Mohamed A. Fareid

Background: Rosmarinus officinalis L. is a medicinally important aromatic plant rich in bioactive secondary metabolites with diverse therapeutic properties. This study aimed to characterize the phytochemical profile of R. officinalis leaf extracts, isolate carnosic acid as a major bioactive diterpene, and evaluate its biological activities. Methods: Leaf extracts were prepared using solvents of increasing polarity and analyzed by phytochemical screening and UHPLC/QTOF-MS. Carnosic acid was isolated by thin-layer chromatography and assessed for antibacterial, antibiofilm, antioxidant, anti-inflammatory, antidiabetic, and antiproliferative activities using in vitro assays. Expression of apoptosis-related genes was also investigated. Results: Methanolic and ethanolic extracts exhibited the highest abundance of phenolic compounds and secondary metabolites, whereas the hexane extract showed lower phytochemical content. UHPLC/QTOF-MS identified seven major metabolites, including phenolic acids, flavonoids, and abietane-type diterpenes. Purified carnosic acid demonstrated potent antibacterial activity (MIC: 10–23 μg/mL) and inhibited biofilm formation by up to 90%. Strong antioxidant activity was observed, with DPPH and ABTS radical-scavenging IC₅₀ values of 125 and 130 μg/mL, respectively. The compound also exhibited notable anti-inflammatory activity and markedly inhibited α-amylase and α-glucosidase activities. Furthermore, carnosic acid exhibited dose-dependent antiproliferative activity against MCF-7, HepG2, and MCF-10A cells, reducing cell viability to 10.8%, 16.9%, and 70.4 ± 1.8%, respectively, at 250 μg/mL, with corresponding IC₅₀ values of 28.3, 37.8, and >250 μg/mL, respectively. Gene expression analysis revealed upregulation of BAX and downregulation of BCL2, indicating activation of mitochondrial-mediated apoptosis. Conclusions:R. officinalis leaves represent a valuable source of multifunctional phytochemicals, particularly carnosic acid. Its broad-spectrum biological activities and apoptosis-inducing potential support its promising application in pharmaceutical, nutraceutical, and biomedical fields.

Background: Nigella sativa (black cumin) seeds are renowned for their ethnomedicinal significance and are rich in bioactive phytochemicals, which contribute to food preservation and the prevention of various diseases through their antimicrobial and antioxidant properties. Accordingly, this study aimed to characterize the phytochemical composition of N. sativa seed extracts, isolate thymoquinone, and assess their antibacterial, antibiofilm, antioxidant, anti-inflammatory and antidiabetic activities. Methods: Nigella sativa seed extracts were prepared using solvents of increasing polarity and analyzed for phytochemical content. Metabolite profiling was performed using UHPLC/QTOF-MS. Thymoquinone, the major constituent, was isolated via thin-layer chromatography (TLC), further purified using semi-preparative reverse-phase high-performance liquid chromatography (RP-HPLC), and evaluated in vitro for antibacterial, antibiofilm, antioxidant, anti-inflammatory, and antidiabetic activities. Results: Extraction yields ranged from 5.5% to 8.4% (w/w), with methanol yielding the highest phenol (6.34 ± 0.31 mg GAE/mL) and flavonoid (5.12 ± 0.26 mg QE/mL) contents. UHPLC/QTOF-MS revealed a chemically diverse profile dominated by thymoquinone (58% relative abundance), alongside p-cymene, carvacrol, longifolene, and nigellidine. Thymoquinone (Rf = 0.56) was initially isolated from the methanolic extract with a yield of 270 mg/g and further purified from preparative TLC fractions using semi-preparative RP-HPLC, affording 82 mg of >95% pure compound with a 68.3% recovery, suitable for subsequent biological assays. It inhibited Gram-positive and Gram-negative bacteria, with MICs of 62.5 µg/mL against Staphylococcus aureus, Bacillus subtilis, and Listeria monocytogenes; 125–250 µg/mL against Escherichia coli and Salmonella typhimurium; and 500 µg/mL against Pseudomonas aeruginosa. Thymoquinone reduced biofilm formation (>80% at 25–50 µg/mL; MBIC₅₀ ≈ 5.4–11.6 µg/mL), exhibited antioxidant activity (DPPH IC₅₀ = 52.3 ± 2. 1 µg/mL; ABTS IC₅₀ = 41.6 ± 1.9 µg/mL), stabilized erythrocyte membranes (IC₅₀ ≈ 14.8 µg/mL), and inhibited carbohydrate-hydrolyzing enzymes, with stronger inhibition of α-glucosidase (~92%) than α-amylase (~84%) at 128 µg/mL. Conclusions: Thymoquinone is a major bioactive constituent of N. sativa seeds, exhibiting consistent multi-target in vitro activity. These findings highlight its functional relevance and in vivo investigations to establish therapeutic potential.

