Aug 2026· Pharmaceuticals· Vol 19, pp. 1256· 0 citations· 78 references
Medicine
TL;DR
Despite its distinct entomological origin, blue geopropolis shared chemical traits with green and red propolis while demonstrating superior Gram-positive antibacterial activity, a higher selectivity index, and potential antifungal applications against Sporothrix spp.
Abstract
Background/Objectives: This study characterized blue geopropolis from Melipona quadrifasciata quadrifasciata (southern Brazil) by comparing its chemical composition, cytotoxicity, antimicrobial activity, and coloration mechanisms directly against green and red Apis mellifera propolis under identical experimental conditions. Methods: Ethanolic extracts of blue geopropolis, green, and red propolis were prepared, followed by hexane and chloroform fractionation. Chemical composition was analyzed by LC-qTOF-MS. Cytotoxicity was assessed in L929 fibroblasts, and antimicrobial activity was determined by minimum inhibitory concentration (MIC) assays against bacterial and fungal strains. The blue coloration was investigated using NaOH and FeCl3 treatments to evaluate the possible involvement of phenolic–iron complexes. Results: Fifty-nine compounds were identified across the three samples, revealing several shared phenolic constituents as well as distinctive chemical features. None of the extracts showed activity against Gram-negative bacteria, including Escherichia coli and Pseudomonas aeruginosa (MIC > 1000 µg/mL). In contrast, activity was observed against Gram-positive bacteria, with MIC values ranging from 20.8 to 1000 µg/mL. Among the samples tested, blue geopropolis showed the strongest activity against Gram-positive bacteria. Blue geopropolis exhibited no significant activity against Candida albicans or Candida parapsilosis (MFC > 1000 µg/mL) but showed variable activity against Sporothrix spp. The colorimetric assay indicated that phenolic–iron complexation may contribute to the blue color. Conclusions: Despite its distinct entomological origin, blue geopropolis shared chemical traits with green and red propolis while demonstrating superior Gram-positive antibacterial activity, a higher selectivity index, and potential antifungal applications against Sporothrix spp., highlighting its promise for biotechnological and pharmacological use.
Background/Objectives: Dittrichia viscosa (L.) W. Greuter (Asteraceae) is a Mediterranean medicinal plant whose polar phenolic fraction remains insufficiently characterized. This study aimed to characterize the phenolic composition and evaluate the antioxidant, antimicrobial, and mechanistic bioactivity of aqueous and methanolic leaf extracts collected from the Rmilate Forest in Tangier, northern Morocco. Methods: Extracts were characterized by ICP-AES for elemental content and by HPLC-PDA-ESI-MS for phenolic annotation, and total phenolic, flavonoid, and tannin contents were quantified. Antioxidant capacity was assessed using DPPH, ABTS, FRAP, and ORAC assays. Antibacterial activity was evaluated against four reference strains, with time–kill kinetics and membrane integrity assays used to probe the mechanism of action, and antifungal activity was tested against dermatophytic and phytopathogenic fungi. Molecular docking against four bacterial, fungal, and antioxidant enzyme targets and ProTox-3 toxicity prediction were also performed. Results: ICP-AES revealed high concentrations of calcium (12,476.75 mg/kg) and potassium (29,699 mg/kg). The methanolic extract showed higher total phenolic (55.05 mg GAE/g), flavonoid (84.18 mg QE/g), and tannin (262.1 mg TAE/g) contents and superior antioxidant activity (DPPH IC50: 0.090 mg/mL). Twelve phenolic compounds were tentatively annotated, including caffeic acid, caffeoylquinic acid derivatives, and quercetin/kaempferol glycosides. Antibacterial activity (MIC: 0.25–1 mg/mL) was consistent with cell envelope disruption, and up to 88% mycelial inhibition was achieved against Trichophyton rubrum. Docking ranked kaempferol-3-O-pentoside (−10.3 kcal/mol) among the top-scoring ligands, and the top compounds were assigned to toxicity class 5. Conclusions: D. viscosa is a promising source of bioactive phenolics for pharmaceutical and agrochemical development.
Bahia Abdelfattah, Oussama Khibech, A. Mrabet et al.· Pharmaceuticals· 0 citations
Eucalyptus globulus Labill essential oil was chemically characterized and evaluated for selected biological activities using integrated in vitro assays supported by exploratory in silico analysis. GC–MS profiling identified 8 constituents, with 1,8-cineole (eucalyptol) representing 90.51% of the total composition, indicating a cineole-dominant chemical profile. Antibacterial screening was performed against three clinical isolates and three reference strains, representing Gram-positive and Gram-negative bacteria. The essential oil produced inhibition zones ranging from 24.3 to 38.8 mm, with minimum inhibitory concentrations (MICs) of 62.5 to 125 µg/mL, depending on the strain. Biofilm biomass testing demonstrated concentration-dependent inhibition, with the strongest reduction observed for Pseudomonas aeruginosa (61.35% at 0.5 MIC). Antioxidant evaluation using DPPH and ABTS assays revealed dose-dependent radical scavenging activity. Cytotoxicity screening in Caco-2 and HepG2 cell lines showed concentration-dependent responses with IC₅₀ values of 24.4 ± 0.15 and 59.52 ± 0.35 µg/mL, respectively. Molecular docking suggested moderate interaction of eucalyptol with bacterial DNA gyrase through hydrophobic contacts and hydrogen bonding. This study provides integrated chemical and functional characterization of Eucalyptus globulus Labill oil and supports further investigation of eucalyptus-derived volatile compositions in antimicrobial and biofilm-control research, while indicating that additional pharmacological, selectivity, and in vivo studies are required before translational application.
