Eutirucallin, a RIP-2 Type Lectin from the Latex of Euphorbia tirucalli L. Presents Proinflammatory Properties

Abstract

Lectins are carbohydrate-binding proteins that recognize and modulate physiological activities and have been used as a toll for detection and identification of biomolecules, and therapy of diseases. In this study we have isolated a lectin present in the latex of Euphorbia tirucalli, and named it Eutirucallin. The latex protein extract was subjected to ion exchange chromatography and showed two peaks with haemagglutinating activity. Polypeptides of 32 kDa protein extract strongly interacted with immobilized galactose (α-lactose > D-N-acetylgalactosamine). The Eutirucallin was obtained with a yield of 5.6% using the α-lactose column. The lectin domain has 32 kDa subunits and at least two of which are joined by disulfide bridges. The agglutinating capacity for human erythrocytes A+, B+ and O+ is inhibited by D-galactose. The haemagglutinating activity of Eutirucallin was independent of Ca2+ and maintained until the temperature of 55°C. Eutirucallin presented biological activities such as neutrophils recruitment and cytokine prodution by macrophages. The analysis of the trypsin-digested Eutirucallin by ms/ms in ESI-Q-TOFF resulted in nine peptides similar to type 2 ribosome-inactivating protein (type-2 RIP). It's partial sequence showed a similarity of 67.4 – 83.1% for the lectin domain of type-2 RIP [Ricin and Abrin (83.1%), Viscumin, Ebulin, Pulchellin, Cinnamomin, Volkensin and type-2 RIP Iris hollandica]. Our data suggest that Eutirucallin is a new member of type 2 ribosome-inactivating protein and presents biotechnological potential.

Isolation of Jatropha Curcas Seeds Isolectins with Variable Affinity for Human and Animal Blood Types

“…These preferential agglutinations of human blood types with this lectin confirm the presence of this lectin in multiform. Our results of agglutination of human blood types with Jatropha curcas isolectins, are in accordance with some published papers on euphorbiaceae family lectins [18,19] whereas in contrary to some other reports [21]. These differences might highlight interesting variability in the affinity sites of these isolectins and through some light on the apparent distinct, thought yet to be disclosed, physiological role of these proteins.…”

“…Precipitation of euphorbiaceae family lectins with salting out using AS is reported in several publications [16][17][18][19]. However, none of these groups detected the presence of isolectins separated by their order of AS solubility.…”

Ehrlich ascites tumor-bearing mice treated with aqueous ethanol plant extract from <i>Euphorbia tirucalli</i> showed signs of systemic toxicity

“…The plant latex is toxic [4,[8][9][10][11]. To be worthy therapeutically, this toxicity had to be evaluated when considering internal administration.…”

“…Other studies showed that E. tirucalli is toxic [4,[7][8][9][10][11]. It contains 4-deoxyphorbol ester, which can suppress the immune system and promote tumor growth.…”

“…The oral administration of one drop of latex for 18 weeks caused splenomegaly in healthy mice [9]. A recent study demonstrated that eutirucallin, a lectin from the latex presents proinflammatory properties [10]. The aqueous extract from E. tirucalli caused cytotoxicity, genotoxicity and changes in antioxidant gene expression in human leukocytes [11].…”