Introduction: Bacillus cereus (B. cereus) is widely distributed in natural environments, particularly in soil and plant matter, and is frequently linked to foodborne illness outbreaks, accounting for approximately 1.4%–12% of food poisoning cases worldwide. This study aimed to assess the presence of toxigenic and emetic genes among B. cereus isolates, evaluate their antibiotic susceptibility, and investigate the antimicrobial potential of Artemisia vulgaris (A. vulgaris) extract. Methods: Polymerase chain reaction (PCR) was employed to detect toxigenic and emetic genes in B. cereus isolates. Antibiotic susceptibility was tested against a panel of agents. The antimicrobial, antibiofilm, antioxidant, cytotoxic, and gene-suppressing activities of methanolic A. vulgaris extract were evaluated using standard microbiological, biochemical, and molecular assays. GC-MS and HPLC analyses were performed to identify major bioactive compounds. Results: PCR revealed that the isolates harbored hemolysin BL (HBL) genes hblA (8.62%) and hblB (20.68%), non-hemolytic enterotoxin (NHE) genes nheA (20.68%) and nheB (22.41%), as well as bceT (29.30%) and ces (15.51%) genes associated with emetic toxin production. Antibiotic testing showed high sensitivity to ciprofloxacin (91.37%) and rifampicin (96.54%), but strong resistance to ampicillin (86.20%) and novobiocin (65.51%). A. vulgaris extract demonstrated potent antibacterial activity (inhibition zones: 19.20 ± 0.25 mm to 27.10 ± 0.13 mm; MICs: 62.5–250 μg/mL), significantly inhibited biofilm formation, and downregulated toxigenic genes by −2.5 to −5.2 fold ( ^*** P < 0.0001). The extract also displayed strong antioxidant activity (IC ₅₀ : 12.7 μg/mL, DPPH; 14.2 μg/mL, ABTS) and low cytotoxicity (IC ₅₀ : 524.7 ± 1.23 μg/mL, Vero cells; 236.5 ± 1.74 μg/mL, HFB4 cells). GC-MS identified dopamine N,N-dimethyl-dimethyl ether (40.31%) and n-hexadecanoic acid (16.57%) as major compounds, while HPLC revealed high levels of chlorogenic acid, luteolin, and quercitrin. Discussion/conclusion: These findings highlight the public health risks posed by toxigenic B. cereus in food contamination. The methanolic extract of A. vulgaris exhibits strong antibacterial, antibiofilm, antioxidant, and gene-suppressing activities, supporting its potential as a natural therapeutic strategy against B. cereus and its virulence factors.

Nanostructured lipid carriers (NLCs), liposomes, and microemulsions represent significant advancements in drug delivery systems. This study aimed to synthesize NLCs encapsulating Bacillus megaterium supernatant (BMS) and magnetic nanoparticles (MNPs) for potential application against MRSA and cancer cells. The NLCs were prepared using the emulsification-solvent evaporation technique and loaded with BMS and MNPs to form NLC-BMS-MNPs. Characterization of the NLC-BMS-MNPs was performed using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential. The NLC-BMS-MNPs exhibited a spherical morphology with an average size of 74.45 nm, a polydispersity index (PDI) of 0.350, and a zeta potential of − 4.44 mV. NLC-BMS-MNPs demonstrated antibacterial activity, with minimum inhibitory concentrations (MICs) ranging from 7.5 to 30 µg/mL. They also significantly downregulated the expression of biofilm-associated genes fnbA, icaA, and cna, with fold changes ranging from − 1.9 to -3, -2 to 3, -4 to5.2, respectively (P < 0.0001). Furthermore, the formulation showed antioxidant activity, with IC₅₀ values of 299 µg/mL and 521 µg/mL in DPPH and ABTS assays, respectively. Additionally, NLC-BMS-MNPs exhibited selective cytotoxicity toward cancer cells. HepG2 and MCF-7 cells displayed significantly reduced viability, with IC₅₀ values of 13.74 ± 0.02 µg/mL and 19.12 ± 0.51 µg/mL, respectively, compared to normal Vero and HFB-4 cells, which showed IC₅₀ values of 36.1 ± 0.65 µg/mL and 33.45 ± 2.29 µg/mL. In conclusion, NLC-BMS-MNPs represent a promising multifunctional nanomaterial with potential applications in both antimicrobial and anticancer therapies.

