GC-MS Characterization, In Vitro Antioxidant, Antimicrobial, and In Silico NADPH Oxidase Inhibition Studies of Anvillea radiata Essential Oils

Abstract

Anvillea radiata is a medicinal plant that has been used in traditional phytotherapy in North Africa as a treatment for various illnesses. In this study, we aim to explore the antioxidant, antifungal, and antibacterial effects of essential oils of Anvillea radiata (EOAR) collected in Morocco. EOAR was extracted by the hydrodistillation method, and the phytochemical identification was carried out by gas chromatography-Mass Spectrometry (GC/MS). The antioxidant capacity was evaluated by the 2.2-diphenyl-1-picrylhydrazyl (DPPH) method, ferricyanide method (FRAP) as well as total antioxidant capacity (TAC). Antifungal and antibacterial properties were determined by use of the disc diffusion and minimum inhibitory concentration assays. The microbial strains used in the antimicrobial evaluation were: Aspergillus niger (MTCC 282), Aspergillus flavus (MTCC 9606), Fusarium oxysporum (MTCC 9913), Candida albicans (ATCC 10231), Escherichia coli (ATB 97/BGM), Staphylococcus aureus (ATCC 6633), Bacillus subtills (DSM 6333), and Escherichia coli (ATB 57/B6N). Based on in silico simulations, the inhibitory power of EOAR against nicotinamide adenine dinucleotide phosphate oxidase (NADPH) was evaluated. The yield of the oil was 0.96% wherein 12 compounds were identified including α-cuprenene (33.48%) camphor (21.41%) and α-himachalene (15.88%) as major compounds. The antioxidant capacity showed an IC50 of 32.36 µg/mL (DPPH) and an EC-50 value of 64.60 ± 3.71 µg/mL in the FRAP assay. The total antioxidant capacity showed a concentration of 977.51 ± 22.38 µg AAE/mg (TAC). As for the antimicrobial effects, the inhibition diameter of the studied bacteria ranged from 23.50 ± 2.31 to mm 29.50 ± 2.21 mm, while for fungi, ranged from 25.12 ± 2.82 mm to 11.42 ± 1.90 mm. Minimum Inhibitory Concentration (MIC) ranged from 12.71 ± 1.59 µg/mL to 23.53 ± 0.78 µg/mL for bacterial strains and 10.31 ± 1.34 µg/mL to 22.75 ± 1.06 µg/mL for fungal strains. In silico, among all Anvillea radiata essential oils analyzed, the sesquiterpene γ-dehydro-ar-himachalene, monoterpenoid phenol carvacrol, as well as sesquiterpene α-cadinene were the most active compounds against NADPH oxidase with a glide score of −6.233, −6.082, and −5.057 Kcal/mol, respectively. Taken together, these data showed that EOAR exhibited enormous significance as an antioxidant, antifungal, and antibacterial agent.