Free radical–scavenging activity and DNA damaging potential of auxins IAA and 2‐methyl‐IAA evaluated in human neutrophils by the alkaline comet assay

Abstract

Auxins, of which indole-3-acetic acid (IAA) is the most widespread representative, are plant hormones. In addition to plants, IAA also naturally occurs in humans in micromolar concentrations. In the presence of peroxidase, indolic auxins are converted to cytotoxic oxidation products and have thus been proposed for use in gene-directed enzyme/prodrug tumor therapy. Since data on the genotoxicity of IAA and its derivatives are not consistent, here we investigate the early DNA damaging effects (2-h treatment) of the auxins, IAA, and 2-methyl-indole-3-acetic acid (2-Me-IAA) by the alkaline comet assay and compare them with their free radical-scavenging activity measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Human neutrophils are chosen as the test system since they possess inherent peroxidase activity. The results of the comet assay indicate an increase in DNA damage in a dose-dependent manner up to 1.00 mM of both auxins. Generally, IAA applied in the same concentration had greater potential to damage DNA in human neutrophils than did 2-Me-IAA. The genotoxicities of the two examined auxins are negatively correlated with their antioxidant activities, as measured by the DPPH assay; 2-Me-IAA showed a higher antioxidant capacity than did IAA. We assume that differences in the molecular structure of the tested auxins contributed to differences in their metabolism, in particular, with respect to interactions with peroxidases and other oxidative enzymes in neutrophils. However, the exact mechanisms have to be elucidated in future studies.

Assessment of Tryptophol Genotoxicity in Four Cell Lines In Vitro: A Pilot Study with Alkaline Comet Assay

“…This versatile method was used here mainly because it is capable of detecting a wide variety of DNA damage in a single cell: DNA singlestrand breaks, double-strand breaks, DNA-DNA/ DNA-protein cross-links, base damage, alkali-labile sites, and sites subjected to DNA repair (29). The method was also recently applied to assess the genotoxicity of indoleacetic acid and 2-methylindoleacetic acid, which are structurally related with tryptophol (30).…”

Antioxidative capacity of phenolic compounds extracted from Lolium perenne and Lolium arundinaceum infected with Neotyphodium (Hypocreales: Clavicipitaceae)

“…In our study, both germplasms were allowed to grow in a glasshouse at average temp 21°C. Given that in the growth of Mediterranean germplasms but not the Continental germplasms is altered as part of the process of adaption to this temperature (Assuero et al 2002), it is possible that the Mediterranean germplasms adapted to this temperature by accumulating higher levels of antioxidants-possibly grass growth hormones (auxins) with antioxidant potential (Salopek-Sondi et al 2010)-compared with Continental germplasms.…”

Comparison study of gut microbiota in case of Parkinson’s disease and other neurological disorders

“…Бактерии вида Intestinibacter bartlettii (ранее причисляемые к роду клостридий [26]) участвуют в метаболизме белков, получаемых с растительной пищей, а именно в переработке ароматических аминокислот до фенилуксусной, 4-гидроксифенилуксусной и, наиболее активно, β-индолилуксусной кислоты -вещества группы ауксинов, растительных гормонов [27]. Сама β-индолилуксусная кислота оказывает туморо-токсический ýффект из-за повреждения ДНК клеток [28,29]. Одно из производных β-индо-лилуксусной кислоты, митохониевая кислота, оказывает защитное воздействие на фибробла-сты, полученные от больных с нейродегенера-тивной патологией, вероятнее всего благодаря олигомеризации АТФ-синтазы и последующей продукции большего количества АТФ [30].…”