Chemical Characterization and Biological Activities of Phenolic‐Rich Fraction from Cauline Leaves of Isatis tinctoria L. (Brassicaceae) Growing in Sicily, Italy

Abstract

The present work focused on the evaluation of the antioxidant and cytotoxic activities of the phenolic-rich fraction (ItJ-EAF) obtained from cauline leaves collected in January from Isatis tinctoria L. (Brassicaceae) growing wild around Acireale (Sicily, Italy). The total phenolic, flavonoid, and condensed tannin contents of the fraction were determined spectrophotometrically, whereas the phenolic profile was assessed by HPLC-PDA/ESI-MS analysis. A total of 20 compounds were positively identified and twelve out of them were never previously reported in I. tinctoria leaves. The fraction exhibited good radical scavenging activity in DPPH test (IC = 0.6657 ± 0.0024 mg/ml) and reducing power (3.87 ± 0.71 ASE/ml), whereas, it neither showed chelating activity nor was able to counteract H O induced oxidative stress damage in Escherichia coli. The antiproliferative effect was evaluated in vitro on two human anaplastic thyroid carcinoma cell lines (CAL-62 and 8505C) by MTT assay. At the highest tested concentration ItJ-EAF significantly reduced (80%) the growth of CAL-62 cells. No cytotoxicity against Artemia salina was observed. It can be concluded that I. tinctoria cauline leaves represent a source of phenolic compounds which could be potentially used as chemopreventive or adjuvant agents against cancer.

Isatis tinctoria L. (Woad): A Review of Its Botany, Ethnobotanical Uses, Phytochemistry, Biological Activities, and Biotechnological Studies

“…The anti-proliferative properties of the phenolic-rich fraction obtained from I. tinctoria cauline leaf polar extract has been demonstrated, which caused 80% and 65% growth inhibition in CAL-62 and 8505C cells, respectively, after 48 h of exposure at the maximum tested dose (0.1 mg/mL). The activity of the phenolic-rich fraction against these cell lines was similar to that of Sunitinib used as a positive control, when tested at the dose of 10 µM for 72 h [46].…”

“…The calculated coefficient of determination (R 2 ) indicated that flavonoids were the phenolic compounds mainly involved in the observed antioxidant properties. Another study carried out by the same authors on the phenolic-rich fraction obtained from I. tinctoria cauline leaf polar extract confirmed that phenolics were mainly responsible for the good radical scavenging properties [46]. In particular, the activity has been mainly related to the flavonols detected in the fraction, which have all the essential structural elements for potent radical scavenging activity.…”

“…Phenolics can be divided into three main categories: flavonoids, phenolic acid, and their conjugates [16]. The identified flavonoids represent the major class of the phenolic constituent and are derivatives of flavones and of flavonols [46].…”

“…Miceli et al [46] characterised, for the first time, the phenolic compounds of the hydroalcoholic extract (70% methanol) from I. tinctoria lyophilized cauline leaves. Among 13 identified flavonoids, derivatives of flavones and flavonols, which were quantitatively dominant, were vicenin-2, isovitexin, and apigenin glucosides.…”

Chemical Composition and Antioxidant Potential Differences between Cynomorium coccineum L. Growing in Italy and in Tunisia: Effect of Environmental Stress

“…Since phenolics are the main component responsible for antioxidant activity [22][23][24], this fraction was spectrophotometrically determined using the Folin-Ciocalteu assay. Anthocyanins (a subclass of phenolics) were also determined.…”