Flaxseed Mucilage/Hydroxypropyl Methylcellulose and Sodium Alginate/Polyvinyl Alcohol Composite Bilayer Film as a Promising Drug Carrier for Periodontal Treatment

Objectives

The present study focused on the formulation of mucoadhesive bilayer composite films for the treatment of periodontitis and evaluation of their physicochemical properties.

Materials and Methods

The solvent casting technique was used to prepare films. The primary layer (D) was prepared with flaxseed and hydroxypropyl methylcellulose composite to sustain the release of doxycycline hyclate. The second layer (S) comprised sodium alginate and polyvinyl alcohol composite for faster release of clove oil. Both layers were combined to generate the bilayer film (B). All formulations were characterized further to obtain an optimized formulation.

Results

Attenuated total reflection-Fourier transform infrared radiation results showed intactness of drug and clove oil in the presence of excipients. The pH of the films was compatible with the periodontal cavity and the thickness was suitable for inserting into the cavity. The immediate release layer showed faster disintegration and swelling. The content of clove oil was above 80%. The rate of swelling of the primary layer was slow and drug content complied with the United States Pharmacopoeia. Scanning electron microscope analysis revealed intact, non-porous and smooth films. Films exhibited better mechanical strength and bioadhesiveness. Clove oil was released from the immediate release layer within 10 min, and doxycycline hyclate release was retarded to a minimum of up to 8 h in the primary layer as well as the bilayer. Formulation also had a significant effect on both Escherichia coli and Staphylococcus aureus.

Conclusion

In the current study, bilayers were successfully prepared and characterized. The optimized formulation can be effectively used for the treatment of periodontitis.

Evaluation of Antimicrobial and Preservative Effects of Cinnamaldehyde and Clove Oil in Catfish (Ictalurus punctatus) Fillets Stored at 4 °C

This study aimed to evaluate cinnamaldehyde (CN) and clove oil (CO) effectiveness in inhibiting growth and killing spoilage and total aerobic bacteria when overlaid with catfish fillet stored at 4 °C. A 1.00 mL concentration of CO inhibited growth by 2.90, 1.96, and 1.96 cm, respectively, for S. baltica, A. hydrophilia, and total bacteria. Similarly, treatment with 1.00 mL of CN resulted in ZIB of 2.17, 2.10, and 1.10 cm, respectively, for S. baltica, A. hydrophilia, and total bacteria from catfish exudates. Total bacteria from catfish exudates treated with 0.50 mL CN for 40 min, resulted in a 6.84 log decrease, and treatment with 1.00 mL resulted in a 5.66 log decrease at 40 min. Total bacteria exudates treated with 0.50 mL CO resulted in a 9.69 log reduction at 40 min. Total bacteria treated with 1.00 mL CO resulted in a 7.69 log decrease at 7 days, while untreated pads overlaid with catfish resulted in ≥9.00 CFU/mL. However, treated absorbent pads with catfish at 7 days, using 0.50 mL and 1.00 mL CN, had a bacterial recovery of 5.53 and 1.88 log CFU/mL, respectively. Furthermore, CO at 0.50 mL and 1.00 mL reduced the bacteria count to 5.21 and 1.53 log CFU/mL, respectively, at day 7.

Peer review of the pesticide risk assessment of the active substance clove oil

The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State, Malta, for the pesticide active substance clove oil are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions for the amendment of approval were reached on the basis of the evaluation of the representative use of clove oil as a preharvest nematicide on tomatoes and cucumbers (permanent greenhouse use). The representative use evaluated for the renewal of approval of clove oil was as post-harvest fungicide and bactericide on apples, pears and peaches (indoor uses). The reliable endpoints appropriate for use in regulatory risk assessment are presented. Endpoints not relevant to the scope of the proposed amendment of approval conditions will be addressed in the context of the renewal of approval procedure of clove oil running in parallel (AIR IV, EFSA Q-2016-00809). Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.

Chitosan-Oxidized Pullulan Hydrogels Loaded with Essential Clove Oil: Synthesis, Characterization, Antioxidant and Antimicrobial Properties

Emulsion hydrogels are promising materials for encapsulating and stabilizing high amounts of hydrophobic essential oils in hydrophilic matrices. In this work, clove oil-loaded hydrogels (CS/OP-C) are synthesized by combining covalent and physical cross-linking approaches. First, clove oil (CO) was emulsified and stabilized in a chitosan (CS) solution, which was further hardened by Schiff base covalent cross-linking with oxidized pullulan (OP). Second, the hydrogels were subjected to freeze-thaw cycles and, as a result, the clove oil was stabilized in physically cross-linked polymeric walls. Moreover, due to cryogelation, the obtained hydrogels exhibited sponge-like porous interconnected morphology (160-250 µm). By varying the clove oil content in the starting emulsion and the degree of cross-linking, the hydrogels displayed a high water retention capacity (swelling ratios between 1300 and 2000%), excellent elastic properties with fast shape recovery (20 s) after 70% compression, and controlled in vitro clove oil release in simulated skin conditions for 360 h. Furthermore, the prepared clove oil-loaded hydrogels had a strong scavenging activity of 83% and antibacterial and antifungal properties, showing a bacteriostatic effect after 48 and 72 h against S. aureus and E. coli. Our results recommend the new clove oil-embedded emulsion hydrogels as promising future materials for application as wound dressings.

Larvicidal evaluation of two novel cationic gemini surfactants against the potential vector of West Nile virus Culex pipiens Linnaeus (Diptera: Culicidae)

The development of insecticide resistance is a serious consequence of the widespread applications of synthetic insecticides. Recent studies have provided alternatives to currently available insecticides. Here, novel cationic gemini surfactants were synthesized to assess their insecticidal activities using laboratory and field strains larvae of Culex pipiens Linnaeus (Diptera: Culicidae). The efficacy of these surfactants was compared to that of clove oil and spinosad. The two surfactants G1 and G2 showed good insecticidal activities in laboratory strain with LC50 0.013 and 0.054 ppm, respectively, relative to spinosad with LC50 0.027 ppm, 48 h posttreatment. Although spinosad showed high efficiency against lab strain, it exhibited a high resistance ratio (RR) of 15.111 and 13.111 toward the field strain at 24 and 48 h posttreatment, respectively. The two gemini surfactants have a good safety profile and low RR (RR <5), which is close to clove oil; however, G1 and G2 presented high activities with 11,043.230 and 2658.648 folds, respectively, compared to clove oil. The treated Cx. pipiens larvae showed severe morphological malformations after treatment with gemini surfactants. The results of this study are promising in terms of developing novel, effective, affordable, and safe approaches for mosquito control strategies to reduce the risk of arbovirus transmission, which remains a global public health threat.

Benchmark Dose Approach to DNA and Liver Damage by Chlorpyrifos and Imidacloprid in Male Rats: The Protective Effect of a Clove-Oil-Based Nanoemulsion Loaded with Pomegranate Peel Extract

Pesticides are widely used around the world to increase crop production. They also have negative impacts on animals, humans, and the ecosystem. This is the first report evaluating a novel pomegranate-extract-loaded clove-oil-based nanoemulsion (PELCN) and its potential for reducing oxidative stress and DNA damage, as well as its hepatoprotective effects against imidacloprid (IM) and chlorpyrifos (CPF) toxicity in male rats. The benchmark dose (BMD) approach was also used to study the dose-response toxicity of IM and CPF. IM and CPF were administered daily for 28 days at doses of 14, 28, and 54 mg/kg body weight (bw) of IM and 1, 2, and 4 mg/kg bw of CPF via drinking water. The PELCN was administered orally at a dose of 50 mg/kg bw/day of pomegranate extract, 500 mg/kg bw of the clove oil nanoemulsion, and IM or CPF at high doses in the drinking water. In male rats, IM and CPF caused a reduction in body weight gain and hepatotoxic effects as evidenced by increases in the liver enzymes AST, ALT, and ALP. They caused oxidative damage in the liver of male rats as indicated by the decreased liver activity of the GST, GPX, SOD, and CAT enzymes and decreased serum TAC. IM and CPF produced a significant dose-dependent increase in DNA damage in hepatocyte cells, resulting in moderate to severe liver damage with cells that are more inflammatory and have enlarged sinusoids and compacted nuclei. IM had a higher BMD than CPF for both body and liver weight, suggesting that CPF was more dose-dependently toxic than IM. Albumin was a highly sensitive liver biomarker for IM, while total protein was a biomarker for the CPF-treated rats. GPx was an extremely sensitive biomarker of oxidative stress in the IM treatment, while CAT and GPx were highly sensitive parameters in the CPF-treated rats. Therefore, at comparable doses, CPF has a higher potential to cause liver damage and oxidative stress than IM. The hepatotoxicity of IM and CPF can be mitigated by administering a nanoemulsion containing clove oil and pomegranate extract. The nanoemulsion acts as a protector against the oxidative stress caused by these insecticides, especially at high doses. The nanoemulsion based on clove oil increases the bioavailability and stability of the pomegranate extract, which has antioxidant properties.