Methicillin-resistant Staphylococcus aureus (MRSA) continues to represent a significant clinical challenge, characterized by consistently elevated rates of morbidity and mortality. Care regimen success is still difficult and necessitates assessing new antibiotics as well as supplemental services, including source control and searching for alternative approaches to combating it. Hence, we propose to synthesize silver nanoparticles (Ag-NPs) by employing a cell-free filter (CFF) of Streptomyces sp. to augment antibiotic activity and combat biofilm-forming MRSA. Seven bacterial isolates from clinical samples were identified, antibiotics were profiled with Vitek-2, and the phenotypic detecting of biofilm with Congo red medium and microplate assay was carried out. The PCR technique was used for detecting genes (icaA and icaD) coded in biofilm forming. The characterization of Ag-NPs was performed using several analytical methods, such as UV spectroscopy, dynamic light scattering (DLS), zeta potential measurement, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The antibacterial properties of Ag-NPs and oxacillin–Ag-NPs were assessed against standard strains and clinical isolates by employing the agar well diffusion technique and the microdilution assay. The biogenic synthesis Ag-NPs resulted in uniformly spherical particles, with an average size of 20 nm. These Ag-NPs demonstrated significant activity against biofilm-forming MRSA, with minimum inhibitory concentrations (MICs) ranging from 12 to 15 μg/mL. Additionally, Ag-NPs completely impede biofilm formation by MRSA at sublethal doses of 0.75 MICs. The expression levels of the icaA and icaD genes were reduced by 1.9- to 2.2- and 2.4- to 2.8-fold, respectively. A significant synergistic effect was noted when Ag-NPs were used in combination with oxacillin, leading to reduced MICs of 1.87 μg/mL for oxacillin and 4.0 μg/mL for Ag-NPs against MRSA. The FICi of 0.375 further validated the synergistic relationship between oxacillin and Ag-NPs at the concentrations of 1.87 and 4 μg/mL. Findings from the time-kill test demonstrated the highest reduction in log₁₀ (CFU)/mL of the initial MRSA inoculum after 12-hour exposure. The cytotoxicity analysis of Ag-NPs revealed no significant cytotoxic effects on the human skin cell line HFB-4 at low concentrations, with IC₅₀ values of 61.40 µg/mL for HFB-4 and 34.2 µg/mL for HepG-2. Comparable with oxacillin–Ag-NPs, Ag-NPs showed no cytotoxic effects on HFB-4 at different concentrations and exhibited an IC₅₀ value of 31.2 against HepG-2-cells. In conclusion, the biosynthesis of Ag-NPs has demonstrated effective antibacterial activity against MRSA and has completely hindered biofilm formation, suggesting a valuable alternative for clinical applications.

We aimed to investigate the potential anticonvulsant effect of green synthetized selenium nanoparticles (SeNPs) using Syzygium aromaticum extract (SAE) (SAE-SeNPs) against epileptic seizures and cortical damage induced by pentylenetetrazole (PTZ) injection in rats and its mechanism. A total of 84 rats were divided into six groups; control, PTZ-exposed group, SAE + PTZ-treated group, sodium selenite (Na₂SeO₃) + PTZ-treated group, SAE-SeNPs + PTZ-treated group, and diazepam + PTZ-treated group. SAE-SeNPs significantly increase (p < 0.05) the latency time to seizures and reduce both the seizure duration and death rate, which were enhanced by the PTZ injection. SAE-SeNPs counteracted the PTZ-induced changes in the oxidants and antioxidants. Furthermore, SAE-SeNPs significantly restored (p < 0.05) the pro-inflammatory cytokines (interleukin-1β, interleukin-6, and tumor necrosis factor-α) to their normal levels and suppressed the activity of the glial fibrillary acidic protein showing their inhibitory effect on the epilepsy-associated inflammation. In addition, SAE-SeNPs significantly reduced (p < 0.05) PTZ-induced cortical cell apoptosis, as revealed by a reduction in the pro-apoptotic Bax and caspase-3 levels, and an elevation of the anti-apoptotic Bcl-2 level. Moreover, SAE-SeNPs significantly modulate (p < 0.05) the PTZ-induced changes in the neurotransmitter norepinephrine level and acetylcholinesterase enzymatic activity. These data concluded the anticonvulsant activity of SAE-SeNPs via their antioxidant, anti-inflammatory, and anti-apoptotic effects, along with their ability to modulate neurotransmitters.

The present study evaluated the effects of Hail Salvia officinalis total extract (SOTE) and its high flavonoid fraction (SOHFF) on the high-fat diet (HFD)-induced obesity and hepatorenal damage in rats. Salvia officinalis plants were collected from Hail region, Saudi Arabia. Rats were fed HFD and supplemented orally with SOTE (250 mg kg⁻¹) or SOHFF (100 mg kg⁻¹) or simvastatin (SVS; 10 mg kg⁻¹) every day for 8 weeks. Compared to the controls, HFD-induced obesity led to significant increases in body weight, body weight gained, blood insulin, leptin, cardiac enzymes (LDH and CPK) activity, and atherogenic index (AI). HFD rats also showed higher levels of hepatic and renal function biomarkers (ALT, urea, and creatinine), as well as lower levels of PPARγ and Nrf2-gene expression and a disrupted lipid profile. Moreover, HFD rats had lower levels of hepatic and renal antioxidant biomarkers (CAT, GPx, SOD, GR, and GSH), accompanied by higher levels of hepatic and renal lipid peroxidation (LPO), nitric oxide (NO), and inflammatory mediators (interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α)). In addition, histological examination of hepatic and renal tissues revealed histopathological changes that validated the biochemical findings. Compared to HFD group, SOTE and SOHFF treatment led to marked amelioration of all the aforementioned parameters. Collectively, supplementation with SOTE and SOHFF effectively reversed HFD-induced alterations through its antioxidant, hypolipidemic, and anti-inflammatory properties. Hence, SOTE and SOHFF have therapeutic potential in controlling obesity and related pathologies.