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Antibacterial and antifungal activity of aromatic constituents of essential oils
Abstract
Five aromatic constituents of essential oils (cineole, citral, geraniol, linalool and menthol) were tested for antimicrobial activity against eighteen bacteria (including Gram-positive cocci and rods, and Gram-negative rods) and twelve fungi (three yeast-like and nine filamentous). In terms of antibacterial activity linalool was the most effective and inhibited seventeen bacteria, followed by cineole, geraniol (each of which inhibited sixteen bacteria), menthol and citral aromatic compounds, which inhibited fifteen and fourteen bacteria, respectively. Against fungi the citral and geraniol oils were the most effective (inhibiting all twelve fungi), followed by linalool (inhibiting ten fungi), cineole and menthol (each of which inhibited seven fungi) compounds.
... Peppermint oil and menthol have mild antibacterial effects against both Gram-positive and Gram-negative bacteria (El-Kady, 2003). Peppermint extracts are bacteriostatic against Streptococcus thermophilus and Lactobacillus bulgaricus (Pattnaik, 2007). Menthol is bactericidal against strains like Staphylococcus pyogenes, S. aureus, Streptococcus pyogenes, Serratia marcescens, Escherichia coli, and Mycobacterium avium (Pattnaik, 2007). ...
... Peppermint extracts are bacteriostatic against Streptococcus thermophilus and Lactobacillus bulgaricus (Pattnaik, 2007). Menthol is bactericidal against strains like Staphylococcus pyogenes, S. aureus, Streptococcus pyogenes, Serratia marcescens, Escherichia coli, and Mycobacterium avium (Pattnaik, 2007). Menthol and peppermint oil are fungicidal against Candida albicans, Aspergillus albus and dermatophytic fungi (El-Kady, 2003). ...
Plants have formed the basis of sophisticated traditional medicine system and natural products make excellent leads for new drug development (Newman et al, 2007). Many plants in Africa are medicinal. The use of medicinal natural plants predates the establishment of antibiotics and other modern drugs into the African continent. The antibacterial activity of Mentha piperita and a synthetic antibiotic (Gentamycin) on a clinical isolate of Staphylococcus aureus was evaluated in vivo using albino rats. Thirty two (32) male and female rats with weight ranging from 60-150g were purchased, housed, fed and nurtured for 14days of acclimatization before experiment commenced. Sixteen (16) albino (4 groups containing 4 rats each) was used for toxicological study (LD 50) which was determined to be 56568.54 mg/kg. Then the other 16rats were grouped into 4groups having 4rats each for in vivo antibacterial testing and were inoculated with 0.1 ml growing broth culture of Staphylococcus aureus. Blood was collected from the rats prior, during and after inoculation and treatment for septicemia. Treatment was done by administering 1ml of Gentamycin (equivalent to 4mg) to rat group D and 25980.75 mg/kg of purified aqueous plant extract to group B rats, Group C rats weren't given any treatment while group A rats were only fed with feed and water. Results indicated that the extract of Mentha piperita leaves possesses moderate antibacterial activity but lesser than the antibiotic Gentamycin popularly used in antibacterial therapy. This result has shown the relative potency of Mentha piperita against Staphylococcus aureus bacteria that causes Septicemia in vivo. Hence cannot substitute for antibiotics but their treatment maybe useful to intensify and strengthen the effects of antibiotics on pathogenic Staphylococcus aureus.
... Furthermore, monoterpenes may induce oxidative stress within bacterial cells, causing irreversible damage to proteins and nucleic acids [114]. Additionally, linalool, as monoterpene alcohol poses antibacterial and antifungal properties [151], as well as antioxidant [152]. Its action primarily involves disrupting the integrity of bacterial cell membranes, increasing membrane permeability, which leads to leakage of essential intracellular components such as ions, nucleotides, and ATP. ...
