Antioxidant Capacity and Antiplatelet Activity of Aqueous Extracts of Common Bean (Phaseolus vulgaris L.) Obtained with Microwave and Ultrasound Assisted Extraction

Abstract

Phaseolus vulgaris L. has beneficial effects on several chronic non-communicable diseases (e.g., cardiovascular diseases) related to oxidative stress. This redox state may influence platelet activation and aggregation; which is crucial in thrombus formation. In this work, the antiplatelet and antioxidant potential of aqueous extracts obtained by green processes, microwave-assisted extraction and ultrasound-assisted extraction, from 25 landraces of common beans were investigated. Phenol content and antioxidant potential were determined using the Folin-Ciocalteu method, total monomeric anthocyanin and ORAC assay, respectively. The antiplatelet potential of the extracts was explored by turbidimetry. Microwave extraction showed higher phenol content and antioxidant activity in most extracts. Soja landrace extract obtained by microwave-assisted extraction showed higher phenol content and antioxidant activity (893.45 ± 87.30 mg GAE/g and 35,642.85 ± 2588.88 ORAC μmolTE/g, respectively). Although most of the extracts obtained by microwave-assisted extraction showed antiplatelet activity, the extract of Hallado Aleman landrace obtained by ultrasound-assisted extraction (IC₅₀ = 0.152 ± 0.018 mg/mL) had the highest antiplatelet potential. The extraction method, MAE and UAE, influences the biological potential of the beans, specifically the antiplatelet activity and antioxidant activity. The functional value of this legume for direct consumption by the population was evidenced, as well as its inclusion in food formulations.

Keywords: antioxidant; antiplatelet; common bean; microwave assisted extraction; ultrasonic assisted extraction.

Figure 1

Cytotoxicity on platelets. The results were obtained by LDH release from supernatant on washed platelets and measured at 490 nm in a microplate reader. Data expressed as mean ± SD, n = 6 independent trials; Vehicle = PBS. Triton X-100 as a positive control (maximum LDH release). The statistical analysis was performed using the ANOVA (Dunnet test). *** p < 0.001 vs. vehicle.

Figure 2

Platelet inhibition of more active extracts of P. vulgaris L. The more active extracts, with the percentage of platelet inhibition above 50%, were selected to evaluate the concentration necessary to reduce platelet aggregation by 50% (IC₅₀), determined from the concentration curves of the extracts of common bean at 0.025, 0.05, 0.10, 0.25, 0.50, 0.75 and 1.00 mg/mL.