In vivo antipyretic, antiemetic, in vitro membrane stabilization, antimicrobial, and cytotoxic activities of different extracts from Spilanthes paniculata leaves

BACKGROUND: The study was conducted to evaluate the in vitro antimicrobial activity, cytotoxic, and membrane stabilization activities, and in vivo antiemetic and antipyretic potentials of ethanolic extract, n-hexane and ethyl acetate soluble fractions of Spilanthes paniculata leaves for the first time widely used in the traditional treatments in Bangladesh. RESULTS: In antipyretic activity assay, a significant reduction (P < 0.05) was observed in the temperature in the mice tested. At dose 400 mg/kg-body weight, the n-hexane soluble fraction showed the effect (36.7 ± 0.63°C ) as like as the standard (dose 150 mg/kg-body weight) after 5 h of administration. Extracts showed significant (P < 0.001) potential when tested for the antiemetic activity compared to the standard, metoclopramide. At dose 50 mg/kg-body weight, the standard showed 67.23% inhibition, whereas n-hexane and ethyl acetate soluble fractions showed 37.53% and 24.93% inhibition of emesis respectively at dose 400 mg/kg-body weight. In antimicrobial activity assay, the n-hexane soluble fraction (400 µg/disc) showed salient activity against the tested organisms. It exerts highest activity against Salmonella typhi (16.9 mm zone of inhibition); besides, crude, and ethyl acetate extracts showed resistance to Bacillus cereus and Bacillus subtilis, and Vibrio cholera respectively. All the extracts were tested for lysis of the erythrocytes. At the concentration of 1mg/ml, ethanol extract, and n-hexane and ethyl acetate soluble fractions significantly inhibited hypotonic solution induced lysis of the human red blood cell (HRBC) (27.406 ± 3.57, 46.034 ± 3.251, and 30.72 ± 5.679% respectively); where standard drug acetylsalicylic acid (concentration 0.1 mg/ml) showed 77.276 ± 0.321% inhibition. In case of heat induced HRBC hemolysis, the plant extracts also showed significant activity (34.21 ± 4.72, 21.81 ± 3.08, and 27.62 ± 8.79% inhibition respectively). In the brine shrimp lethality bioassay, the n-hexane fraction showed potent (LC50 value 48.978 µg/ml) activity, whereas ethyl acetate fraction showed mild (LC50 value 216.77 µg/ml) cytotoxic activity. CONCLUSIONS: Our results showed that the n-hexane extract has better effects than the other in all trials. In the context, it can be said that the leaves of S. paniculata possess remarkable pharmacological effects, and justify its folkloric use as antimicrobial, antipyretic, anti-inflammatory, and antiemetic agent. Therefore, further research may be suggested to find possible mode of action of the plant part.

Gender differences in alcohol-induced oxidative stress and altered membrane properties in erythrocytes of rats.

Alcohol-induced oxidative stress leads to imbalance between reactive oxygen species (ROS) and the antioxidant defense system, resulting in oxidative damage to membrane components such as lipids and proteins, ultimately altering membrane properties. In this study, we assessed oxidative stress status and alterations in erythrocyte membrane properties in alcohol-administered rats with respect to gender difference. Alcohol (20% v/v) administered rats of both genders showed significant changes in plasma lipid profile with elevated nitrite/nitrate levels. Furthermore, alcohol-administration significantly decreased erythrocyte antioxidant enzymes and enhanced erythrocyte membrane lipid peroxidation, cholesterol/phospholipid (C/P) ratio and Na+/K+-ATPase activity in both males and females. Besides, anisotropic studies revealed that alcohol-administration significantly decreased erythrocyte membrane fluidity. In conclusion, alcohol- administration significantly increased oxidative stress by decreasing antioxidant status, and subsequent generation of ROS altered membrane properties by altering fluidity and Na+/K+-ATPase activity. Female rats were more vulnerable to alcohol-induced biochemical and biophysical changes in plasma and erythrocyte including oxidative stress than male rats.