Controlled Size Oils Based Green Fabrication of Silver Nanoparticles for Photocatalytic and Antimicrobial Application

The particle size at the nanometric level allows the manifestation of remarkable properties, chiefly due to changes in surface-to-volume ratio. This study is attributed to the novel green synthesis of nano silver by using essential oils as a capping and reducing agent. Clove oil, cinnamon oil, and cardamom oil were selected for the eco-friendly and low-cost fabrication of silver nanoparticles. The prepared nanoparticles were characterized by photoluminescence spectroscopy, FT-IR spectroscopy, X-Ray diffraction, energy dispersive X-ray spectroscopy, dynamic laser light scattering, thermogravimetric analysis, and transmission electron microscopy. It was found that samples prepared by using cinnamon oil (20 nm) and cardamom oil (12 nm) had smaller particle sizes as compared to those synthesized by using clove oil (45 nm). All the prepared samples exhibited very strong antimicrobial activities with a clear zone of inhibition (6-24 mm) against Staphylococcus aureus, Klebsiella pneumoniae, and Candida albicans. Very resilient photocatalytic activities of the samples were observed against Allura red and fast green dyes. It was concluded that the cinnamon oil-based system is the best size reducer and size homogenizer (less chances of agglomeration) as compared to clove oil and cardamom oil (more chances of agglomeration) for the synthesis of silver nanoparticles.

Rapid molecular assay for the evaluation of clove essential oil antifungal activity against wheat common bunt

Common bunt of durum wheat (DW), Triticum turgidum L. ssp. durum (Desf.) Husn., is caused by the two closely related fungal species belonging to Tilletia genus (Tilletiales, Exobasidiomycetes, Ustilaginomycotina): Tilletia laevis Kühn (syn. T. foetida (Wallr.) Liro.) and T. caries (DC) Tul. (syn. T. tritici (Bjerk.) G. Winter). This is one of the most devastating diseases in wheat growing areas worldwide, causing considerable yield loss and reduction of wheat grains and flour quality. For these reasons, a fast, specific, sensitive, and cost-effective method for an early diagnosis of common bunt in wheat seedlings is urgent. Several molecular and serological methods were developed for diagnosis of common bunt in wheat seedlings but at late phenological stages (inflorescence) or based on conventional PCR amplification, with low sensitivity. In this study, a TaqMan Real Time PCR-based assay was developed for rapid diagnosis and quantification of T. laevis in young wheat seedlings, before tillering stage. This method, along with phenotypic analysis, was used to study conditions favoring pathogen infection and to evaluate the effectiveness of clove oil-based seed dressing in controlling the disease. The overall results showed that: i) the Real Time PCR assay was able to quantify T. laevis in young wheat seedlings after seed dressing by clove oil in different formulations, greatly reducing times of analysis. It showed high sensitivity, detecting up to 10 fg of pathogen DNA, specificity and robustness, allowing to directly analyze crude plant extracts and representing a useful tool to speed up the tests of genetic breeding for disease resistance; ii) temperature was a critical point for disease development when using wheat seeds contaminated by T. laevis spores; iii) at least one of the clove oil-based formulations tested was able to efficiently control wheat common bunt, suggesting that clove oil dressing could represent a promising tool for managing the disease, especially in sustainable farming.

Physical, morphological and storage stability of clove oil nanoemulsion based delivery system

Clove oil based Nanoemulsions (NE) were prepared ultrasonically using Tween 80 and soy lecithin as synthetic and natural surfactants, respectively. The developed NEs were characterized for various parameters (particle size, polydispersity index, zeta potential, morphology, viscosity, colour, turbidity and pH) and the comparative effect of both the surfactants at variable levels (oil:tween 80-1:1, 1:2, 1:3 and 1:4 and oil: soy lecithin- 1:1, 1:1.5 and 1:2) was assessed. It was found that the type of surfactant and oil to surfactant ratio significantly affected particle size and stability of NEs. The NE prepared using tween 80 @1:3 had smallest average droplet diameter (40.9 nm). The formulated NEs were stored at 25 °C and 4 °C and analyzed for turbidity, pH and phase separation up to 90 days. Results revealed that the type and concentration of the surfactant significantly influenced the particle size and stability of NEs. NEs prepared using tween 80 were found to be more viscous than those prepared with soy lecithin. The prepared clove oil NEs have important implication to be used as a natural delivery system to increase the shelf life of food products.

Nanoemulsions of Clove Oil Stabilized with Chitosan Oleate-Antioxidant and Wound-Healing Activity

Clove oil (CO) is a powerful antioxidant essential oil (EO) with anti-inflammatory, anesthetic, and anti-infective properties. It can be therefore considered a good candidate for wound-healing applications, especially for chronic or diabetic wounds or burns, where the balance of reactive oxygen species (ROS) production and detoxification is altered. However, EOs require suitable formulations to be efficiently administered in moist wound environments. Chitosan hydrophobically modified by an ionic interaction with oleic acid (chitosan oleate, CSO) was used in the present work to stabilize CO nanoemulsions (NEs). The dimensions of the NE were maintained at around 300 nm as the volume distribution for up to six months, and the CO content did not decrease to under 80% over 4 months, confirming the good stabilizing properties of CSO. The antioxidant properties of the CO NE were evaluated in vitro by a 2,2-diphenil-2-picrylhydrazyl hydrate (DPPH) assay, and in fibroblast cell lines by electron paramagnetic resonance (EPR) using α-phenyl-N-tert-butyl nitrone (PBN) as a spin trap; a protective effect was obtained comparable to that obtained with α-tocopherol treatment. In a murine burn model, the ability of CO formulations to favor macroscopic wound closure was evidenced, and a histological analysis revealed a positive effect of the CO NE on the reparation of the lesion after 18 days. Samples of wounds at 7 days were subjected to a histological analysis and parallel dosage of lipid peroxidation by means of a thiobarbituric acid-reactive substances (TBARS) assay, confirming the antioxidant and anti-inflammatory activity of the CO NE.

Formulation Development and In Vitro/In Vivo Characterization of Methotrexate-Loaded Nanoemulsion Gel Formulations for Enhanced Topical Delivery

Methotrexate-loaded oil-in-water nanoemulsion formulations were prepared using the high shear homogenization technique. A drug excipient study (ATR-FTIR) was carried out to investigate the compatibility between the drug, the polymers, and its admixtures. The thermal stability of the nanoemulsion formulations was evaluated by subjecting them to a heating and cooling cycle. The prepared nanoemulsion formulations (FNE1 to FNE6) were evaluated for particle size, PDI value, and entrapment efficiency (EE). They were analyzed for morphological information using transmission electron microscopy. The drug (methotrexate)-loaded nanoemulsion formulations (FNE2, FNE4, and FNE6) were then converted into nanoemulsion gel formulations by adding 1% chitosan (polymer) as a gelling agent. The nanoemulsion gel formulations (FNEG2, FNEG4, and FNEG6) were investigated for physicochemical parameters, viscosity, spreadability, extrudability, drug content, and skin irritation. Various penetration enhancers (olive oil, clove, and almond oil) were employed to examine the potency of the prepared nanoemulsion gel formulations. In vitro drug release, ex vivo permeation, skin drug retention, and stability tests were carried out for evaluation of the prepared nanoemulsion gel formulations (FNEG2, FNEG4, and FNEG6). The data obtained from the in vitro study were subjected to the kinetic model, and the Korsemeyer-Peppas model was best fitted to the data. The nanoemulsion gel formulation FNEG6 showed the maximum controlled drug release and followed an anomalous, non-Fickian release mechanism. The use of almond oil in the preparation of the nanoemulsion gel formulation FNEG6 helped the penetration of the drug across stratum corneum and the restructuring of the properties of skin and resulted in a higher penetration and retention of methotrexate in a deeper layer of the skin. The current study concluded that the methotrexate-loaded nanoemulsion gel formulation FNEG6 showed the best optimum release, permeation, and retention results as compared to the available oral tablets' formulations, followed by a low serum concentration and the maximum drug retention, which is beneficial in treating skin infections and reducing systemic toxicity.

Effects of Supplementing Quails' (Coturnix japonica) Diets with a Blend of Clove (Syzygium aromaticum) and Black Cumin (Nigella sativa) Oils on Growth Performance and Health Aspects

In an attempt to discover a safe growth promoter and partial alternative for antibiotics, this existing study explores the efficacy of using assorted levels of cold-pressed oil mixtures consisting of 1:1 clove and black cumin (Nigella sativa) oils (CLNS) against the indices of growth and carcass traits, as well as blood components of growing Japanese quails. In a complete randomized design, three hundred growing unsexed Japanese quails (one week of age) were included in this experiment. The treated groups were as follows: (1) control basal diet (CLNS0), (2) basal diet + 1.50 mL CLNS/kg diet (CLNS1.5), and (3) basal diet + 3.00 mL CLNS/kg diet (CLNS3). The results showed that supplementing the diet with a 3.00 mL CLNS/kg diet insignificantly improved body weight (BW) compared with the CLNS0 and CLNS1.5 groups. A significantly (p < 0.05) higher feed intake and feed conversion ratio—FCR— (deterioration of feed conversion) were reported after the addition of CLNS. Feeding the quails on a 3.00 mL CLNS/kg enriched-diet yielded superior values of dressing percentage, carcass yield, and breast and thigh relative weights compared to other groups. A significant decline was noticed in creatinine and BUN levels in birds fed a 1.50 and 3.00 mL CLNS/kg diet compared with the CLNS0 group The liver enzymes and total bilirubin activities showed insignificant effects in quails fed CLNS-enriched diets. The total protein and globulins concentrations presented a significant augment in quails that received CLNS. The antiradical activity of CLNS supplementation showed increases in hepatic reduced glutathione (GSH) activity and the levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase, glutathione S transferase (GST), and glutathione reductase (GR) in birds. The concentration of MDA in hepatic homogenates that received CLNS-diets was significantly decreased compared with the control quails. These findings clarified that the dietary inclusion of CLNS can enhance the growth performance and antioxidative status of growing Japanese quails.

