Promising Antioxidant and Anticorrosion Activities of Mild Steel in 1.0 M Hydrochloric Acid Solution by Withania frutescens L. Essential Oil

Chemical Profiling and Antioxidant, Antimicrobial, and Hemolytic Properties of Euphorbia calyptrata (l.) Essential oils: in Vitro and in Silico Analysis

In this work, we sought to validate the use of Euphorbia calyptrata (L.), a Saharan and Mediterranean medicinal plant, in traditional pharmacopeia. GC-MS/MS identified volatile compounds of potential therapeutic interest. Antioxidant tests were performed using β-carotene decolorization, DPPH radical scavenging, FRAP, beta-carotene bleaching, and TAC. The antimicrobial activity was evaluated on solid and liquid media for bacterial and fungal strains to determine the zone of inhibition and the minimum growth concentration (MIC) of the microbes tested. The hemolytic activity of these essential oils was assessed on red blood cells isolated from rat blood. Phytochemical characterization of the terpenic compounds by GC-MS/MS revealed 31 compounds, with alpha-Pinene dominating (35.96 %). The antioxidant power of the essential oils tested revealed an IC50 of 67.28 μg/mL (DPPH), EC50 of 80.25.08±1.42 μg/mL (FRAP), 94.83±2.11 μg/mL (beta carotene) and 985.07±0.70 μg/mL (TAC). Evaluating solid media's antibacterial and antifungal properties revealed a zone of inhibition between 10.28 mm and 25.80 mm and 31.48 and 34.21 mm, respectively. On liquid media, the MIC ranged from 10.27 μg/mL to 24.91 μg/mL for bacterial strains and from 9.32 μg/mL to 19.08 μg/mL for fungal strains. In molecular docking analysis, the compounds naphthalene, shogunal, and manol oxide showed the greatest activity against NADPH oxidase, with Glide G scores of -5.294, -5.218 and -5.161 kcal/mol, respectively. For antibacterial activity against E. coli beta-ketoacyl-[acyl carrier protein] synthase, the most potent molecules were cis-Calamenene, alpha.-Muurolene and Terpineol, with Glide G-scores of -6.804, -6.424 and -6.313 kcal/mol, respectively. Hemolytic activity revealed a final inhibition of 9.42±0.33 % for a 100 μg/mL concentration. The essential oils tested have good antioxidant, antimicrobial, and hemolytic properties thanks to their rich phytochemical composition, and molecular docking analysis confirmed their biological potency.

Antioxidant, Antimicrobial and In Silico NADPH Oxidase Inhibition of Chemically-Analyzed Essential Oils Derived from Ballota deserti (Noë) Jury

Ballota deserti (Noë) Jury (B. deserti) is a medicinal plant used in Ayurvedic medicine. The chemical composition, antioxidant, antibacterial, and antifungal properties of essential oils from B. deserti (EOBD) against drug-resistant microorganisms were examined in this work. Hydrodistillation was used to extract EOBD, and gas chromatography–mass spectrometry was used to identify its constituents. Ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and total antioxidant capacity (TAC) were used to assess the antioxidant effect of EOBD. The disc diffusion agar and the microdilution tests were used in the assessment of the antibacterial properties of EOBD against clinically resistant pathogenic microorganisms. An in silico approach was used to evaluate the inhibitory potential of EOBD against NADPH oxidase. The yield of EOBD was 0.41%, and was primarily composed of linalool (37.82%), cineole (12.04%), and borneol (11.07%). EOBD had good antioxidant potency, with calculated values of 19.82 ± 1.14 µg/mL (DPPH), 64.78 ± 5.21 µg/mL (FRAP), 996.84 ± 20.18 µg EAA/ mg (TAC). Both Gram-negative and Gram-positive bacteria were inhibited by EOBD with inhibition zones ranging from 17.481.75 mm to 28.471.44 mm. EOBD exhibited MICs ranging from 10.78 g/mL to 22.48 g/mL when tested against bacteria using the minimum inhibitory concentration (MIC) assay. Similarly, impressive antifungal activity was observed against fungal strains with inhibition zone widths ranging from 16.761.83 to 36.791.35 mm. Results of MICs assay against fungi showed that EOBD had MICs values ranging from 15.32 ± 1.47 to 23.74 ± 1.54 µg/mL. Docking results showed that thujone, o-cymene, and butanoic acid contained in EOBD possessed strong activity against NADPH oxidase, with glide scores of −5.403, −5.344, and −4.973 Kcal/mol, respectively. In light of these findings, the EOBD may be seen as a potential source of chemical compounds with significant biological capabilities that can be advantageous as natural antioxidants and develop an effective weapon against a wide range of pathogenic bacteria.

