Antibacterial, Antibiofilm and Anti-Inflammatory Activities of Eugenol Clove Essential Oil against Resistant Helicobacter pylori

Tiryāq in traditional Persian medicine: a survey of antidotal plants and their modern pharmacological potential

Purpose

Tiryāq (Theriac) refers to a single or compound medication historically utilized as a general antidote against numerous poisons in several ethnomedical traditions, especially in traditional Persian medicine (PM). This study aims to summarize the traditional uses, phytochemistry, and pharmacological activities of medicinal plants with tiryāq properties, with a particular focus on their anti-hepatotoxic, hepatoprotective, neuroprotective, and cardioprotective activities.

Methods

Classical texts of traditional PM were broadly reviewed to extract information about tiryāq and its mechanisms. In addition, a detailed search of scientific databases was performed to validate the pharmacological properties of plants traditionally recognized for their antidotal effects.

Results

Thirty-one medicinal plants with antidote properties were identified. The primary function of tiryāq, as described in PM, is to neutralize toxins and bolster the immune system. These plants have cardiotonic, hepatoprotective, and neuroprotective properties. In addition to their antidotal applications, tiryāq remedies were traditionally used to manage chronic cough, stomachache, asthma, colic, and other ailments. Modern pharmacological studies support these applications, highlighting the plants' antiviral, immunomodulatory, and antioxidant properties, especially against acute respiratory viral infections and other inflammatory circumstances.

Conclusion

Tiryāq plays a pivotal role in fortifying essential organs, including the heart, brain, and liver. Its prophylactic use during epidemics, along with its antioxidant and immune-stimulating properties, underscores its therapeutic potential. Further research is needed to conclusively determine the efficacy and broader therapeutic applications of medicinal plants with tiryāq properties.

Edible and herbal plants against Helicobacter pylori infection: From epidemiological, experimental studies to clinical perspectives

Helicobacter pylori (H. pylori) infection is an important global public health concern, causing conditions like gastritis, gastroduodenal ulcers, gastric lymphoma, distal gastric cancer and other gastric diseases. With the increasing prevalence of antibiotics resistance, the cure rate of antibiotics-based triple or quadruple therapy has declined to 80 % or less. Moreover, side effects still remain. Hence, alternative, more potent and safer anti-H. pylori medications are required. Numerous studies have indicated that natural products from medical plants are valuable repositories for the prevention of H. pylori infection with advantages in little side effects due to the co-evolution with biological systems for millions of years. In this review, we highlighted the anti-H. pylori activities and the responsive mechanism of edible and medical plants based on epidemiological, experimental, and clinical studies, providing the basis for future development of functional foods or drugs against H. pylori.

Neuroprotective Properties of Clove (Syzygium aromaticum): State of the Art and Future Pharmaceutical Applications for Alzheimer's Disease

This study explores the neuropharmacological potential of various molecular and amino acid components derived from Syzygium aromaticum (clove), an aromatic spice with a long history of culinary and medicinal use. Key bioactive compounds such as eugenol, α-humulene, β-caryophyllene, gallic acid, quercetin, and luteolin demonstrate antioxidant, anti-inflammatory, and neuroprotective properties by scavenging free radicals, modulating calcium channels, and reducing neuroinflammation and oxidative stress. Moreover, gallic acid and asiatic acid may exhibit protective effects, including neuronal apoptosis inhibition, while other useful properties of clove phytocompounds include NF-κB pathway inhibition, membrane stabilization, and suppression of pro-inflammatory pathways, possibly in neurons or other relevant cell types, further contributing to neuroprotection and cognitive enhancement. Amino acid analysis revealed essential and non-essential amino acids such as aspartic acid, serine, glutamic acid, glycine, histidine, and arginine in various clove parts (buds, fruits, branches, and leaves). These amino acids play crucial roles in neurotransmitter synthesis, immune modulation, antioxidant defense, and metabolic regulation. Collectively, these bioactive molecules and amino acids contribute to clove's antioxidant, anti-inflammatory, neurotrophic, and neurotransmitter-modulating effects, highlighting its potential as a preventive and therapeutic candidate for neurodegenerative disorders. While preliminary preclinical studies support these neuroprotective properties, further research, including clinical trials, is needed to validate the efficacy and safety of clove-based interventions in neuroprotection.