Detection of β-Lactamase Resistance and Biofilm Genes in Pseudomonas Species Isolated from Chickens

Bacteria of the genus Pseudomonas are pathogens in both humans and animals. The most prevalent nosocomial pathogen is P. aeruginosa, particularly strains with elevated antibiotic resistance. In this study, a total of eighteen previously identified Pseudomonas species strains, were isolated from chicken. These strains were screened for biofilm formation and antibiotic resistance. In addition, we evaluated clove oil’s effectiveness against Pseudomonas isolates as an antibiofilm agent. The results showed that Pseudomonas species isolates were resistant to most antibiotics tested, particularly those from the β-lactamase family. A significant correlation (p < 0.05) between the development of multidrug-resistant isolates and biofilms is too informal. After amplifying the AmpC-plasmid-mediated genes (blaCMY, blaMIR, DHA, and FOX) and biofilm-related genes (psld, rhlA, and pelA) in most of our isolates, PCR confirmed this relationship. Clove oil has a potent antibiofilm effect against Pseudomonas isolates, and may provide a treatment for bacteria that form biofilms and are resistant to antimicrobials.

Active Antioxidant Packaging from Essential Oils Incorporated Polylactic Acid/Poly(butylene adipate-co-terephthalate)/Thermoplastic Starch for Preserving Straw Mushroom

The short-term shelf life of straw mushrooms (Volvariella volvacea) is a major challenge, hampering their wide distribution. Thus, the aim of this work was to develop a novel active packaging composed of essential oils (EOs), particularly clove oil (CO) and peppermint oil (PO), to reduce autolysis of straw mushrooms. The morphological characterizations, mechanical properties, barrier properties, and antioxidant activities of the films were characterized. The suppressive effects of the EOs on straw mushroom autolysis were estimated during storage at 16 ± 1 °C for 96 h. The results indicated that the addition of EOs weakened the mechanical and barrier properties of the films. The radical-scavenging activities of polylactic acid/poly(butylene adipate-co-terephthalate)/thermoplastic starch-peppermint oil (PLA/PBAT/TPS-PO) and polylactic acid/poly(butylene adipate-co-terephthalate)/thermoplastic starch-clove oil (PLA/PBAT/TPS-CO) films for 2,2-diphenyl-1-picrylhydrazyl were 56.0% and 91.3%, respectively. However, the PLA/PBAT/TPS-PO film was more effective in reducing polyphenol oxidase activity and maintaining the total phenol content of straw mushrooms, demonstrating better antioxidative activity. Mushrooms packaged with the PLA/PBAT/TPS-PO film exhibited the lowest autolysis rate (42.29%, p < 0.05) after 96 h of storage. Thus, PO is a good preservative agent for straw mushroom.

Clove Oil-Incorporated Antibacterial Gelatin-Chitosan Cryogels for Tissue Engineering: An In Vitro Study

Infections are a leading cause of mortality and amputations among patients with burns and chronic wounds, respectively. Moreover, the extensive use of antibiotics has led to the rapid spreading of drug resistance among microorganisms. Alternatively, plant-derived natural products, which have been used as traditional therapies for several centuries, are recently gaining popularity as they are relatively affordable and easily available in many developing countries where modern medications are expensive or unavailable. In this study, clove essential oil is used for its antimicrobial property and is further incorporated into cryogels to increase its bioavailability and prolong its bioactivity. The oil-incorporated cryogels are macroporous, biodegradable, possess mechanical properties similar to commercial skin substitutes, are cytocompatible, antibacterial, and allow long-term sustained release of oil for up to at least 14 days. Additionally, clove oil aids the faster closure of in vitro scratch wounds by improving the migration of fibroblasts. This work presents a novel, bioactive scaffold that has the potential to be used as a dermal substitute and serves as an alternative to commercial skin substitutes.

Application of Clove Oil and Sonication Process on the Influence of the Functional Properties of Mung Bean Flour-Based Edible Film

The present study was aimed to investigate the effects of sonication and clove oil incorporation on the improvement of physical, antioxidant, and antimicrobial properties and lipid oxidation inhibiting abilities of mung bean flour (MF)-based films. There were three groups of films tested (1) MF: mung bean flour alone, (2) MFC: MF incorporated with 2% clove oil (C), and (3) MFCU: MFC prepared with sonication (25 kHz, 100% amplitude, 10 min). Film thickness and bulk density showed slight differences, and moisture content, solubility, and water vapor permeability significantly differed between the formulations. Tensile strength, elongation at break, and Young’s modulus were highest for the MFCU films, followed by MFC and MF in rank order. Furthermore, the Fourier-transform infrared spectroscopy results also demonstrated that the clove oil and sonication treatment had improved the interconnections of the biopolymers, thus increasing the physical strength of the film. Phytochemicals in terms of total phenolics and total flavonoids were elevated in the MFCU films and contributed to stronger radical scavenging abilities (p < 0.05). MFC and MFCU films showed a strong antibacterial control of the Gram-positive Staphylococcus aureus (S. aureus) and also of the Gram-negative Campylobacter jejuni (C. jejuni). Overall, the lipid oxidation indicators Thiobarbituric acid reactive substances (TBARS, peroxide value, p-anisidine value, and totox value) showed significantly high inhibition, attributed to radical scavenging activities in the MFCU and MFC samples. The mung bean flour films incorporated with clove oil and prepared with sonication have good potential as packaging materials for food due to strong physical, antimicrobial, and antioxidant properties, as well as lipid oxidation inhibiting abilities.

A Multi-Site Assessment of Anesthetic Overdose, Hypothermic Shock, and Electrical Stunning as Methods of Euthanasia for Zebrafish (Danio rerio) Embryos and Larvae

Euthanasia in zebrafish (Danio rerio) younger than 5 days post fertilization (dpf) is poorly described in the literature, and standardized protocols are lacking, most likely because larvae not capable of independent feeding are often not protected under national legislations. We assessed the euthanasia efficacy in laboratories in different countries of a one hour anesthetic overdose immersion with buffered lidocaine hydrochloride (1 g/L, with or without 50 mL/L of ethanol), buffered tricaine (1 g/L), clove oil (0.1%), benzocaine (1 g/L), or 2-phenoxyethanol (3 mL/L), as well as the efficacy of hypothermic shock (one hour immersion) and electrical stunning (for one minute), on zebrafish at <12 h post fertilization (hpf), 24 hpf, and 4 dpf. Based on the survival/recovery rates 24 h after treatment, the most effective methods were clove oil, lidocaine with ethanol, and electrical stunning. For 4 dpf larvae, signs of aversion during treatment demonstrated that all anesthetics, except lidocaine, induced aversive behavior. Therefore, the most suited euthanasic treatment was lidocaine hydrochloride 1 g/L, buffered with 2 g/L of sodium bicarbonate and mixed with 50 mL/L of ethanol, which euthanized both embryos and larvae in an efficient and stress-free manner. Electrical stunning also euthanized embryos and larvae efficiently and without signs of aversion; this method needs further assessment in other laboratories to draw firm conclusions.

Carcass characteristics and meat evaluation of cattle finished in temperate pasture and supplemented with natural additive containing clove, cashew oil, castor oils, and a microencapsulated blend of eugenol, thymol, and vanillin

BACKGROUND

Forty crossbred steers were supplemented with different doses (from 0 control to 6000 mg/animal/day) of natural additive blend containing clove essential oil, cashew oil, castor oil, and a microencapsulated blend of eugenol, thymol, and vanillin for 80 days. Carcass characteristics, drip loss, and antioxidant activity were evaluated 24 h post mortem on longissimus thoracis, and the effects of aging (until 14 days) were evaluated for water losses (thawing/aging and cooking), texture, color, and lipid oxidation.

RESULTS

The use of the natural additive blend did not modify (P > 0.05) carcass characteristics but did, however, modify body composition (P < 0.05). Drip losses were unaffected by the treatments tested (P > 0.05). There was an observed quadratic effect (P < 0.05) on losses from thawing/aging on the first day of storage. Regarding the effects of natural additives on cooking losses, there was a quadratic effect (P < 0.05) among the treatments on day 7 of aging. Differences between days of aging were only observed with control treatment. Shear force was similar among treatments on days 1 and 7 of aging. On day 14 a linear effect (P < 0.05) was observed. Also, a linear effect (P < 0.05) appeared on meat lightness, meat from the control group being clearer on day 1. No changes were observed in redness among treatments or days of storage (P > 0.05). Yellowness was not modified by the treatments (P > 0.05)but only by the days of storage in control and the lowest dosage used.

CONCLUSION

The blend of natural additives has potential use in pasture feeding and could improve meat quality. However, doses should be adjusted. © 2021 Society of Chemical Industry.

