Article

Lectin-like activity from Persea americana

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Abstract

An extract from the seeds of Persea americana possessed an erythro-agglutinating activity. The agglutinin was devoid of specificity for carbohydrates, but interacted readily with basic proteins or basic polyamino acids. The interaction between the agglutinin and egg-white lysozyme was not inhibited by chaotropic salts, but was sensitive to relatively low concentrations of urea. An affinity chromatographic procedure was developed in an effort to purify the agglutinin. Products from the chromatographic procedure were found not to contain higher specific agglutinating activities than the crude extract. Amino acid acid analyses of the extract showed the presence of relatively high proportions of glutamic and aspartic acids. In addition, the extract contained phosphorus and a visible chromophore. The agglutinin was resistant to detergents and denaturants, and proteases, nucleases, and other enzymes. The results suggest that, as opposed to other plant agglutinins, the active component from Persea is not a protein. Similarly, in contrast to many lectins, the agglutinin from Persea was not mitogenic for mouse lymphocytes. The agglutinin partially inhibited the mitogenesis of lymphocytes when the cells were treated with concanavalin A, or with bacterial lipopolysaccharide.

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... (LCA) and Persea americana (PAA) were prepared and standardized as described elsewhere [7]. The lectins of Canat'alia ensiformis (conA), Helix pomatia (HPA), Limulus polyphemus (LPA), Solanum tuberosum (STA), Triticum l'ulgaris (TVA) and Ulex europaeus (UEA) were obtained from Sigma (Poole, U.K.). ...
... (LCA) and Persea americana (PAA) were prepared and standardized as described elsewhere[7]. The lectins of Canat'alia ensiformis (conA), Helix pomatia (HPA), Limulus polyphemus (LPA), Solanum tuberosum (STA), Triticum l'ulgaris (TVA) and Ulex europaeus (UEA) were obtained from Sigma (Poole, U.K.). ...
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Phase I cells of Bordetella pertussis but not those of B. parapertussis, B. bronchiseptica or B. avium were agglutinated by Limulus polyphemus lectin. Most strains of B. pertussis but not those of the other species were also agglutinated by Helix pomatia lectin. In precipitation reactions between lectins and purified Bordetella lipopolysaccharide (LPS) preparations a similar pattern occurred. Lectin agglutination provides a rapid presumptive method for the differentiation of B. pertussis from B. parapertussis and other Bordetella species.
... Onde foi constatado que no pH 8,2 havia uma maior expressão da atividade hemaglutinante específica. Meade et al., (1980) com o extrato das sementes da espécie, onde foi cerificado a capacidade de realizar a aglutinação, outros testes foram realizados pelos autores onde foi confirmado que a substância presente no extrato não tinha especificidade por carboidratos e não se tratava de uma proteína. ...
... In P. americana extract we detected the presence of flavonoids, terpenes, tannins, and saccharides (Table 1), as reported by others (Antia et al., 2005). Although, the aqueous extract of this plant was shown to possess anti-inflammatory and analgesic activities (Adeyemi et al., 2002), lectins from its seeds were not mitogenic for mouse lymphocytes (Meade et al., 1980), and "persin" from avocado leaves was shown to have antifungal properties and to be toxic to silkworms (Oelrichs et al., 1995), immune enhancing properties of this plant has not been previously reported. In addition, we observed the presence of alkaloids, saponins, terpenes, tannins, and saccharides in P. virginica extracts; the presence of such compounds has been reported in Plantago species (Samuelsen, 2000). ...
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Medicinal plants have been used for centuries and have become part of complementary medicine worldwide because of their potential health benefits. Some of their metabolites have been successfully used directly in the treatment and prevention of infectious diseases and cancer, or indirectly by stimulating the immune system. In the present study, we investigated the effects of methanol and aqueous extracts of the Mexican plants Ocinum basilicum, Persea americana, Plantago virginica, and Rosa spp. on in vitro rat lymphocyte proliferation. Methanol extracts of O. basilicum, P. americana, P. virginica, and Rosa spp. stimulated up to 80, 16, 69 and 66% lymphoproliferation, respectively, whereas their respective aqueous extracts induced up to 83, 48, 31 and 83% lymphoproliferation, as compared with untreated controls. The effect of O. basilicum aqueous extract at concentrations of 31.25, 62.5, 125 and 250 mu g/ml on lymphoproliferation was significantly different (p < 0.05) than the effects of P. americana and P. virginica at the same concentrations. We also observed that the lymphoproliferative effect of Rosa spp. aqueous extract was significantly higher (p < 0.05) than that of the methanol extract. Methanol and aqueous vehicles did not affect lymphocyte viability nor proliferation activity. The observed immunostimulatory effect may be of benefit in increasing the pool of lymphocytes in immunodeficiency patients.
... Polyphenolic compounds, such as tannic acid, are frequently found in extracts of higher plants and have broad antiviral spectra, inactivating a variety of virions extracellularly (Cheng and Yeung, 1988). Additionally, Animashaun et al. (1993) have shown that lectins from plants have the ability to prevent HIV-1 infection while Mead et al. (1980) have described a lectin-like activity from P. americana seeds. ...
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Aqueous (PA1) and methanolic extracts (PA2a–d; PA3) from the tropical tree Persea americana Mill. (Lauraceae), were evaluated for their cellular toxicity and anti-HIV-1 activity both in virustatic and virucidal assays. With the exception of PA3 and PA2d, all extracts showed anti-HIV-1 activity at concentrations which were not toxic for the H9 indicator cells. From the methanol insoluble extract (PA2) four different fractions (PA2a–d) were obtained using reverse-phase column chromatography, and two of the fractions (b and c) showed detectable virucidal effect. One fraction (PA2a) showed virustatic effects inhibiting HIV syncytium formation and viral p24 antigen formation at concentrations which were not toxic for the indicator cells. The results demonstrate for the first time that extracts from P. americana leaves have moderate anti-HIV-1 activity in vitro.
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1.1.|A new method is described for the isolation and purification of concanavalin A based on its specific adsorption on cross-linked dextran gels and subsequent displacement with d-glucose.2.2.|The yield of concanavalin A by this method is approx. 2.0–2.4 g/100 g jack bean meal. The chromatographic recovery is of the order of 94%.3.3.|Concanavalin A obtained by this procedure is approx. 98% precipitable with dextran NRRL B-1355-S.4.4.|(NH4)2SO4 fractionation of a saline extract of jack bean meal showed the maximum localization of concanavalin A activity to be in the fraction precipitated between 0.50 and 0.60 saturation of (NH4)2SO4.5.5.|The nature and specificity of binding of concanavalin A to cross-linked dextran gels have been shown to be generally similar to that of concanavalin A-polysaccharide interaction by demonstrating the reversal of the binding and subsequent elution of the protein from Sephadex G-50 with the same low molecular weight carbohydrates which inhibit concanavalin A-polysaccharide interaction.
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The first plant agglutinin was discovered by Stillmark in 1888. It was non-specific. Landsteiner later observed a certain degree of species specificity in some plant agglutinins, and Boyd and Renkonen found some to be blood antigen specific. Various plant hemagglutinins, called “lectins” by Boyd have a number of interesting and sometimes useful specificities: Anti-A, anti-A1, anti-B, anti-H, anti-A+B, anti-B+H, anti-M, anti-N, and anti-Gy (peanut factor). No anti-Rh lectins have thus far been found.