Antibacterial activity of traditional spices against lower respiratory tract pathogens: combinatorial effects of Trachyspermum ammi essential oil with conventional antibiotics

Effects of Supplemented Coriander, Ajwain, and Dill Seed Essential Oils on Growth Performance, Carcass Characteristics, Gut Health, Meat Quality, and Immune Status in Broilers

Numerous studies have assessed the benefits and optimal dosage of supplementation with essential oils (EOs), including extracts from plants of the Apiaceae family, as an alternative to antibiotic growth promoters (AGPs) in broilers. However, little consideration has been given to the actual chemical composition of the evaluated EOs when drawing critical conclusions, even though EO composition can vary with different extraction conditions and plant characteristics. Therefore, the present study was conducted to evaluate the effects of EOs from seeds of plants of the Apiaceae family: coriander (CEO), ajwain (AjEO), and dill (DEO), containing 56.8% linalool, 68.2% thymol, and 41.1% carvone, respectively, on the growth performance, gut health, and immune status of broilers. In total, 660 one-day-old broiler chicks were divided into 11 experimental diet groups and fed for 35 days with either the control diet, basal diet with added AGP (lincomycin, 500 mg/kg), or one of nine EO diets supplemented with CEO, AjEO, or DEO at 200, 400, and 600 mg/kg. Final body weights were improved by supplementation with not only AGP but also any EO except AjEO at 600 mg/kg; within each EO, supplementation of CEO at 400 mg/kg, AjEO at 200 mg/kg, and DEO at 200 mg/kg afforded the best growth performance. EO supplementation had beneficial effects on gut morphology, such as increased villus height in the duodenum, jejunum, and ileum, and against harmful microbiota, such as reduction of Escherichia coli and Salmonella spp. populations. Furthermore, EOs enhanced humoral immunity and improved meat quality by reducing drip loss, likely consequent to their antioxidant properties. Overall, this study presents evidence that CEO, AjEO, and DEO can each play a pivotal role in replacing AGPs, as well as providing information regarding optimal doses for broilers.

Chemical Profile and Bioactivity Evaluation of Salvia Species from Eastern Europe

The Salvia genus comprises about 1000 species endowed with medicinal, aromatic, cosmetic, and ornamental applications. Even though the genus is one of the most-studied taxa of the Lamiaceae family, data on the chemical composition and biological properties of certain locally used Salvia species are still scarce. The present work aimed to evaluate the phytochemical profile and antimicrobial, antioxidant, and cytotoxic potential of ten Salvia species that grow in Eastern Europe (e.g., the Republic of Moldova). LC-HRMS/MS metabolite profiling allowed for the annotation of 15 phenolic and organic acids, 18 flavonoids, 19 diterpenes, 5 sesterpenes, and 2 triterpenes. Multivariate analysis (e.g., principal component analysis, hierarchical cluster analysis) revealed that S. austriaca, S. nutans, and S. officinalis formed individual clusters, whereas the remaining species had a similar composition. S. officinalis showed the highest activity against Staphylococcus aureus and Streptococcus pneumoniae (MIC = 0.625 mg/mL). As evaluated in DPPH, ABTS, and FRAP assays, S. officinalis was one of the most potent radical scavenging and metal-reducing agents (CE50 values of 25.33, 8.13, and 21.01 μg/mL, respectively), followed by S. verticillata, S. sclarea, S. kopetdaghensis, S. aethiopis, and S. tesquicola. Pearson correlation analysis revealed strong correlations with rosmarinic acid, luteolin-O-glucuronide, and hydroxybenzoic acid. When the cytotoxic activity was evaluated in human breast carcinoma MCF-7 and MDA-MB-231 cells, no significant reduction in cell viability was observed over the concentrations ranging from 25 and 100 μg/mL. The results confirm the potential use of understudied Salvia species as promising sources of antioxidant compounds for developing novel pharmaceutical, nutraceutical, or cosmeceutical products.