Antibacterial activity of cinnamon and clove oil against wound pathogens

A wound is a complicated health issue, and it severely affects the injured area because of the growth of many pathogenic microorganisms. Cinnamon and clove oil exhibit antibacterial activity against wound pathogens like Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae were identified by the disc diffusion method. Cinnamon and clove oils are effective antibacterial agents because of their importance in reducing virulence and pathogenicity of drug-resistant bacteria in vivo. The increased frequency in clinically observed cases of antibiotic resistance has been attributed to many factors, such as the misuse and overuse of antibiotics. In some countries, antibiotics are sold over the counter without a prescription; hence, this study aimed to investigate the antimicrobial effect of clove and cinnamon on clinically isolated resistant strains of P. aeruginosa, E. coli, and K. pneumoniae.

Anticancer Properties of Eugenol: A Review

Conventional cancer treatments have shown several unfavourable adverse effects, as well as an increase in anticancer drug resistance, which worsens the impending cancer therapy. Thus, the emphasis is currently en route for natural products. There is currently great interest in the natural bioactive components from medicinal plants possessing anticancer characteristics. For example, clove (Syzygium aromaticum L.) (Family Myrtaceae) is a highly prized spice that has been historically utilized as a food preservative and for diverse medical uses. It is reckoned amongst the valued sources of phenolics. It is indigenous to Indonesia but currently is cultivated in various places of the world. Among diverse active components, eugenol, the principal active component of S. aromaticum, has optimistic properties comprising antioxidant, anti-inflammatory, and anticancer actions. Eugenol (4-allyl-2-methoxyphenol) is a musky oil that is mainly obtained from clove. It has long been utilized all over the world as a result of its broad properties like antioxidant, anticancer, anti-inflammatory, and antimicrobial activities. Eugenol continues to pique investigators’ interest because of its multidirectional activities, which suggests it could be used in medications to treat different ailments. Anticancer effects of eugenol are accomplished by various mechanisms like inducing cell death, cell cycle arrest, inhibition of migration, metastasis, and angiogenesis on several cancer cell lines. Besides, eugenol might be utilized as an adjunct remedy for patients who are treated with conventional chemotherapy. This combination leads to a boosted effectiveness with decreased toxicity. The present review focuses on the anticancer properties of eugenol to treat several cancer types and their possible mechanisms.

Investigating Antiarthritic Potential of Nanostructured Clove Oil (Syzygium aromaticum) in FCA-Induced Arthritic Rats: Pharmaceutical Action and Delivery Strategies

The combined application of clove oil in a lipid nanocarrier opens a promising avenue for bone and joints therapy. In this study, we successfully developed a tunable controlled-release lipid platform for the efficient delivery of clove oil (CO) for the treatment of rheumatoid arthritis (RA). The ultra-small nanostructured lipid carriers co-loaded with CO (CONCs) were developed through an aqueous titration method followed by microfluidization. The CONCs appeared to be spherical (particle size of 120 nm), stable (zeta potential of −27 mV), and entrapped efficiently (84.5%). In toluene:acetone:glacial acetic acid (90:9:1 percent v/v/v) solvent systems, high-performance thin layer chromatography (HPTLC) analysis revealed the primary components in CO as eugenol (R_F = 0.58). The CONCs greatly increased the therapeutic impact of CO in both in vitro and in vivo biological tests, which was further supported by excellent antiarthritic action. The CONC had an antiarthritic activity that was slightly higher than neat CO and slightly lower than standard, according to our data. The improved formulation inhibited serum lysosomal enzymes and proinflammatory cytokines while also improving hind leg function. This study provides a proof of concept to treat RA with a new strategy utilizing essential oils via nanodelivery.

Formulation, optimization, and nephrotoxicity evaluation of an antifungal in situ nasal gel loaded with voriconazole‒clove oil transferosomal nanoparticles

Fungal infections of the paranasal cavity are among the most widely spread illnesses nowadays. The aim of the current study was to estimate the effectiveness of an in situ gel loaded with voriconazole‒clove oil nano-transferosomes (VRC-CO-NT) in enhancing the activity of voriconazole against Aspergillus flavus, which causes rhinosinusitis. The nephrotoxic side effects of voriconazole may be reduced through the incorporation of the clove oil, which has antioxidant activity that protects tissue. The Box‒Behnken design was applied to formulate the VRC-CO-NT. The particle size, entrapment efficiency, antifungal inhibition zone, and serum creatinine concentration were considered dependent variables, and the soybean lecithin, VRC, and CO concentrations were considered independent ones. The final optimized formulation was loaded into a deacetylated gellan gum base and evaluated for its gelation, rheological properties, drug release profile, permeation capabilities, and in vivo nephrotoxicity. The optimum formulation was determined to be composed of 50 mg/mL lecithin, 18 mg/mL VRC, and 75 mg/mL CO, with a minimum particle size of 102.96 nm, an entrapment efficiency of 71.70%, an inhibition zone of 21.76 mm, and a serum creatinine level of 0.119 mmol/L. The optimized loaded in situ gel released 82.5% VRC after 12 hours and resulted in a 5.4-fold increase in drug permeation. The in vivo results obtained using rabbits resulted in a nonsignificant differentiation among the renal function parameters compared with the negative control group. In conclusion, nasal in situ gel loaded with VRC-CO-NT is considered an efficient novel carrier with enhanced antifungal properties with no signs of nephrotoxicity.

In vitro inhibition of a multispecies oral cavity biofilm by Syzygium aromaticum essential oil

OBJECTIVE

To evaluate the anti-fungal activity of Syzygium aromaticum essential oil and its inhibition of a multispecies biofilm in patients with oral candidiasis.

BACKGROUND

Inhibiting biofilm formation on the denture surface is an important practice for preventing denture stomatitis.

MATERIALS AND METHODS

The anti-fungal activity against Candida albicans and non-albicans Candida species was evaluated through the microdilution method to define Minimal Inhibitory (MIC) and Fungicidal (MFC) Concentrations. Time-kill assay assessed growth kinetics of C. albicans based on pre-determined time points (0, 1, 2, 4, 6 and 24 hours). A multi-species biofilm was formed using human saliva from patients with oral candidiasis and anti-biofilm activity determined by Colony Forming Units per milliliter (CFU/mL) count, fluorescence microscopy with calcofluor white to observe yeast presence and structure, and metabolic activity by XTT (2,3-Bis-(2Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-carboxanilide) reduction assay.

RESULTS

The essential oil showed an anti-fungal activity against all Candida species (MIC 500-1000 µg/mL, MFC 1000-2000 µg/mL), and the time-kill assay showed that 2000 µg/mL (from 2 hours onward) and 1000 µg/mL (from 4 hours onward) concentrations had substantially lower yeast growth than the negative control. In the biofilm analysis, the essential oil had a lower CFU/mL count and a biofilm metabolic activity (91.4%) than seen with its negative control, and in both analyses, the essential oil was not significantly different from the positive control (chlorhexidine). Morphological analysis showed amorphous and fragmented cellular structures after treatment with the essential oil.

CONCLUSION

Syzygium aromaticum essential oil had anti-fungal activities, reduced the Candida growth kinetics substantially and inhibited the multi-species biofilm formation.

Gellan Gum-Based Bilayer Mucoadhesive Films Loaded with Moxifloxacin Hydrochloride and Clove Oil for Possible Treatment of Periodontitis

Background/Objective

Periodontitis is a widely spread oral infection and various antibiotics are utilized for its treatment, but high oral doses and development of antibiotic resistance limit their use. This study was aimed at development of natural polymer-based mucoadhesive bilayer films loaded with moxifloxacin hydrochloride (Mox) and clove essential oil (CEO) to potentially combat bacterial infection associated with periodontitis.

Methods

Films were synthesized by double solvent casting technique having an antibiotic in the gellan gum-based primary layer with clove oil in a hydroxyethyl cellulose-based secondary layer.

Results

Prepared films were transparent, flexible, and showed high antibacterial response against both gram-positive and gram-negative bacteria. The films showed excellent pharmaceutical attributes in terms of drug content, folding endurance, swelling index, and mucoadhesive strength. Solid state characterization of formulation showed successful incorporation of drug and oil in separate layers of hydrogel structure. An in-vitro release study showed an initial burst release of drug followed by sustained release for up to 48 hours.

Conclusion

The prepared mucoadhesive bilayer buccal films could be used as a potential therapeutic option for the management of periodontitis.

Glimepiride-Loaded Nanoemulgel; Development, In Vitro Characterization, Ex Vivo Permeation and In Vivo Antidiabetic Evaluation

Glimepiride (GMP), an oral hypoglycemic agent is extensively employed in the treatment of type 2 diabetes. Transdermal delivery of GMP has been widely investigated as a promising alternative to an oral approach but the delivery of GMP is hindered owing to its low solubility and permeation. The present study was designed to formulate topical nanoemulgel GMP system and previously reported solubility enhanced glimepiride (GMP/βCD/GEL-44/16) in combination with anti-diabetic oil to enhance the hypoglycemic effect. Nanoemulsions were developed using clove oil, Tween-80, and PEG-400 and were gelled using xanthan gum (3%, w/w) to achieve the final nanoemulgel formulations. All of the formulations were evaluated in terms of particle size, zeta potential, pH, conductivity, viscosity, and in vitro skin permeation studies. In vivo hypoglycemic activity of the optimized nanoemulgel formulations was evaluated using a streptozocin-induced diabetes model. It was found that a synergistic combination of GMP with clove oil improved the overall drug permeation across the skin membrane and the hypoglycemic activity of GMP. The results showed that GMP/βCD/GEL-44/16-loaded nanoemulgel enhanced the in vitro skin permeation and improved the hypoglycemic activity in comparison with pure and marketed GMP. It is suggested that topical nano emulsion-based GMP gel and GMP/βCD/GEL-44/16 could be an effective alternative for oral therapy in the treatment of diabetes.

