Assessment of the Antimicrobial, Antioxidant, and Antiproliferative Potential of Sideritis raeseri subps. raeseri Essential Oil

Abstract

<jats:p>The aim of the present study was to investigate the antimicrobial potential of Sideritis raeseri subps. raeseri essential oil (EO) against common food spoilage and pathogenic microorganisms and evaluate its antioxidant and antiproliferative activity. The EO was isolated by steam distillation and analyzed by GC/MS. The main constituents identified were geranyl-p-cymene (25.08%), geranyl-γ-terpinene (15.17%), and geranyl-linalool (14.04%). Initially, its activity against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Listeria monocytogenes, Salmonella Enteritidis, Salmonella Typhimurium, Pseudomonas fragi, Saccharomyces cerevisiae, and Aspergillus niger was screened by the disk diffusion method. Subsequently, minimum inhibitory concentration (MIC), non-inhibitory concentration (NIC), and minimum lethal concentration (MLC) values were determined. Growth inhibition of all microorganisms tested was documented, although it was significantly lower compared to gentamycin, ciproxin, and voriconazole, which were used as positive controls. In a next step, its direct antioxidant properties were examined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, and the IC50 values were determined. The potential cytoprotective activity of the oil against H2O2–induced oxidative stress and DNA damage was studied in human immortalized keratinocyte (HaCaT) cells using the comet assay. Finally, the antiproliferative activity of the oil was evaluated against a panel of cancer cell lines including A375, Caco2, PC3, and DU145 and the non-cancerous HaCaT cell line using the sulforhodamine B (SRB) assay, and the EC50 values were determined. The oil demonstrated weak radical scavenging activity, noteworthy cytoprotective activity against H2O2–induced oxidative stress and DNA damage in HaCaT cells, and antiproliferative activity against all cell lines tested, being more sensitive against the in vitro model of skin melanoma.</jats:p>

Antioxidant and Cytoprotective Potential of the Essential Oil Pistacia lentiscus var. chia and Its Major Components Myrcene and α-Pinene

“…Sideritis raeseri essential oil possessed weak radical scavenging activity but demonstrated substantial cytoprotective activity against H 2 O 2 -induced oxidative stress and DNA damage in HaCaT cells. The main components of the oil were geranyl- p -cymene (25.08%), geranyl- γ -terpinene (15.17%), and geranyl-linalool (14.04%), but α-pinene (2.13%) and caryophyllene (2.88%) are common with mastic essential oil [ 63 ]. The essential oils of Citrus sinensis and Citrus latifolia were found to efficiently decrease apoptosis in HaCaT cells following exposure to H 2 O 2 and to lower intracellular superoxide ion.…”

Chemical Composition of Essential Oils of Aromatic and Medicinal Herbs Cultivated in Greece—Benefits and Drawbacks

“…They are used extensively in cosmetics and medicine due to their sweet-smelling odors and pharmacological properties [8]. Furthermore, the essential oils of many plant species show antioxidant [9], antiproliferative [10] and antimicrobial activity. They can also be used as substitutes to antibiotics [11], and have proven to be effective in a wide range of applications by lessening the growth of pathogen microorganisms [12], or by providing promising activity against antibiotic-resistant bacteria and chemotherapeuticresistant tumors [13].…”

HPTLC Fingerprint Authentication of Selected Sideritis spp. Using a Pharmacognostic Approach

“…As for the phytochemical composition, Sideritis species generally contain sterols, flavone aglycones and their glycosides, [16,17], coumarins, diterpenes (Venturella and Bellino, 1979 cited in [18]), lignans [9] and sesquiterpenes [14,19]. The essential oil content is reported to be very low in yield (< 0.1 %) [20,21]. From these phytochemical compound classes, phenolic compounds form the largest group, and might also be the primary agents responsible for health benefit properties.…”