Antimicrobial resistance is a growing global health challenge, highlighting the need for new bioactive compounds from medicinal plants. Vepris nobilis is traditionally used in East Africa for treating infections and respiratory disorders; however, its essential oil (EO) composition and antimicrobial mechanisms remain poorly characterized. This study investigated the chemical composition and antimicrobial activity of V. nobilis EO, along with an in silico evaluation of its major constituent, germacrene D. The EO was extracted by hydrodistillation and analyzed using gas chromatography-mass spectrometry (GC–MS). Its antimicrobial activity was evaluated against 26 bacterial and 4 fungal strains using disc diffusion, broth microdilution, and MBC/MFC (Minimum Bactericidal Concentration/Minimum Fungicidal Concentration) assays. Germacrene D showed stronger activity than the EO, particularly against both multidrug resistant (MDR) and non-MDR Gram-negative bacterial strains (MIC = 10 µg/mL), with bactericidal and fungicidal effect. Molecular docking of germacrene D against two clinically relevant enzymes—dehydrosqualene synthase (CrtM) from Staphylococcus aureus and SWISS-modeled sterol 14-α-demethylase (CYP51) from Penicillium funiculosum—suggested potential interactions with both targets, with a favorable predicted binding affinity for CrtM (−7.654 kcal/mol) and for CYP51 (−5.898 kcal/mol). These findings provide preliminary insights into a possible antimicrobial mechanism, although experimental validation is needed to confirm this hypothesis. ADMET analysis suggested favorable drug-like properties despite limited solubility. These findings provide scientific support for the traditional use of V. nobilis leaves in the treatment of respiratory infections and highlight germacrene D as a promising lead compound for further antimicrobial development.
Unknown authors· International Journal of Mol...· 0 citations
The growing prevalence of antimicrobial resistance and cancer has intensified interest in natural products as sources of biologically active compounds with potential pharmaceutical relevance. In this study, the phytochemical composition of the methanolic extract of Artemisia abyssinica aerial parts (MEAA) was comprehensively characterized using liquid chromatography–tandem mass spectrometry (LC–MS/MS) and gas chromatography–mass spectrometry (GC–MS), and its in vitro antimicrobial, antioxidant, cytotoxic, and molecular docking properties were evaluated. LC–MS/MS analysis revealed a diverse profile dominated by flavonoids and phenolic compounds, including myricetin, quercetin, apigenin derivatives, hispidulin, and taxifolin, while GC–MS analysis tentatively identified several non-polar constituents, with gitoxigenin as a putative major component. MEAA exhibited moderate antibacterial activity against Micrococcus luteus (inhibition zone 15 mm; MIC = 2 mg/mL) and moderate activity against Streptococcus pneumoniae and Escherichia coli. The extract demonstrated weak antioxidant activity in the DPPH assay (IC50 = 268.15 µg/mL) and moderate cytotoxicity against HepG-2 hepatocellular carcinoma cells (IC50 = 59.2 µg/mL) compared with Adriamycin (IC50 = 6.9 µg/mL). Molecular docking was employed to provide supportive structural insights, suggesting that selected flavonoids, particularly myricetin, apigenin, and hispidulin, may interact favorably with DNA gyrase, epidermal growth factor receptor, and urease. Overall, this study provides an analytical and biological profile of MEAA and highlights its phytochemical richness and early-stage bioactivity, supporting its relevance for further pharmaceutical investigation as well as its potential as a natural bioresource for future applications.
Abdu Aldarhami, Suliman A. Alderhami, Hassen Harzali et al.· Bioresources and Bioprocessi...· 0 citations
Medicinal Plants are a rich source of bioactive compounds having anti-microbial properties and effectiveness against infectious diseases, have a greater affinity to mitigate antibiotic resistance, and to produce alternative, economical veterinary therapeutics. This study aimed to determine the phytochemical composition of Azadirachta Indica, Melia Azedarach, Withania Coagulans, and Nigella Sativa, and their antimicrobial properties against E. coli O157:H7. The plants were sequentially extracted using hydro-methanolic solvent. Phenolic acids (Gallic acid, Sinapic acid, Caffeic acid) and Flavonols (Myricetin, Quercetin, Kaempferol) were quantified using Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC). Antibacterial activity was assessed using the Agar Well diffusion assay at concentrations of 100–400 mg/mL, with ciprofloxacin as the positive control. HPLC revealed gallic acid as the predominant phenolic compound in A. indica (83.28%), M. azedarach (83.36%), and W. coagulans (98.61%), while sinapic acid dominated in N. sativa (74.59%). Flavonol composition varied, with kaempferol highest in A. indica (80.84%), myricetin in M. azedarach (63.08%) and N. sativa (100%), and quercetin in W. coagulans (65.92%). Antibacterial activity was dose-dependent, with the hydro-methanolic extract showing the highest activity at 400 mg/mL. M. azedarach exhibited the largest inhibition zone (12.21 ± 1.16 mm), followed by N. sativa (9.03 ± 1.47 mm), A. indica (8.98 ± 1.97 mm), and W. coagulans (8.81 ± 1.39 mm). The study concluded that the medicinal plants used were rich in phenolic compounds, showing strong antimicrobial properties against E. coli O157:H7, and can be used as a promising candidate for an affordable antibiotic alternative.
A. Khan, Muhammad Muneeb, A. Shaukat et al.· Kashmir Journal of Academic...· 0 citations
It is suggested that homoeopathic preparations of Hydrocotyle asiatica possess measurable antimicrobial properties and favorable pharmacokinetic drug properties and provides a scientific rationale for its potential as a source of bioactive antimicrobial agents.
Rekhit Rakesh Jain, K. Das, Priyanka Chourasia et al.· Homœopathic Links· 0 citations
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