PB0748 - Essential oils of Colombian plants reduce platelet death and spreading area induced by Dengue Virus and NS1-protein

Background: Severe dengue is a serious health problem and there are no effective drugs for its prevention. Dengue Virus (DENV) and DENV nonstructural protein-1 (NS1) protein-driven exacerbate platelet activation and contribute to thrombocytopenia during dengue. Essential oils (EOs) can serve for developing drugs that prevent dengue from progressing to severity.

Aims: To evaluate the in vitro inhibitory effect of EOs on human platelet spreading area induced by DENV-2 and NS1-protein and the in-silico interaction with platelet proteins.

Methods: EOs were extracted by MWHD. GC/MS was used to determine the chemical composition of EOs: Lippia origanoides, Turnera diffusa and Lippia alba. Platelets isolated from healthy donors blood and purified by CD45 depletion were exposed to DENV-2 (MOI=1) or recombinant NS1 (5µg/mL) for 4h in the presence of noncytotoxic EOs concentrations. Platelet death was determined by LDH essay and caspase-1 was quantified by flow cytometry. Platelet spreading was determined through platelet adhesion in fibrinogen-coated surfaces and labeled with phalloidin. Molecular interactions with DENV-platelets proteins were predicted with an in-silico analysis.

Results: Eighty-eight compounds in the EOs were identified. EOs exposition for 4h did not affect platelet viability. Treatment with the EOs reduced the platelet death induced by DENV-2 (p < 0.0001) but not by NS1-protein, possibly because the caspase-1 pathway was activated by DENV-2 but not by NS1-protein. The EOs reduced (p < 0.0001) the spreading area of platelets caused by DENV-2 and NS1 activation, L. origanoides and L. alba EOs significantly reduced the spreading area in the activated platelets. Sesquiterpenes (germacrene D, trans-β-caryophyllene and α-cadinene) interacted strongly with the DENV-platelet receptor DC-SIGN and HSP70; germacrene-D, trans-β-caryophyllene, α-copaene, β-bourbonene, β-gurjunene, and α-cadinene bonded strongly to NS1-platelet TLR1/2- and TLR4/MAD-2 receptors.

Conclusion(s): The EOs reduces platelet death and spreading induced by DENV-2 and NS1-protein and may act as a starting point for developing phytomedicines to control platelet activation in dengue.