Exploring the Antibacterial Potential of Lamiaceae Plant Extracts: Inhibition of Bacterial Growth, Adhesion, Invasion, and Biofilm Formation and Degradation in Pseudomonas aeruginosa PAO1.

In response to the global rise in antibiotic resistance and the prevalence of bacterial biofilm-related infections, the antibacterial efficacy of methanolic, ethanolic, and aqueous extracts of 18 Lamiaceae plants from Serbia was evaluated. The total coumarins and triterpenes were detected spectrophotometrically, while a microdilution assay measured their effects on bacterial growth. Additionally, the impact of these extracts was assessed on Pseudomonas aeruginosa PAO1 adhesion and invasion in human fibroblasts and biofilm formation and degradation. The alcoholic extracts had the highest phytochemical content, with Teucrium montanum and Lavandula angustifolia being the richest in coumarins and triterpenes, respectively. Gram-positive bacteria, particularly Bacillus subtilis, were more susceptible to the extracts. Hyssopus officinalis ethanolic and Sideritis scardica methanolic extracts inhibited bacterial growth the most efficiently. Although the extracts did not inhibit bacterial adhesion, most ethanolic extracts significantly reduced bacterial invasion. Origanum vulgare and H. officinalis ethanolic extracts significantly inhibited biofilm formation, while Teucrium chamaedrys extract was the most active in biofilm degradation. This study significantly contributes to the literature by examining the antibacterial activity of Lamiaceae extracts, addressing major literature gaps, and underscoring their antibacterial potential, particularly Satureja montana and O. vulgare ethanolic extracts, linking their efficacy to coumarins and triterpenes.

Leaves micromorphology, chemical profile, and bioactivity of in vitro-propagated Nepeta cyrenaica (Lamiaceae).

INTRODUCTION: The endemic species Nepeta cyrenaica Quézel & Zaffran, native to northeastern Libya, is valued as an important honey-bearing plant. OBJECTIVES: This study was aimed to examine the micromorphology, phytochemistry, and bioactivity of in vitro-propagated N. cyrenaica for the first time. MATERIALS AND METHODS: The leaf indumentum was examined using light and scanning electron microscopy and further characterised for histochemistry. The chemical composition of essential oil (EO) was performed using GC-MS analysis, while dichloromethane (DCM), methanol (ME), ethanol (ET), and aqueous (AQ) extracts were analysed using qualitative and quantitative LC/MS analyses. The antioxidant activities of EO and extracts were assessed using three parallel assays, while enzyme-inhibiting effects were evaluated against four enzymes. RESULTS: The leaves bear various types of glandular trichomes, with lipophilic secretion predominating. The main EO component of EO was 1,8-cineole. A considerable number of phenolics and iridoids were tentatively identified in the ME extract. Quantitative LC/MS analysis confirmed that ferulic acid, rosmarinic acid, and epigallocatechin gallate were present in the highest amount in the extracts, in which three iridoids were also quantified. Although the ME extract contained the highest amount of polyphenolics and iridoids, the DCM extract showed the best overall biological potential. Additionally, EO exerted the strongest acetylcholinesterase and tyrosinase inhibition. CONCLUSION: This study demonstrated that the endemic N. cyrenaica can be efficiently grown under in vitro conditions, where it develops various glandular trichomes that are thought to secrete and/or accumulate bioactive compounds with valuable medicinal potential.

The Influence of Seasonality on Secondary Metabolite Profiles and Neuroprotective Activities of Moss Hypnum cupressiforme Extracts: In Vitro and In Silico Study.

Numerous representatives of mosses, including Hypnum cupressiforme, have been used to alleviate different inflammation-related conditions. However, the mode of action underlying this anti-inflammatory potential has been poorly understood. Moreover, the influence of seasonality on the chemical composition and biological activity of mosses is generally overlooked. This study aimed to investigate the influence of seasonal changes (spring, summer, and autumn) on secondary metabolite composition and biological activities of ethyl acetate H. cupressiforme extracts. Antioxidant activity was measured using ß-carotene bleaching assay, while MTT, NBT, ELISA, and Griess assays were carried out to explore the anti-neuroinflammatory and neuroprotective potential of extracts. Inhibitory activities on acetylcholinesterase and tyrosinase were assessed experimentally and by docking analysis. The highest content of secondary metabolites and antioxidant activity were observed in moss during the summer. Extracts inhibited the secretion of ROS, NO, TNF-α, and IL-6, alleviating the inflammatory potential of H2O2 and LPS in microglial and neuronal cells. Strong inhibitory effects on acetylcholinesterase and tyrosinase were observed in vitro. Docking analyses revealed high-affinity interactions of secondary metabolites present in H. cupressiforme with important enzyme residues. Altogether, these results reveal the neuroprotective potential and the significance of seasonal fluctuations on secondary metabolite content and biological activities in moss H. cupressiforme.

A Study of Phytochemistry, Genoprotective Activity, and Antitumor Effects of Extracts of the Selected Lamiaceae Species.

This study was designed to evaluate the genoprotective, antigenotoxic, as well as antitumor potential of methanolic, ethanolic, and aqueous extracts of Melissa officinalis, Mentha × piperita, Ocimum basilicum, Rosmarinus officinalis, Salvia officinalis, and Satureja montana (Lamiaceae), in different model systems. The polyphenols in these extracts were quantified both spectrophotometrically and using HPLC-DAD technique, while DPPH assay was used to assess the antioxidant activity. The genoprotective potential was tested on pUC19 Escherichia coli XL1-blue, and the antigenotoxicity on Salmonella typhimurium TA1535/pSK1002 and human lung fibroblasts, while the antitumor activity was assessed on colorectal cancer cells. Rosmarinic acid, quercetin, rutin, and luteolin-7-O-glucoside were among the identified compounds. Methanolic extracts had the best DPPH-scavenging and SOS-inducing activities, while ethanolic extracts exhibited the highest antigenotoxicity. Additionally, all extracts exhibited genoprotective potential on plasmid DNA. The antitumor effect was mediated by modulation of reactive oxygen species (ROS), nitric oxide (NO) production, and exhibition of genotoxic effects on tumor cells, especially with O. basilicum ethanolic extract. Generally, the investigated extracts were able to provide antioxidant protection for the acellular, prokaryotic, and normal human DNA, while also modulating the production of ROS and NO in tumor cells, leading to genotoxicity toward these cells and their decrease in proliferation.