Evaluating the multifaceted bioactivity of Syzygium aromaticum essential oil: the central role of eugenol

Background/aim

Syzygium aromaticum L. is a versatile plant traditionally used to treat digestive and respiratory issues, improve oral health, and relieve pain, particularly in regions such as Southeast Asia, South Asia, and parts of the Middle East. Its essential oil (EO), predominantly composed of eugenol, is rich in bioactive compounds. This study aims to clarify the specific contribution of eugenol to the antioxidant, antibacterial, antifungal, and insecticidal activities of S. aromaticum EO by comparing their individual effects. Additionally, density functional theory (DFT) calculations were employed to examine the antioxidant mechanism of eugenol and its role in enhancing the overall activity of the EO.

Materials and methods

The EO was obtained from S. aromaticum and analyzed using GC-MS to determine its composition. Antioxidant activity was assessed through the DPPH scavenging assay. Antibacterial and antifungal activities were evaluated using the disk diffusion method against various strains, while insecticidal and repellent effects were tested on Bruchus lentis at different concentrations and exposure times. Antioxidant mechanisms were investigated using DFT calculations.

Results

The findings underscore the strong antioxidant, antibacterial, antifungal, and insecticidal properties of S. aromaticum EO, with eugenol identified as the primary active component driving the antioxidant and insecticidal effects. Additionally, eugenol has been found to exhibit moderate scavenging activity in lipid media. However, its activity is higher in polar media, with a k overall = 1.70 ⊠ 106 M-1s-1 comparable to that of ascorbic acid. The single-electron transfer mechanism from the deprotonated state was found to play a decisive role under these conditions.

Conclusion

S. aromaticum EO exhibits remarkable antioxidant, antibacterial, antifungal, and insecticidal activities. A significant portion of these properties can be attributed to the presence of eugenol. This suggests that eugenol plays a critical role in the EO's overall efficacy, making S. aromaticum a promising candidate for applications in natural health products, pharmaceuticals, and agricultural pest management.

Antibacterial, antioxidant, cytotoxicity, and phytochemical screening of Moringa oleifera leaves

Bacterial resistance to antibiotics remains a significant clinical challenge, contributing to persistently high rates of morbidity and mortality. Achieving treatment success is increasingly difficult, necessitating the evaluation of new antibiotics and complementary approaches, including source control and alternative therapies. This study aimed to investigate the antibacterial, antioxidant, cytotoxic, and phytochemical properties of Moringa oleifera leaf extract using high-performance liquid chromatography (HPLC), and to evaluate the pharmacokinetic properties of its major compound. The extract demonstrated strong antibacterial activity against standard strains and foodborne bacterial species. It also showed significant antioxidant potential, supported by the presence of high concentrations of phenolic and flavonoid compounds. HPLC analysis identified multiple bioactive compounds, with quercetin as the predominant component. The cytotoxicity study confirmed the safety of the extract at low and moderate concentrations, and ADMET analysis indicated favorable pharmacokinetic characteristics of quercetin. In conclusion, Moringa oleifera exhibits promising potential for medical and food industry applications due to its significant antibacterial and antioxidant activities, combined with a strong safety profile and rich phytochemical content.

Insights into molecular mechanisms of phytochemicals in quorum sensing modulation for bacterial biofilm control

Biofilm formation is a common mechanism by which bacteria undergo phenotypic changes to adapt to environmental stressors. The formation of biofilms has a detrimental impact in clinical settings by contributing to chronic infections and promoting antibiotic resistance. Delving into the molecular mechanisms, the quorum sensing (QS) system involves the release of chemical signals for bacterial cell-to-cell communication, which activates and regulates the expression of various genes and virulence factors, including those related to biofilm formation. Accordingly, the QS system becomes a potential target for combating biofilm-associated concerns. Natural products derived from plants have a long history of treating infectious diseases in humans due to their antimicrobial properties, making them valuable resources for screening anti-biofilm agents. This review aims to discover the mechanisms by which phytochemical agents inhibit QS, potentially offering promising new therapies for treating biofilm-associated infections. By targeting the QS system, these phytochemical agents can prevent bacterial aggregation and biofilm formation while also diminishing other bacterial virulence factors. Additionally, it is important to focus on the advancement of techniques and experiments to investigate their molecular mechanisms. A thorough understanding of these mechanisms may encourage further studies to evaluate the safety and efficacy of phytochemical agents used alone or in combination with other strategies.

