurium y el efecto genotóxico en células U937. Resultados. Se seleccionaron cinco extractos como promisorios (28MA1, 29MA1, 51MA1, 55MA1 y 61MA1), los cuales fueron activos en las cepas de P. falciparum con concentración inhibitoria 50 (CI 50 ) entre 9,8 y 54,8 µg/ml. El extracto 29MA1 fue el más selectivo para Plasmodium, con índice de selectividad de 4,4 y 14,5 para las células U937 y HepG2, respectivamente. En ningún extracto se observó efecto hemolítico a 250 µg/ml, no causaron mutaciones en las cepas TA98 y TA100 de S.Typhimurium, ni generaron efectos genotóxicos en células U937. Conclusiones. La utilización de extractos estandarizados de S. nudum contribuye con los trabajos encaminados al desarrollo de una nueva formulación farmacéutica para tratar la malaria a partir de productos naturales.

Introduction. The plant Solanum nudum (Solanaceae) is extensively used for the treatment of malaria-related symptoms in traditional medicine practices in the Colombian Pacific. Recently, it has become a significant source of promising new molecules for developing a pharmaceutical malaria treatment. Objective. This research aimed to evaluate the cytotoxic effect and the genetic damage of standardized extracts of S. nudumon different cells. Materials and methods. Sixty six standardized S. nudum extracts were used, evaluating cytotoxicity in U937 and HepG2 cells and the antiplasmodial activity using both a chloroquine-sensitive (NF54) and a chloroquine-resistant (FCB2) strain. The hemolytic effect on healthy O + erythrocytes, the mutagenic effect on S.Typhimurium TA98 and TA100 strains and the genotoxic effect on U937 cells were evaluated. The extracts that displayed both antiplasmodial activity and low toxicity were selected. Results. Five extracts were selected: 28MA1, 29MA1, 51MA1, 55MA1 and 61MA1. These extracts were active against P. falciparum with IC 50 between 9.8 and 54.8 µg/ml and selectivity indexes were calculated between 0.9 and 4.4, the latter for 29MA1. Also, no hemolytic effects in healthy O + erythrocytes were shown at a concentration of 250 µg/ml, nor did they cause mutations in the TA98 and TA100 strains or generate genotoxic effects in U937cells. Conclusion. The use of standardized extracts of S. nudum could contribute to the body of work aimed at developing a new pharmaceutical treatment for malaria using natural products.

Assessment of total phenolic content and antioxidant potential of methanol extract of Peltophorum pterocarpum [DC.] Backer ex K Heyne

Plants are rich in a variety of chemical compounds. Many are secondary metabolites including aromatic substances most of them are phenols or their oxygen substituted derivatives. Medicinal plants are also rich in antioxidant constituents such as phenols, tocopherols, ascorbic acid, carotenoids, and flavonoids etc. They are found to acquire free radical scavenging activity and used worldwide for the treatment of various immune system dependent diseases. Peltophorum pterocarpum [DC] Backer ex K. Heyne [Caesalpiniaceae] is a beautiful ornamental tree, widely grown in tropical regions and its parts are used in traditional medicine as an effective therapeutic agent. Fresh pods of Peltophorum pterocarpum was evaluated for its antioxidant potential by using various methods including DPPH, superoxide anion, nitric oxide scavenging, and metal chelating activity. TPC via Folin-Ciocalteau's reagent and anti haemolytic activity red blood cells respectively have also been measured. The methanol extract of pods of Peltophorum pterocarpum was found to possess the significant amount 439.21 +/- 0.17 mg GAE [gallic acid equivalents] / g of TPC. The antioxidant potential of pods extract at mature stage showed potent activity and measured as, free radical scavenging activity 73.29 +/- 0.81%, superoxide anion scavenging activity 89.03 +/- 1.07%, nitric oxide scavenging activity 84.25 +/- 1.18%, and metal chelating activity 64.12 +/- 0.11%. The extract also showed potent anti haemolytic activity 79.09 +/- 75%. Peltophorum pterocarpum exhibited strong but varying level of antioxidant and anti haemolytic activity in various methods along with total phenolic contents

