Effect of Extraction Methods on Polyphenols, Flavonoids, Mineral Elements, and Biological Activities of Essential Oil and Extracts of Mentha pulegium L.

Mohammed Messaoudi,Mohamed Amine Ferhat,Imane Larkem,Hamza Ouakouak,Sihem Boubekeur,Chukwuebuka Egbuna,Naima Benchikha,Chinaza Godswill Awuchi,Samir Begaa,Abdelkrim Rebiai,Maria Atanassova,Barbara Sawicka

doi:10.3390/molecules27010011

Abstract

Our study evaluated the in vitro antioxidant properties, antibacterial and antifungal activities, anti-inflammatory properties, and chemical composition of the essential oils (EOs), total phenol, and total flavonoid of wild Mentha pulegium L. This study also determined the mineral (nutritional and toxic) elements in the plant. The EOs were extracted using three techniques—hydro distillation (HD), steam distillation (SD), and microwave-assisted distillation (MAD)—and were analyzed using chromatography coupled with flame ionization (GC-FID) and gas chromatography attached with mass spectrometry detector (GC-MS). The antioxidant effects of the EOs were tested with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), while the antibacterial and antifungal activities of the EO and methanolic extract were tested using Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. Twenty-six compounds were identified in the essential oil, representing 97.73% of the total oil, with 0.202% yield. The major components were pulegone (74.81%), menthone (13.01%) and piperitone (3.82%). Twenty-one elements, including macro- and micro-elements (Ba, Br, Ca, Cl, Co, Cr, Cs, Eu, Fe, K, Mg, Mn, Mo, Na, Rb, Sb, Sc, Sr, Th, U and Zn), were detected using neutron activation analysis (INAA) and inductively coupled plasma optical emission spectrometry (ICP-OES), with the concentration of mineral element close to the FAO recommendation. The results show that the EOs and extracts from Mentha pulegium L. had significant antimicrobial activities against the microorganisms, including five human pathogenic bacteria, one yeast (Candida albicans), and one phytopathogenic fungi. The in vivo anti-inflammatory activities of the leaf extracts were confirmed. The results indicate that the EOs and extracts from Mentha pulegium L. have promising applications in the pharmaceutical industries, clinical applications, and in medical research.

Highlights

Medicinal plants and their medicinal properties have been widely studied, especially in developing countries [1,2,3,4]
The mineral elements are very important, especially the micro- and macro-nutrients, which are essential to various human metabolic processes, and significantly contribute to human health [40]
This study reports the phytochemical analysis, mineral elements, biological potentials, and effect of extraction methods on the chemical compositions of essential oil of aerial parts of the plant M. pulegium L., a wild-growing plant in the Algerian high plains

Summary

Introduction

Medicinal plants and their medicinal properties have been widely studied, especially in developing countries [1,2,3,4]. The World Health Organization has acknowledged the importance of medicinal plants, along with traditional medicine, which has received global attention [5,6]. In many countries, such as Algeria, there is a search for alternative medicine, including traditional herbal treatments. The demand for natural medicines for primary health care is increasing globally, causing manufacturers of herbal extracts and producers of essential oils to turn attention to medicinal plants and their phytoconstituents, using the most appropriate extraction techniques. Several different methods are used to produce extracts and essential oils of specific quality with active compounds from plant materials, even though the extraction of bioactive components from plants has always been a challenge for researchers

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