Electron paramagnetic resonance study of lipid and protein membrane components of erythrocytes oxidized with hydrogen peroxide

Electron paramagnetic resonance (EPR) spectroscopy of spin labels was used to monitor membrane dynamic changes in erythrocytes subjected to oxidative stress with hydrogen peroxide (H2O2). The lipid spin label, 5-doxyl stearic acid, responded to dramatic reductions in membrane fluidity, which was correlated with increases in the protein content of the membrane. Membrane rigidity, associated with the binding of hemoglobin (Hb) to the erythrocyte membrane, was also indicated by a spin-labeled maleimide, 5-MSL, covalently bound to the sulfhydryl groups of membrane proteins. At 2% hematocrit, these alterations in membrane occurred at very low concentrations of H2O2 (50 µM) after only 5 min of incubation at 37°C in azide phosphate buffer, pH 7.4. Lipid peroxidation, suggested by oxidative hemolysis and malondialdehyde formation, started at 300 µM H2O2 (for incubation of 3 h), which is a concentration about six times higher than those detected with the probes. Ascorbic acid and α-tocopherol protected the membrane against lipoperoxidation, but did not prevent the binding of proteins to the erythrocyte membrane. Moreover, the antioxidant (+)-catechin, which also failed to prevent the cross-linking of cytoskeletal proteins with Hb, was very effective in protecting erythrocyte ghosts from lipid peroxidation induced by the Fenton reaction. This study also showed that EPR spectroscopy can be useful to assess the molecular dynamics of red blood cell membranes in both the lipid and protein domains and examine oxidation processes in a system that is so vulnerable to oxidation.

Ascaris lumbricoides: alteration of the erythrocyte superficial charge using the Partition Method in aqueous two-phase system / Ascaris lumbricoides: alteración de la carga superficial eritrocitaria usando el Método de Partición en sistemas bifásicos acuosos

Sialic acid is responsible for the negative charge of the erythrocyte. The decrease of sialic acid has hemodynamical and hemorheological importance. The aim was to study the effect of A. lumbricoides on the erythrocyte superficial charge using the Partition Method in aqueous two-phase system in order to indirectly evaluate the alteration of sialic acid in the red cells. We worked with five parasite extracts (AE) and larvae concentrate (LC). Erythrocyte superficial charge was studied by working with non-treated (Controls) and treated erythrocytes. The treatment consisted of incubating the erythrocytes with AE or LC for 30 minutes at 4 ºC, 20 ºC and 37 ºC. The red cells were separated in a sensitive charge two-phase system (Dx/ PEG). The partition coefficient (P) of treated and untreated erythrocytes were calculated. The results showed a P decrease at the three temperatures for red cells treated with four of the AE. The remaining extract did change P values at any of the temperatures studied. The erythrocytes treated with LC showed a decrease in the P value at 37 ºC and 4 ºC but no change was observed at 25 ºC. Statistical analysis concluded that P values were significantly lower in treated erythrocytes than in their corresponding untreated ones (p < 0.05). The Partition Method showed that this parasite alters the erythrocyte superficial charge which may indicate that it can catch sialic acid.

La disminución de ácido sialico, responsable de la carga negativa del eritrocito, tiene importancia hemodinámica y hemorreológica. El objetivo fue estudiar el efecto de A. lumbricoides sobre la carga superficial eritrocitaria aplicando el método de partición en sistemas bifásicos acuosos, a los fines de evaluar de manera indirecta la alteración de acido sialico de los eritrocitos. Se trabajó con 5 extractos del parásito adulto (EA) y con un concentrado de larvas (500-600 larvas/mL) (CL). Se estudió la carga superficial eritrocitaria, trabajando con eritrocitos no tratados y tratados. El tratamiento consistió en la incubación de los eritrocitos con EA o CL durante 30 minutos a 4 ºC, 25 ºC y 37 ºC. Los eritrocitos fueron sometidos a la separación en un sistema bifásico carga sensible constituido por Dx / PEG. Se calculó el coeficiente de reparto (P), de los eritrocitos sin tratar y tratados. Los resultados mostraron disminución de P a las 3 temperaturas, en hematíes tratados con 4 de los EA. El EA restante no modificó los valores de P a ninguna de las temperaturas estudiadas. CL produjo la disminución de P a 37 ºC y 4 ºC, pero no se observó modificación a 25 ºC. Los análisis estadísticos concluyeron que los valores de P son significativamente menores en los eritrocitos tratados que en los respectivos eritrocitos sin tratar (p < 0.05). El método de partición demostró que A. lumbricoides altera la carga superficial eritrocitaria lo que indicaría que el parásito, tanto en su estado adulto como en sus fases larvales, puede captar acido sialico.

