Modulation of Oxidative Stress and Hemostasis by Flavonoids from Lentil Aerial Parts

Abstract

While specific metabolites of lentil (Lens culinaris L.) seeds and their biological activity have been well described, other organs of this plant have attracted little scientific attention. In recent years, green parts of lentils have been shown to contain diverse acylated flavonoids. This work presents the results of the research on the effect of the crude extract, the phenolic fraction, and seven flavonoids obtained from aerial parts of lentils on oxidative damage induced by H₂O₂/Fe to lipid and protein constituents of human plasma. Another goal was to determine their effect on hemostasis parameters of human plasma in vitro. Most of the purified lentil flavonoids had antioxidant and anticoagulant properties. The crude extract and the phenolic fraction of lentil aerial parts showed antioxidant activity, only at the highest tested concentration (50 µg/mL). Our results indicate that aerial parts of lentils may be recommended as a source of bioactive substances.

Keywords: Lens culinaris; flavonoids; hemostasis; lentil leaves; oxidative stress.

Figure 1

Structures of the investigated flavonoids.

Figure 2

Ultra-high-performance liquid chromatographic-photodiode array chromatogram (λ = 255 nm) of the phenolic fraction of lentil aerial parts (AU—absorbance units). 1—quercetin 3-O-β-d-glucopyranosyl-(1→2)-β-d-galactopyranoside-7-O-β-d-glucuropyranoside; 2—quercetin 3-O-[(6-O-E-caffeoyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-β-d-glucuropyranoside; 3—quercetin 3-O-[(6-O-E-p-coumaroyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-β-d-glucuropyranoside; 4—quercetin 3-O-[(6-O-E-feruloyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-β-d-glucuropyranoside; 5—kaempferol 3-O-[(6-O-E-feruloyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-β-d-glucuropyranoside; 6—kaempferol 3-O-{[(6-O-E-p-coumaroyl)-β-d-glucopyranosyl(1→2)]-α-l-rhamnopyranosyl-(1→6)}-β-d-galactopyranoside-7-O-α-l-rhamnopyranoside; 7—kaempferol 3-O-[(6-O-E-caffeoyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-(2-O-E-caffeoyl’)-β-d-glucuropyranoside; 8—kaempferol 3-O-[(6-O-E-caffeoyl)-β-d-glucopyranosyl-(1→2)]-β-d- galactopyranoside-7-O-β-d-glucuropyranoside; 9—kaempferol 3-O-[(6-O-E-p-coumaroyl)-β-d-glucopyranosyl-(1→2)]- β-d-galactopyranoside-7-O-β-d-glucuropyranoside 10—quercetin 3-O-[(6-O-E-caffeoyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-(2-O-E-caffeoyl’)-β-d-glucuropyranoside; 11—kaempferol 3-O-β-d-rhamnopyranoside.

Figure 3

Effects of the crude extract, the phenolic fraction and flavonoids from lentil aerial parts (1–50 μg/mL) and commercial flavonoids (quercetin and kaempferol) on plasma lipid peroxidation (A), plasma protein carbonylation (B), and oxidation of thiol groups (C), induced by H₂O₂/Fe. Control negative (neg) refers to plasma not treated with H₂O₂/Fe, whereas control positive (pos) to plasma treated with H₂O₂/Fe. Data represent means ± SD of 6 independent experiments. * p < 0.05 (vs. control (pos)), n.s. (statistically irrelevant) p > 0.05 (vs. control (pos)), p < 0.05 (between control (neg) and control (pos)); “-“ means the range of concentration of used extracts.

Figure 4

Effects of the crude extract, the phenolic fraction and flavonoids from lentil aerial parts (1–50 μg/mL) and commercial flavonoids (quercetin and kaempferol) on selected hemostatic parameters of plasma: the activated partial thromboplastin time (APTT) (A), the prothrombin time (PT) (B) and the thrombin time (TT) (C). Data represent means ± SD of 6 independent experiments. * p < 0.05 (vs. control), n.s. p > 0.05 (vs. control).