A comparative study of the antioxidant/prooxidant activities of eugenol and isoeugenol with various concentrations and oxidation conditions

Isoeugenol Inhibits Adipogenesis in 3T3-L1 Preadipocytes with Impaired Mitotic Clonal Expansion

Isoeugenol (IEG), a natural component of clove oil, possesses antioxidant, anti-inflammatory, and antibacterial properties. However, the effects of IEG on adipogenesis have not yet been elucidated. Here, we showed that IEG blocks adipogenesis in 3T3-L1 cells at an early stage. IEG inhibits lipid accumulation in adipocytes in a concentration-dependent manner and reduces the expression of mature adipocyte-related factors including PPARγ, C/EBPα, and FABP4. IEG treatment at different stages of adipogenesis showed that IEG inhibited adipocyte differentiation by suppressing the early stage, as confirmed by lipid accumulation and adipocyte-related biomarkers. The early stage stimulates growth-arrested preadipocytes to enter mitotic clonal expansion (MCE) and initiates their differentiation into adipocytes by regulating cell cycle-related factors. IEG arrested 3T3-L1 preadipocytes in the G0/G1 phase of the cell cycle and attenuated cell cycle-related factors including cyclinD1, CDK6, CDK2, and cyclinB1 during the MCE stage. Furthermore, IEG suppresses reactive oxygen species (ROS) production during MCE and inhibits ROS-related antioxidant enzymes, including superoxide dismutase1 (SOD1) and catalase. The expression of cell proliferation-related biomarkers, including pAKT and pERK1/2, was attenuated by the IEG treatment of 3T3-L1 preadipocytes. These findings suggest that it is a potential therapeutic agent for the treatment of obesity.

Transcriptome-wide analysis of PIP reductase gene family identified a phenylpropene synthase crucial for the biosynthesis of dibenzocyclooctadiene lignans in Schisandra chinensis

Phenylpropenes, such as isoeugenol and eugenol, are produced as defend compounds, floral attractants, and flavor constituents by phenylpropene synthases belonging to the PIP reductase family. Moreover, isoeugenol is proposed to be involved in the biosynthesis of dibenzocyclooctadiene lignans, the main active compounds of Schisandra chinensis (Turcz.) Baill. fruits (SCF). S. chinensis, a woody vine plant, is widely used for its medicinal, horticultural, edible, and economic values. In this study, nine ScPIP genes were identified and characterized from the transcriptome datasets of SCF. The expression profiles revealed that ScPIP genes were differentially expressed during different developmental stages of SCF. Three ScPIPs were selected and cloned as candidate genes encoding phenylpropene synthases according to phylogenetic analysis. ScPIP1 was proved to function as isoeugenol synthase (IGS) and designated as ScIGS1 through in vivo functional characterization in Escherichia coli. Subcellular localization analysis demonstrated that ScIGS1 was localized in both the cytoplasm and nucleus. The three-dimensional (3D) model of ScIGS1 was obtained using homology modeling. Site-directed mutagenesis experiments revealed that the substitution of residues at positions 110 and 113 impacted the product specificity of ScIGS1 and the mutation of Lys157 to Ala abolishing catalytic function. Moreover, the kcat values of mutants were lower than that of ScIGS1 using a deep learning approach. In conclusion, this study provides a basis for further research on PIP reductases and the biosynthetic pathway of dibenzocyclooctadiene lignans.

Pharmacodynamic, pharmacokinetic, toxicity, and recent advances in Eugenol's potential benefits against natural and chemical noxious agents: A mechanistic review