Validation of Broth Macrodilution Volatilization Method for Testing of Essential Oils in Liquid and Vapor Phase: Chemical Composition, Cytotoxicity, and Antibacterial Effect of Indian Medicinal Plants against Pneumonia-Causing Pathogens

Essential oils (EOs) have great potential in inhalation therapy for the treatment of respiratory infections. However, innovative methods for evaluation of antimicrobial activity of their vapors are still needed. The current study reports validation of the broth macrodilution volatilization method for assessment of the antibacterial properties of EOs and shows the growth-inhibitory effect of Indian medicinal plants against pneumonia-causing bacteria in liquid and vapor phase. Among all samples tested, Trachyspermum ammi EO exhibits the strongest antibacterial effect against Haemophilus influenzae, with minimum inhibitory concentrations of 128 and 256 µg/mL in the liquid and vapor phases, respectively. Furthermore, Cyperus scariosus EO is found to be nontoxic to normal lung fibroblasts assessed by modified thiazolyl blue tetrazolium bromide assay. Chemical analysis performed using gas chromatography-mass spectrometry identified α-citral, cyperotundone, and thymol as the main constituents of Cymbopogon citratus, C. scariosus, and T. ammi EOs, respectively. In addition, β-cymene is identified as the major compound of T. ammi EO vapors when analyzed using solid-phase microextraction and gas-tight syringe sampling techniques. This study demonstrates the validity of the broth macrodilution volatilization method for antimicrobial screening of volatile compounds in the vapor phase and suggests the therapeutic potential of Indian medicinal plants in inhalation therapy.

Current State of Knowledge Regarding WHO High Priority Pathogens-Resistance Mechanisms and Proposed Solutions through Candidates Such as Essential Oils: A Systematic Review

Combating antimicrobial resistance (AMR) is among the 10 global health issues identified by the World Health Organization (WHO) in 2021. While AMR is a naturally occurring process, the inappropriate use of antibiotics in different settings and legislative gaps has led to its rapid progression. As a result, AMR has grown into a serious global menace that impacts not only humans but also animals and, ultimately, the entire environment. Thus, effective prophylactic measures, as well as more potent and non-toxic antimicrobial agents, are pressingly needed. The antimicrobial activity of essential oils (EOs) is supported by consistent research in the field. Although EOs have been used for centuries, they are newcomers when it comes to managing infections in clinical settings; it is mainly because methodological settings are largely non-overlapping and there are insufficient data regarding EOs' in vivo activity and toxicity. This review considers the concept of AMR and its main determinants, the modality by which the issue has been globally addressed and the potential of EOs as alternative or auxiliary therapy. The focus is shifted towards the pathogenesis, mechanism of resistance and activity of several EOs against the six high priority pathogens listed by WHO in 2017, for which new therapeutic solutions are pressingly required.

Aromatherapeutic and Antibacterial Properties of Cotton Materials Treated with Emulsions Containing Peppermint Essential Oil (Menthae piperitae aetheroleum)

The objective of the work was to obtain materials with aromatherapeutic and antibacterial properties by applying emulsions based on peppermint essential oil (PEO) onto cotton fabric. For this purpose, some emulsions based on PEO incorporated in various matrices (chitosan + gelatin + beeswax; chitosan + beeswax; gelatin + beeswax and gelatin + chitosan) were prepared. Tween 80 was used as a synthetic emulsifier. The influence of the nature of matrices and of the concentration of Tween 80 on the stability of the emulsions was evaluated by the creaming indices. The materials treated with the stable emulsions were analyzed in terms of sensory activity, of the comfort characteristics, and of the gradual release of the PEO in the artificial perspiration solution. The sum of volatile components retained by samples after exposure to air was determined by GC-MS. The results regarding antibacterial activity showed that materials treated with emulsions have a good inhibitory effect on S. aureus (diameters of the inhibition zones between 53.6 and 64.0 mm) and on E. coli (diameters of the inhibition zones between 38.3 and 64.0 mm). Our data suggest that by applying peppermint-oil-based emulsions on a cotton support, aromatherapeutic patches, bandages and dressings with antibacterial properties can be obtained.