effects of mefenamic Acid on the osmotic fragility of lacertilian erythrocytes

Osmotic fragility of red cells is increased by the use of mefenamic acid. The use of this analgesic induces hemolytic anemia. Study of osmotic f agility of RBCs of control and test was observed following administration of 7.1 mg, 10.5 mg and 14 mg/day mefenamic acid to each lizard. Increased osmotic fragility was observed with increase in the amount of dose on day 6 and day 12

Estudo da deformabilidade da membrana da hemacia com a pinca optica / Erythrocyte membrane deformability study with of the \"optical tweezer\"

A pinca optica, baseada na tecnica de transferencia de momentum de fotons para capturar e manipular particulas biologicas, foi desenvolvida por A. Ashkin et al. em 1987. Desde entao, ela tem sido utilizada em estudos de genetica molecular, fertilizacao assistida, dentre outros. Neste trabalho, utilizamos a pinca optica para estudar a deformabilidade da membrana da hemacia, com o auxilio de um laser Nd:YAG, cujo feixe e focalizado num microscopio Olympus com um aumento de ate 100 vezes. A hemacia, na sua funcao de captar o oxigenio dos pulmoes e leva-lo para todas as celulas atraves da hemoglobina, percorre todos os vasos sanguineos do organismo por aproximadamente 500.000 vezes, durante sua vida media de 120 dias, atravessando uma distancia de 250km...

Electroporation of red blood cell membrane and its use as a drug carrier system.

Application of external electric field to cell suspension maintained at ice temperature induces pores in the cell membrane. At this stage, a drug added to the cell suspension equilibrates across the membrane. On raising the temperature to 37 degrees C, the pores appear to be sealed as the drug is retained in the cells. This method was used for encapsulation of Co-57 labelled cynocobalamin in rabbit erythrocytes. It was seen from the in vivo biokinetic study of the drug-loaded erythrocytes that the rate of elimination of the drug was considerably reduced as compared to that of the free drug, indicating that drug delivery by electroencapsulation can give a sustained release of the drug.

Mechanism of host cell membrane modification by tumour: a model for paraneoplastic syndromes.

A not well-appreciated but clinically important aspect of malignant tumours is their effects on distantly located host cells. The effects, termed paraneoplastic syndromes, also pose an intriguing mechanistic problem: how do malignant cells influence properties of host cells not in contact with them? Erythrocytes from the circulation of rats bearing intraperitoneal Yoshida ascites sarcoma exhibit higher agglutinability with concanavalin A (Con A) than the cells from normal animals. Since the tumour and the red cells are not in contact, the enhanced agglutinability of the latter is a paraneoplastic effect. The mechanism by which the tumour brings about this effect is investigated as a model for paraneoplastic syndromes. The cell-free ascites fluid is able to impart high agglutinability on cells from normal animals in vitro. Also, when injected intraperitoneally in normal animals, the ascites fluid is able to enhance the agglutinability of erythrocytes in circulation. Apparently the tumour produces a substance(s) that appears in the ascites fluid and is able to diffuse into circulation, explaining the mechanism by which it can reach distant sites. From the cell-free ascites fluid three fractions have been isolated that are active in vitro. Of these, only one showed activity in vivo. From this fraction, a glycoprotein has been purified to homogeneity that confers maximal Con A-agglutinability on normal erythrocytes at 8 x 10(-7)M, at which concentration 6,400 molecules bind per cell. The protein has a molecular weight of 600 kDa in the native state and a pI of 5.35. It is made up of 4 identical subunits of Mr 170,000. It is detected in the plasma of tumour-bearing but not normal rats.(ABSTRACT TRUNCATED AT 250 WORDS)