Chemistry and multibeneficial bioactivities of carvacrol (4-isopropyl-2-methylphenol), a component of essential oils produced by aromatic plants and spices

Evidence of the protective role of Carvacrol in a retinal degeneration animal model

Neurodegenerative pathologies affecting the posterior segment of the eye, are characterized by being devastating and responsible for the majority of visual dysfunctions worldwide. These diseases are primarily degenerative, progressing chronically, and can inflict gradual harm to the optic nerve, retinal ganglion cells (RGC), photoreceptors, and other retinal cells. This retinal damage leads to a progressive loss of vision, marking these conditions as a significant health concern worldwide. The intravitreal administration of the phytochemical Carvacrol (CAR) is expected to demonstrate a neuroprotective and antiapoptotic effect on retinal cells, with a specific focus on RGC. This effect will be observed in a retinal degeneration model (RDM) in rabbits induced by cytotoxic and oxidative agents, namely glutamate (GLUT) and L-buthionine-S, R-sulfoximine (BSO). An in vivo study was conducted using New Zealand rabbits in which retinal damage was created to evaluate the effectiveness of CAR. The effectiveness of CAR on the functionality of retinal neuronal cells in RDM was evaluated using pupillary light reflection (PLR). Furthermore, the phytotherapeutic's influence on cell viability was determined through flow cytometry analysis. Finally, the neuroprotective and antiapoptotic capabilities of CAR were specifically scrutinized in RGC through histological studies, quantifying cell survival, and employing immunohistochemical assays to detect the apoptotic index (%) using the TUNEL technique. Our results demonstrated that CAR promoted the recovery of the pupillary contraction profile over time, maintaining the functionality of retinal cells as healthy controls. Additionally, it showed increased cell viability under oxidative and cytotoxic conditions given by GLUT-BSO agents. Finally, we found that CAR protects the survival of RGC and decreases the percentage of apoptotic cells when compared to RDM. CAR demonstrated to have positive effects on the functionality of photoreceptive nerve cells by restoring pupillary contraction. Likewise, it was shown to have neuroprotective and antiapoptotic effects when evaluated in a general and specific way on retinal nerve cells.

Effect of Microfluidization on the Volatiles and Antibacterial, Antifungal, and Cytotoxic Activities of Algerian Satureja hortensis L. Oil-Loaded Nanoemulsions: In Vitro and In Silico Study

This study aimed to increase the stability and solubility of the Algerian Satureja hortensis L. (ASHO) essential oil through nanoencapsulation. Nanoemulsions of ASHO (MF-ASHEO) were developed to evaluate their antioxidant and antimicrobial potential, stability, and cytotoxicity using microfluidization at 150 MPa for five cycles. MF-ASHO showed 8 compounds (99.56%) vs ASHEO's 26 compounds (95.46%). Carvacrol increased to 94.51%, replacing γ-terpinene, which decreased to 0.43%. The MF-ASHEO nanoemulsion had a mean particle size of 41.72 nm, a monomodal size distribution pattern, a mean ζ-potential of -39.4 mV, and a polydispersity index (PDI) mean value of 0.291. Micrographs showed spherical nanoparticles with varying diameters in nm. ASHEO was more toxic than MF-ASHEO against HepG2, Vero, and WI-38, according to the MTT and WST-1 assays. ASHEO demonstrated antiradical and antibacterial activity and inhibited biofilm formation. It also had an enhanced antifungal effect and reduced mycotoxin production. The MF-ASHEO sample showed no activity except in reducing mycotoxin production, where it performed better than ASHEO. In silico and ADME results confirmed the inhibitory action of carvacrol on the key enzymes of the aflatoxin biosynthetic mechanism and the target proteins associated with bactericidal/bacteriostatic effects. The microfluidization process dramatically affects not only the oil's volatile content but also its biological activity.

Efficacy of Essential Oil Vapours in Reducing Postharvest Rots and Effect on the Fruit Mycobiome of Nectarines

Nectarines can be affected by many diseases, resulting in significant production losses. Natural products, such as essential oils (EOs), are promising alternatives to pesticides to control storage rots. This work aimed to test the efficacy of biofumigation with EOs in the control of nectarine postharvest diseases while also evaluating the effect on the quality parameters (firmness, total soluble solids, and titratable acidity) and on the fruit fungal microbiome. Basil, fennel, lemon, oregano, and thyme EOs were first tested in vitro at 0.1, 0.5, and 1.0% concentrations to evaluate their inhibition activity against Monilinia fructicola. Subsequently, an in vivo screening trial was performed by treating nectarines inoculated with M. fructicola, with the five EOs at 2.0% concentration by biofumigation, performed using slow-release diffusers placed inside the storage cabinets. Fennel, lemon, and basil EOs were the most effective after storage and were selected to be tested in efficacy trials using naturally infected nectarines. After 28 days of storage, all treatments showed a significant rot reduction compared to the untreated control. Additionally, no evident phytotoxic effects were observed on the treated fruits. EO vapors did not affect the overall quality of the fruits but showed a positive effect in reducing firmness loss. Metabarcoding analysis showed a significant impact of tissue, treatment, and sampling time on the fruit microbiome composition. Treatments were able to reduce the abundance of Monilinia spp., but basil EO favored a significant increase in Penicillium spp. Moreover, the abundance of other fungal genera was found to be modified.

Effects of carvacrol on ketamine-induced cardiac injury in rats: an experimental study

AIM

We aimed to investigate the preventive effects of carvacrol against ketamine-induced cardiotoxicity biochemically and histopathologically in an experimental model.

MATERIAL AND METHOD

The rats were divided into three groups; healthy control (HC), ketamine alone (KG), and ketamine + carvacrol (KCG) groups. Serum Creatine Kinase Myocardial Band (CK-MB) and Troponin I (TP I) levels were determined. Malondialdehyde (MDA), Glutathione (GSH), Superoxide Dismutase (SOD), Tumor Necrosis Factor α (TNF-α), Interleukin 1 beta (IL-1beta), and Interleukin 6 (IL-6) levels were measured in the heart tissues of the rats. Heart tissues were also evaluated histopathologically.

RESULTS

In the ketamine-treated group, tissue MDA, TNF-α, IL-1beta, and IL-6 levels increased while tissue GSH and SOD levels decreased significantly compared with the control group. However, in the ketamine plus carvacrol applied group, all those alterations were significantly less pronounced, close to the healthy controls. Severe mononuclear cell infiltrations, degenerated myocytes and hemorrhage were determined in the ketamine alone administered group, and these alterations were at a mild level in the carvacrol + ketamine administered group.

CONCLUSION

Prolonged exposure to ketamine resulted in induced oxidative stress in rat heart tissue; concomitant carvacrol application could counteract the negative effects of ketamine by protecting tissues from lipid peroxidation and decreasing the inflammatory response.

Exploring effect of herbal monomers in treating gouty arthritis based on nuclear factor-kappa B signaling: A review

Gouty arthritis (GA) is an inflammatory disease caused by disorders of the purine metabolism. Although increasing number of drugs have been used to treat GA with the deepening of relevant research, GA still cannot be cured by simple drug therapy. The nuclear factor-kappa B (NF-κB) signaling pathway plays a key role in the pathogenesis of GA. A considerable number of Chinese herbal medicines have emerged as new drugs for the treatment of GA. This article collected relevant research on traditional Chinese medicine monomers in the treatment of GA using NF-κB, GA, etc. as keywords; and conducted a systematic search of relevant published articles using the PubMed database. In this study, we analyzed the therapeutic effects of traditional Chinese medicine monomers on GA in the existing literature through in vivo and in vitro experiments using animal and cell models. Based on this review, we believe that traditional Chinese medicine monomers that can treat GA through the NF-κB signaling pathway are potential new drug development targets. This study provides research ideas for the development and application of new drugs for GA.

