Modulation of the Pharmacological Activities of Secretory Phospholipase A2 from Crotalus durissus cascavella Induced by Naringin

Abstract

In this work we have characterized the action of the naringin, a flavonoid found in grapefruit and known for its various pharmacological effects, which include antioxidant, blood lipid lowering and anticancer activity, on the structure and biochemical activities of a secretory phospholipase A (sPLA2) from Crotalus durissus cascavella, an important protein involved in the releasinge of arachidonic acid in phospholipid membranes. sPLA2 was incubated with naringin (mol:mol) at 37 °C and a discrete reduction in the UV scanning signal and a modification of the circular dichroism spectra were observed after treatment with naringin, suggesting modifications of the secondary structure of the protein. This flavonoid was able to decrease enzymatic activity and some pharmacological effects, such as myonecrosis, platelet aggregation, and neurotoxic activity caused by sPLA2, however, the inflammatory effect was not affected by naringin. In addition, small angle X-ray scattering (SAXS) data were collected for sPLA2 and naringin-treated sPLA2 to evaluate possible modifications of the protein structure. These structural investigations have shown that sPLA2 is an elongated dimer in solution and after treatment with naringin a conformational change in the dimeric configuration was observed. Our results suggest that structural modification may be correlated with the loss of enzymatic activity and alterations in pharmacological properties.

Preclinical Evidence for the Pharmacological Actions of Naringin: A Review

“…It (0.25 and 0.5 mmol/L) also significantly inhibited the TNF-α/IFN-γ-induced RANTES expression in human HaCaT cells via the NF-κB-dependent signaling pathway [87]. It significantly attenuated enzymatic activity of sPLA2 and its associated pharmacological effects such as myonecrosis, platelet aggregation, and cytotoxicity [88]. It (10-50 µg/ml) also interfered with monocyte adhesion and subsequently reduced high-glucose-induced vascular inflammation in HUVECs [89].…”

Phospholipases A2 Protein Structure and Natural Products Interactions in Development of New Pharmaceuticals

“…The most remarkable result derived from our work corresponds to a conformational change observed for the PLA2 dimer after naringin treatment. SAXS envelope obtained for naringin-treated PLA2 exhibited a clear bending in comparison with the models for native PLA2 that has been attributed to the action of naringin in the dimerization interface of this protein (Santos, Toyama, Oliveira et al, 2011).…”

“…Mass Spectrometry (MS) can also be used for the evaluation of sPLA2 modifications induced by NC treatment, as was previously done to naringin and quercetin (Cotrim, De Oliveira, Diz Filho et al, 2010;Santos, Toyama, Oliveira et al, 2011). This technique can be applied to measure the mass-to-charge ratio of native and NC-treated PLA2.…”

“…Recently, such method has been used for the evaluation of the sPLA2 treatment with different NC, mainly flavonoids. (Cotrim, De Oliveira, Diz Filho et al, 2010;De Oliveira et al, 2009;Iglesias, Aparicio, Rodrigues-Simioni et al, 2005;Santos et al, 2011;Toyama, Diz Filho, Cavada et al, 2011). In these studies native and modified PLA2 with different flavonoids (naringin, quercetin and morin) were prepared in 10 mM sodium phosphate buffer pH 7.4.…”

“…Using SAXS, structural information about tertiary and quaternary structures of proteins at the nanometer level can be recovered from the elastic scattering of X-rays by the sample. Such methodology has been also employed in the study of structural modifications induced in PLA2 by its treatment with different flavonoids, especially naringin (Santos, Toyama, Oliveira et al, 2011). SAXS measurements were carried out at the D02A-SAXS2 beamline of the Brazilian Synchrotron Light Laboratory (LNLS) (Kellermann et al, 1997).…”