Promising Antioxidant and Antimicrobial Potencies of Chemically-Profiled Extract from Withania aristata (Aiton) Pauquy against Clinically-Pathogenic Microbial Strains

Abstract

Withania aristata (Aiton) Pauquy, a medicinal plant endemic to North African Sahara, is widely employed in traditional herbal pharmacotherapy. In the present study, the chemical composition, antioxidant, antibacterial, and antifungal potencies of extract from the roots of Withania aristata (Aiton) Pauquy (RWA) against drug-resistant microbes were investigated. Briefly, RWA was obtained by maceration with hydro-ethanol and its compounds were identified by use of high-performance liquid chromatography (HPLC). The antioxidant activity of RWA was determined by use of ferric-reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and total antioxidant capacity (TAC). The evaluation of the antimicrobial potential of RWA was performed against drug-resistant pathogenic microbial strains of clinical importance by use of the disc diffusion agar and microdilution assays. Seven compounds were identified in RWA according to HPLC analysis, including cichoric acid, caffeic acid, apigenin, epicatechin, luteolin, quercetin, and p-catechic acid. RWA had excellent antioxidant potency with calculated values of 14.0 ± 0.8 µg/mL (DPPH), 0.37 ± 0.08 mg/mL (FRAP), 760 ± 10 mg AAE/g (TAC), and 81.4% (β-carotene). RWA demonstrated good antibacterial potential against both Gram-negative and Gram-positive bacteria, with inhibition zone diameters ranging from 15.24 ± 1.31 to 19.51 ± 0.74 mm, while all antibiotics used as drug references were infective, except for Oxacillin against S. aureus. Results of the minimum inhibitory concentration (MIC) assay against bacteria showed that RWA had MIC values ranging from 2.13 to 4.83 mg/mL compared to drug references, which had values ranging from 0.031 ± 0.003 to 0.064 ± 0.009 mg/mL. Similarly, respectable antifungal potency was recorded against the fungal strains with inhibition zone diameters ranging from 25.65 ± 1.14 to 29.00 ± 1.51 mm compared to Fluconazole, used as a drug reference, which had values ranging from 31.69 ± 1.92 to 37.74 ± 1.34 mg/mL. Results of MIC assays against fungi showed that RWA had MIC values ranging from 2.84 ± 0.61 to 5.71 ± 0.54 mg/mL compared to drug references, which had values ranging from 2.52 ± 0.03 to 3.21 ± 0.04 mg/mL. According to these outcomes, RWA is considered a promising source of chemical compounds with potent biological properties that can be beneficial as natural antioxidants and formulate a valuable weapon in the fight against a broad spectrum of pathogenic microbes.

Promising Antioxidant and Insecticidal Properties of Chemically Characterized Hydroethanol Extract from Withania adpressa Coss. ex Batt

“…Luteolin and methyl gallate were the predominant compounds in the extract of W. adpressa, representing 86.13 ± 0.58 µg/mg and 54.37 ± 0.61 µg/mg, respectively (Table 1). These results are in agreement with previous works reporting that the genus Withania possesses phenols including steroidal lactones, tannin, alkaloids, flavonoids [25][26][27][28]. More than twelve alkaloids, forty withanolides, and many sitoindosides were isolated from the leaves, fruits, and roots of Withania [25].…”

“…More than twelve alkaloids, forty withanolides, and many sitoindosides were isolated from the leaves, fruits, and roots of Withania [25]. Crude extracts from the genus Withania are predicted to possess several compounds, such as 2-(4-hydroxy-3,5 dimethoxyphenyl)-3oxetanamine, N-4-(3-furoylamine)-1-butanol, withanolides, apocarotenoids, carotenoid, tetra-acetylated apocarotenoid, glucosides, hydroxywithanolide F, withanolide A, withacoagulin, withanoside IV, physagulin D, 27-hydroxywithanone, withanoside V, withaferin A, withastramonolide, withanone, withanolide B, isopelletierine, anaferine, withaferins, and withanolide D [28]. Row values with the same letters are not significantly different (n = 3, ANOVA, Tukey's HSD, pvalue less than 0.05 considered to be significant).…”

New Triazole-Isoxazole Hybrids as Antibacterial Agents: Design, Synthesis, Characterization, In Vitro, and In Silico Studies

“…Before evaluating the tested molecules, the susceptibility of the bacterial strains to standards drugs was examined using the Kirby–Bauer disk diffusion process [ 59 ]. This method classified the strains into sensitive and resistant categories.…”

“…These antibiotic disks were placed onto Mueller-Hinton agar previously inoculated with a bacterial suspension, followed by an incubation period at 37 • C for 24 h. The concentration per disk of the antibiotics used is detailed in Table 7. The antibacterial action of the examined molecules was determined through the disk diffusion technique [59]. This technique involves utilizing sterile filter paper disks with a diameter of 6 mm, impregnated with the highest concentration employed for each molecule under investigation, specifically 30 mg/mL, at a rate of 10 µL per disk.…”

Anti-Struvite, Antimicrobial, and Anti-Inflammatory Activities of Aqueous and Ethanolic Extracts of Saussurea costus (Falc) Lipsch Asteraceae

“…The antimicrobial effect of S. costus extracts was determined by the sterile disk diffusion method; this method consists of using sterile filter paper disks, 6 mm in diameter and impregnated with aqueous and ethanolic extracts of the plant studied, notably with (200 mg mL −1 and 400 mg mL −1 ), at a rate of 5 μL/disk. These disks are placed on the surface of an agar medium (Muller-Hinton), previously inoculated with a bacterial suspension, The disks are left 15 to 30 min at room temperature, then incubated at 37 °C for 24 h [ 36 , 37 ].…”