Influence of myoglobin on the antibacterial activity of carvacrol and the binding mechanism between the two compounds

BACKGROUND

Myoglobin (MB), a pigmentation protein, can adversely affect the antibacterial activity of carvacrol (CAR) and weaken its bacteriostasis effect. This study aimed to clarify the influence of MB on the antibacterial activity of CAR and ascertain the mechanism involved in the observed influence, especially the interaction between the two compounds.

RESULTS

Microbiological analysis indicated that the presence of MB significantly suppressed the antibacterial activity of CAR against Listeria monocytogenes. Ultraviolet-visible spectrometry and fluorescence spectroscopic analysis confirmed the interaction between CAR and MB. The stoichiometric number was determined as ~0.7 via double logarithmic Stern-Volmer equation analysis, while thermodynamic analysis showed that the conjugation of the two compounds occurred as an exothermal reaction (ΔH° = -32.3 ± 11.4 kJ mol-1 and ΔS° = -75 J mol-1  K-1 ). Circular dichroism, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy showed hydrogen bonding in the carvacrol-myoglobin complex (CAR-MB). Molecular docking analysis confirmed that amino acid residues, including GLY80 and HIS82, were most likely to form hydrogen bonds with CAR, while hydrogen bonds represented the main driving force for CAR-MB formation.

CONCLUSION

CAR antibacterial activity was significantly inhibited by the presence of MB in the environment due to the notable reduction in the effective concentration of CAR caused by CAR-MB formation. © 2023 Society of Chemical Industry.

Evaluation of antifungal activity of natural compounds on growth and aflatoxin B1 production of Aspergillus parasiticus and Aspergillus flavus

BACKGROUND

Aspergillus species cause broad spectrum infections especially invasive lethal infections in immunocompromised patients. This study aimed to assess the antifungal activity of plants and compounds including Aloe vera, Thyme, carvacrol, and nano-encapsulation of carvacrol on the growth and production of aflatoxin B1 production by Aspergillus parasiticus and Aspergillus flavus.

METHODS AND RESULTS

Minimum inhibitory concentrations of extracts Aloe vera, Thyme, carvacrol, and nanocarvacrol, and fluconazole as a control were determined according to Clinical and Laboratory Standards Institute by serial microdilution protocol. Then, the effect of inhibitory concentrations of these compounds on the aflatoxin B1 production level was evaluated by real-time PCR and high-performance liquid chromatography. Our results indicate that the Aspergillus parasiticus and Aspergillus flavusare sensitive to selected plants and compounds.

CONCLUSION

Our findings showed that the compounds are appropriate alternative candidates against growth and production of aflatoxin of Aspergillus spp.

Antiviral Natural Products, Their Mechanisms of Action and Potential Applications as Sanitizers and Disinfectants

Plant extracts, natural products and plant oils contain natural virucidal actives that can be used to replace active ingredients in commercial sanitizers and disinfectants. This review focuses on the virucidal mechanisms of natural substances that may exhibit potential for indoor air and fomite disinfection. Review of scientific studies indicates: (1) most natural product studies use crude extracts and do not isolate or identify exact active antiviral substances; (2) many natural product studies contain unclear explanations of virucidal mechanisms of action; (3) natural product evaluations of virucidal activity should include methods that validate efficacy under standardized disinfectant testing procedures (e.g., carrier tests on applicable surfaces or activity against aerosolized viruses, etc.). The development of natural product disinfectants requires a better understanding of the mechanisms of action (MOA), chemical profiles, compound specificities, activity spectra, and the chemical formulations required for maximum activity. Combinations of natural antiviral substances and possibly the addition of synthetic compounds might be needed to increase inactivation of a broader spectrum of viruses, thereby providing the required efficacy for surface and air disinfection.

Carvacrol is potential molecule for diabetes treatment

Diabetes is an important chronic disease that can lead to various negative consequences and complications. In recent years, several new alternative treatments have been developed to improve diabetes. Carvacrol found in essential oils of numerous plant species and has crucial potential effects on diabetes. The anti-diabetic effects of carvacrol have also been comprehensively studied in diabetic animal and cell models. In addition, carvacrol could improve diabetes through affecting diabetes-related enzymes, insulin resistance, insulin sensitivity, glucose uptake, anti-oxidant, and anti-inflammatory mechanisms. The use of carvacrol alone or in combination with anti-diabetic therapies could show a significant potential effect in the treatment of diabetes. This review contributes an overview of the effect of carvacrol in diabetes and anti-diabetic mechanisms.

Bamboo polysaccharides elicit hypocrellin A biosynthesis of a bambusicolous fungus Shiraia sp. S9

Hypocrellin A (HA), a fungal perylenequinone from bambusicolous Shiraia species, is a newly developed photosensitizer for photodynamic therapy in cancer and other infectious diseases. The lower yield of HA is an important bottleneck for its biomedical application. This study is the first report of the enhancement of HA production in mycelium culture of Shiraia sp. S9 by the polysaccharides from its host bamboo which serve as a strong elicitor. A purified bamboo polysaccharide (BPSE) with an average molecular weight of 34.2 kDa was found to be the most effective elicitor to enhance fungal HA production and characterized as a polysaccharide fraction mainly composed of arabinose and galactose (53.7: 36.9). When BPSE was added to the culture at 10 mg/L on day 3, the highest HA production of 422.8 mg/L was achieved on day 8, which was about 4.0-fold of the control. BPSE changed the gene expressions mainly responsible for central carbon metabolism and the cellular oxidative stress. The induced generation of H2O2 and nitric oxide was found to be involved in both the permeabilization of cell membrane and HA biosynthesis, leading to enhancements in both intra- and extracellular HA production. Our results indicated the roles of plant polysaccharides in host-fungal interactions and provided a new elicitation technique to improve fungal perylenequinone production in mycelium cultures.

Antioxidant and Antibacterial Activity of Mexican Oregano Essential Oil, Extracted from Plants Occurring Naturally in Semiarid Areas and Cultivated in the Field and Greenhouse in Northern Mexico

In recent years, the determination of the antioxidant and antibacterial activity of essential oils in wild plants, such as Mexican oregano (Lippia graveolens Kunth), has become increasingly important. The objective was to compare the antioxidant and antibacterial activity of Mexican oregano essential oil obtained from plants occurring naturally in semiarid areas (Wild1 and Wild2), and those cultivated in the field (CField) and greenhouse (CGreenhouse) in northern Mexico. The Mexican oregano essential oil extraction was performed using the hydrodistillation method, the antioxidant activity was determined using the ABTS method, and the antibacterial activity was assessed through bioassays under the microwell method at nine different concentrations. The aim was to determine the diameter of the inhibition zone and, consequently, understand the sensitivity level for four bacterial species. The results revealed an antioxidant activity ranging from 90% to 94% at the sampling sites, with Wild1 standing out for having the highest average antioxidant activity values. Likewise, six out of the nine concentrations analyzed showed some degree of sensitivity for all the sampling sites. In this regard, the 25 µL mL-1 concentration showed the highest diameter of inhibition zone values, highlighting the Wild2 site, which showed an average diameter greater than 30 mm for the four bacteria tested. Only in the case of S. typhi did the CGreenhouse site surpass the Wild2, with an average diameter of the inhibition zone of 36.7 mm. These findings contribute to the search for new antioxidant and antibacterial options, addressing the challenges that humanity faces in the quest for opportunities to increase life expectancy.