The active biological phytochemicals, crucial compounds employed in creating hundreds of medications, are derived from valuable and medicinally significant plants. These phytochemicals offer excellent protection from various illnesses, including inflammatory disorders and chronic conditions caused by oxidative stress. A phenolic monoterpenoid known as eugenol (EUG), it is typically found in the essential oils of many plant species from the Myristicaceae, Myrtaceae, Lamiaceae, and Lauraceae families. One of the main ingredients of clove oil (Syzygium aromaticum (L.), Myrtaceae), it has several applications in industry, including flavoring food, pharmaceutics, dentistry, agriculture, and cosmeceuticals. Due to its excellent potential for avoiding many chronic illnesses, it has lately attracted attention. EUG has been classified as a nonmutant, generally acknowledged as a safe (GRAS) chemical by the World Health Organization (WHO). According to the existing research, EUG possesses notable anti-inflammatory, antioxidant, analgesic, antibacterial, antispasmodic, and apoptosis-promoting properties, which have lately gained attention for its ability to control chronic inflammation, oxidative stress, and mitochondrial malfunction and dramatically impact human wellness. The purpose of this review is to evaluate the scientific evidence from the most significant research studies that have been published regarding the protective role and detoxifying effects of EUG against a wide range of toxins, including biological and chemical toxins, as well as different drugs and pesticides that produce a variety of toxicities, throughout view of the possible advantages of EUG.

Antioxidant Activity and Skin Sensitization of Eugenol and Isoeugenol: Two Sides of the Same Coin?

Eugenol and isoeugenol are well acknowledged to possess antioxidant and thus cytoprotective activities. Yet both compounds are also important skin sensitizers, compelling the cosmetics and fragrance industries to notify their presence in manufactured products. While they are structurally very similar, they show significant differences in their sensitization properties. Consequently, eugenol and isoeugenol have been the subject of many mechanistic studies where the final oxidation forms, electrophilic ortho-quinone and quinone methide, are blamed as the reactive species forming an antigenic complex with nucleophilic residues of skin proteins, inducing skin sensitization. However, radical mechanisms could compete with such an electrophilic-nucleophilic pathway. The antioxidant activity results from neutralizing reactive oxygen radicals by the release of the phenolic hydrogen atom. The so-formed phenoxyl radicals can then fully delocalize upon the structure, becoming potentially reactive toward skin proteins at several positions. To obtain in-depth insights into such reactivity, we investigated in situ the formation of radicals from eugenol and isoeugenol using electron paramagnetic resonance combined with spin trapping in reconstructed human epidermis (RHE), mimicking human skin and closer to what may happen in vivo. Two modes of radical initiation were used, exposing RHE to (i) horseradish peroxidase (HRP), complementing RHE metabolic capacities, and mimicking peroxidases present in vivo or (ii) solar light using a AM 1.5 solar simulator. In both experimental approaches, where the antioxidant character of both compounds is revealed, oxygen- and carbon-centered radicals were formed in RHE. Our hypothesis is that such carbon radicals are relevant candidates to form antigenic entities prior to conversion into electrophilic quinones. On this basis, these studies suggest that pro- or prehapten fingerprints could be advanced depending on the radical initiation method. The introduction of HRP suggested that eugenol and isoeugenol behave as prohaptens, while when exposed to light, a prehapten nature could be highlighted.

Chemo-enzymatic synthesis and biological activity evaluation of propenylbenzene derivatives

Propenylbenzenes, including isosafrole, anethole, isoeugenol, and their derivatives, are natural compounds found in essential oils from various plants. Compounds of this group are important and valuable, and are used in the flavour and fragrance industries as well as the pharmaceutical and cosmetic industries. The aim of this study was to develop an efficient process for synthesising oxygenated derivatives of these compounds and evaluate their potential biological activities. In this paper, we propose a two-step chemo-enzymatic method. The first step involves the synthesis of corresponding diols 1b-5b from propenylbenzenes 1a-5avia lipase catalysed epoxidation followed by epoxide hydrolysis. The second step involves the microbial oxidation of a diasteroisomeric mixture of diols 1b-5b to yield the corresponding hydroxy ketones 1c-4c, which in this study was performed on a preparative scale using Dietzia sp. DSM44016, Rhodococcus erythropolis DSM44534, R. erythropolis PCM2150, and Rhodococcus ruber PCM2166. Application of scaled-up processes allowed to obtain hydroxy ketones 1-4c with the following yield range 36-62.5%. The propenylbenzene derivatives thus obtained and the starting compounds were tested for various biological activities, including antimicrobial, antioxidant, haemolytic, and anticancer activities, and their impact on membrane fluidity. Fungistatic activity assay against selected strains of Candida albicans results in MIC₅₀ value varied from 37 to 124 μg/mL for compounds 1a, 3a-c, 4a,b, and 5a,b. The highest antiradical activity was shown by propenylbenzenes 1-5a with a double bond in their structure with EC₅₀ value ranged from 19 to 31 μg/mL. Haemolytic activity assay showed no cytotoxicity of the tested compounds on human RBCs whereas, compounds 2b-4b and 2c-4c affected the fluidity of the RBCs membrane. The tested compounds depending on their concentration showed different antiproliferative activity against HepG2, Caco-2, and MG63. The results indicate the potential utility of these compounds as fungistatics, antioxidants, and proliferation inhibitors of selected cell lines.