Efecto inhibitorio de extractos de Renealmia alpinia Rottb. Maas (Zingiberaceae) sobre el veneno de Bothrops asper (mapaná) / Evaluation of the inhibitory effect of extracts from leaves of Renealmia alpinia Rottb. Maas (Zingiberaceae) on the venom of Bothrops asper (mapaná)

Introducción. La medicina tradicional es una invaluable fuente de investigación de nuevos remedios como complemento para el tratamiento del accidente ofídico, considerado como un grave problema de salud pública a nivel mundial. Objetivo. Este trabajo de investigación pretende comprobar la capacidad de neutralizar los efectos hemorrágicos, coagulantes y proteolíticos, de los extractos de hojas de Renealmia alpinia, usada tradicionalmente por los indígenas del Chocó (Colombia) contra la mordedura de la serpiente Bothrops asper, causante de la gran mayoría de los accidentes ofídicos en nuestro país. Materiales y métodos. Se llevaron a cabo ensayos de toxicidad aguda y de actividad analgésica in vivo de R. alpinia. Además, se hicieron ensayos in vitro sobre inhibición de las actividades coagulante, hemolítica y proteolítica del veneno de B. asper. Resultados. El presente estudio demuestra que R. alpinia no produce efectos tóxicos en animales de experimentación; además, presenta efectos analgésicos in vivo y antiofídicos in vitro,y protege contra los efectos letales del veneno de B. asper, in vivo. Conclusión. Renealmia alpinia puede ser una buena alternativa terapéutica como complemento al tratamiento con antiveneno en el accidente ofídico, por sus efectos analgésicos y antiofídicos.

Introduction. Traditional medicine is an invaluable source of research into new medicines as a supplement for the treatment of snakebite, considered as a serious public health problem worldwide. The extracts of the medicinal plant, Renealmia alpina, have been used traditionally by indigenous people of Chocó (Colombia) against Bothrops asper snakebite, a snake responsible for the majority of snakebite accidents in Colombia. Objective. The ability of extracts of R. alpinia leaves was tested for its ability to neutralize the hemorrhagic, coagulant and proteolytic effects of the snakebite venom of B. asper. Materials and methods. The acute toxicity tests and analgesic activity of R. alpina were evaluated in vivo. In addition, tests were undertaken in in vitro conditions to demonstrate inhibition of coagulant, haemolytic and proteolytic activity of the B. asper venom. Results. Renealmia alpinia extracts had no toxic effects in experimental animals and also provided analgesic and antiophidian effects and protection against the lethal effects of the venom of B. asper. Conclusion. Renealmia. alpinia was an effective therapeutic alternative in association with antivenom treatment in the event of a B. asper snakebite accident. It was demonstrated to protect against the lethal effects and provided analgesic properties as well.

Disturbance in hemoglobin metabolism and in vivo antimalarial activity of azole antimycotics / Alteración en el metabolismo de la hemoglobina y actividad antimalárica in vivo de azoles antimicóticos

Plasmodium parasites degrade host hemoglobin to obtain free amino acids, essential for protein synthesis. During this event, free toxic heme moieties crystallize spontaneously to produce a non-toxic pigment called hemozoin or ß-hematin. In this context, a group of azole antimycotics, clotrimazole (CTZ), ketoconazole (KTZ) and fluconazole (FCZ), were investigated for their abilities to inhibit ß-hematin synthesis (IßHS) and hemoglobin proteolysis (IHbP) in vitro. The ß-hematin synthesis was recorded by spectrophotometry at 405 nm and the hemoglobin proteolysis was determined by SDS-PAGE 12.5 percent, followed by densitometric analysis. Compounds were also assayed in vivo in a malaria murine model. CTZ and KTZ exhibited the maximal effects inhibiting both biochemical events, showing inhibition of β-hematin synthesis (IC50 values of 12.4 ± 0.9 µM and 14.4 ± 1.4 µM respectively) and inhibition of hemoglobin proteolysis (80.1 ± 2.0 percent and 55.3 ± 3.6 percent, respectively). There is a broad correlation to the in vivo results, especially CTZ, which reduced the parasitemia ( percentP) of infected-mice at 4th day post-infection significantly compared to non-treated controls (12.4 ± 3.0 percent compared to 26.6 ± 3.7 percent, p = 0.014) and prolonged the survival days post-infection. The results indicated that the inhibition of the hemoglobin metabolism by the azole antimycotics could be responsible for their antimalarial effect.