Characteristics of Essential Oils of Apiaceae Family: Their Chemical Compositions, in vitro Properties and Effects on Broiler Production

There has been an upsurge of interest in the phytobiotics coincident with the onset of the potential ban on the use of antibiotic growth promoters (AGPs) in the broiler industry and because many kinds of nutraceuticals play an important role in improving growth performance, feed efficiency, and gut health of broilers. In the previous years, significant biological activities of essential oils (EOs) belonging to phytobiotics were observed, including anti-bacterial, antifungal, antiviral, and antioxidant properties. We found new perspectives on the roles of EOs, particularly extracts from the Apiaceae family, which is one of the largest plant families, in potential replacement of AGPs, and on the chemical composition involved in regulating microorganism activity and oxidative damage. Furthermore, the positive effects of EOs on broiler production and the possible mechanisms inducing the involvement of gut health and growth performance have been studied.

Nanoparticles—Attractive Carriers of Antimicrobial Essential Oils

Microbial pathogens are the most prevalent cause of chronic infections and fatalities around the world. Antimicrobial agents including antibiotics have been frequently utilized in the treatment of infections due to their exceptional outcomes. However, their widespread use has resulted in the emergence of multidrug-resistant strains of bacteria, fungi, viruses, and parasites. Furthermore, due to inherent resistance to antimicrobial drugs and the host defence system, the advent of new infectious diseases, chronic infections, and the occurrence of biofilms pose a tougher challenge to the current treatment line. Essential oils (EOs) and their biologically and structurally diverse constituents provide a distinctive, inexhaustible, and novel source of antibacterial, antiviral, antifungal, and antiparasitic agents. However, due to their volatile nature, chemical susceptibility, and poor solubility, their development as antimicrobials is limited. Nanoparticles composed of biodegradable polymeric and inorganic materials have been studied extensively to overcome these limitations. Nanoparticles are being investigated as nanocarriers for antimicrobial delivery, antimicrobial coatings for food products, implantable devices, and medicinal materials in dressings and packaging materials due to their intrinsic capacity to overcome microbial resistance. Essential oil-loaded nanoparticles may offer the potential benefits of synergism in antimicrobial activity, high loading capacity, increased solubility, decreased volatility, chemical stability, and enhancement of the bioavailability and shelf life of EOs and their constituents. This review focuses on the potentiation of the antimicrobial activity of essential oils and their constituents in nanoparticulate delivery systems for a wide range of applications, such as food preservation, packaging, and alternative treatments for infectious diseases.

Original Contributions to the Chemical Composition, Microbicidal, Virulence-Arresting and Antibiotic-Enhancing Activity of Essential Oils from Four Coniferous Species

This study aimed to establish the essential oil (EO) composition from young shoots of Picea abies, Larix decidua, Pseudotsuga menziesii, and Pinus nigra harvested from Romania and evaluate their antimicrobial and anti-virulence activity, as well as potential synergies with currently used antibiotics. The samples' EO average content varied between 0.62% and 1.02% (mL/100 g plant). The mono- and sesquiterpene hydrocarbons were dominant in the composition of the studied EOs. The antimicrobial activity revealed that the minimum inhibitory concentration (MIC) values for the tested EOs and some pure compounds known for their antimicrobial activity ranged from 6.25 to 100 µL/mL. The most intensive antimicrobial effect was obtained for the Pinus nigra EO, which exhibited the best synergistic effect with some antibiotics against Staphylococcus aureus strains (i.e., oxacillin, tetracycline, erythromycin and gentamycin). The subinhibitory concentrations (sMIC) of the coniferous EOs inhibited the expression of soluble virulence factors (DN-ase, lipase, lecithinase, hemolysins, caseinase and siderophore-like), their efficiency being similar to that of the tested pure compounds, and inhibited the rhl gene expression in Pseudomonas aeruginosa, suggesting their virulence-arresting drug potential.

