Chemical profile, antioxidant and photoprotective activities of essential oil and crude extracts of Algerian Thymus serpyllum

Danilo Falconieri,Nariman Madouni,Pascal Sonnet,Yavuz S Cakmak,Tir Touil Aicha,Chawki Bensouici,Boumediene Meddah,Alessandra Piras

doi:10.36547/nbc.916

Abstract

Thymus serpyllum is an aromatic and medicinal plant widely used in Algerian folk medicine. It was collected from Mascara region North West of Algeria and studied in the aim to provide more knowledge about chemical composition, antioxidant and photo-protective activities of essential oil, ethanolic and infusion extracts. The chemical analysis of investigated T. serpyllum EO was performed for the first time in this research work. It was carried out by GC/MS for identifying 25 components where the dominated compounds were Carvacrol (66%) and γ–Terpinene (11.5%). The phenolic profile of ethanolic and aqueous infusion extracts was performed using HPLC chromatography and the data showed the Benzoic acid and Rosmarinc acid were found as major compounds. Extracts showed an excellent source of total phenols and flavonoids. Antioxidant activity was evaluated using DPPH, Galvinoxyl radical (GOR), CUPRAC, reducing power and O-phenanthroline approaches. All extracts showed a significant antioxidant capacity with different mechanisms. However, ethanol and infusion extracts showed stronger capacity than EO. Moreover, the photoprotective activity of T. serpyllum extracts was explored for the first time in our study. Extracts exhibited high values of sun protective factors (SFP) with 38.34±2.29 and 38.82±2.23 for ethanol and infusion extract respectively. Results of our study may encourage the pharmacologic, food and cosmetic sectors to use the wild thyme as natural and healthy source of active compounds.

Highlights

A permanent exposure to various stimulus and aggressors can generate the production of Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS) with higher concentrations
Based on the bioactivity of wild thyme reported in literature and no such investigations were performed about T. serpyllum of the Mascara region, the aim of this study was to explore the chemical profile and to determinate different mechanisms of antioxidant potential of essential oil (EO), ethanol and infusion extracts
Thymus serpyllum extracts were evaluated for their chemical profile, antioxidant, and skin-protective activities

Summary

Introduction

A permanent exposure to various stimulus and aggressors can generate the production of Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS) with higher concentrations. An increasing interest in natural antioxidants provides aromatic and medicinal plants as an alternative (Zehiroglu and Sarikaya 2019). Among these plants, those belonging to Thyme genus comprising of 215 species, mainly prevalent in Mediterranean regions, North Africa, South Europe, and Asia (Jarić et al 2015). Based on the bioactivity of wild thyme reported in literature and no such investigations were performed about T. serpyllum of the Mascara region, the aim of this study was to explore the chemical profile and to determinate different mechanisms of antioxidant potential of EO, ethanol and infusion extracts. Further a skin-protective activity was investigated to estimate the sun protection factor (SPF)

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