Evaluation of Antioxidants Using Electrochemical Sensors: A Bibliometric Analysis

The imbalance of oxidation and antioxidant systems in the biological system can lead to oxidative stress, which is closely related to the pathogenesis of many diseases. Substances with antioxidant capacity can effectively resist the harmful damage of oxidative stress. How to measure the antioxidant capacity of antioxidants has essential application value in medicine and food. Techniques such as DPPH radical scavenging have been developed to measure antioxidant capacity. However, these traditional analytical techniques take time and require large instruments. It is a more convenient method to evaluate the antioxidant capacity of antioxidants based on their electrochemical oxidation and reduction behaviors. This review summarizes the evaluation of antioxidants using electrochemical sensors by bibliometrics. The development of this topic was described, and the research priorities at different stages were discussed. The topic was investigated in 1999 and became popular after 2010 and has remained popular ever since. A total of 758 papers were published during this period. In the early stages, electrochemical techniques were used only as quantitative techniques and other analytical techniques. Subsequently, cyclic voltammetry was used to directly study the electrochemical behavior of different antioxidants and evaluate antioxidant capacity. With methodological innovations and assistance from materials science, advanced electrochemical sensors have been fabricated to serve this purpose. In this review, we also cluster the keywords to analyze different investigation directions under the topic. Through co-citation of papers, important papers were analyzed as were how they have influenced the topic. In addition, the author’s country distribution and category distribution were also interpreted in detail. In the end, we also proposed perspectives for the future development of this topic.

Essential Oils from Leaves of Juniperus thurifera L., Exhibiting Antioxidant, Antifungal and Antibacterial Activities against Antibiotic-Resistant Microbes

The antioxidant, antibacterial and antifungal properties of essential oils (EOs) of Juniperus thurifera L., a plant utilized in traditional, herbal medicine, were investigated. The EOs were extracted by use of a Clevenger apparatus and phytochemicals identified by gas chromatography coupled with mass spectrometry (GC/MS/MS). The antioxidant capacity of EOs of J. thurifera was determined by 2,2-diphenyl-1-picrylhydrazil (DPPH), total antioxidant capacity (TAC), and ferric reducing antioxidant power (FRAP). Antimicrobial activity of EOs of J. thurifera was determined against four fungal strains, Candida albicans; ATCC 10231, Aspergillus niger; MTCC 282, Aspergillus flavus; MTCC 9606 and Fusarium oxysporum; MTCC 9913 and four bacterial strains, Staphylococcus aureus; ATCC 6633, Escherichia coli; K12, Bacillus subtilis; DSM 6333, and Pseudomonas aeruginosa; CIP A22, by use of the disk diffusion method, and microdilution method used to determine the minimum inhibitory concentration (MIC). EOs of J. thurifera consisted of 31 compounds and were dominated by α-thujene (25%), elemol (12%) and muurolol (12%). Antioxidant activity recorded an IC50 of 24 ± 0.71 µg/mL (DPPF), EC50 of 0.19 ± 0.01 mg/mL (FRAP), and 9.3 × 102 ± 38 mg EAA/g (TAC). The EOs of J. thurifera exhibited significant antibacterial activity against all bacterial strains under investigation, especially P. aeruginosa; CIP A22 with an inhibition diameter of 28 ± 1.5 mm and MIC of 4.8 × 10−2 ± 0. 001 µg/mL. EOs of J. thurifera also exhibited significant antifungal activity against C. albicans; ATCC 10231 and F. oxysporum; MTCC 9913 with an activity of 21 ± 2.1 mm, 32 ± 2.3%, and MIC of 9.5 × 10−2 ± 0.001 Bioactive molecules found in EOs of J. thurifera could be used as an alternative solution to antibiotics available on the market to combat microbial resistance.

Antioxidant and Antimicrobial Activities of Chemically-Characterized Essential Oil from Artemisia aragonensis Lam. against Drug-Resistant Microbes

This study investigated the chemical composition, antioxidant and antimicrobial activity of essential oil extracted from Artemisia aragonensis Lam. (EOA). Hydrodistillation was employed to extract EOA. Gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry analyses (GC-MS) were used to determine the phytochemical composition of EOA. Antioxidant potential was examined in vitro by use of three tests: 2.2-diphenyl-1-picrilhidrazil (DPPH), ferric reducing activity power (FRAP) and total antioxidant capacity assay (TAC). Agar diffusion and microdilution bioassays were used to assess antimicrobial activity. GC/MS and GC-FID detected 34 constituents in the studied EOA. The major component was Camphor (24.97%) followed by Borneol (13.20%), 1,8 Cineol (10.88%), and Artemisia alcohol (10.20%). EOA exhibited significant antioxidant activity as measured by DPPH and FRAP assays, with IC50 and EC50 values of 0.034 ± 0.004 and 0.118 ± 0.008 mg/mL, respectively. EOA exhibited total antioxidant capacity of 7.299 ± 1.774 mg EAA/g. EOA exhibited potent antibacterial activity as judged by the low minimum inhibitory concentration (MIC) values against selected clinically-important pathogenic bacteria. MIC values of 6.568 ± 1.033, 5.971 ± 1.033, 7.164 ± 0.0 and 5.375 ± 0.0 μg/mL were observed against S. aureus, B. subtills, E. coli 97 and E. coli 57, respectively. EOA displayed significant antifungal activity against four strains of fungi: F. oxysporum, C. albicans, A. flavus and A. niger with values of 21.50 ± 0.43, 5.31 ± 0.10, 21.50 ± 0.46 and 5.30 ± 0.036 μg/mL, respectively. The results of the current study highlight the importance of EOA as an alternative source of natural antioxidant and antibacterial drugs to combat antibiotic-resistant microbes and free radicals implicated in the inflammatory responses accompanying microbial infection.