<i>Thymus zygis</i> subsp. <i>zygis</i> an Endemic Portuguese Plant: Phytochemical Profiling, Antioxidant, Anti-Proliferative and Anti-Inflammatory Activities

• Main Authors: Amélia M. Silva (Author), Carlos Martins-Gomes (Author), Eliana B. Souto (Author), Judith Schäfer (Author), João A. Santos (Author), Mirko Bunzel (Author), Fernando M. Nunes (Author)
• Format: Book
• Published: MDPI AG, 2020-06-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

<i>Thymus zygis</i> subsp. <i>zygis</i> is an endemic Portuguese plant belonging to the <i>Thymus zygis</i> species. Although <i>T. zygis</i> is commonly used as a condiment and as a medicinal herb, a detailed description of the polyphenol composition of hydroethanolic (HE) and aqueous decoction (AD) extracts is not available. In this work, we describe for the first time a detailed phenolic composition of <i>Thymus</i> <i>zygis</i> subsp. <i>zygis</i> HE and AD extracts, together with their antioxidant, anti-proliferative and anti-inflammatory activities. Unlike other <i>Thymus</i> species, <i>T.</i> <i>zygis</i> subsp. <i>zygis</i> extracts contain higher amounts of luteolin-(?)-<i>O</i>-hexoside. However, the major phenolic compound is rosmarinic acid, and high amounts of salvianolic acids K and I were also detected. <i>T.</i> <i>zygis</i> subsp. <i>zygis</i> extracts exhibited significant scavenging activity of ABTS⁺, hydroxyl (^•OH), and nitric oxide (NO) radicals. Regarding the anti-proliferative/cytotoxic effect, tested against Caco-2 and HepG2 cells, the AD extract only slightly reduced cell viability at higher concentrations (IC₅₀ > 600 µg/mL, 48 h exposure), denoting very low toxicity, while the HE extract showed a high anti-proliferative effect, especially at 48 h exposure (IC₅₀ of 85.01 ± 15.10 μg/mL and 82.19 ± 2.46 μg/mL, for Caco-2 and HepG2, respectively). At non-cytotoxic concentrations, both extracts reduced the nitric oxide (NO) release by lipopolysaccharide (LPS)-stimulated RAW 264.7 cells (at 50 μg/mL, HE and AD extracts inhibited NO release in ~89% and 48%, respectively). In conclusion, the results highlight the non-toxic effect of aqueous extracts, both resembling the consumption of antioxidants in foodstuff or in functional food. Furthermore, the HE extract of <i>T.</i> <i>zygis</i> subsp. <i>zygis</i> is a source of promising molecules with antioxidant, anti-inflammatory and anticancer activities, highlighting its potential as a source of bioactive ingredients for nutraceutical and pharmaceutical industries.

Item Description

10.3390/antiox9060482
2076-3921