Bioactive Potential of Aqueous Phenolic Extracts of Spices for Their Use in the Food Industry-A Systematic Review

The interest on the use of natural sources in the food industry has promoted the study of plants' phenolic compounds as potential additives. However, the literature has been focusing on essential oils, with very few studies published regarding aqueous extracts, their phenolic composition, and bioactivity. A systematic review was conducted on different databases following PRISMA guidelines to evaluate the relevance of the phenolic content of different aromatic spices (oregano, rosemary, thyme, ginger, clove, and pepper), as related to their bioactivity and potential application as food additives. Although different extraction methods have been applied in the literature, the use of green approaches using ethanol and deep eutectic solvents has increased, leading to the development of products more apt for human consumption. The studied plants present an interesting phenolic profile, ranging from phenolic acids to flavonoids, establishing a correlation between their phenolic content and bioactivity. In this sense, results have proven to be very promising, presenting those extracts as having similar if not higher bioactivity than synthetic additives already in use, with associated health concerns. Nevertheless, the study of spices' phenolic extracts is somehow limited to in vitro studies. Therefore, research in food matrices is needed for more understanding of factors interfering with their preservation activity.

Improvement of Fresh Ovine "Tuma" Cheese Quality Characteristics by Application of Oregano Essential Oils

In the present work, oregano essential oils (OEOs) were applied to process the fresh ovine cheese "Tuma" obtained by pressed cheese technology. Cheese making trials were performed under industrial conditions using ewe's pasteurized milk and two strains of Lactococcus lactis (NT1 and NT4) as fermenting agents. Two experimental cheese products (ECP) were obtained through the addition of 100 (ECP100) and 200 (ECP200) µL/L of OEO to milk, while the control cheese product (CCP) was OEO-free. Both Lc. lactis strains showed in vitro and in vivo ability to grow in the presence of OEOs and to dominate over indigenous milk lactic acid bacteria (LAB) resistant to pasteurization. In the presence of OEOs, the most abundant compound found in cheese was carvacrol, constituting more than 65% of the volatile fraction in both experimental products. The addition of OEOs did not influence ash, fat, or protein content, but it increased by 43% the antioxidant capacity of the experimental cheeses. ECP100 cheeses showed the best appreciation scores by the sensory panel. In order to investigate the ability OEOs to be used as a natural preservative, a test of artificial contamination was carried out, and the results showed a significant reduction of the main dairy pathogens in OEO-added cheeses.

Carvacrol-A Natural Phenolic Compound with Antimicrobial Properties

The main purpose of this article is to present the latest research related to selected biological properties of carvacrol, such as antimicrobial, anti-inflammatory, and antioxidant activity. As a monoterpenoid phenol, carvacrol is a component of many essential oils and is usually found in plants together with its isomer, thymol. Carvacrol, either alone or in combination with other compounds, has a strong antimicrobial effect on many different strains of bacteria and fungi that are dangerous to humans or can cause significant losses in the economy. Carvacrol also exerts strong anti-inflammatory properties by preventing the peroxidation of polyunsaturated fatty acids by inducing SOD, GPx, GR, and CAT, as well as reducing the level of pro-inflammatory cytokines in the body. It also affects the body's immune response generated by LPS. Carvacrol is considered a safe compound despite the limited amount of data on its metabolism in humans. This review also discusses the biotransformations of carvacrol, because the knowledge of the possible degradation pathways of this compound may help to minimize the risk of environmental contamination with phenolic compounds.

Attenuation of Endoplasmic Reticulum Stress Enhances Carvacrol-Induced Apoptosis in Osteosarcoma Cell Lines

Carvacrol is a monoterpenoid phenol that has excellent antimicrobial, antiviral, and anti-inflammatory activities. It can also improve wound healing. However, few studies have explored its antitumor effect on osteosarcoma. In this report, we tried to determine the potential efficacy of carvacrol against osteosarcoma cell lines. Our data revealed that carvacrol exposure inhibited the proliferation of osteosarcoma HOS and U-2 OS cells. In addition, carvacrol exposure enhanced the levels of cleaved PARP and caspase 3 and increased annexin V-positive cells, indicating that carvacrol exposure triggers apoptosis in osteosarcoma cell lines. Furthermore, the levels of reactive oxygen species (ROS) were enhanced after carvacrol exposure and cotreatment with NAC, the ROS scavenger, decreased the levels of cleaved PARP and caspase 3, suggesting the involvement of ROS in carvacrol-induced apoptosis. Importantly, we found that carvacrol exposure triggered several protein expressions related to endoplasmic reticulum (ER) stress, including GRP78/Bip, IRE1a, PERK, and CHOP, in HOS and U-2 OS cells, indicating that carvacrol exposure could result in ER stress in these cell lines. Cotreatment with the ER stress inhibitor 4-PBA increased the levels of cleaved PARP and caspase 3 and further suppressed cellular proliferation in carvacrol-exposed osteosarcoma cell lines. Overall, the results indicate that induced ER stress can protect cells from apoptosis, but increased ROS contributes to apoptosis in carvacrol-treated cells. In this report, we first demonstrate the role of ER stress in carvacrol-induced apoptosis and suggest that ER stress could be targeted to enhance the antitumor activity of carvacrol in osteosarcoma cell lines.

Therapeutic Oral Application of Carvacrol Alleviates Acute Campylobacteriosis in Mice Harboring a Human Gut Microbiota

Human Campylobacter jejuni infections are rising globally. Since antibiotics are usually not indicated in acute campylobacteriosis, antibiotic-independent intervention measures are desirable. The phenolic compound carvacrol constitutes a promising candidate molecule given its antimicrobial and immune-modulatory features. To test the disease-alleviating effects of oral carvacrol treatment in acute murine campylobacteriosis, IL-10^-/- mice harboring a human gut microbiota were perorally infected with C. jejuni and treated with carvacrol via the drinking water. Whereas C. jejuni stably established in the gastrointestinal tract of mice from the placebo cohort, carvacrol treatment resulted in lower pathogen loads in the small intestines on day 6 post infection. When compared to placebo, carvacrol ameliorated pathogen-induced symptoms including bloody diarrhea that was accompanied by less distinct histopathological and apoptotic cell responses in the colon. Furthermore, innate and adaptive immune cell numbers were lower in the colon of carvacrol- versus placebo-treated mice. Notably, carvacrol application dampened C. jejuni-induced secretion of pro-inflammatory mediators in intestinal, extra-intestinal and systemic organs to naive levels and furthermore, resulted in distinct shifts in the fecal microbiota composition. In conclusion, our preclinical placebo-controlled intervention study provides evidence that therapeutic carvacrol application constitutes a promising option to alleviate campylobacteriosis in the infected vertebrate host.

