Poster Topical Area: Dietary Bioactive Components

Location: Hall D

Poster Board Number: 357

P08-099 - Amaranth peptides decreased the activity and expression of cellular tissue factor on LPS activated THP-1 human monocytes

Monday, Jun 11
8:00 AM – 3:00 PM

Objectives: the objective of the present research was to evaluate the antithrombotic and anti-inflammatory effect of amaranth peptides on tissue factor (TF) activity, and the expression of THP-1 activated cells.

Methods: Amaranthus mantegazzianus protein isolates were obtained through alkaline precipitation, and simulated gastrointestinal digestion (SGD) was performed using pepsin and pancreatin pool of enzymes. An active anticoagulant peptide fraction (AF) was acquired using FPLC chromatography. Human THP-1 monocytes were treated for 24 h with different concentrations of sterile-filtered SGD and AF; then cells were activated with 10 μg/mL LPS dissolved in growth media for 4 h. TF expression was measured by western blot and the activity was analyzed through a tissue factor human chromogenic activity assay. Immunocytochemical fluorescence confocal microscopy analysis after amaranth peptides treatment was also performed. The expression profile of thrombosis-inflammation related proteins was evaluated with a Human XL Cytokine Array.

Results: The AF was found to inhibit TF expression (IC50= 0.39 mg/mL) and activity (IC50 = 0.58 mg/mL). Localization of TF showed that treated monocytes decreased 49% in the membrane and increased two-fold in nuclei compared to positive control (p < 0.05), indicating that the treatment reduced active membrane TF and decreased the initiation of the coagulation cascade. Moreover, cytokines array indicated that AF peptides produced suppression in the expression of MIP-3α, interleukin-1β, interleukin-1 α, TARC, PDGF-AA and Pentaxin 3 compared to Ctrl+, with reductions of 79%, 62%, 54%, 43%, 38% and 38%, respectively, (p < 0.05). According to these results, the cytokines with the highest inhibition of expression were involved in the induction of NF-κB pathway and platelet adhesion, aggregation, activation process.

Conclusions: Results provide potential mechanistic information on the antithrombotic and anti-inflammatory effect of AF, indicating that amaranth peptides could inhibit TF expression by producing a negative feedback regulator role over the NF-κB pathway. This effect could result in the prevention of hypercoagulability states and subsequent thrombosis and inflammation pathologies.

Funding Source: Fulbright Scholar Program provided research grant support.

CoAuthors: Diego Luna-Vital – University of Illinois; María Cristina Añón – Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA); Elvira Gonzalez de Mejia – University of Illinois

Ana Clara Sabbione

Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA)
La Plata, Buenos Aires, Argentina