Combating bacterial biofilms and related drug resistance: Role of phyto-derived adjuvant and nanomaterials

The emergence of antimicrobial resistance (AMR) in clinical microbes has led to a search for novel antibiotics for combating bacterial infections. The treatment of bacterial infections becomes more challenging with the onset of biofilm formation. AMR is further accelerated by biofilm physiology and differential gene expression in bacteria with an inherent resistance to conventional antibiotics. In the search for innovative strategies to control the spread of AMR in clinical isolates, plant-derived therapeutic metabolites can be repurposed to control biofilm-associated drug resistance. Unlike antibiotics, designed to act on a single cellular process, phytochemicals can simultaneously target multiple cellular components. Furthermore, they can disrupt biofilm formation and inhibit quorum sensing, offering a comprehensive approach to combat bacterial infections. In bacterial biofilms, the first line of AMR is due to biofilms associated with the extracellular matrix, diffusion barriers, quorum sensing, and persister cells. These extracellular barriers can be overcome using phytochemical-based antibiotic adjuvants to increase the efficacy of antibiotic treatment and restrict the spread of AMR. Furthermore, phytochemicals can be used to target bacterial intracellular machinery such as DNA replication, protein synthesis, efflux pumps, and degrading enzymes. In parallel with pristine phytochemicals, phyto-derived nanomaterials have emerged as an effective means of fighting bacterial biofilms. These nanomaterials can be formulated to cross the biofilm barriers and function on cellular targets. This review focuses on the synergistic effects of phytochemicals and phyto-derived nanomaterials in controlling the progression of biofilm-related AMR. IT provides comprehensive insights into recent advancements and the underlying mechanisms of the use of phyto-derived adjuvants and nanomaterials.

Molecular Insights on Coffee Components as Chemical Antioxidants

Coffee is not only a delicious beverage but also an important dietary source of natural antioxidants. We live in a world where it is impossible to avoid pollution, stress, food additives, radiation, and other sources of oxidants that eventually lead to severe health disorders. Fortunately, there are chemicals in our diet that counteract the hazards posed by the reactive species that trigger oxidative stress. They are usually referred to as antioxidants; some of them can be versatile compounds that exert such a role in many ways. This review summarizes, from a chemical point of view, the antioxidant effects of relevant molecules found in coffee. Their mechanisms of action, trends in activity, and the influence of media and pH in aqueous solutions, are analyzed. Structure-activity relationships are discussed, and the protective roles of these compounds are examined. A particular section is devoted to derivatives of some coffee components, and another one to their bioactivity. The data used in the analysis come from theoretical and computational protocols, which have been proven to be very useful in this context. Hopefully, the information provided here will pro-mote further investigations into the amazing chemistry contained in our morning coffee cup.   Resumen. El café no solo es una bebida deliciosa, sino también una importante fuente dietética de antioxidantes naturales. Vivimos en un mundo donde es imposible evitar la contaminación, el estrés, los aditivos alimentarios, la radiación y otras fuentes de oxidantes que eventualmente conducen a trastornos de salud graves. Afortunadamente, existen sustancias químicas en nuestra dieta que contrarrestan los peligros planteados por las especies reactivas que desencadenan el estrés oxidativo. Por lo general, se les denomina antioxidantes; algunos de ellos pueden ser compuestos versátiles que ejercen dicho papel de muchas maneras. Este artículo de revisión resume, desde un punto de vista químico, los efectos antioxidantes de moléculas relevantes encontradas en el café. Se analizan sus mecanismos de acción, tendencias en la actividad y la influencia del medio y el pH en soluciones acuosas. Se discuten las relaciones estructura-actividad, y se examinan los roles protectores de estos compuestos. Se dedica una sección particular a los derivados de algunos componentes del café, y otra a su bioactividad. Los datos utilizados en el análisis provienen de protocolos teóricos y computacionales, que han demostrado ser muy útiles en este contexto. Se espera que la información proporcionada aquí promueva investigaciones futuras sobre la química contenida en nuestra taza de café matutina.

