Antioxidant, Volatile Compounds; Antimicrobial, Anti-Inflammatory, and Dermatoprotective Properties of Cedrus atlantica (Endl.) Manetti Ex Carriere Essential Oil: In Vitro and In Silico Investigations

Abstract

Cedrus atlantica (Endl.) Manetti ex Carriere is an endemic tree possessing valuable health benefits which has been widely used since time immemorial in international traditional pharmacopoeia. The aim of this exploratory investigation is to determine the volatile compounds of C. atlantica essential oils (CAEOs) and to examine their in vitro antimicrobial, antioxidant, anti-inflammatory, and dermatoprotective properties. In silico simulations, including molecular docking and pharmacokinetics absorption, distribution, metabolism, excretion, and toxicity (ADMET), and drug-likeness prediction were used to reveal the processes underlying in vitro biological properties. Gas chromatography–mass spectrophotometry (GC-MS) was used for the chemical screening of CAEO. The antioxidant activity of CAEO was investigated using four in vitro complementary techniques, including ABTS and DPPH radicals scavenging activity, ferric reductive power, and inhibition of lipid peroxidation (β-carotene test). Lipoxygenase (5-LOX) inhibition and tyrosinase inhibitory assays were used for testing the anti-inflammatory and dermatoprotective properties. GC-MS analysis indicated that the main components of CAEO are β-himachalene (28.99%), α-himachalene (14.43%), and longifolene (12.2%). An in vitro antimicrobial activity of CAEO was examined against eleven strains of Gram-positive bacteria (three strains), Gram-negative bacteria (four strains), and fungi (four strains). The results demonstrated high antibacterial and antifungal activity against ten of them (>15 mm zone of inhibition) using the disc-diffusion assay. The microdilution test showed that the lowest values of MIC and MBC were recorded with the Gram-positive bacteria in particular, which ranged from 0.0625 to 0.25 % v/v for MIC and from 0.5 to 0.125 % v/v for MBC. The MIC and MFC of the fungal strains ranged from 0.5 to 4.0% (MIC) and 0.5 to 8.0% v/v (MFC). According to the MBC/MIC and MFC/MIC ratios, CAEO has bactericidal and fungicidal activity. The results of the in vitro antioxidant assays revealed that CAEO possesses remarkable antioxidant activity. The inhibitory effects on 5-LOX and tyrosinase enzymes was also significant (p < 0.05). ADMET investigation suggests that the main compounds of CAEO possess favorable pharmacokinetic properties. These findings provide scientific validation of the traditional uses of this plant and suggest its potential application as natural drugs.

Petroselinum crispum L., essential oil as promising source of bioactive compounds, antioxidant, antimicrobial activities: In vitro and in silico predictions

“…Table 3 outlines the inhibitory halos and antibacterial/antifungal properties of the PC-tested oil. Eo activities were categorized as low (<10 mm), moderate (>10–15 mm), and high (>15 mm) based on the inhibition zone diameter [ 20 ]. The PC-Eo exhibited the highest antibacterial activity against Salmonella enterica serotype Typhi (27.43 ± 0.56 mm), followed by Bacillus subtilis (22.43 ± 1.34 mm), and Staphylococcus aureus (17.69 ± 1.45 mm), while moderate activity was observed against Escherichia coli (11.07 ± 2.25 mm).…”

“…According to this ratio, it should be possible to obtain tested agent concentrations that are capable of eliminating 99.9 % of the treated microorganisms. Ratios higher than 4.0 could suggest difficulties in administering dosages high enough to kill microorganisms at the same level, designating the substance as bacteriostatic [ 20 ].…”

“…Equation (2) was used to calculate the antioxidant properties based on residual color inhibition relative to the control. where Abs (t = 100 min) represents the absorbance of β-carotene after 100 min of experimentation in the presence of PC-Eo, and Abs (t = 0) represents the absorbance of β-carotene at the start of the assay [ 20 ].…”

“…The MIC of PC-Eo was determined following a previously documented method [ 20 ], with minor adjustments. Serial two-fold dilutions of the PC-Eo were prepared, spanning concentrations from 8.0 to 0.0625 % (v/v) in Mueller–Hinton broth, supplemented with 5 % dimethyl sulfoxide (DMSO).…”

“…The MBC or MFC was the highest dilution at which no single bacterial colony was visible on the plates. Furthermore, MBC/MIC and MFC/MIC ratios were also computed [ 20 ].…”