Antibacterial Effect of 16 Essential Oils and Modulation of mex Efflux Pumps Gene Expression on Multidrug-Resistant Pseudomonas aeruginosa Clinical Isolates: Is Cinnamon a Good Fighter?

The purpose of the study was to describe the antimicrobial activity of 16 common essential oils (EOs) on multidrug-resistant (MDR) Pseudomonas aeruginosa clinical isolates, including the determination of the effects on mex efflux pumps gene expression. Seventy-two clinical isolates of P. aeruginosa collected between 2020-2022 were screened for susceptibility to EOs using Kirby-Bauer disk diffusion to identify potential candidates for future alternative therapies. The minimal inhibitory concentration (MIC) was further determined for the EO that proved antibacterial activity following the disk diffusion screening. Positive and negative controls were also used for method validation. Since cinnamon EO exhibited the best antimicrobial activity, it was further used to evaluate its influence on mex A, B, C, E, and X efflux pumps gene expression using real-time RT-PCR. Cinnamon EO inhibited all P. aeruginosa strains, followed by thyme EO (37.5%, n = 27) and lavender EO (12.5%, n = 9). The other EOs were less efficient. The MIC detection showed that cinnamon at a concentration of 0.05% v/v inhibited all MDR P. aeruginosa isolates. Thyme, turmeric, peppermint, basil, clove, and lavender EOs presented various results, most of them having activity at concentrations higher than 12.5% v/v. By studying the activity of cinnamon EO on mex efflux pumps, it was found that mexA and mexB (66.5%) were generally under-expressed. The remarkable results produced using the very low concentrations of cinnamon EO, with 100% antimicrobial activity against multi-, extended-, and pan- drug-resistant (MDR, XDR, PDR) P. aeruginosa clinical isolates, completed with the severe alteration of the RNA messaging system, supports its potential to be used as adjuvant treatment, with impact on therapeutic results.

New insights in ferroptosis: Potential therapeutic targets for the treatment of ischemic stroke

Stroke is a common disease in clinical practice, which seriously endangers people's physical and mental health. The neurovascular unit (NVU) plays a key role in the occurrence and development of ischemic stroke. Different from other classical types of cell death such as apoptosis, necrosis, autophagy, and pyroptosis, ferroptosis is an iron-dependent lipid peroxidation-driven new form of cell death. Interestingly, the function of NVU and stroke development can be regulated by activating or inhibiting ferroptosis. This review systematically describes the NVU in ischemic stroke, provides a comprehensive overview of the regulatory mechanisms and key regulators of ferroptosis, and uncovers the role of ferroptosis in the NVU and the progression of ischemic stroke. We further discuss the latest progress in the intervention of ferroptosis as a therapeutic target for ischemic stroke and summarize the research progress and regulatory mechanism of ferroptosis inhibitors on stroke. In conclusion, ferroptosis, as a new form of cell death, plays a key role in ischemic stroke and is expected to become a new therapeutic target for this disease.

Determining the Antibiofilm Efficacy of Oregano Gel in an Ex Vivo Model of Percutaneous Osseointegrated Implants

Biofilm contamination is common in patients with percutaneous osseointegrated (OI) implants, leading to frequent infections, irritation, and discomfort. Reported infection rates soar up to 65% as the recalcitrant nature of biofilms complicates treatment. There is persistent need for therapies to manage biofilm burden. In response, we formulated and tested oregano essential oil in a topical gel as a potential biofilm management therapy. We developed an ex vivo system based on an established ovine OI implant model with Staphylococcus aureus ATCC 6538 biofilms as initial inocula. Gel was administered to the samples across a period of five days. Samples were quantified and colony forming unit (CFU) counts were compared against a positive control (initial bacterial inocula without treatment). Significant biofilm reduction was observed in samples treated with oregano gel compared to controls, demonstrating the potential of an oregano oil-based gel as a biofilm management therapy at the skin-implant interface of percutaneous OI implants.

Carvacrol preserves antioxidant status and attenuates kidney fibrosis via modulation of TGF-β1/Smad signaling and inflammation

Chronic kidney disease (CKD) with diverse aetiologies is emerging as a challenging kidney disorder associated with inflammation and interstitial fibrosis. Carvacrol (CVL) is a bioactive monoterpenoid found abundantly in oregano, thyme, and bergamot, having diverse pharmacological benefits. However, the effect of CVL against fibrotic changes in the kidneys is poorly defined. In the current study, a robust mouse model of renal fibrosis induced through unilateral ureteral obstruction (UUO) is used to investigate the anti-fibrotic activity of CVL. The mice were treated with two different oral doses of CVL (25 mg kg^-1 and 50 mg kg^-1 body weight) for 14 consecutive days. The UUO induction resulted in impaired renal function, severe histological damage, and collagen deposition in the obstructed kidney. Our findings revealed profound activation of transforming growth factor-β1 (TGF-β1) and NF-κB (p65) signaling along with the downregulation of antioxidant proteins, nuclear factor-erythroid factor 2-related factor 2 (Nrf2), NAD(P)H: quinone oxidoreductase 1 (NQO1), and superoxide dismutase (SOD) in the obstructed kidney. CVL administration markedly recovered antioxidant proteins and kidney histological changes. In addition, CVL blunted the NF-κB (p65) phosphorylation and reduced the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and cyclooxygenase 2 (COX-2) compared to the UUO control group. CVL also alleviated the increased fibrotic protein levels of TGF-β1, pSmad2/3, collagen I, collagen III, fibronectin, and myofibroblast activation and epithelial-mesenchymal transition (EMT) markers, including alpha-smooth muscle actin (α-SMA), E-cadherin, and vimentin in the kidneys. Findings from in vitro study also confirmed that CVL inhibits the EMT process in TGF-β1 stimulated renal tubular epithelial cells (NRK 52E cells). Collectively, our findings indicate that CVL administration attenuates kidney fibrosis by targeting oxidative stress and inflammation.

Antibacterial Activity of Clove, Oregano, Thyme, Eucalyptus, and Tea Tree Essential Oils against Escherichia coli and Klebsiella pneumoniae strains

Background: In view of the high recurrence rate of urinary tract infections and the increasing number of germs resistant to multiple antibiotics, the aim of the present study was to evaluate the antibacterial properties of clove, oregano, thyme, eucalyptus, tea tree essential oils (EOs) against 32 isolates of Escherichia coli and 28 isolates of Klebsiella pneumoniae from patients with urinary tract infections (UTI).

Methods: The agar disk diffusion method was used to assess the susceptibility of these isolates to essential oils and the minimal inhibitory concentration (MIC), and the minimal bactericidal concentration (MBC) were determined.

Results: Our results suggest that volatile phenols (such as carvacrol in oregano EO, thymol in thyme EO, and eugenol in clove EO) are more efficacious as antibacterial than non-aromatic compounds (such as eucalyptol in eucalyptus EO and terpinene derivatives in tea tree EO).

Conclusion : The oregano EO, followed by thyme appear to have the highest efficacy against Escherichia coli and Klebsiella pneumoniae isolates investigated.