Clove essential oil and its major component, eugenol: a comparative study of their in vitro antioxidant and anticancer properties

Syzygium aromaticum L. (clove) is a species native to subtropical countries. Its dried flower buds are rich in essential oils, which have shown insecticidal, anti-inflammatory and anaesthetic effects. This work was aimed to study the differences in antioxidant and anticancer activities between clove essential oil (CEO) and its major component, eugenol. The chemical composition of the CEO was determined by GC-MS. The physicochemical properties and antioxidant activity were determined in CEO and eugenol. Finally, anticancer activities were assayed against seven cell lines. Chemical analysis revealed that 80% of the CEO was eugenol. The density and IR were similar, and the colour was ΔE*>3. CEO had a lower phenolic content, but similar antioxidant activity to eugenol. The anticancer activity of the CEO was greater than that of eugenol in all the cell lines except for HeLa cells. These results suggest that secondary compounds in CEO enhance its antioxidant and -anticancer activities.

Impact of eugenol on biofilm development in Shigella flexneri 1457: a plant terpenoid based-approach to inhibit food-borne pathogen

Shigella flexneri is a gram-negative bacterium responsible for shigellosis and bacterial dysentery. Despite using various synthetic antimicrobial agents and antibiotics, their efficacy is limited, prompting concerns over antibiotic resistance and associated health risks. This study investigated eugenol, a polyphenol with inherent antioxidant and antibacterial properties, as a potential alternative treatment. We aimed to evaluate eugenol's antibacterial effects and mechanisms of action against S. flexneri and its impact on biofilm formation. We observed significant growth suppression of S. flexneri with eugenol concentrations of 8-10 mM (98.29%). Quantitative analysis using the Crystal Violet assay demonstrated a marked reduction in biofilm formation at 10 mM (97.01 %). Assessment of Cell Viability and morphology via Fluorescence-Activated Cell Sorting and Scanning Electron Microscopy confirmed these findings. Additionally, qPCR analysis revealed the downregulation of key genes responsible for adhesion (yebL), quorum sensing (rcsC, sdiA), and EPS production (s0482) associated with bacterial growth and biofilm formation. The present study suggests eugenol could offer a promising alternative to conventional antibiotics for treating shigellosis caused by S. flexneri.

Bioactivity of Eugenol: A Potential Antibiotic Adjuvant with Minimal Ecotoxicological Impact

Combining commercial antibiotics with adjuvants to lower their minimum inhibitory concentration (MIC) is vital in combating antimicrobial resistance. Evaluating the ecotoxicity of such compounds is crucial due to environmental and health risks. Here, eugenol was assessed as an adjuvant for 7 commercial antibiotics against 14 pathogenic bacteria in vitro, also examining its acute ecotoxicity on various soil and water organisms (microbiota, Vibrio fischeri, Daphnia magna, Eisenia foetida, and Allium cepa). Using microdilution methods, checkerboard assays, and kinetic studies, the MICs for eugenol were determined together with the nature of its combinations with antibiotics against bacteria, some unexposed to eugenol previously. The lethal dose for the non-target organisms was also determined, as well as the Average Well Color Development and the Community-Level Physiological Profiling for soil and water microbiota. Our findings indicate that eugenol significantly reduces MICs by 75 to 98%, which means that it could be a potent adjuvant. Ecotoxicological assessments showed eugenol to be less harmful to water and soil microbiota compared to studied antibiotics. While Vibrio fischeri and Daphnia magna were susceptible, Allium cepa and Eisenia foetida were minimally affected. Given that only 0.1% of eugenol is excreted by humans without metabolism, its environmental risk when used with antibiotics appears minimal.

Antibacterial effectiveness of trans-cinnamaldehyde against foodborne Enterobacteriaceae and its adjuvant effect with gentamicin

The Enterobacteriaceae family is recognized as a primary group of Gram-negative pathogens responsible for foodborne illnesses and is frequently associated with antibiotic resistance. The present study explores the natural-based compound trans-cinnamaldehyde (TC) against drug-resistant Enterobacteriaceae and its synergism with gentamicin (GEN) to address this issue. The research employs three strains of Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae, previously isolated from shrimp. The antibacterial activity was evaluated by the disk diffusion method, microdilution test, kinetics of growth, and time-kill curve. In addition, the synergistic effect between TC/GEN was investigated by checkerboard assay. All strains showed sensitivity to TC with an inhibition zone diameter > 35 mm. The TC showed inhibitory and bactericidal action in the most tested bacteria around 625 μg/mL. Sub-inhibitory amounts (1/2 and 1/4 MIC) of TC interfered with the growth kinetics by lag phase extension and decreased the log phase. Time-kill curves show a reduction of viable cells after the first hour of TC treatment at bactericidal concentrations. The synergistic effect between TC/GEN was observed for E. coli and E. cloacae strains with FICi ranging from 0.15 to 0.50. These findings, therefore, suggest TC as a promising alternative in the fight against drug-resistant Enterobacteriaceae that can cause foodborne illnesses.

