Chemical composition, antimicrobial, antioxidant and anti-cancer activities of Nepeta deflersiana Schweinf. Ex Hedge and Marrubium vulgare L. essential oils: a comparative study

Abstract

This work focuses on evaluating the chemical composition, biological potency and in silico computational studies of selected identified molecules in the essential oils obtained from Nepeta deflersiana (Lamiaceae) and Marrubium vulgare (Lamiaceae) plants. The essential oils were extracted using Clevenger-type system and analyzed by gas chromatography-based techniques (GC-FID and GC-MS) using a HP-5MS column. Twenty constituents were identified in Nepeta deflersiana essential oil (NDEO) whereas forty-three were identified in Marrubium vulgare essential oil (MVEO) representing 99.55% and 94.75% of the total essential oil composition, respectively. 4aα,7α,7aα Nepetalactone was the major component in both NDEO (77.79%) and MVEO (63.67%) and first time reported in Marrubium genus by our group. The antioxidant activity has been determined using DPPH, TEAC and FRAP methods and expressed as μmol Trolox equivalent/g. All the spectrophotometric assays proved the strong radical scavenging and reducing power of MVEO. The antimicrobial activities revealed moderate to significant antibacterial potential and no inhibitory effect was observed against C. albicans. NDEO showed the highest effectiveness against S. pneumoniae (24 mm zone of inhibition, MIC 25 μg/mL). Cytotoxicity assessment against two breast cancers (MCF-7 and MDA-MB-231) and one prostate cancer cell (PC-3) revealed that MVEO was more cytotoxic than NDEO to the tested breast cell lines (IC50 = 30.11 for MCF-7 and 68.25 μg/mL for MDA-MB-231) while moderately inhibited prostate cancer cells (IC50 = 135.60 μg/mL). In silico computation study for selected ingredients suggested that they have drug-likeness properties.