Los parásitos del género Plasmodium degradan la hemoglobina hospedera obteniendo aminoácidos libres para su síntesis proteica. Durante este evento, unidades de hemo libre tóxicas cristalizan espontáneamente formando un pigmento no tóxico denominado ß-hematina. En este trabajo, se investigó la capacidad de un grupo de azoles antimicóticos: clotrimazol (CTZ), ketoconazol (KTZ) y fluconazol (FCZ), en inhibir la síntesis de ß-hematina y la proteólisis de la globina. La síntesis de ß-hematina se registro por espectrofotometría a 405 nm y la proteólisis de la hemoglobina se determino por SDS-PAGE 15 por ciento seguido por análisis densitométrico de las bandas de hemoglobina intactas. Los compuestos fueron también ensayados in vivo en un modelo de malaria murina. CTZ y KTZ inhibieron la síntesis de ß-hematina con CI50 entre 10 y 15 µM y bloquearon la proteólisis de la hemoglobina (80.01 ± 2.04 por ciento y 55.33 ± 3.57 por ciento, respectivamente). En relación directa con los resultados encontrados in vitro, el CTZ redujo la parasitemia de ratones infectados en forma significativa, así como prolongó lo días de sobrevivencia post-infección en comparación con animales controles no tratados. Se sugiere así que la inhibición del metabolismo de la hemoglobina por los antimicóticos azólicos pudiera ser el mecanismo responsable de su actividad antimalárica.

Leucocytes show improvement growth on PHA polymer surface

Polyhydroxyalkanoate [PHA] from one fermentation process shows diverse physical properties when extracted using different methods. Pseudomonas aeruginosa strain has been previously isolated from the Egyptian ecosystem was cultivated on olive oil as a carbon source under PHA accumulation conditions. PHA was extracted using four different extraction methods and the polymer give different biological properties. Leucocytes grown in different rate on each preparation. RBCs haemolysis test was used to determine the polymers toxicity. PHA isolated directly with chloroform give the highest leucocytes number [19.4 10 4 Cells/48 hr] and the lowest Haemolytic index [2.28]. Bioassays used in this study are recommended for evaluating the in vitro polymer biocompatibility aiming to in vivo application or as a cell line-supporting matrix

in vitro effect of chloramphenicol and salicylate on erythrocytes of patients with favism

Glucose 6-phosphate dehydrogenase [G6PD] deficiency is the most common of all clinically significant enzyme defects. A long list of drugs thought to cause haemolysis in patients with this enzyme defect. To determine whether chloramphenicol and salicylate can act as in vitro exogenous oxidizing agents and subsequently cause haemolysis of G6PD deficient erythrocytes and matching the result with the data obtained from the clinical observations which includes the intake of trimethoprim-sulfamethoxazole, salicylate or nalidixic acid by favic patient. Sixty six patients admitted to the hospital [Karbala teaching hospital for Children, Karbala, Iraq] with history of sudden onset of pallor and dark urine after fava beans ingestion were studied. Each patient was fully examined and his parents were asked about the type of fava beans ingested and the past drug history. Of the sixty six patients, ten were evaluated 1-3 months later and blood samples were taken from them along with blood samples from ten healthy volunteers. Blood samples from both groups were incubated in vitro with chloramphenicol and salicylate separately. Mean [SD] of methaemoglobin concentrations at baseline and after incubation with therapeutic and toxic concentrations of chloramphenicol [15 micro g/ml and 25 micro g/ml] and salicylate [150 micro g/ml and 300 micro g/ml] were calculated for both the control and the study groups. Paired t-test showed no significant differences [P> 0.05] in methaemoglobin concentrations at baseline and after incubation with therapeutic and toxic concentrations of these drugs. Mean percentage differences from baseline for G6PD deficient group were not significantly different from control group at both concentrations of these drugs as tested by student t-test. Hemolysis in G[6]PD deficient patients occurs mainly after fresh fava beans ingestion. chloramphenicol and acetylsalicylic acid do not cause significant hemolysis in G[6]PD deficient erythrocytes in vitro

Effects of different general anesthetics on serum hemolysis and hepatic and muscular glycogenolysis in rats

