Functional Studies in the Year of Pulses: the case of Zolfino landraces (Phaesolus vulgaris L.)

The United Nations declared 2016 the International Year of Pulses, to emphasise their key role as a major source of plant protein and nutrients for much of the world’s population. Eating pulses is highly recommended by health organizations, as a part of healthy diet to address obesity and to prevent and help manage chronic diseases like diabetes, coronary events and cancer. To contribute to heighten scientific awareness of the functional benefits of pulses, we focused on Zolfino landraces (Phaesolus vulgaris L.), a small, pale yellow bean growing in Tuscany, in the region of Pratomagno, between the provinces of Arezzo and Florence. This particular variety of bean differs from the others for the higher content of flavonols, known for their antioxidant and chelating properties.1 It contains also a number of hydrophobic compounds, but their functional activities have not been studied yet. Referring to these latter, we investigated their ability to interfere with the key enzyme of the polyol pathway, namely aldose reductase (ALR2), whose hyperactivity govern both long term diabetic complications and inflammatory responses.2 The methanolic extract of Zolfino landraces was purified with a solid phase extraction (SPE), to eliminate the hydrophilic portion, and the purified portion was fractionated through HPLC, collecting 18 different fractions. The inhibitory activity of each fraction was tested against ALR2, using both L-idose and 4-hydroxynonenal (HNE) as substrates for the enzyme, to evaluate their differential inhibition properties (Fig. 2). Results obtained will be discussed.