Apiaceae Essential Oils: Boosters of Terbinafine Activity against Dermatophytes and Potent Anti-Inflammatory Effectors

Dermatophyte infections represent an important public health concern, affecting up to 25% of the world's population. Trichophyton rubrum and T. mentagrophytes are the predominant dermatophytes in cutaneous infections, with a prevalence accounting for 70% of dermatophytoses. Although terbinafine represents the preferred treatment, its clinical use is hampered by side effects, drug-drug interactions, and the emergence of resistant clinical isolates. Combination therapy, associating terbinafine and essential oils (EOs), represents a promising strategy in the treatment of dermatophytosis. In this study, we screened the potential of selected Apiaceae EOs (ajowan, coriander, caraway, and anise) to improve the antifungal activity of terbinafine against T. rubrum ATCC 28188 and T. mentagrophytes ATCC 9533. The chemical profile of EOs was analyzed by gas chromatography. The minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of EOs/main compounds were determined according to EUCAST-AFST guidelines, with minor modifications. The checkerboard microtiter method was used to identify putative synergistic combinations of EOs/main constituents with terbinafine. The influence of EOs on the viability and pro-inflammatory cytokine production (IL-1β, IL-8 and TNF-α) was determined using an ex vivo human neutrophils model. The binary associations of tested EOs with terbinafine were found to be synergistic against T. rubrum, with FICI values of 0.26-0.31. At the tested concentrations (6.25-25 mg/L), EOs did not exert cytotoxic effects towards human neutrophils. Anise EO was the most potent inhibitor of IL-1β release (46.49% inhibition at 25 mg/L), while coriander EO displayed the highest inhibition towards IL-8 and TNF-α production (54.15% and 54.91%, respectively). In conclusion, the synergistic combinations of terbinafine and investigated Apiaceae EOs could be a starting point in the development of novel topical therapies against T. rubrum-related dermatophytosis.

Physically cross-linked chitosan/dextrin cryogels entrapping Thymus vulgaris essential oil with enhanced mechanical, antioxidant and antifungal properties

Herein, we entrapped Thymus vulgaris essential oil (EO) within the physically cross-linked sponge-like architecture of cryogels by ice template-assisted freeze-drying. Their 3D cryogenically-structured network was built through hydrogen bonding formed by blending two naturally-derived polysaccharides, chitosan and dextrin. The embedment of EOs within the cryogel matrix generates porous films with an increased elasticity that allows their fast shape recovery after full compression. Thus, the swollen EOs-loaded cryogel films exhibited an elastic modulus of 3.00 MPa, which is more than 40 times higher than that of polysaccharide films without EOs (an elastic modulus of only 0.07 MPa). In addition, the encapsulation of bioactive compounds endows the bio-based films with both antioxidant and antifungal properties, showing a radical scavenging activity of 65% and a zone inhibition diameter of 40 mm for Candida parapsilosis fungi. Our results recommend the entrapment of EOs into bio-based cryogel carriers as a straightforward approach to provide 'green' polysaccharide-based films having both improved physicochemical properties and remarkable antifungal activity.

Supplementation of a combination of herbs improves immunity, uterine cleansing and facilitate early resumption of ovarian cyclicity: A study on post-partum dairy buffaloes

ETHNOPHARMACOLOGICAL RELEVANCE

A combination of Trachyspermum ammi L., Curcuma longa L., Cuminum cyminum L., Trigonella foenum-graecum L., Foeniculum vulgare Mill., Anethum graveolens L and Zingiber officinale Roscoe is used as immunity booster and reproductive efficiency enhancing agents in folklore medicine.

AIM OF THE STUDY

The present study aimed to assess the immunomodulatory, uterine cleansing and reproduction enhancing effects of polyherbal mixture in post-partum buffaloes.

MATERIALS AND METHODS

Enzyme linked immunosorbent assay (ELISA) was used to investigate the effects of polyherbal mixture feeding on for quantification of neutrophil functions and blood progesterone hormone estimation. Ultrasonography was used to assess the status of uterine involution, fluid in uterus and ovarian follicular status. Quantitative real time PCR (qRT-PCR) was used to measure the expression of chemokine genes CXCR1, CXCR2 AND IL-8. Artificial insemination with cryopreserved semen was used to breed the animals. Reproductive efficiency parameters were assessed using standard calculation methods.