Biological Properties and Prospects for the Application of Eugenol-A Review

Eugenol is a phenolic aromatic compound obtained mainly from clove oil. Due to its known antibacterial, antiviral, antifungal, anticancer, anti-inflammatory and antioxidant properties, it has long been used in various areas, such as cosmetology, medicine, and pharmacology. However, high concentrations can be toxic. A dose of 2.5 mg/kg body weight is regarded as safe. This paper reviews the current state of knowledge regarding the activities and application of eugenol and its derivatives and recent research of these compounds. This review is based on information concerning eugenol characteristics and recent research from articles in PubMed. Eugenol remains of great interest to researchers, since its multidirectional action allows it to be a potential component of drugs and other products with therapeutic potential against a range of diseases.

Discovering Penicillium polinicum with High-Lytic Capacity on Helianthus tuberosus Tubers: Oil-Based Preservation for Mold Management

During preservation, Jerusalem artichoke (JA) tubers are subjected to deterioration by mold fungi under storage, which signifies a serious problem. A new blue mold (Penicillium polonium) was recorded for the first time on JA tubers. Penicillium mold was isolated, identified (morphologically, and molecularly), and deposited in GenBank; (MW041259). The fungus has a multi-lytic capacity, facilitated by various enzymes capable of severely destroying the tuber components. An economic oil-based procedure was applied for preserving and retaining the nutritive value of JA tubers under storage conditions. Caraway and clove essential oils, at a concentration of 2%, were selected based on their strong antifungal actions. JA tubers were treated with individual oils under storage, kept between peat moss layers, and stored at room temperature. Tubers treated with both oils exhibited lower blue mold severity, sprouting and weight loss, and higher levels of carbohydrates, inulin, and protein contents accompanied by increased levels of defense-related phytochemicals (total phenols, peroxidase, and polyphenol oxidase). Caraway was superior, but the results endorse the use of both essential oils for the preservation of JA tubers at room temperature, as an economic and eco-safe storage technique against the new blue mold.

Therapeutic potential of essential oil based microemulsions: Reviewing state-of-the-art

A pre-eminent emulsion based micellar drug delivery system, "microemulsion", comprising of drug in oil or water phase, stabilized by surfactants and co-surfactants, has been evidenced to have phenomenal role in number of applications. Oils play an important role in formation of ME and increase the drug absorption at the site of action. Oils employed in microemulsion formulation solubilize lipophilic drug. As concept of "natural" therapies is recently gaining importance amongst researchers all over the world, scientists are employing essential oil as an organic component in this system. The active components of essential oils include flavonoids, phenylpropanoids, monoterpenes and polyunsaturated of mega-6-fatty acids. These oils are enriched with characteristic intrinsic properties such as anti-oxidant, anti-bacterial, anti-viral, etc. bestows an enhanced supremacy to whole microemulsion system. This mini-review is the first to document various types of essential oils employed in microemulsion systems and highlight their therapeutic potential and applications as drug delivery vehicles. Key inferences from this study suggest: 1) Clove oil is the most explored oil for incorporation into microemulsion based system, followed by peppermint and Tea Tree Oil (TTO). 2) Penetration enhancing effects of these oils is due to the presence of terpenic constituents. 3) Essential oil based microemulsions protect volatility of ethereal oils and protect them from degradation in presence of light, air, temperature. 4) These systems may also be explored for their applications in different industries like aromatherapy, food, drink, fragrance, flavour, cosmeceutical, soap, petroleum and pharmaceutical industry.

Characterization of Efficacy and Animal Safety across Four Caprine Disbudding Methodologies

Simple Summary

Disbudding of dairy goat kids is a routine, necessary, but painful husbandry procedure. Heat cautery disbudding is the industry standard since it is effective and can be rapidly performed by lay personnel on large numbers of kids. Efforts to improve welfare associated with heat cautery disbudding commonly focus on adjunct anesthesia and analgesia but there are often technical, legal, and safety barriers to routine use of these adjunct therapies in production settings. This project explores four alternative methods to heat cautery disbudding for safety, efficacy, and vocal evidence of duress during the procedure. We found that heat cautery was the most effective, was similar to the sham procedure for vocalization count during the procedure, and did not cause any serious or lasting complications. Clove oil injection, short-term topical application of caustic paste, and two cryosurgical methods were not consistently effective; additionally, the latter two created significantly more vocalization efforts. Clove oil injection was associated with several unexpected and severe complications including unintended tissue necrosis, temporary paresis, skull defects, meningitis, and death. Collectively, we did not find that any of the alternative methods of disbudding provided a feasible option over heat cautery to improve welfare associated with the disbudding process.

Abstract

There is a strong industry demand for technically simple and highly efficacious alternatives to heat cautery disbudding in goat kids that can be performed as a stand-alone procedure without adjunct anesthesia, and that result in improved overall welfare through reduced acute pain, reduced tissues healing interval, and a consistent safety record. The objective of this study was to consider the net effect of disbudding techniques on goat welfare by examining vocalization frequency, long-term efficacy and animal safety associated with four alternative caprine disbudding methods against sham-disbudded and heat-cautery controls. Sixty-five commercial male dairy kids were disbudded at 3–10 days of age with one of six disbudding treatments (clove oil injection, caustic paste, two cryosurgical methods, heat-cautery, and sham procedure). Heat cautery was 91% effective, caustic paste was 55% effective, and the other treatments were ineffective. Heat cautery and sham procedures resulted in similar vocalization efforts; freezing with a liquid-nitrogen cooled iron resulted in significantly greater vocalization numbers. No unintended paste transfer injuries were observed with short-term application of the caustic paste. Heat cautery resulted in numerous superficial infections but no permanent injury. Clove oil injection was associated with several unexpected and severe complications including unintended tissue necrosis, temporary paresis, skull defects, meningitis, and death. Collectively, we did not find that any of the alternative methods of disbudding provided a feasible option over heat cautery to improve welfare.

Development, optimization and characterization of nanoemulsion loaded with clove oil-naftifine antifungal for the management of tinea

Tinea is a common superficial infection caused by keratinophylic fungi called dermatophytes. The objective of the current investigation was to develop and optimize a self-nanoemulsion drug delivery system (SENDDs) using clove oil loaded with naftifine (NF). Clove oil possesses good anti-inflammatory and antifungal properties that can support naftifine action. Box–Behnken designs were used to prepare plain and naftifine loaded SENDDs. The plain SENDDs were evaluated for their globule size. The medicated formulations (NF-CO-SENDDs) were characterized by measuring their globular size, ex vivo % NF permeated, level of interleukin-31 in rats, and antifungal activity. The optimum clove oil level was found to be 10–17%, while NF-CO-SENDDs formulations displayed globular sizes ranging from 119 to 310 nm. The statistical design confirmed the synergistic effect of clove oil and NF in the treatment of fungal infections, confirming that the anti-inflammatory effect of clove oil can counteract the side effects of NF. The optimized formulation composed of 14% clove oil, 12.5 mg Naftifine, and prepared with an Smix ratio equaling 3:1, exhibited good antifungal and anti-inflammatory activity, achieving up to 2-, 3-, 5.75-, and 2.74-fold increases in the amount of permeated NF, steady-state flux, permeability, and diffusion coefficients, respectively, compared with a commercial product. Moreover, the optimum formulation revealed an adequate zeta potential value of 28.31 ± 1.37 mV and showed reasonable stability with no or mild signs of skin sensitivity. Therefore, the designed nanoemulsions containing a combination of clove oil and naftifine could be considered promising delivery systems for the treatment of tinea.

Anaesthetic Efficiency of Cymbopogon citratus Essential Oil and Clove Oil on Macrobrachium rosenbergii

&lt;b&gt;Background and Objective:&lt;/b&gt; Studies on plant herbs as alternatives to chemical anaesthetics in fish species are numerous, but little is known on crustaceans. A study was conducted to investigate the efficacy of &lt;i&gt;C. citratus&lt;/i&gt; Essential Oil (EO) on the induction and recovery of &lt;i&gt;M. rosenbergii&lt;/i&gt;. &lt;b&gt;Materials and Methods:&lt;/b&gt; The &lt;i&gt;C. citratus&lt;/i&gt; EO was obtained by hydrodistillation and analyzed using GC-MS. The prawns were exposed to &lt;i&gt;C. citratus&lt;/i&gt; EO and clove oil in 100-1000 and 200-1000 μL L&lt;sup&gt;1&lt;/sup&gt;, respectively. Different stages of induction and recovery times were recorded. &lt;b&gt;Results:&lt;/b&gt; In GC-MS, citral (78.47%) was detected as a major compound in &lt;i&gt;C. citratus&lt;/i&gt; EO. Prawns reached loss equilibrium at 500-1000 μL L&lt;sup&gt;1&lt;/sup&gt; &lt;i&gt;C. citratus&lt;/i&gt; EO within 15.55-6.52 min. Exposure of prawn to &lt;u&gt;<&lt;/u&gt;500 μL L&lt;sup&gt;1&lt;/sup&gt; &lt;i&gt;C. citratus&lt;/i&gt; EO resulted in a high survival rate (100-94%). In clove oil, all tested concentrations caused significant induction in &lt;i&gt;M. rosenbergii&lt;/i&gt; within 20.61-6.47 min. Recovery time and survival rate were significantly decreased with the increase of EO concentrations. The regression model showed the induction time in both anaesthetic agents was dependent on the concentration (R&lt;sup&gt;2 &lt;/sup&gt;= 0.86-0.96). The recovery time of &lt;i&gt;C. citratus&lt;/i&gt; EO-exposed prawn was dependent on the concentrations (R&lt;sup&gt;2 &lt;/sup&gt;= 0.59). &lt;b&gt;Conclusion:&lt;/b&gt; The study shows the potentiality of &lt;i&gt;C. citratus&lt;/i&gt; EO as a natural anaesthetic in &lt;i&gt;M. rosenbergii&lt;/i&gt;, although not as efficient as clove oil.