Fabrication of electrospun nanofibers with moisture-triggered carvacrol release in fresh produce packaging

In this study, by incorporating polyethylene glycol (PEG) into the polylactic acid (PLA) nanofibers, a moisture-controlled system was developed in the release of carvacrol to the food package headspaces. With the use of electrospinning technology, an optimized solution (80:20 [PLA:PEG] polymer mixture incorporated with a carvacrol content of 20% [w/w polymer]) generated nanofibers with excellent encapsulation efficiency, loading capacity, and controlled release of carvacrol at different humidity levels. Carvacrol was prevented from release when the fibers were kept in dry states. When placed in food packaging with high humidity levels, the nanofibers manifested high and continuous release of carvacrol into the headspace. The shelf life of strawberries determined by visual inspection was extended for 2 extra days when packaged with the optimized nanofibers and had a significantly lower yeasts and mold counts (4.28 ± 0.34 log CFU/g) compared to strawberries packaged without nanofibers (5.22 ± 0.47 log CFU/g) 3 days after applying the nanofibers (p < 0.05). PRACTICAL APPLICATION: The nanofibers with PEG content as developed in this study represent a step forward in practical application of the electrospinning technology to enhance food quality in food preservation.

Recent Advances in Antimicrobial Nano-Drug Delivery Systems

Infectious diseases are among the major health issues of the 21st century. The substantial use of antibiotics over the years has contributed to the dissemination of multidrug resistant bacteria. According to a recent report by the World Health Organization, antibacterial (ATB) drug resistance has been one of the biggest challenges, as well as the development of effective long-term ATBs. Since pathogens quickly adapt and evolve through several strategies, regular ATBs usually may result in temporary or noneffective treatments. Therefore, the demand for new therapies methods, such as nano-drug delivery systems (NDDS), has aroused huge interest due to its potentialities to improve the drug bioavailability and targeting efficiency, including liposomes, nanoemulsions, solid lipid nanoparticles, polymeric nanoparticles, metal nanoparticles, and others. Given the relevance of this subject, this review aims to summarize the progress of recent research in antibacterial therapeutic drugs supported by nanobiotechnological tools.

Carvacrol Arrests the Proliferation of Hypopharyngeal Carcinoma Cells by Suppressing Ornithine Decarboxylase and Hyaluronidase Activities

Carvacrol, a monoterpene known for its pharmacological activities, is present in the essential oil of Origanum majorana, Origanum vulgare, Thymus vulgaris, and Lippia graveolens. It is used in food as a flavoring and preservative agent in cosmetics and medicines because of its useful bioactivities in clinical practice. However, carvacrol was not much explored for its anticancer potential. Targeting enzymes involved in carcinogenesis, such as ornithine decarboxylase (ODC), cyclooxygenase-2 (COX-2), lipoxygenase-5 (LOX-5), and hyaluronidase (HYAL) by monoterpenes are amongst the efficient approaches for cancer prevention and treatment. In this study, the efficacy of carvacrol was investigated against deregulated cancer biomarkers/targets in organ-specific human cancer cell lines (FaDu, K562, and A549) utilizing in vitro, in silico, and in vivo approaches. The efficacy of carvacrol was evaluated on human cancer cell lines using neutral red uptake (NRU), sulpho rhodamine B (SRB), and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. The mechanistic study was carried out in cell-based test systems. Further, the potency of carvacrol was confirmed by the quantitative real-time PCR analysis and molecular docking studies. The in vivo anti-tumor potential of carvacrol was performed on mice S-180 model, and the toxicity examination was accomplished through in silico approach. Carvacrol significantly impeded the growth of FaDu, K562, and A549 cell lines with IC₅₀ values ranging from 9.61 ± 0.05 to 81.32 ± 11.83 μM. Further, the efficacy of carvacrol was explored against different cancer targets in FaDu, K562, and A549 cell lines. Carvacrol inhibits the ODC, COX-2, LOX-5, and HYAL activities in FaDu cell line and ODC, COX-2, and HYAL activities in K562 cell line. The results were validated by expression analysis revealing the downregulation of the targeted gene with a significant change in the transcript level of ODC and HYAL in FaDu cell line with a fold change of 1.56 and 1.61, respectively. A non-significant effect of carvacrol was observed on the downstream signaling pathway of PI3K and HIF-1α/vascular endothelial growth factor (VEGF) in FaDu cells. The cell cycle, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and Annexin V-fluorescein isothiocyanate (FITC) experiments demonstrate that carvacrol induces apoptosis of FaDu cells. Further, the potency of carvacrol was also evaluated in vivo on mice S-180 tumor model, wherein it inhibits tumor growth (72%) at 75 mg/kg body weight (bw). ADMET studies predicted carvacrol as a safe molecule. Overall, carvacrol delayed the growth of FaDu, K562, and A549 cell lines by targeting enzymes involved in the carcinogenesis process. The existence of one hydroxyl group at the para position of carvacrol could be responsible for the anti-proliferative activity. Thus, carvacrol could be used as a pharmacophore to develop a safe and effective multi-targeted anti-cancer medicament.

Carvacrol Enhances the Antimicrobial Potency of Berberine in Bacillus subtilis

The essential oil carvacrol from oregano displays a wide range of biological activities among which is found the inhibition of efflux pumps. Thus, using carvacrol, the current work undertook the effort to potentiate the antimicrobial activity of berberine, a natural product with limited antimicrobial efficacy due to its efflux. Following the selection of concentrations for the combinatorial treatments, guided by checkerboard microtiter plate assay and growth experiments, ethidium bromide accumulation assay was used to find that 25 μg mL^-1 carvacrol displayed a weak efflux pump inhibitor character in Bacillus subtilis. Scanning electron microscopy images and cellular material leakage assays showed that carvacrol at this concentration neither altered the morphology nor the permeability of the membrane alone but when combined with 75 μg mL^-1 berberine. Among the efflux pumps of different families found in B. subtilis, except for BmrA and Mdr, the increase in the expressional changes was striking, with Blt displaying ~ 4500-fold increase in expression under the combination treatment. Overall, the findings demonstrated that carvacrol potentiated the effect of berberine; however, not only multiple pumps but also different targets may be responsible for the observed activity.

Conjugation of triphenylantimony(V) with carvacrol against human breast cancer cells

The organoantimony derivative of formula trans-O,O-[Ph₃Sb^V(Carv)₂] (TPAC) (CarvH = carvacrol) is obtained by the oxidation of triphenylstibine (Ph₃Sb^III) with hydrogen peroxide in the presence of carvacrol (CarvH). Physical methods such as X-ray Fluorescence (XRF) spectroscopy, single crystal and powder X-ray diffraction analysis (XRD and PXRD), Attenuated Total Reflection Fourier Transform Infra-red (ATR-FTIR) spectroscopy, Thermogravimetric Differential Thermal Analysis (TG-DTA) and Differential Scanning Calorimetry (DTG/DSC), confirm the retention of the formula of TPAC throughout the sample mass in solid state, while UV-Vis spectroscopy in the solution. TPAC is the first example of carvacrol (the main ingredient of oregano) covalently bonded to any metal ion. Only the trans-O,O-[Ph₃Sb(Carv)₂] isomer was isolated suggesting stereo-selectivity of the preparation route. TPAC inhibits in vitro both human breast adenocarcinoma cell lines: MCF-7 (positive to hormones receptor (HR +)), MDA-MB-231 (negative to hormones receptor (HR-)) stronger than normal human fetal lung fibroblast cells (MRC-5). The MCF-7 cells morphology, DNA fragmentation, Acridine Orange/Ethidium Bromide (AO/EB) Staining, cell cycle arrest and mitochondrial membrane permeabilization tests suggest an apoptotic pathway for cell death, especially, through the mitochondrion damage. The binding type of TPAC toward the calf thymus CT-DNA was initially deduced ex vivo from the differentiation of the DNA solution viscosity. Fluorescence spectroscopy confirms the interaction mode suggested. Spectroscopic evidence (FTIR, UV-Vis) suggest that glutathione (GSH) (a tripeptide over-expressed in tumor cells) induces conversion of non-active pentavalent antimony, which is contained in TPAC, to active trivalent one, providing a new strategy for the development of targeted chemotherapeutics.