Anesthetics can affect the structure and biological function of tissues and systems differentially. The aim of the present study was to compare three injectable anesthetics generally used in experiments with animals in terms of the degree of hemolysis and glycogenolysis occurring after profound anesthesia. Twenty-four male Wistar rats (330-440 g) were divided into three groups (N = 8): chloral hydrate (CH), ketamine + xylazine (KX), Zoletil 50® (zolazepam and tiletamine) + xylazine (ZTX). After deep anesthesia, total blood was collected. The liver and white (WG) and red gastrocnemius (RG) muscles were also immediately removed. The degree of serum hemolysis was quantified on the basis of hemoglobin concentration (g/L). Hepatic and muscular glycogen concentrations (mmol/kg wet tissue) were quantified by the phenol-sulfuric method. The CH and KX groups exhibited serum hemolysis (4.0 ± 2.2 and 1.9 ± 0.9 g/L, respectively; P < 0.05) compared to the ZTX group, which presented none. Only KX induced elevated glycogenolysis (mmol/kg wet tissue) in the liver (86.9 ± 63.2) and in WG (18.7 ± 9.0) and RG (15.2 ± 7.2; P < 0.05). The CH and ZTX groups exhibited no glycogenolysis in the liver (164.4 ± 41.1 and 176.8 ± 54.4, respectively), WG (28.8 ± 4.4, 32.0 ± 6.5, respectively) or RG (29.0 ± 4.9; 25.3 ± 8.6, respectively). Our data indicate that ZTX seems to be an appropriate general anesthetic for studies that seek to simultaneously quantify the concentration of glycogen and serum biochemical markers without interferences. ZTX is reasonably priced, found easily at veterinary markets, quickly induces deep anesthesia, and presents a low mortality rate.

Effect of Solanum nudum steroids on uninfected and Plasmodium falciparum-infected erythrocytes

Steroids from Solanum nudum (SNs) have demonstrated antiplasmodial activity against erythrocytic stages of the Plasmodium falciparum strain FCB-2. It is well known that steroids can alter the membrane function of erythrocytes. Thus, we assessed alterations in the membranes of uninfected red blood cells, the parasite invasiveness and the solute-induced lysis of parasitised red blood cells (pRBCs). induced by SNs. We found that most merozoites were unable to invade SN-treated erythrocytes. However, transmission electron microscopy revealed no effect on the morphology of uninfected erythrocytes treated with either SN2 or diosgenone and neither SN induced haemolysis of uninfected erythrocytes. SN2 and SN4 inhibited isosmotic sorbitol and alanine-induced haemolysis of pRBCs. In contrast, diosgenone and SN1 did not inhibit solute-induced haemolysis. The inhibition of solute-induced lysis of parasitised erythrocytes by SN2 and SN4 suggest an action of these SNs on new permeability pathways of pRBCs.

Biological activity of neosergeolide and isobrucein B (and two semi-synthetic derivatives) isolated from the Amazonian medicinal plant Picrolemma sprucei (Simaroubaceae)

In the present study, in vitro techniques were used to investigate a range of biological activities of known natural quassinoids isobrucein B (1) and neosergeolide (2), known semi-synthetic derivative 1,12-diacetylisobrucein B (3), and a new semi-synthetic derivative, 12-acetylneosergeolide (4). These compounds were evaluated for general toxicity toward the brine shrimp species Artemia franciscana, cytotoxicity toward human tumour cells, larvicidal activity toward the dengue fever mosquito vector Aedes aegypti, haemolytic activity in mouse erythrocytes and antimalarial activity against the human malaria parasite Plasmodium falciparum. Compounds 1 and 2 exhibited the greatest cytotoxicity against all the tumor cells tested (IC50 = 5-27 µg/L) and against multidrug-resistant P. falciparum K1 strain (IC50 = 1.0-4.0 g/L) and 3 was only cytotoxic toward the leukaemia HL-60 strain (IC50 = 11.8 µg/L). Quassinoids 1 and 2 (LC50 = 3.2-4.4 mg/L) displayed greater lethality than derivative 4 (LC50 = 75.0 mg/L) toward A. aegypti larvae, while derivative 3 was inactive. These results suggest a novel application for these natural quassinoids as larvicides. The toxicity toward A. franciscana could be correlated with the activity in several biological models, a finding that is in agreement with the literature. Importantly, none of the studied compounds exhibited in vitro haemolytic activity, suggesting specificity of the observed cytotoxic effects. This study reveals the biological potential of quassinoids 1 and 2 and to a lesser extent their semi-synthetic derivatives for their in vitro antimalarial and cytotoxic activities.