Nasal Gel Loaded with Amphotericin Nanotransferosomes as Antifungal Treatment for Fungal Sinusitis

On the basis of fungal involvement, rhinosinusitis is categorized into allergic, mycetoma, chronic, and acute invasive types. The aim of the current study was to evaluate the efficacy of an amphotericin gel in situ loaded with nanotransferosomes against Aspergillus flavus, which causes allergic rhinosinusitis. A Box–Behnken design was utilized to study the interaction among the nanotransferosomes and optimize independent variables in formulating them, in order to match the prerequisites of selected responses. The optimal formulation was determined to be 300 mg/mL soybean lecithin, 200 mg/mL amphotericin B (AMP), and 150 mg/mL clove oil, resulting in a particle size of 155.09 nm, 84.30% entrapment efficacy (EE), inhibition zone of 16.0 mm, and 0.1197 mmol serum creatinine. The optimized batch was further prepared into an in situ gel and evaluated for various parameters. The optimized formulation released 79.25% AMP and enhanced permeation through the nasal membrane, while the other formulations did not achieve complete absorption. According to in vivo tests using rabbits as animal models, the optimized AMP-nanotransferosomal formulations (NT) in in situ gel result in a non-significant difference among the various kidney function parameters. In conclusion, nasal in situ gel loaded with AMP-clove oil nanotreansfersomes can act as a promising novel carrier that enhances antifungal activity and decreases AMP nephrotoxicity.

Nanoencapsulated Clove Oil Applied as an Anesthetic at Slaughtering Decreases Stress, Extends the Freshness, and Lengthens Shelf Life of Cultured Fish

In the aquaculture industry, fish are stunned using a wide range of methods, but all of them trigger stress responses and affect the fish flesh quality. Chilled water is considered one of the most efficient methods, but even this is not a stress-free experience for the fish. Anesthetics included in the ice slurry or in water could decrease this stress and delay the loss of flesh quality. In this work, we analyze the effect of clove oil (CO) nanoencapsulated in β-cyclodextrins (β-CD) (CO + β-CD), incorporated in the stunning bath, on the stress response and the organoleptic attributes of fresh marine and freshwater fish from four economically important fish species: Atlantic salmon, European seabass, Nile tilapia, and Rainbow trout. CO + β-CD reduces the time required to induce anesthesia, independently of water salinity, habitat or water temperature. The plasmatic glucose and cortisol levels decreased in all four species, although the concentrations of CO varied between species. Moreover, plasmatic lactate level differed between the marine and freshwater fish. The use of CO + β-CD extended the shelf life of fish from all the species studied (by 3-7 days). In conclusion, using CO encapsulated in β-CD for anesthetizing fish can be regarded as an improved fish-stunning technique that reduces the anesthesia-induction time, decreases the stress response, and extends the shelf life of fresh fish.

Physical, Thermal, and Antibacterial Effects of Active Essential Oils with Potential for Biomedical Applications Loaded onto Cellulose Acetate/Polycaprolactone Wet-Spun Microfibers

New approaches to deal with the growing concern associated with antibiotic-resistant bacteria are emerging daily. Essential oils (EOs) are natural antimicrobial substances with great potential to mitigate this situation. However, their volatile nature, in their liquid-free form, has restricted their generalized application in biomedicine. Here, we propose the use of cellulose acetate (CA)/polycaprolactone (PCL) wet-spun fibers as potential delivery platforms of selected EOs to fight infections caused by Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Twenty EOs were selected and screened for their minimal inhibitory concentration (MIC), using the antibiotic ampicillin as positive control. The cinnamon leaf oil (CLO), cajeput oil (CJO), and the clove oil (CO) were the most effective EOs, against the Gram-positive (MIC < 22.38 mg/mL) and the Gram-negative (MIC < 11.19 mg/mL) bacteria. Uniform microfibers were successfully wet-spun from CA/PCL with an averaged diameter of 53.9 ± 4.5 µm, and then modified by immersion with CLO, CJO and CO at 2 × MIC value. EOs incorporation was confirmed by UV-visible spectroscopy, Fourier-transformed infrared spectroscopy, and thermal gravimetric analysis. However, while microfibers contained ampicillin at MIC (control) after the 72 h modification, the CLO, CO and CJO-loaded fibers registered ≈ 14%, 66%, and 76% of their MIC value, respectively. Data showed that even at small amounts the EO-modified microfibers were effective against the tested bacteria, both by killing bacteria more quickly or by disrupting more easily their cytoplasmic membrane than ampicillin. Considering the amount immobilized, CLO-modified fibers were deemed the most effective from the EOs group. These results indicate that CA/PCL microfibers loaded with EOs can be easily produced with increased antibacterial action, envisioning their use as scaffolding materials for the treatment of infections.

Clove Oil (Syzygium aromaticum L.) Activity against Alicyclobacillus acidoterrestris Biofilm on Technical Surfaces

Acidotermophilic bacteria Alicyclobacillus acidoterrestris is one of the main contaminants in the fruit industry forming biofilms which are difficult to remove from the production line by conventional methods. An alternative approach aims for the use of essential oils to prevent Alicyclobacillus biofilm development. The effect of clove essential oil on A. acidoterrestris biofilms on glass and polyvinyl chloride surfaces under static and agitated culture conditions was investigated by atomic force microscopy and the plate count method. The medium-flow and the type of technical surface significantly influenced A. acidoterrestris biofilm. The PVC was colonized in a greater extent comparing to glass. Clove essential oil in 0.05% (v/v) caused 25.1–65.0% reduction of biofilms on the technical surfaces along with substantial changes in their morphology by a decrease in the biofilm: height, surface roughness, and surface area difference. The oil also induced alteration in individual bacterial cells length and visible increase of their roughness. Clove essential oil seems to release EPS from biofilm and thus induce detachment of bacteria from the surface. Due to anti-A. acidoterrestris biofilm activity, the clove oil may be used in the juice industry to hinder a development of A. acidoterrestris biofilms on production surfaces.

Bactericidal Effect of Clove Oil against Multidrug-Resistant Streptococcus suis Isolated from Human Patients and Slaughtered Pigs

Streptococcus suis is a zoonotic pathogen that is currently considered an emerging multidrug-resistant (MDR). Increasing antibiotic resistance can lead to the unsuccessful treatment of S. suis infection. Recently, many investigations of medicinal plants were conducted for the treatment of infection as a result of the increase of antibiotic-resistant bacteria. The aims of this study were to determine the chemical composition of essential oil from Syzygium aromaticum (L.) Merr. & L.M. Perry and the antibacterial activities of clove oil on MDR S. suis. Using gas chromatography coupled to a mass spectrometer, eugenol (97.76%) was found to be the major active ingredient of clove oil. In vitro antibacterial activities of clove oil against MDR S. suis were evaluated. Using the agar disc diffusion test, the clove oil showed a maximum zone of inhibition at 15% (v/v) oil concentration. In a broth microdilution method, the minimum bactericidal concentration of clove oil against all MDR S. suis isolates was 0.1% (v/v). A time-kill analysis was performed, and the killing kinetics of clove oil showed that MDR S. suis was completely reduced after 15 min of exposure to clove oil. In addition, clove oil exhibited a strong antibacterial activity at all pH values applied following incubation of MDR S. suis in pH-adjusted media with clove oil. Moreover, scanning electron microscopy revealed the nonviable S. suis isolates clearly showed atypical form and cell membrane lysis after incubation with clove oil. This study confirms the efficacy of clove oil as a natural antimicrobial against MDR S. suis and suggests the possibility of employing it as a promising alternative product for control of infectious diseases caused by S. suis in animal and human patients.

The effects of commonly used anaesthetics on colour measurements across body regions in the poeciliid fish, Girardinus metallicus

The effects of common anaesthetics on the hue, saturation and brightness measurements of the poeciliid fish Girardinus metallicus were investigated in two experiments. For both experiments the coloration of four body regions was measured from digital images of the same males obtained under three conditions: (1) control (in a water-filled chamber); (2) anaesthetised with MS-222; and (3) anaesthetised with eugenol (clove oil). In experiment 1 anaesthetised fish were photographed out of water. In experiment 2 all photographs were taken in a water-filled chamber. Anaesthetics altered coloration in both experiments. In the more methodologically consistent experiment 2 we found significantly different hue, increased saturation and decreased brightness in anaesthetic v. control conditions, consistent with darkening caused by the anaesthetics. The body regions differed in coloration consistent with countershading but did not differentially change in response to anaesthesia. These findings suggest that photographing fish in a water-filled chamber without anaesthetic is preferable for obtaining digital images for colour analysis and that multiple body regions of fish should be measured when assessing coloration patterns meaningful in behavioural contexts, to account for the gradients caused by countershading. We are encouraged that some researchers employ such methods already and caution against using anaesthetics except when absolutely necessary for immobilisation.