Comparative study of the antioxidant activity of the essential oils of five plants against the H2O2 induced stress in Saccharomyces cerevisiae

The purpose of this work was to investigate the protective effect of five essential oils (EOs); Rosmarinus officinalis, Thymus vulgaris, Origanum compactum Benth., Eucalyptus globulus Labill. and Ocimum basilicum L.; against oxidative stress induced by hydrogen peroxide in Saccharomyces cerevisiae. The chemical composition of the EOs was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). The in vitro antioxidant activity was evaluated and the protective effect of EOs was investigated. Yeast cells were pretreated with different concentrations of EOs (6.25–25 µg/ml) for an hour then incubated with H₂O₂ (2 mM) for an additional hour. Cell viability, antioxidants (Catalase, Superoxide dismutase and Glutathione reductase) and metabolic (Succinate dehydrogenase) enzymes, as well as the level of lipid peroxidation (LPO) and protein carbonyl content (PCO) were evaluated. The chemical composition of EOs has shown the difference qualitatively and quantitatively. Indeed, O. compactum mainly contained Carvacrol, O. basilicum was mainly composed of Linalool, T. vulgaris was rich in thymol, R. officinalis had high α-Pinene amount and for E. globulus, eucalyptol was the major compound. The EOs of basil, oregano and thyme were found to possess the highest amount of total phenolic compounds. Moreover, they have shown the best protective effect on yeast cells against oxidative stress induced by H₂O₂. In addition, in a dose dependent manner of EOs in yeast medium, treated cells had lower levels of LPO, lower antioxidant and metabolic enzymes activity than cells exposed to H₂O₂ only. The cell viability was also improved. It seems that the studied EOs are efficient natural antioxidants, which can be exploited to protect against damages and serious diseases related to oxidative stress.

Transcriptomic analysis of interactions between Lymantria dispar larvae and carvacrol

Due to its biological activity, carvacrol (CAR) is widely used in medicine, agriculture, and forestry. Our previous studies showed that in Lymantria dispar larvae, CAR treatment can induce the production of antifeedants and lead to growth inhibition and death of larvae. However, the effect CAR exerts on RNA levels in L. dispar larvae remains unclear. In this study, the Illumina HiSeq4000 sequencing platform was used to sequence the total RNA of L. dispar larvae. A total of six cDNA libraries (three treatments and three controls) were established and 39,807 genes were generated. Compared with the control group, 296 differentially expressed genes (DEGs) (142 up-regulated and 154 down-regulated) were identified after CAR treatment. GO and KEGG enrichment analyses showed that these DEGs mainly clustered in the metabolism of xenobiotics, carbohydrates, and lipids. Furthermore, 12 DEGs were found to be involved in detoxification, including six cytochrome P450s, two esterases, one glutathione peroxidase, one UDP-glycosyltransferase gene, and two genes encoding heat shock proteins. The expression levels of detoxification genes changed under CAR treatment (especially P450s), which further yielded candidate genes for explorations of the insecticidal mechanism of CAR. The reliability of transcriptome data was verified by qRT-PCR. The enzyme activities of CYP450 and acid phosphatase significantly increased (by 38.52 U/mg·prot and 0.12 μmol/min·mg, respectively) 72 h after CAR treatment. However, the activity of alkaline phosphatase did not change significantly. These changes in enzyme activity corroborated the reliability of the transcriptome data at the protein level. The results of GO enrichment analysis of DEGs indicated that CAR influenced the oxidation-reduction process in L. dispar larvae. Furthermore, CAR can cause oxidative stress in L. dispar larvae, identified through the determination of peroxidase and polyphenol oxidase activities, total antioxidant capacity, and hydrogen peroxide content. This study provides useful insight into the insecticidal mechanism of CAR.

Antifungal Carvacrol Loaded Chitosan Nanoparticles

The increased prevalence and incidence of fungal infections, of which Candida albicans represents one of the most life-threatening organisms, is prompting the scientific community to develop novel antifungal molecules. Many essential oils components are attracting attention for their interesting antifungal activities. Given the chemical and physical characteristics of these compounds, the use of appropriate nanodelivery systems is becoming increasingly widespread. In this study, chitosan nanoparticles were prepared using an ionic gelation procedure and loaded with the phenolic monoterpene carvacrol. After a bioassay guided optimization, the best nanoparticle formulation was structurally characterized by means of different spectroscopic (UV, FTIR and DLS) and microscopy techniques (SEM) and described for their functional features (encapsulation efficiency, loading capacity and release kinetics). The antifungal activity of this formulation was assayed with different Candida spp., both in planktonic and biofilm forms. From these studies, it emerged that the carvacrol loaded nanoparticles were particularly active against planktonic forms and that the antibiofilm activity was highly dependent on the species tested, with the C. tropicalis and C. krusei strains resulting as the most susceptible.

Anti-Inflammatory and Antioxidant Properties of Carvacrol and Magnolol, in Periodontal Disease and Diabetes Mellitus

Periodontal disease and diabetes mellitus are two pathologies that are extremely widespread worldwide and share the feature of chronic inflammation. Carvacrol is a phenolic monoterpenoid, produced by a variety of herbs, the most well-known of which is Origanum vulgare. Magnolol is a traditional polyphenolic compound isolated from the stem bark of Magnolia officinalis, mainly used in Chinese medicine. The purpose of this paper is to review the therapeutic properties of these bioactive compounds, in the treatment of periodontitis and diabetes. Based on our search strategy we conducted a literature search in the PubMed and Google Scholar databases to identify studies. A total of one hundred eighty-four papers were included in the current review. The results show that carvacrol and magnolol have anti-inflammatory, antioxidant, antimicrobial, anti-osteoclastic, and anti-diabetic properties that benefit both pathologies. Knowledge of the multiple activities of carvacrol and magnolol can assist with the development of new treatment strategies, and the design of clinical animal and human trials will maximize the potential benefits of these extracts in subjects suffering from periodontitis or diabetes.

New carvacrol and thymol derivatives as potential insecticides: synthesis, biological activity, computational studies and nanoencapsulation

New compounds with potential insecticide activity were synthesized by structural modifications performed in the monoterpenoid phenolic moieties of carvacrol and thymol, resulting in a set of derivatives with the ether function containing the propyl, chloropropyl or hydroxypropyl chains, as well as a bicyclic ether with an unsaturated chain containing a carboxylic acid terminal. In addition, an analogue of carvacrol and thymol isomers bearing methoxyl, 1-hydroxyethyl and (3-chlorobenzoyl)oxy, instead of the three original methyl groups, was also synthesized. Several structural changes that resulted in diminished insecticide activity have been identified, but two significantly active molecules have been synthesized, one of them being less toxic to human cells than the naturally-derived starting materials. Structure-based inverted virtual screening and molecular dynamics simulations demonstrate that these active molecules likely target the insect odorant binding proteins and/or acetylcholinesterase and are able to form stable complexes. For the most promising compounds, nanoencapsulation assays were carried out in liposomes of egg phosphatidylcholine/cholesterol (7 : 3) prepared by both thin film hydration and ethanolic injection methods. The compound-loaded liposomes were generally monodisperse and with sizes smaller than or around 200 nm. The thin film hydration method allowed high encapsulation efficiencies (above 85%) for both compounds and a delayed release, while for the systems prepared by ethanolic injection the encapsulation efficiency is lower than 50%, but the release is almost complete in two days.

