Phytochemical Analysis and Antioxidant, Antibacterial, and Antifungal Effects of Essential Oil of Black Caraway (Nigella sativa L.) Seeds against Drug-Resistant Clinically Pathogenic Microorganisms

Abstract

Nigella sativa (NS) is a plant that has long been utilized in traditional medicine as a treatment for certain diseases. The aim of this work was to valorize the essential oil (EO) of this species by phytochemical analysis and antimicrobial and antioxidant evaluation. EO was extracted by hydrodistillation from the seeds of Nigella sativa (EO-NS). Phytochemical content of EO-NS was evaluated by use of gas chromatography coupled to mass spectrometry (GC-MS/MS). Antioxidant ability was in vitro determined by use of three assays: 2.2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing power (FRAP), and total antioxidant capacity (TAC) relative to two synthetic antioxidants: BHT and quercetin. Antimicrobial effect was evaluated against four clinically important bacterial strains (Staphylococcus aureus, ATCC 6633; Escherichia coli, K12; Bacillus subtilis, DSM 6333; and Proteus mirabilis, ATCC 29906) and against four fungal strains (Candida albicans, ATCC 10231; Aspergillus niger, MTCC 282; Aspergillus flavus, MTCC 9606; and Fusarium oxysporum, MTCC 9913). Fifteen constituents that accounted for the majority of the mass of the EO-NS were identified and quantified by use of GC-MSMS. The main component was O-cymene (37.82%), followed by carvacrol (17.68%), α-pinene (10.09%), trans-sabinene hydrate (9.90%), and 4-terpineol (7.15%). EO-NS exhibited significant antioxidant activity with IC50, EC50, and total antioxidant capacity (TAC) of 0.017 ± 0.0002 , 0.1196 ± 0.012 , and 114.059 ± 0.97 mg EAA/g, respectively. Additionally, EO-NS exhibited promising antibacterial activity on all strains under investigation, especially on E. coli K12 resulting in inhibition diameter of 38.67 ± 0.58 mm and a minimum inhibitory concentration (MIC) of 1.34 ± 0.00 μg/mL. Also, EO-NS had significant antifungal efficacy, with a percentage of inhibition of 67.45 ± 2.31 % and MIC of 2.69 ± 0.00 μg/mL against F. oxysporum, MTCC 9913 and with a diameter of inhibition 42 ± 0.00 mm and MIC of 0.67 ± 0.00 μg/mL against C. albicans. To minimize development of antibiotic-resistant bacteria, EO-NS can be utilized as a natural, alternative to synthetic antibiotics and antioxidants to treat free radicals implicated in microbial infection-related inflammatory reactions.

In vitro antioxidant and free-radical scavenging activities of polar leaf extracts of Vernonia amygdalina

“…The crude leaf extract contains phenolic and tannin compounds which are potential sources of antioxidants [ 58 – 60 ]. These bioactive compounds possess many biological properties including antioxidants such as anti-fungi [ 10 , 11 ], antibacterial [ 11 , 14 ], anti-inflammatory [ 12 ], antioxidant [ 12 , 61 ], anticancer [ 12 ], antiviral [ 13 ]. The below figures (Figs.…”

“…[ 9 ]. Phytochemicals have several pharmacological roles such as antioxidant [ 10 , 11 ], antiviral [ 12 ], anticancer [ 13 ], antimicrobial [ 14 ], antifungal [ 10 ] and antiparasitic [ 15 ]. Essential oils (volatile oils) are used in order to exploit physiological and psychological properties of individual response to volatile biostructures, with the aim to reduce stress and to speed up the healing processes [ 16 , 17 ].…”

Antibacterial, Antioxidant, and in silico NADPH Oxidase Inhibition Studies of Essential Oils of Lavandula dentata against Foodborne Pathogens

“…Similarly, the 1,8 cineole (63.25%) was also found to be the major component of the EO of lavender growing in Brazil [ 28 ]. Carvacrol (14.82%), terpinen-4-ol (5.98%), α -pinene (2.57%), and linalool (0.54%) compounds were also found in N. sativa (black Caraway) EOs [ 29 ]. Camphor, α -pinene, and terpinen-4-ol were also reported among the compounds figured in the EO of Tunisian and French fennel ( F. vulgare Mill.)…”

Chemical Composition and Evaluation of Antifungal and Insecticidal Activities of Essential Oils Extracted from Jambosa caryophyllus (Thunb.) Nied: Clove Buds

“…Sterile Whatman paper discs (6 mm diameter) were placed in the center of the Petri dish and then impregnated with 20 μ L of EO-JC (1 mg/mL) and fluconazole (positive controls) at a dose of 5 mg/mL, whereas the fungal strains were incubated at 37°C. 7 days for A. niger , A. flavus , and F. oxysporum , percent inhibition was evaluated [ 31 , 32 ]. The percentage of inhibition was calculated according to the mathematical formula: where I (%) is the percentage of inhibition; Dc is the diameter of the control; Ds is the diameter in the presence of essential oils.…”

“…Microplates were prepared under aseptic conditions, each sterile 96-well microplate was labeled, 100 μ L of EO used for the test in 10% (v/v) DMSO was pipetted into the first column of the plate, and 50 μ L of sterile ME (malt extract) for the fungal strains was added to all other wells; serial dilutions were made using a multichannel pipette, and finally 30 L after 7 days at 37°C for A. niger , A. flavus , and F. oxysporum [ 28 , 30 ]. The MIC endpoint is established by direct observation of good development or colorimetric technique 0.2 percent (w/v) [ 32 , 33 ].…”