[ effect of sub-minimum inhibitory concentration [S-MIC] of ciprofloxacin and ampicillin on hemolysin activity of Escherichia coli]

Sub-minimum inhibitory concentration [S-MIC] can induce changes in morphology, virulence factors and biochemical properties of bacterial pathogens. The goal of this study is to determine the Sub-MIC effect of ciprofloxacin and ampicillin on the haemolytic activity of E. coli. Two clinical isolates of E. coli with high haemolytic activity was selected. Changes in haemolytic activity of the isolates was assessed after exposing them to MIC and Sub-MIC of ciprofloxacin and ampicillin. Ciprofloxacin decreased haemolytic activity at 1/2, 1/4 and 1/8 Sub-MIC, whereas ampicillin showed no effect on haemolytic activity. We conclude that Sub-MIC concentrations of ciprofloxacin decreased the haemolytic activity of E. coli, whereas ampicillin had no such effect

Coagulopathy in patients who experience snakebite

BACKGROUND/AIMS: Coagulopathy is a common complication of snakebite, but there is little information on the clinical importance of coagulopathy. We analyzed the characteristics of coagulopathy after envenomation. METHODS: Ninety-eight patients who experienced snakebite were enrolled in this study. We divided all the patients into three groups by the ISTH DIC scoring system: the normal, simple coagulopathy and DIC groups. The coagulopathy group included both the simple coagulopathy and DIC groups. We then conducted a case-control study. RESULTS: There was a significant decrease in the Hct, protein, albumin, ALP and cholesterol levels in the coagulopathy group, and only the cholesterol level was deceased in the DIC group (p<0.05). Leukocytosis and rhabdomyolysis were significantly associated with coagulopathy, and hemolysis and rhabdomyolysis were associated with DIC (p<0.05). The presence of rhabdomyolysis was considered a risk factor for coagulopathy (p<0.05). These conditions continued for up to six to seven days after the snakebite. CONCLUSIONS: Evaluation of coagulopathy with using these characteristics is helpful to properly manage the patients who experience snakebite.

Evaluation of free radical scavenging activity of Butea monosperma Lam.

In the present study, ethyl acetate, butanol and aqueous fractions derived from total methanol extract of Butea monosperma flowers were evaluated for radical scavenging activities using different in vitro models like reducing power assay, scavenging of 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical, nitric oxide radical, superoxide anion radical, hydroxyl radical and inhibition of erythrocyte hemolysis using 2, 2' azo-bis (amidinopropane) dihydrochloride (AAPH). Methanol extract along with its ethyl acetate and butanol fractions showed potent free radical scavenging activity, whereas aqueous fraction was found to be devoid of any radical scavenging properties. The observed activity could be due to the higher phenolic content in the extracts (16.1, 25.29, and 17.74% w/w in methanol extract, ethyl acetate and butanol fractions respectively). HPTLC fingerprint profile of the ethyl acetate and butanol fractions were developed which would serve as reference standard for quality control of the extracts.

Construction of an immunotoxin by linking a monoclonal antibody against the human epidermal growth factor receptor and a hemolytic toxin

Hybrid molecules obtained through conjugation of monoclonal antibodies and toxins constitute an approach under exploration to generate potential agents for the treatment of cancer and other diseases. A frequently employed toxic component in the construction of such immunotoxins is ricin, a plant toxin which inhibits protein synthesis at ribosomal level and so requires to be internalized by the cell. A hemolytic toxin isolated from the sea anemone Stichodactyla helianthus, which is active at the cell membrane level, was linked through a disulfide bond to the anti-epidermal growth factor receptor monoclonal antibody ior egf/r3. The resulting immunotoxin did not exhibit hemolytic activity except under reducing conditions. It was toxic for H125 cells that express the human epidermal growth factor receptor, but non-toxic for U1906 cells that do not express this receptor.