Conformational Space, IR-Induced, and UV-Induced Chemistry of Carvacrol Isolated in a Low-Temperature Argon Matrix

In this work, monomers of carvacrol (5-isopropyl-2-methylphenol), a natural monoterpene exhibiting wide range bioactivity, were trapped in a cryogenic argon matrix and characterized by infrared spectroscopy, while quantum chemical calculations at the B3LYP and MP2 levels were employed to characterize the conformational landscape of the isolated molecule. Four conformers have been localized on the potential energy surface, and the factors accounting for their relative stability were analyzed. The two most stable conformers of carvacrol, differing in the relative orientation of the isopropyl group and both having the OH group pointing away from the vicinal methyl fragment, were identified in the cryomatrix for the first time. The individual spectral signatures of the two conformers were distinguished based on the change in their relative abundance induced by exposing the matrix to broadband infrared light. Matrix-isolated carvacrol was also irradiated with broadband UV light (λ > 200 nm), which resulted in the cleavage of the OH group. Recombination of the released H atom at the ortho- or para-position of the ring resulted in the formation of alkyl-substituted cyclohexadienones. These were found to undergo subsequent valence and open-ring isomerizations, leading, respectively, to the formation of a Dewar isomer and open-chain conjugated ketenes. Decarbonylation of the photoproducts was also observed for longer irradiation times. A mechanistic analysis of the observed photochemical transformations is presented.

Feasibility of Using Carvacrol/Starch Edible Coatings to Improve the Quality of Paipa Cheese

Paipa cheese is the only Colombian semi-ripened cheese with protected geographical indication. In the current work, the effect of applying starch coatings carrying carvacrol on Paipa cheeses was analyzed. Coatings were prepared based on blends of potato starch (2 g/100 g), carvacrol (0.1 g/100 g), polysorbate 80, glycerol, and water and applied to the cheese's surface by brushing. Uncoated cheeses were also analyzed for comparison. Moreover, films were prepared and characterized in terms of their moisture content, water vapor permeability, mechanical properties, transparency, water solubility, swelling (%), and antioxidant activity. Carvacrol/starch films showed a slight decrease in their water solubility and Young's modulus, while not significant changes were observed in water vapor permeability, moisture content, transparency, and swelling behavior, in comparison with the starch films. After application on the Paipa cheeses, the carvacrol/starch coatings enhanced the brightness of the cheeses without causing significant changes in water activity, moisture content, color attributes, and mesophilic aerobic bacteria and molds/yeasts count. Moreover, edible coatings have a significant effect on the hardness, the gumminess, the springiness, and the chewiness of the Paipa cheese. Coated cheeses were better preserved at day 60 of storage because they did not show changes in their lightness, hardness, and springiness.

The Effect of Controlled-Release Carvacrol on Safety and Quality of Blueberries Stored in Perforated Packaging

The objective of this research was to evaluate the use of a controlled-release carvacrol powder to delay storage decay and maintain the safety of blueberries. The controlled-release carvacrol powder was a microcapsule of carvacrol (11% (w/w) active carvacrol) surrounded by a pectin/sodium alginate matrix. The microcapsules were packed in an air-permeable pouch, and then attached to the top of a clamshell filled with blueberries. The blueberries, inoculated with Escherichia coli or Colletotrichum acutatum, or non-inoculated control, were monitored for microbial growth and quality for 10 days at 10 °C and 5 days at 20 °C. Three treatments were compared: controlled-release microencapsulated carvacrol, non-encapsulated carvacrol, and control. The results showed that both the microencapsulated carvacrol and the non-encapsulated carvacrol treatments significantly reduced the populations of yeast and mold, and of E. coli and mesophilic aerobic bacteria. The microencapsulated carvacrol treated berries retained better quality due to significantly lower weight loss than control after 10 days at 10 °C. Sensory panelists found that the microencapsulated carvacrol berries had significantly higher overall blueberry flavor and lower discernible off-flavor in comparison with the non-encapsulated treatment after 3 days at 20 °C. The fruit internal quality, including total soluble solids content (SSC), and titratable acidity (TA), was not significantly affected by any treatment. These results indicate that pectin/sodium alginate controlled-release microencapsulated carvacrol can be used for the preservation of blueberries or other small fruit.

Action of Carvacrol on Parascaris sp. and Antagonistic Effect on Nicotinic Acetylcholine Receptors

Parascaris sp. is the only ascarid parasitic nematode in equids and one of the most threatening infectious organisms in horses. Only a limited number of compounds are available for treatment of horse helminthiasis, and Parascaris sp. worms have developed resistance to the three major anthelmintic families. In order to overcome the appearance of resistance, there is an urgent need for new therapeutic strategies. The active ingredients of herbal essential oils are potentially effective antiparasitic drugs. Carvacrol is one of the principal chemicals of essential oil from Origanum, Thymus, Coridothymus, Thymbra, Satureja and Lippia herbs. However, the antiparasitic mode of action of carvacrol is poorly understood. Here, the objective of the work was to characterize the activity of carvacrol on Parascaris sp. nicotinic acetylcholine receptor (nAChR) function both in vivo with the use of worm neuromuscular flap preparations and in vitro with two-electrode voltage-clamp electrophysiology on nAChRs expressed in Xenopus oocytes. We developed a neuromuscular contraction assay for Parascaris body flaps and obtained acetylcholine concentration-dependent contraction responses. Strikingly, we observed that 300 µM carvacrol fully and irreversibly abolished Parascaris sp. muscle contractions elicited by acetylcholine. Similarly, carvacrol antagonized acetylcholine-induced currents from both the nicotine-sensitive AChR and the morantel-sensitive AChR subtypes. Thus, we show for the first time that body muscle flap preparation is a tractable approach to investigating the pharmacology of Parascaris sp. neuromuscular system. Our results suggest an intriguing mode of action for carvacrol, being a potent antagonist of muscle nAChRs of Parascaris sp. worms, which may account for its antiparasitic potency.

Effect of Replacing in-Feed Antibiotic Growth Promoters with a Combination of Egg Immunoglobulins and Phytomolecules on the Performance, Serum Immunity, and Intestinal Health of Weaned Pigs Challenged with Escherichia coli K88

Simple Summary

Post-weaning diarrhea (PWD) in pigs caused by Escherichia coli (E. coli) is a global problem which results in substantial economic losses, due to decreased performance and a high incidence of mortality and morbidity. Due to the banning of antibiotic growth promoters (AGPs) by many countries, it would be valuable to find environmentally friendly and non-antibiotic alternatives to AGPs and to evaluate their effectiveness. Both immunoglobulins and phytomolecules are separately reported as benefiting animal growth, but the efficiency of combinations of immunoglobulins and phytomolecules as AGP alternatives is largely unknown. In this study, the results showed that a mixture of immunoglobulin and phytomolecule administration had positive effects on feed efficiency, diarrhea reduction, intestinal morphology, and coliform control. Combinations of immunoglobulins and phytomolecules can be used as a potential alternative to AGPs in weanling piglets.