Essential Oils as Antimicrobial Agents-Myth or Real Alternative?

Herbs and the essential oils derived from them have been used from the beginning of human history for different purposes. Their beneficial properties have been applied to mask unpleasant odors, attract the attention of other people, add flavor and aroma properties to prepared dishes, perfumes, and cosmetics, etc. Herbs and essential oils (EOs) have also been used in medicine because of their biological properties, such as larvicidal action, analgesic and anti-inflammatory properties, antioxidant, fungicide, and antitumor activities, and many more. Many EOs exhibit antimicrobial properties, which is extremely important in fields of science and industry, such as medicine, agriculture, or cosmetology. Among the 250 EOs which are commercially available, about a dozen possess high antimicrobial potential. According to available papers and patents, EOs seem to be a potential alternative to synthetic compounds, especially because of the resistance that has been increasingly developed by pathogenic microorganisms. In this review we summarize the latest research studies about the most-active EOs that are known and used because of their antimicrobial properties. Finally, it is noteworthy that the antimicrobial activities of EOs are not preeminent for all strains. Further investigations should, thus, focus on targeting EOs and microorganisms.

Transport and Recovery of Gilthead Seabream (Sparus aurata L.) Sedated With Clove Oil and MS-222: Effects on Stress Axis Regulation and Intermediary Metabolism

Transport processes between aquaculture facilities activate the stress response in fish. To deal with these situations, the hypothalamic-pituitary-interrenal (HPI) axis releases cortisol, leading to an increase in circulating energy resources to restore homeostasis. However, if the allostatic load generated exceeds fish tolerance limits, stress-related responses will compromise health and welfare of the animals. In this context, anesthetics have arisen as potential agents aiming to reduce negative effects of stress response. Here we assessed the effects of a sedative dose of clove oil (CO) and MS-222 on hallmarks involved in HPI axis regulation and energy management after simulated transport, and further recovery, in gilthead seabream (Sparus aurata L.) juveniles. Fish were placed in a mobile setup of water tanks where transport conditions were simulated for 6 h. Sedation doses of either CO (2.5 mg L⁻¹) or MS-222 (5 mg L⁻¹) were added in the water tanks. A control group without anesthetics was also included in the setup. Half of the animals (n = 12 per group) were sampled immediately after transport, while remaining animals were allowed to recover for 18 h in clean water tanks and then sampled. Our results showed that the HPI axis response was modified at peripheral level, with differences depending on the anesthetic employed. Head kidney gene-expressions related to cortisol production (star and cyp11b1) matched concomitantly with increased plasma cortisol levels immediately after transport in CO-sedated fish, but these levels remained constant in MS-222-sedated fish. Differential changes in the energy management of carbohydrates, lipids and amino acids, depending on the anesthetic employed, were also observed. The use of CO stimulated amino acids catabolism, while MS-222-sedated fish tended to consume liver glycogen and mobilize triglycerides. Further studies, including alternative doses of both anestethics, as well as the assessment of time-course HPI activation and longer recovery periods, are necessary to better understand if the use of clove oil and MS-222 is beneficial for S. aurata under these circumstances.

Transport and Recovery of Gilthead Sea Bream (Sparus aurata L.) Sedated With Clove Oil and MS222: Effects on Oxidative Stress Status

The use of anesthesia is a common practice in aquaculture to sedate fish and mitigate handling stress. Although the employ of anesthesia is considered beneficial for fish, as it reduces stress and improves welfare, at the same time it may induce hazardous side-effects. The aim of the present study was to investigate the effects of clove oil (CO) and tricaine methanesulfonate (MS222), two of the most used anesthetics, on several oxidative stress related parameters in gilthead sea bream (Sparus aurata), as these types of effects of anesthetics have been seldom investigated. To assess these effects, S. aurata juveniles were placed in a setup of mobile water tanks and were transported during 6 h with either 2.5 mg/L CO or 5 mg/L MS222. After transport, half of the fish were sampled, whereas the remaining fish were transferred to tanks without anesthetics where they were allowed to recover for 18 h before sampling. Changes in the expression levels of several target genes related with the antioxidant response and cell-tissue repair were evaluated in the gills, liver and brain. Those transcripts included glutathione peroxidase 1 (gpx1), catalase (cat), glutathione S-transferase 3 (gst3), glutathione reductase (gr), superoxide dismutase [Zn] (sod2), heat shock protein-70 (hsp70), and metallothionein (mt). Antioxidant enzymatic activities glutathione S-transferase, GST; catalase, CAT; and glutathione reductase, GR, levels of non-enzymatic antioxidants (non-protein thiols - NPT), and pro-oxidative damage, assessed as lipid peroxidation (LPO), were determined in gills, liver and brain. Acetylcholinesterase activity (AChE) was determined in plasma, gills, brain, muscle and heart as an indicator of neuro-muscular alterations. In plasma, the total antioxidant capacity (TAC) and total oxidative status (TOS) were also measured. Results showed that the use of both anesthetic agents, CO and MS222, interferes with fish antioxidant status. All tested biological matrices displayed alterations in antioxidant endpoints, confirming that these substances, although minimizing the effects of transport stress, may have long term effects on fish defenses. This result is of high relevance to aquaculture considering that the oxidative stress, may increase the susceptibility to different environmental or biotic stress and different types of pathologies.

Short communication: Evaluation of the efficacy of novel disbudding methods for dairy calves

The objectives of this study were to (1) evaluate whether cryoablation or the administration of clove oil was as efficacious as cautery disbudding at preventing horn growth, and (2) evaluate whether the efficacy of cautery disbudding is affected by removing or leaving the horn bud tissue intact after disbudding of dairy calves. At approximately 4 d of age (4.0 ± 0.88 d of age, mean ± SD), 265 dairy heifer calves from 3 dairy farms (farm 1: n = 129 calves; farm 2: n = 109 calves; farm 3: n = 27 calves) were disbudded. Each calf had 1 of 4 treatments randomly assigned to each horn bud: (1) clove oil (0.5 mL) administered subcutaneously under the horn bud (CLOV, n = 135 buds); (2) a liquid nitrogen-filled probe applied to the horn bud area for 30 s (CRYO, n = 134 buds); (3) cautery disbudding using an electric hot-iron and the horn bud removed (BUDOFF, n = 130); or (4) cautery disbudding and the horn bud tissue left intact (BUDON, n = 131). Calves were assessed for signs of infection at the disbudding site frequently within the first month after disbudding. At approximately 6 mo of age (6 ± 2.2 mo, mean ± SD) calves were assessed for scur or horn growth. The disbudding procedures were considered successful if no scur or horn development was observed. Within the first month, 12% of disbudding wounds showed some indication of infection, such as pus, exudate, or swelling; of the infected buds, 52% were associated with the BUDON treatment, 27% with CLOV, 25% with BUDOFF, and 2% with CRYO treatments. At 6 mo of age, BUDOFF was the most effective method of preventing horn growth and CRYO was the least efficacious [mean percentage of success: BUDOFF: 100% (95% CI: 97.7-100.0); CRYO: 1% (95% CI: 0.2-5.3)]. Injecting clove oil under the horn bud was 87% (95% CI: 80.6-92.5) successful. Not removing the horn bud tissue after cautery disbudding reduced the efficacy of this method by 9% [91% success (95% CI: 83.8-95.7)]; moreover, this method was associated with more infection at the site of disbudding. It appears as though the clove oil treatment could be used as an alternative to cautery disbudding of dairy calves; however, further research is needed to evaluate the tissue damage and associated pain caused by clove oil and to refine this technique (i.e., administration methods to improve efficacy) before it could be considered an alternative to cautery.

Progress on the Antimicrobial Activity Research of Clove Oil and Eugenol in the Food Antisepsis Field

As potential and valuable antiseptics in the food industry, clove oil and its main effective composition eugenol show beneficial advantages on antibacterial and antifungal activity, aromaticity, and safety. Researches find that both clove oil and eugenol express significantly inhibitory effects on numerous kinds of food source microorganisms, and the mechanisms are associated with reducing the migratory and adhesion and inhibiting the synthesis of biofilm and various virulence factors of these microorganisms. Clove oil and eugenol are generally regarded as safe in vivo experiments. However, they may express certain cytotoxicity on fibroblasts and other cells in vitro. Studies on the quality and additive standard of clove oil and eugenol should be strengthened to promote the antiseptic effects of them in the food antiseptic field.

