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.

The present study explored the phytochemicals, antibacterial, antioxidant and cytotoxic effect of Tridax procumbens leaves. The leaves were dried and extracted with various organic solvents. The leaves contained the phytochemicals such as alkaloids, carbohydrates, polyphenols and tannins respectively. Antimicrobial potentials of the extracts were determined by performing the disc diffusion techniques. Results revealed that different organic solvents extracts namely methanol, ethanol and ethyl acetate extracts documented comparatively good activity against the studied microbial strains. The methanol extract of leaves of T. procumbens showed combatively better antioxidant potential. The tested plant leaf extract showed high activity against human lung cancer cells than breast cancer cell lines. 250 µg/ml plants extract showed 84 ± 2.8% toxicity against human lung cancer cells.

Aminoglycosides (AMGs) have been extensively used to treat infectious diseases caused by Gram-negative bacteria in livestock and humans. A selective and sensitive colorimetric probe for the determination of streptomycin and kanamycin was proposed based on chlortetracycline-coated silver nanoparticles (AgNPs–CTC) as the sensing element. Almost all of the tested aminoglycoside antibiotics can rapidly induce the aggregation of AgNPs, along with a color change from yellow to orange/red. The selective detection of aminoglycoside antibiotics, including tobramycin, streptomycin, amikacin, gentamicin, neomycin, and kanamycin, with other types of antibiotics, can be achieved by ultraviolet (UV) spectroscopy. This developed colorimetric assay has ability to detect various AMGs using in-depth surface plasmon resonance (SPR) studies. With this determination of streptomycin and kanamycin was achieved at the picomolar level (pM) by using a UV–visible spectrophotometer. Under aqueous conditions, the linear range of the colorimetric sensor for streptomycin and kanamycin was 1000–1,1000 and 120–480 pM, respectively. The corresponding limit of detection was 2000 pM and 120 pM, respectively. Thus, the validated dual colorimetric and ratiometric method can find various analytical applications for the ultrasensitive and rapid detection of AMG antibiotics in water samples.

The current study aimed to screen the preliminary phytochemicals in the leaf extract of the medicinal plant Simarouba glauca and to analyze its potential antimicrobial, antioxidant and anticancer properties. The phytochemical profile of the methanol extract was analyzed, and bioactive compounds were identified using chromatography, FTIR and GCMS. Antimicrobial activity and Minimum Inhibitory Concentration (MIC) were determined against 14 bacterial and 6 fungal strains. Moreover, the synergistic effect of a plant extract with commercially available antibiotics was also evaluated using the checkerboard method. The ethanolic and methanolic extracts showed exclusive activity against S. aureus and profound activity against E. coli and S. marcescens. Upon comparing breakpoints, methanolic extract demonstrated higher antimicrobial activity with a MIC value of 3.2 mg/mL against the test pathogens. Furthermore, the extracts demonstrated potential antioxidant activity; methanol extract had higher antioxidant potential compared to the ethanol extract. The major proactive bioactive compound with maximum antioxidant capacity was observed to be terpenoids. The methanol extract of S. glauca showed significant cytotoxicity against the MCF-7 breast cancer cell line with an IC₅₀ value of 16.12 µg/mL. The overall results of our work provide significant evidence for the usage of methanolic extract of S. glauca as an efficient ethnomedicinal agent and a potential candidate for relieving many human ailments.

Green fabrication of nanoparticles has been established by means of a simple, economical and environmentally pleasant process. The present investigation describes the use of Myrtus communis plant leaves extract for the biosynthesis of the silver nanoparticle. The surface plasmon resonance peak at 435 nm, distinctive for silver, determined the synthesis of AgNP. The morphology of the particles was spherical and in size with an average diameter of ∼ 15 nm. Energy dispersive X-ray Fourier Transformed Infrared and X-ray diffraction techniques investigated the crystalline structure, purity and functional groups. The biogenic nanoparticles revealed the antibacterial efficacy against both gram-positive bacteria and gram-negative bacteria, suggesting its prospective applicability as an effective antibacterial agent.

Discovering new antifungal drugs from natural products is a key target for the treatment of infections, such as candidiasis and other Candida-related infections. As current therapeutic drugs for the treatment of infections, such as candidiasis and other Candida-related infections, have adverse effects on human health, discovering new antifungal drugs from natural products is urgently needed. The objective of this study was to evaluate the antifungal activity of the methanolic and sodium phosphate buffer extracts derived from various parts of Myrtus communis, a plant that is traditionally used in Saudi Arabia, against Candida albicans (ATCC 10213), Candida glabrata (ATCC 2001), Candida kefyr (ATCC 66028), Candida parapsilosis (ATCC 22019), and Candida tropicalis (ATCC 750). A well diffusion assay was performed to assess the antifungal activity through the measurement of the zone of inhibition. Of the extracts, those extracted with methanol from the roots and leaves displayed strong inhibitory activity against Candida glabrata ( and , respectively), at 50 mg/ml, with 5 mg/ml fluconazole administered as the standard control. The minimal inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values were 12.5 mg/ml and 25 mg/ml for the M. communis root extract and 25 mg/ml and 50 mg/ml for the M. communis leaf extract against Candida glabrata. The results were confirmed by scanning electron microscopy (SEM) imaging of the control and treated strains of Candida glabrata. Based on SEM, these extracts could alter the morphology and cause loss of cell integrity. The effect of M. communis root and leaf extracts on Candida cells was also determined by measuring the absorbance at 260 nm after treatment for 1 h at 37°C. Interestingly, the 260 nm absorbing material was higher in Candida glabrata than in the resistant strain, Candida parapsilosis (ATCC 22019). Based on our findings, the crude methanolic extract of M. communis roots and leaves exhibited good antifungal activity against the Candida glabrata strain. SEM results and estimation of the 260 nm absorbance material proved that the extract might act on the cell wall and cell membrane of Candida cells, further leading to cell death.