3 resultados para lectin

em Bioline International


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Purpose: To identify lectins in Sophora japonica L. (green flower buds, fully formed flower buds, and flower buds as they begin to open) and to study their activity. Methods: Lectin activity was studied using rat hemagglutination method. The protein concentration of the extracts of the agglutinate was determined using Bradford assay. Results: Lectin activity of green flower buds was 1.61 ± 0.11 units/mg protein; fully formed flower buds, 1.81 ± 0.08 units/mg protein; flower buds as they began to open, and 2.05 ± 0.05 units/mg protein. The protein content of extracts from the buds of Sophora japonica L. collected at the stage of green flower buds, at the stage of formed buds, and at the stage of opening flower buds were 3.97 ± 0,04, 3.53 ± 0.07 and 3.13 ± 0.09 mg/ml respectively. Conclusion: This study shows the existence of lectins in Sophora japonica L. buds studied at three different stages of development. The highest lectin activity and protein content are found in the stage of green flower buds.

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Aphids cause significant losses in many agricultural crops and in many cases cause repeated insecticide sprays, which increase the risk of resistance. Therefore, other alternatives are needed to control them. The toxic, antireproductive, and feeding deterrent effects of a mannosebinding lectin isolated from bulbs of Phycella australis Ravenna (Amaryllidaceae), named Phycella australis agglutinin (PAA) was assayed on nymphs of the aphids Acyrthosiphon pisum Harris and Myzus persicae Sulzer fed with an artificial diet. After 72 h of PAA exposure, lethal concentration (LC50) values were 109 and 313 μg mL-1 for A. pisum and M. persicae, respectively, while LC90 values were 248 and 634 μg mL-1. Sub-lethal concentrations of PAA significantly reduced the aphid fecundity at a concentration of 80 μg mL-1. Only a total of 5.7 descendants per female were recorded for A. pisum (32% control progeny) and 12.4 for M. persicae (39% control progeny). Acyrthosiphon pisum was strongly deterred by PAA under choice conditions, as after 72 h exposed to 80 μg PAA mL-1 of diet, the feeding deterrent index was 0.91 for A. pisum and only 0.38 for M. persicae. In conclusion, the mannosebinding lectin isolated from bulbs of P. australis showed acute and chronical insecticidal activity against the pea and green peach aphids.

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Background: Sertoli cells play a pivotal role in creating microenvironments essential for spermatogonial stem cells (SSCs) self-renewal and commitment to differentiation. Maintenance of SSCs and or induction of in vitro spermiogenesis may provide a therapeutic strategy to treat male infertility. Objective: This study investigated the role of luekemia inhibitory factor (LIF) on the propagation of SSCs and both functions of Sertoli cells on the proliferation and differentiation of these cells. Materials and Methods: SSCs were sorted from the testes of adult male mice by magnetic activated cell sorting and thymus cell antigen 1 antibody. On the other hand, isolated Sertoli cells were enriched using lectin coated plates. SSCs were cultured on Sertoli cells for 7 days in the absence or presence of LIF. The effects of these conditions were evaluated by microscopy and expression of meiotic and post meiotic transcripts by reverse transcriptase polymerase chain reaction. Results: Our data showed that SSCs co-cultured with Sertoli cells in the presence of LIF formed colonies on top of the Sertoli cells. These colonies had alkaline phosphatesase activity and expressed SSCs specific genes. SSCs were enjoyed limited development after the mere removal of LIF, and exhibiting expression of meiotic and postmeiotic transcript and loss of SSCs specific gene expression (p< 0.05). Conclusion: Our findings represent co-culture of SSCs with Sertoli cells provides conditions that may allow efficient proliferation and differentiation of SSCs for male infertility treatment.