Abstract

The study was conducted to investigate the effects of replacing antibiotic growth promoters (AGPs) with an egg immunoglobulin (IgY) combined with phytomolecules (PM) on the growth rate, serum immunity, and intestinal health of weaned pigs challenged with Escherichia coli K88 (E. coli K88). A total of 192 piglets were weaned at 28 days old with an average weight of 7.29 (± 0.04) kg. They were randomly divided into four treatments containing eight replicates with six piglets per replicate. The treatment groups were NC and PC fed a basal diet, AGP fed a basal diet supplemented with 75 mg/kg chlortetracycline, 50 mg/kg oxytetracycline calcium, and 40 mg/kg zinc bacitracin, IPM fed a basal diet supplemented with IgY at dose of 2.5 g/kg and 1.0 g/kg and PM at dose of 300 mg/kg and 150 mg/kg during days 1 to 17 and 18 to 42, respectively. On days 7 to 9 of the experiment, piglets in the PC, AGP, and IPM groups were orally challenged with 20 mL E. coli K88 (10⁹ CFU/mL), while piglets in the NC group were challenged with 20 mL medium without E. coli K88. The E. coli K88 challenge model was successful as the incidence of post-weaning diarrhea (PWD) of piglets challenged with E. coli K88 was significantly higher than that of those unchallenged piglets during the challenge time (days 7 to 9) and days 1 to 7 of post-challenge (p < 0.05). A diet with combinations of IgY and PM and AGPs significantly decreased the incidence of PWD during the challenge time and days 1 to 7 of post-challenge (p < 0.05) compared to the PC group and significantly improved the ratio of feed to weight gain (F:G) during days 1 to 17 of the experiment compared to the NC and PC groups (p < 0.05). In comparison with the PC group, piglets in the IPM group had significantly higher serum levels of IgA, IgG, and IgM (p < 0.05), but lower serum IL-1β on day 17 of experiement (p < 0.05). Besides, diet supplementation with AGP significantly decreased serum IL-1β, IL-6, and TNF-α on days 17 and 42 (p < 0.05) with comparison to the PC group. Piglets in the IPM group showed a significantly lower level of fecal coliforms (p < 0.05), but a higher villus height of jejunum and ileum and higher ratio of villus height to crypt depth of duodenum and jejunum (p < 0.05) than those piglets in the PC group. In summary, diet supplementation with a mixture of IgY and PM decreased the incidence of PWD and coliforms, increased feed conversion ratio, and improved intestinal histology and immune function.

Antifungal Activity of Novel Formulations Based on Terpenoid Prodrugs against C. albicans in a Mouse Model

Carvacrol (CAR), a phenolic monoterpenoid, has been extensively investigated for its antimicrobial and antifungal activity. As a result of its poor physicochemical properties, water soluble carvacrol prodrugs (WSCPs) with improved water solubility were previously synthesized and found to possess antimicrobial activity. Here, three novel CAR analogs, WSCP1, WSCP2, and WSCP3, were tested against fluconazole (FLU)-sensitive and -resistant strains where they showed greater antifungal activity than CAR against C. albicans. The probable mechanism by which the CAR prodrugs exert the antifungal activity was studied. Results from medium acidification assays demonstrated that the CAR and its synthetically designed prodrugs inhibit the yeast plasma membrane H+-ATPase (Pma1p), an essential target in fungi. In other words, in vitro data indicated that CAR analogs can prove to be a better alternative to CAR considering their improved water solubility. In addition, CAR and WSCP1 were developed into intravaginal formulations and administered at test doses of 50 mg/kg in a mouse model of vulvovaginal candidiasis (VVC). Whereas the CAR and WSCP1 formulations both exhibited antifungal efficacy in the mouse model of VVC, the WSCP1 formulation was superior to CAR, showing a remarkable decrease in infection by ~120-fold compared to the control (infected, untreated animals). Taken together, a synthetically designed prodrug of CAR, namely WSCP1, proved to be a possible solution for poorly water-soluble drugs, an inhibitor of an essential yeast pump in vitro and an effective and promising antifungal agent in vivo.

The Neurotrophic-Like Effect of Carvacrol: Perspective for Axonal and Synaptic Regeneration

Carvacrol (CARV) is a phytochemical widely used as flavoring, preservative, and fragrance in food and cosmetic industries. CARV is able to cross the blood-brain barrier (BBB) and has demonstrated protective potential against neurodegenerative diseases by several mechanisms, including antioxidant, anti-inflammatory, anticholinesterase, and antiapoptotic effects. However, it is not known whether CARV is able to modulate axonal and synaptic plasticity, crucial events in cognition, memory, and learning. Abnormalities in axonal and synaptic plasticity, low levels of neurotrophins, and bioenergetic failure have been associated with the pathogenesis of neurodegenerative diseases, including Parkinson's (PD) and Alzheimer's diseases (ADs). Small lipophilic molecules with neurotrophic activity might be able to restore the axonal and synaptic networks that are lost in neurodegenerative processes. Therefore, this study investigated the neurotrophic potential of CARV in PC12 cell-based neuronal model. Carvacrol induced neurite outgrowth by activating the NGF high-affinity trkA receptor and the downstream PI3K-AKT and MAPK-ERK pathways, without depending on NGF. In addition, CARV increased the expression of proteins involved in neuronal plasticity (β-tubulin III, F-actin, 200-kDa neurofilament, GAP-43 and synapsin-I) and improved bioenergetics (AMPKα, p-AMPKα, and ATP). Our study showed, for the first time, a promising neurotrophic mechanism of CARV that could be beneficial in neurodegenerative and neurological diseases.

Chemical Composition of Essential Oil from Flower of 'Shanzhizi' (Gardenia jasminoides Ellis) and Involvement of Serotonergic System in Its Anxiolytic Effect

Gardenia jasminoides Ellis is a famous fragrant flower in China. Previous pharmacological research mainly focuses on its fruit. In this study, the essential oil of the flower of 'Shanzhizi', which was a major variety for traditional Chinese medicine use, was extracted by hydro distillation and analyzed by GC-MS. Mouse anxiety models included open field, elevated plus maze (EPM), and light and dark box (LDB), which were used to evaluate its anxiolytic effect via inhalation. The involvement of monoamine system was studied by pretreatment with neurotransmitter receptor antagonists WAY100635, flumazenil and sulpiride. The monoamine neurotransmitters contents in the prefrontal cortex (PFC) and hippocampus after aroma inhalation were also analyzed. The results showed that inhalation of G. jasminoides essential oil could significantly elevated the time and entries into open arms in EPM tests and the time explored in the light chamber in LDB tests with no sedative effect. WAY100635 and sulpiride, but not flumazenil, blocked its anxiolytic effect. Inhalation of G. jasminoides essential oil significantly down-regulated the 5-HIAA/5-HT in the PFC and reduced the 5-HIAA content in hippocampus compared to the control treatment. In conclusion, inhalation of gardenia essential oil showed an anxiolytic effect in mice. Monoamine, especially the serotonergic system, was involved in its anxiolytic effect.