Name: HELENA BULHÕES FIOROTTI
Publication date: 03/04/2020
Advisor:
Name |
Role |
|---|---|
| SUELY GOMES DE FIGUEIREDO | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| JULIANA BARBOSA COITINHO GONCALVES | External Examiner * |
| LEONARDO DOS SANTOS | Internal Examiner * |
| SUELY GOMES DE FIGUEIREDO | Advisor * |
Summary: Amongst a number of relevant biological activities, the Scorpaena plumieri fish venom (Sp-V) is known to promote hemagglutination. Although this activity is usually assigned to the presence of C-type lectins in the venom, it has not yet been characterized, neither chemically nor functionally. In the present work we sought to advance the characterization of the hemagglutinating fractions associated to this venom. In order to do so, Sp-V was fractionated by saline precipitation followed by size exclusion chromatography, resulting in the purification of two fractions FH1 and FH3 with specific and Ca2+-dependent agglutinating activity against rabbit erythrocytes, remaining stable upon storage at 4 or -80oC. Circular dichroism analysis revealed that both fractions had a high proportion of beta-sheets in their secondary structures. We found that FH1 and FH3 were bacteriostatic against Gram-positive bacteria (Staphylococcus aureus), displaying minimum inhibitory concentration (MIC) of 50 and 200 μg/mL, respectively. In addition, a resazurin-based viability assay revealed that both fractions, at doses up to 370 μg/mL, were cytotoxic against tumor and non-tumor cell lines. A tendency towards edema formation was detected when the active fractions particularly FH1 were injected into mice footpads. Finally, FH1 promoted a concentration-dependent (5, 10 e 50 µg/mL) vasodilator effect on rat isolated aortic rings in vitro. We believe our data contribute to a better understanding of the biological properties of the so often neglected fish venoms.