RESULTS

Neutrophil functions and transcriptional abundance of chemokine genes were significantly (P < 0.05) higher in buffaloes supplemented with polyherbal mixture compared to buffaloes in control group. The rate of cervical and uterine involution was significantly (P < 0.05) higher in treatment group compared to control group. The service period was shorter, days to first insemination was earlier and the number of services per conception was lower in buffaloes supplemented with polyherbal mixture compared to the buffaloes in control group. The proportion of buffaloes with large ovarian follicles within 28 days of post-partum was also significantly (P < 0.05) higher in treatment group compared to the control group.

CONCLUSIONS

The polyherbal mixture used in the study improved the immunity of the buffaloes, facilitated early involution of cervix and uterus, efficient cleansing of lochia and improved subsequent fertility. It has the potential to be used in dairy animals for improving post-partum reproductive efficiency.

Antimicrobial core-shell electrospun nanofibers containing Ajwain essential oil for accelerating infected wound healing

Treatment of skin injuries is still facing major challenges, such as chronicity and infections, particularly those caused by multi-drug resistance pathogens. An effective treatment of such wounds should accelerate the wound healing process while preventing bacterial contamination. Here, a novel core-shell nanofiber mat was fabricated comprising gelatin/polyvinyl alcohol (as a core) and aloe vera/arabinose/polyvinylpyrrolidone (as a shell) for accelerating the healing process of bacteria-infected wounds. Trachyspermum Ammi (Ajwain) essential oil (EO), as a potent and natural antimicrobial agent against microorganisms, was incorporated into the core of nanofiber mats using coaxial electrospinning. The microscopy images demonstrated the successful fabrication of the core-shell structure with a uniform fiber size of 564 ± 106.35 nm. Moreover, Ajwain EO-loaded nanofiber mat (core-shell/EO) provided excellent antimicrobial activity and antioxidant ability. The in vitro and ex vivo release of Ajwain EO from the fabricated nanofiber mat corroborated a prolonged release profile. Furthermore, in vivo antibacterial activity, wound closure, and histomorphological examinations showed the high efficacy of the core-shell/EO mat in the treatment of Staphylococcus aureus-infected full-thickness rat wounds compared to standard control treatment with a gauze. Overall, these results represent the core-shell/EO mat's potential as a newly developed wound dressing for bacteria-infected full-thickness skin injuries.

An Up-to-Date Review on Bio-Resource Therapeutics Effective against Bacterial Species Frequently Associated with Chronic Sinusitis and Tonsillitis

Upper respiratory tract infections include inflammations of the nose, sinuses (sinusitis), pharynx (tonsillitis, pharyngitis) and larynx (laryngitis) with bacteria or viruses as the main cause of these conditions. Due to their repetitive nature, chronic respiratory infections represent a global problem which is often a result of improper treatment. If not treated adequately, these conditions may have serious consequences. On the other hand, mis - and overuse of antibiotics has reduced their efficiency and accelerated the development of resistant bacterial strains, which further complicates the treatment of infections. This literature review will focus on current knowledge regarding medicinal plants and mushrooms which have been traditionally used in the treatment of infections caused by chronic sinusitis and tonsillitis commonly linked to bacteria - Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Fusobacterium nucleatum, Haemophilus influenzae and Moraxella catarrhalis. The present literature overview might be considered as a starting point for the development of novel, natural antimicrobial products with potential practical use in the treatment of chronic tonsillitis and sinusitis.

Use of Essential Oils by Health Care Professionals for Health Maintenance

This study explores essential oils' use by health care professionals for health maintenance. A qualitative, descriptive design was employed, and a convenience sample of 10 participants was interviewed. Four themes were identified: an essential oils' community, essential oils' use, essential oils' acceptance, and essential oils' benefits and harms.