Crude extract from the sponge Cinachyrella apion showed cross-reactivity with the polyclonal antibody IgG anti-CvL (Cliona varians lectin) and also a strong haemagglutinating activity towards human erythrocytes of all ABO groups. Thus, it was submitted to acetone fractionation, IgG anti-deglycosylated CvL Sepharose affinity chromatography, and Fast Protein Liquid Chromatography (FPLC-AKTA Purifier) gel filtration on a Superose 6 10/300 column to purify a novel lectin. C. apion lectin (CaL) agglutinated all types of human erythrocytes with preference for papainized type A erythrocytes. The haemagglutinating activity is independent of Ca2+, Mg2+ and Mn2+ ions, and it was strongly inhibited by the disaccharide lactose, up to a minimum concentration of 6.25 mM. CaL molecular mass, determined by FPLC-gel filtration on a Superose 12 10/300 column and SDS gel electrophoresis, was approximately 124 kDa, consisting of eight subunits of 15.5 kDa, assembled by hydrophobic interactions. The lectin was heat-stable between 0 and 60 degrees C and pH-stable. The N-terminal amino acid sequence of CaL was also determined and a blast search on amino acid sequences revealed that the protein showed similarity only with a silicatein. Leishmania chagasi promastigotes were agglutinated by CaL and this activity was abolished by lactose, indicating that lactose receptors could be presented in this parasite stage. These findings are indicative of the potential biotechnological application of CaL as diagnostic of pathogenic protozoa.

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The purpose of this work was to evaluate if the antimalarial activity of Bidens pilosa L. root extract could be enhanced by co-spray drying with the pharmaceutical excipients blend of colloidal silicon dioxide:microcrystalline cellulose and β-cyclodextrin. The in vivo antimalarial activity of the products was evaluated in mice infected with Plasmodium berghei. Acute in vivo and in vitro toxicity in S5 HeLa cells were also carried out. B. pilosa L. root extract was lyophilized and used as a control. The spray-dried preparations enhanced the survival of the infected mice compared to the lyophilized crude root extract. The Bidens extract formulations were able to inhibit up to 71% of the growth of the parasite in the lowest tested dose, being about five times more active than the crude extract, thus showing significant partial antiplasmodial activity. The dried preparations did not show signals of toxicity in both the in vitro and in vivo assays. The results showed strong evidence that the co-spray drying of B. pilosa root extract with the selected pharmaceutical excipients might stabilize the bioactive compounds and enhance its antimalarial activity compared with the lyophilized crude extract.

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