The increase in antimicrobial resistance (AMR) is a major global health problem with implications on human and veterinary medicine, as well as food production. In the poultry industry, the overuse and misuse of antimicrobials has led to the development of resistant or multi-drug resistant (MDR) strains of bacteria such as Salmonella spp., Escherichia coli and Campylobacter spp., which pose a serious risk to meat safety and public health. The genetic transfer of resistance elements between poultry MDR bacteria and human pathogens further exacerbates the AMR crisis and highlights the urgent need for action. Traditional methods of preserving poultry meat, often based on synthetic chemicals, are increasingly being questioned due to their potential impact on human health and the environment. This situation has led to a shift towards natural, sustainable alternatives, such as plant-derived compounds, for meat preservation. Essential oils (EOs) have emerged as promising natural preservatives in the poultry meat industry offering a potential solution to the growing AMR problem by possessing inherent antimicrobial properties making them effective against a broad spectrum of pathogens. Their use in the preservation of poultry meat not only extends shelf life, but also reduces reliance on synthetic preservatives and antibiotics, which contribute significantly to AMR. The unique chemical composition of EOs, that contains a large number of different active compounds, minimizes the risk of bacteria developing resistance. Recent advances in nano-encapsulation technology have further improved the stability, bioavailability and efficacy of EOs, making them more suitable for commercial use. Hence, in this manuscript, the recent literature on the mechanisms of AMR in the most important Gram-negative poultry pathogens and antimicrobial properties of EOs on these meat isolates was reviewed. Additionally, chemical composition, extraction methods of EOs were discussed, as well as future directions of EOs as natural food preservatives. In conclusion, by integrating EOs into poultry meat preservation strategies, the industry can adopt more sustainable and health-conscious practices and ultimately contribute to global efforts to combat AMR.
... Furthermore, viridiflorol demonstrated strong anticancer activity against the Daoy cells and MCF-7 [32] and is widely utilized as an antioxidant, anti-tuberculosis, and anti-inflammatory agent [33]. Linalool has also been found to exhibit anti-inflammatory [34,35], antimicrobial [36][37][38][39], anticancer [40], and neuroprotective activities [41]. ...
The objective of this study was to analyze the chemical composition and evaluate the biological capabilities of the essential oils (EOs) extracted from leaves and stems of wild Aeschynomene indica L. plants by the hydrodistillation method. By using GC-FID/MS, fifty-six and fifty-five compounds, representing 95.1 and 97.6% of the essential oils in the leaves and stems, respectively, were characterized. The predominant constituents of A. indica EOs were (E)-caryophyllene, linalool, viridiflorol, phytol, hexadecanoic acid, trans-verbenol, and α-guaiene. The antibacterial and synergistic activities of the EOs were assessed by microdilution and checkerboard assays. The results revealed a potent inhibition and bactericidal activity against Staphylococcus aureus and Bacillus subtilis with MICs of 0.312–0.625 mg/mL. When combined with traditional antibiotics, the essential oils of A. indica possessed excellent synergistic effects against all tested bacteria. Additionally, the EOs of A. indica leaves showed higher antioxidant activity (IC50 = 0.11 ± 0.01 µg/mL) compared to the stem oil (IC50 = 0.19 ± 0.01 µg/mL) using the ABTS radical scavenging assay. The in vitro cytotoxicity of EOs against human cancer cell lines HepG2, MCF-7, A-549, and HCT-116 was examined, and MTT assays showed that the EOs possessed a significant cytotoxic potential against MCF-7 breast cancer cells, with IC50 values of 10.04 ± 1.82 and 15.89 ± 1.66 μg/mL, and a moderate cytotoxic activity against other tested cells. In conclusion, the A. indica EOs could be considered a potential source of pharmacologically active compounds.
... Bioceramics can be credited with a significant portion of the boom in demand for biomaterials [13]. First-generation bioceramics were bioinert, while second-generation bioceramics are bioactive and can be loaded with therapeutic species for targeted treatment [14,15]. Examples of bioinert bioceramics are alumina, zirconia, and pyrolytic carbon. ...
Carbonate hydroxyapatite is the common derivative of hydroxyapatite found in living systems. It is the building block of most hard tissues, including the teeth and bones. A vast majority of the applications of this versatile material focus on its biomedical applications, which is attributable to its closeness to biological apatites. Hydroxyapatite is a strong precursor to carbonate apatite in nature, and many experiments show that both are similar in a few respects. A significant divergence point is carbonate's obvious impact on its physicochemical properties and concomitant applications. The inclusion of carbonate ions into the lattice of hydroxyapatite results in morphological and physicochemical changes that vary with the method of synthesis and extent of substitution. The unique crystal structure, improved surface area, and porous morphology of carbonate hydroxyapatites also make it useful for catalysis and environmental remediation as adsorbents for heavy metals. This review briefly examines carbonate hydroxyapatite, its synthesis, its modification, and its characterization. It also highlights its biomedical applications while drawing attention to its non-medical potential.