Fabrication and Release Behavior of Microcapsules with Double-Layered Shell Containing Clove Oil for Antibacterial Applications

In this study, double-layer polyurethane/poly(urea-formaldehyde) (PU/PUF) shell microcapsules containing clove oil with antibacterial properties were successfully synthesized via in situ and interfacial polymerization reactions in an oil-in-water emulsion. The morphology, core-shell structure, and composition of the microcapsules were investigated systematically. Additionally, the release behaviors of microcapsules synthesized under different reaction parameters were studied. It was found that the release rate of clove oil can be controlled by tuning the amount of PU reactants and the length of PUF deposition time. The release profile fitted well against the Baker-Lonsdale model, which indicates diffusion as the primary release mechanism. Experimental results based on the ASTM E2315 time kill test revealed that the fabricated microcapsules have great antibacterial activities against the marine bacteria Vibrio coralliilyticus, Escherichia coli, Exiguobacterium aestuarii, and marine biofilm-forming bacteria isolated from the on-site contaminated samples, showing their great potential as an eco-friendly solution to replace existing toxic antifouling agent.

Evaluation of alternatives to cautery disbudding of dairy goat kids using physiological measures of immediate and longer-term pain

We evaluated alternatives to cautery disbudding of goat kids using physiological measures of immediate and longer-term pain. Fifty Saanen doe kids were randomly assigned to 1 of 5 treatments (n = 10/treatment): (1) cautery disbudding (CAUT), (2) caustic paste disbudding (CASP), (3) liquid nitrogen disbudding (CRYO), (4) clove oil injected into the horn bud (CLOV), or (5) sham disbudding (SHAM). Serum cortisol and haptoglobin concentrations were measured from blood samples collected immediately before treatment (baseline) and at 15, 30, 60, and 120 min and then again at 6 and 24 h post-treatment. An infrared thermography camera was used to take images of the horn buds 24 h pre- and 24, 48, and 72 h post-treatment to measure skin temperature. Body weight was measured daily for 1 wk to assess weight change post-treatment. Images of the horn buds were taken at d 1, 2, and 7 and at 6 wk post-treatment to assess tissue damage and wound healing. Mean cortisol concentrations were elevated in CASP kids 1 h post-treatment relative to CAUT kids. Cortisol concentrations of CRYO kids were higher than those of CAUT kids 30 min post-treatment; concentrations for CLOV kids were similar to CAUT kids post-treatment. Mean haptoglobin concentrations were similar across treatments over time; however, CLOV kids had higher concentrations at 24 h post-treatment than all other treatments. Skin temperatures of CASP and CLOV kids were elevated relative to CAUT kids at all time points post-treatment, and all disbudded kids had skin temperatures above those of SHAM kids at 72 h post-treatment. Treatment did not influence weight gain. The CAUT kids had large, open wounds exposing bone; small scabs were still evident 6 wk post-treatment. The CASP kids had red and open, raw wounds that generated large eschars, apparent for up to 6 wk. The CRYO kids had closed, dry wounds initially, but over time lesions appeared that caused open wounds; small scabs were present 6 wk post-treatment. The CLOV kids had closed, dry wounds with blackened skin; healed skin and minimal scabs were present 6 wk post-treatment. Caustic paste and cryosurgical disbudding appeared to cause more pain compared with cautery disbudding; thus, these methods may not provide good alternatives to cautery disbudding. Clove oil appeared to cause a similar pain response as cautery disbudding and smaller wounds with earlier tissue repair; this method shows promise as an alternative to cautery disbudding.

Detection of aflatoxin-producing fungi isolated from Nile tilapia and fish feed

Contamination of fish by fungi and their mycotoxins poses major health concerns to human and animals. Therefore, our study was aimed to investigate Aspergillus flavus (A. flavus) infections and the levels of aflatoxins in Nile tilapia, Oreochromis niloticus (O. niloticus), and fish feed. Samples from O. niloticus and fish feed (n=25 for each) were randomly collected from private fish farms at Qena province, Egypt, during the winter season. Different Aspergillus spp. were detected in 60 % and 64 % of O. niloticus and fish feed, respectively. HPLC-based analysis revealed aflatoxin-producing activity in 75 % and 83 % of A. flavus isolates from fish and fish feed, respectively. While 96 % of O. niloticus muscles and fish feed samples were contaminated with aflatoxins, the detected levels were below the permissible limits, i.e. 20 µg/kg. Moreover, experimental infection with toxicogenic A. flavus isolates was conducted to evaluate their pathogenicity in O. niloticus. Expectedly, experimental infections of O. niloticus with A. flavus were associated with several clinical symptoms reported in naturally infected fish, e.g. yellow coloration with skin ulceration, hemorrhagic ulcerative patches on gills and skin, corneal opacity, fin rot and abdominal distention. Furthermore, aflatoxicogenic A. flavus isolates from fish were sensitive to herbal clove oil. Even though the measured levels of aflatoxin were below permissible limits, effort should be placed on further reduction of exposure to genotoxic and carcinogenic mycotoxins.

Evaluation of topical liposome incorporated clove oil in the treatment of idiopathic palmar hyperhidrosis: Single-blinded placebo-controlled study

INTRODUCTION

Palmar hyperhidrosis is of great concern to patients because of its physical, occupational, and psychological impact on quality of life. Topical clove oil has been used in many conditions due to its major component Eugenol that exerts blocking effect on nerve transmission.

AIM OF THE WORK

To assess the efficacy of topical liposome incorporated clove oil in decreasing the rate of sweating among patients with idiopathic palmar hyperhidrosis.

PATIENTS AND METHOD

Forty patients with palmar hyperhidrosis were treated with clove oil 45% in liposome and another twenty patients were treated as a control group with 0.9% saline solution and evaluation was carried out before and after treatment through gravimetry testing and hyperhidrosis disease severity scale (HDSS).

RESULT

The gravimetry testing among clove oil-treated group showed that the mean sweating rate before treatment was 80.5 ± 41.85 (SD) mg/min which decreased significantly after treatment to 52.98 ± 37.94(SD) mg/min (P value < .001). On the other hand, the placebo-treated group,(control) the mean sweating rate before treatment was 77.40 ± 29.29(SD) which did not show significant improvement after placebo application 77.35 ± 28.29(SD; P value = .957).

CONCLUSION

The topical application of 45% clove oil in liposome twice daily for 2 weeks showing promising result evidenced by declining in the rate of palmar sweating among patients with idiopathic palmar hyperhidrosis.

Pharmacological and Toxicological Properties of Eugenol

Eugenol is a volatile phenolic constituent of clove essential oil obtained from Eugenia caryophyllata buds and leaves. It is a functional ingredient of numerous products which have been used in the pharmaceutical, food and cosmetic industry in restricted concentrations. Its derivatives have been used in medicine as a local antiseptic and anesthetic. The wide range of eugenol activities includes antimicrobial, anti-inflammatory, analgesic and antioxidant. Although eugenol is considered safe as a product, due to the vast range of different applications and extensive use, there has been a great concern about its toxicity in recent years. However, studies about cytotoxicity and genotoxicity of eugenol are very limited and controversial. The pharmacological and toxicological properties of eugenol will be discussed in this review.

Eco-Friendly Acaricidal Effects of Nylon 66 Nanofibers via Grafted Clove Bud Oil-Loaded Capsules on House Dust Mites

Acaricidal nylon 66 fabrics (AN66Fs) grafted with clove oil-loaded microcapsules (COMCs) were developed against Dermatophagoides farina (D. gallinae). The average diameter was about 2.9 µm with a range of 100 nm–8.5 µm. COMCs carried clove oil loading of about 65 vol %. COMCs were chemically grafted to electrospun nylon nanofibers by the chemical reactions between –OH groups of COMCs and –COOH end groups of nylon fabrics to form ester linkages. AN66Fs had an effect on D. farinae depending on COMCs loadings. The increase in COMCs loading of AN66Fs from 5 to 15 wt % increased from 22% to 93% mortality against D. farinae within 72 h. However, AN66Fs containing over 20 wt % COMCs were more effective, showing up to 100% mortality within 24 h because the large amount of monoterpene alcohol, eugenol. This research suggests the use of clove oil and its major constituent eugenol as eco-friendly bioactive agents that can serve as a replacement for synthetic acaricides in controlling the population of D. farinae.

Influence of coral cover and structural complexity on the accuracy of visual surveys of coral-reef fish communities

Using manipulated patch reefs with combinations of varying live-coral cover (low, medium and high) and structural complexity (low and high), common community metrics (abundance, diversity, richness and community composition) collected through standard underwater visual census techniques were compared with exhaustive collections using a fish anaesthetic (clove oil). This study showed that reef condition did not influence underwater visual census estimates at a community level, but reef condition can influence the detectability of some small and cryptic species and this may be exacerbated if surveys are conducted on a larger scale.

Fabrication and Evaluation of Nanostructured Herbal Oil/Hydroxypropyl-β-Cyclodextrin/Polyvinylpyrrolidone Mats for Denture Stomatitis Prevention and Treatment

This work aims to develop the herbal oil-incorporated nanostructure mats with antifungal activity for the prevention and treatment of Candida-associated denture stomatitis. The nanofiber mats loaded with betel oil or clove oil were fabricated via electrospinning process. The morphologies and physicochemical properties of the herbal oil loaded nanofiber mats were examined using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and mechanical testing. The release characteristic, antifungal activity, and cytotoxicity were also investigated. The SEM images confirmed the homogeneous and smooth nanoscale fibers. The addition of the herbal oil into the nanofiber mats reduced the fiber diameters. The DSC and FT-IR results confirmed the presence of the oil in the nanofiber mats. The herbal oils can be released from the mats in a very fast manner and inhibit the growth of candida cells within only few minutes after contact. These nanofiber mats may be beneficial for the prevention and treatment of denture stomatitis.