Antioxidant action of six Trifolium species in blood platelet experimental system in vitro

Abstract

This study includes a comparative evaluation of antioxidant effects of plant extracts (1.5–50.0 μg/ml), derived from six clover (Trifolium) species: T. alexandrinum L., T. fragiferum L., T. hybridum L., T. incarnatum L., T. resupinatum var. majus Boiss., and T. resupinatum var. resupinatum L. Chemical profiles of the extracts contained three or four groups of (poly)phenolic compounds such as phenolic acids, clovamides, isoflavones, and other flavonoids. Antioxidant properties of Trifolium extracts were assessed as the efficacy to reduce oxidative and nitrative damage to blood platelets, exposed to 100 μM peroxynitrite-induced oxidative stress in vitro. Antioxidant actions of the examined extracts were determined by the following biomarkers of oxidative stress: thiol groups, 3-nitrotyrosine, lipid hydroperoxides, and thiobarbituric acid-reactive substances (TBARS). Despite the significant differences in the chemical composition (the total phenolic concentrations varied between 11.30 and 52.55 mg/g of dry mass) of Trifolium extracts, we observed noticeable protective effects of almost all tested plant preparations. The T. alexandrinum extract, containing the highest concentration of phenols, was the most effective antioxidant among the tested extracts. On the other hand, the T. incarnatum extract, which contained a comparable total phenolic content (49.77 mg/g), was less efficient in prevention of tyrosine nitration and generation of TBARS. These findings indicate on the important role of individual phenolic components of the examined clover extracts for the final antioxidative effects. Antioxidative properties of the remaining extracts were noticeably weaker.

Trifoliumspecies – the latest findings on chemical profile, ethnomedicinal use and pharmacological properties

“…A comparative in‐vitro analysis of free radical scavenging properties of extracts from other Trifolium species demonstrated that several clovers might be a source of potent antioxidants. On the other hand, the mentioned works confirmed the importance of individual components for the total antioxidant efficacy of plant extracts.…”

“…Additionally, both clovers (T. repens and T. campestre) displayed moderate cytotoxic effects (LC50 between 30 and 50 lg/ml) against the brine shrimp. [86] A comparative in-vitro analysis of free radical scavenging properties of extracts from other Trifolium species [87][88][89] demonstrated that several clovers might be a source of potent antioxidants. On the other hand, the mentioned works confirmed the importance of individual components for the total antioxidant efficacy of plant extracts.…”

“…majus , T. resupinatum var. resupinatum as well as T. pallidum , T. scabrum and T. pratense (which action was also evaluated for the crude extract) . Among the tested extracts, the phenolic fraction of T. alexandrinum was the most effective DPPH and ABTS radical scavenger, with the EC50 of 2.02 and 5.53 μg/ml, respectively.…”

A phytochemical and computational study on flavonoids isolated from Trifolium resupinatum L. and their novel hepatoprotective activity

“…14 Plants from this genus have been utilized in the treatment of chronic skin diseases and menopausal symptoms. 15 In addition, species from this genus have been employed as a phytoestrogen source, 16 antioxidants, 17,18 anti-inflammatories 19 and in antidiabetic treatment. 20 Previous phytochemical investigation showed that the genus Trifolium contains flavonoids, isoflavonoids, chalcones, terpenes and coumarins.…”

Predictive phytotoxic value of water-soluble allelochemicals in plant extracts for choosing a cover crop or mulch for specific weed control

“…In organic extracts of T. subterraneum, Tava et al (2019) found only low amounts of phenolic compounds (glycosyl derivatives of caffeic acid, and ferulic and coumaric acids), and Oleszek et al (2007) described high concentrations of isoflavonoids and low concentration of phenolic acids and flavonoids. The last authors and Kolodziejczyk-Czepas et al (2015) found shallow total contents of phenolic acids and high amounts of flavonoids -specifically, apigenin and luteolin derivatives (Zgórka, 2011)-in organic extracts of T. incarnatum. These findings are consistent with ours, whereas naringenin and prunetin had not been reported in T. subterraneum until now.…”