Clove Essential Oil: Chemical Profile, Biological Activities, Encapsulation Strategies, and Food Applications

Plants have proven to be important sources for discovering new compounds that are useful in the treatment of various diseases due to their phytoconstituents. Clove (Syzygium aromaticum L.), an aromatic plant widely cultivated around the world, has been traditionally used for food preservation and medicinal purposes. In particular, clove essential oil (CEO) has attracted attention for containing various bioactive compounds, such as phenolics (eugenol and eugenol acetate), terpenes (β-caryophyllene and α-humulene), and hydrocarbons. These constituents have found applications in cosmetics, food, and medicine industries due to their bioactivity. Pharmacologically, CEO has been tested against a variety of parasites and pathogenic microorganisms, demonstrating antibacterial and antifungal properties. Additionally, many studies have also demonstrated the analgesic, antioxidant, anticancer, antiseptic, and anti-inflammatory effects of this essential oil. However, CEO could degrade for different reasons, impacting its quality and bioactivity. To address this challenge, encapsulation is viewed as a promising strategy that could prolong the shelf life of CEO, improving its physicochemical stability and application in various areas. This review examines the phytochemical composition and biological activities of CEO and its constituents, as well as extraction methods to obtain it. Moreover, encapsulation strategies for CEO and numerous applications in different food fields are also highlighted.

Helicobacter pylori infection in humans and phytotherapy, probiotics, and emerging therapeutic interventions: a review

The global prevalence of Helicobacter pylori (H. pylori) infection remains high, indicating a persistent presence of this pathogenic bacterium capable of infecting humans. This review summarizes the population demographics, transmission routes, as well as conventional and novel therapeutic approaches for H. pylori infection. The prevalence of H. pylori infection exceeds 30% in numerous countries worldwide and can be transmitted through interpersonal and zoonotic routes. Cytotoxin-related gene A (CagA) and vacuolar cytotoxin A (VacA) are the main virulence factors of H. pylori, contributing to its steep global infection rate. Preventative measures should be taken from people's living habits and dietary factors to reduce H. pylori infection. Phytotherapy, probiotics therapies and some emerging therapies have emerged as alternative treatments for H. pylori infection, addressing the issue of elevated antibiotic resistance rates. Plant extracts primarily target urease activity and adhesion activity to treat H. pylori, while probiotics prevent H. pylori infection through both immune and non-immune pathways. In the future, the primary research focus will be on combining multiple treatment methods to effectively eradicate H. pylori infection.

Clove Buds Volatile Compounds: Inhibitory Activity on Mycobacterium Growth and Molecular Docking on Mmr Efflux Pump Drug Resistance

Syzygium aromaticum is used in traditional and modern medicine for its various and outstanding pharmacological properties. Here, we studied the chemical composition of hexane extract and non-polar fractions (NPF) obtained from the maceration and fractionation of clove buds, in order to evaluate their in vitro antimycobacterial activity, as well as their contribution against efflux pump (EP) resistance through molecular docking experiments. The gas chromatography-mass spectrometry (GC-MS) analysis of the volatile profiles revealed the presence of eugenol, followed by eugenyl acetate, and β-caryophyllene as common major compounds. According to Resazurin microtiter assay (REMA), Mycobacterium tuberculosis H37 Rv strain was sensitive to all volatile samples at concentration range between 10 and 100 μg/mL. The NPF of ethanol extract was the best inhibitor with a MIC=10 μg/mL. The in silico study revealed a strong binding affinity between eugenol and Mmr EP protein (-8.1 Kcal/mol), involving two binding modes of hydrogen bond and π-alkyl interactions. The non-polarity character of clove volatile constituents, and their potential additive or synergistic effects could be responsible for the antimycobacterial activity. In addition, these findings suggest the benefic effect of eugenol in the management of mycobacterium drug resistance, whether as potential inhibitor of Mmr drug EP, or modulator during combination therapy.