... The antifungal mechanism revealed that camphor could cause the destruction of the plasma membrane, leading to an increase in membrane permeability and a release of intracellular macromolecules, such as nucleic acids and proteins [52]. Other studies have shown that cineole, thymol, carvacrol and linalool exhibit antifungal effect against several fungi [69,70]. In addition, Zuzarte et al. [68] tested the main constituents of essential oils (1,8-cineole, fenchone and camphor), for antifungal activity. ...
... Log(menthol) have been shown to decrease the survival of fruit flies (92). Last, menthol is toxic to a variety of organisms, including fungi and bacteria, suggesting that TRPM8 activation by menthol may have played an important role in early chemical defense mechanisms (93)(94)(95). ...
Transient receptor potential melastatin 8 (TRPM8) is a temperature- and menthol-sensitive ion channel that contributes to diverse physiological roles, including cold sensing and pain perception. Clinical trials targeting TRPM8 have faced repeated setbacks predominantly due to the knowledge gap in unraveling the molecular underpinnings governing polymodal activation. A better understanding of the molecular foundations between the TRPM8 activation modes may aid the development of mode-specific, thermal-neutral therapies. Ancestral sequence reconstruction was used to explore the origins of TRPM8 activation modes. By resurrecting key TRPM8 nodes along the human evolutionary trajectory, we gained valuable insights into the trafficking, stability, and function of these ancestral forms. Notably, this approach unveiled the differential emergence of cold and menthol sensitivity over evolutionary time, providing a fresh perspective on complex polymodal behavior. These studies provide a paradigm for understanding polymodal behavior in TRPM8 and other proteins with the potential to enhance our understanding of sensory receptor biology and pave the way for innovative therapeutic interventions.
Bidens pilosa also known as blackjack, Spanish needles, or beggar’s ticks, is native to central and southern America but has drastically spread to other parts of the world including Europe, Asia, and Africa. Its folklore use as a traditional herb and food supplement has been noted for many years, which triggered research interest in its phytochemistry and possible pharmacological actions. Phytochemical screening of different solvent extracts of B. pilosa has revealed the presence of many phytocompounds of pharmacological importance. In the present review paper, some of the phytochemicals belonging to polyacetylenes, flavonoids, terpenes, steroids, alkaloids, phenolics, and coumarins present in the different solvent extracts of the plant parts or whole plant have been considered to exert a range of therapeutic actions such as analgesic, antipyretic, anti-inflammatory, anti-hemorrhoid, anti-bacterial, antioxidant, anti-diabetic, anti-cancer, anti-ulcer, anti-malarial, hepatoprotective, diuretic, anti-allergy, anti-angiogenic and anti-fungal effects. This review discusses the pharmacological actions of active secondary metabolites in B. pilosa and their potential mechanisms contributing to specific pharmacological actions.
Graphical Abstract
Aromatherapy is a medical practice that uses aromatic compounds or essential oils to influence mood and health. Essential oils used in aromatherapy are created from a wide variety of medicinal plants, flowers, herbs, roots, and trees that are found all over the world and have significant, well-documented benefits on enhancing physical, emotional, and spiritual wellbeing.
This book is a comprehensive reference on aromatic compounds present in essential oils and their therapeutic use. Starting from fundamentals of essential oil biosynthesis the book guides the reader through their basic biochemistry, toxicology, profiling, blending and clinical applications. The concluding chapters also present focused information about the therapeutic effects of essential oils on specific physiological systems, plant sources, skin treatment and cancer therapeutics.
The combination of basic and applied knowledge will provide readers with all the necessary information for understanding how to develop preclinical formulations and standard clinical therapies with essential oils. This is an essential reference for anyone interested in aromatherapy and the science of essential oils.