Influence of Eugenol and Its Novel Methacrylated Derivative on the Polymerization Degree of Resin-Based Composites

The aim of this work was to assess the limiting rate of eugenol (Eg) and eugenyl-glycidyl methacrylate (EgGMA) at which the ideal degree of conversion (DC) of resin composites is achieved. For this, two series of experimental composites, containing, besides reinforcing silica and a photo-initiator system, either EgGMA or Eg molecules at 0-6.8 wt% per resin matrix, principally consisting of urethane dimethacrylate (50 wt% per composite), were prepared and denoted as UGx and UEx, where x refers to the EgGMA or Eg wt% in the composite, respectively. Disc-shaped specimens (5 × 1 mm) were fabricated, photocured for 60 s, and analyzed for their Fourier transform infrared spectra before and after curing. The results revealed concentration-dependent DC, increased from 56.70% (control; UG0 = UE0) to 63.87% and 65.06% for UG3.4 and UE0.4, respectively, then dramatically decreased with the concentration increase. The insufficiency in DC due to EgGMA and Eg incorporation, i.e., DC below the suggested clinical limit (>55%), was observed beyond UG3.4 and UE0.8. The mechanism behind such inhibition is still not fully determined; however, radicals generated by Eg may drive its free radical polymerization inhibitory activity, while the steric hindrance and reactivity of EgGMA express its traced effect at high percentages. Therefore, while Eg is a severe inhibitor for radical polymerization, EgGMA is safer and can be used to benefit resin-based composites when used at a low percentage per resin.

Introduction of Flavor Chemical Eugenol Attenuating the Synergistic Toxicological Interactions of Flavor Mixtures

The flavor chemicals benzyl alcohol (BEA), phenylethanol (PHA), and cinnamaldehyde (CID) and their binary mixtures have high toxicity sensitivity to the lethal endpoint of Caenorhabditis elegans. Some binary flavor mixtures even have synergistic toxicological interactions. Eugenol (EUG) is closely related to human life and has many special nonlethal effects on organisms. The effect of its introduction on the combined toxicities of flavor mixtures is worth studying. We introduced EUG into three binary (BEA-PHA, BEA-CID, and PHA-CID) and one ternary (BEA-PHA-CID) flavor mixture systems. Five representative mixture rays were selected from each of the four mixture systems using the uniform design ray (UD-Ray) method. The lethal toxicity of each mixture ray to C. elegans was measured at three different exposure volumes (100, 200, and 400 μL), and a dose-effect model was established. The new parameter iSPAN was used to quantitatively characterize the toxicity sensitivity of each chemical and mixture ray. The toxicological interaction of each mixture was evaluated by the toxicological interaction heatmap based on the combination index (CI). It can be seen that all flavor chemicals and their ternary and quaternary mixture rays have high iSPANs, and the highest value is 16.160 (BEA-PHA-CID-EUG-R1 at 400 μL). According to the heatmap and CI, the introduction of EUG attenuates the synergistic toxicological interactions of flavor mixtures, leading to the transformation ofsynergistic interactions in flavor mixtures into additive action and even antagonistic interaction, and the CI value of the antagonistic interaction is up to 1.8494 (BEA-CID-EUG-R4 at 400 μL).

Phytochemical Profiling, Anti-Inflammatory, Anti-Oxidant and In-Silico Approach of Cornus macrophylla Bioss (Bark)

The objective of the current study was to evaluate the phytochemical and pharmacological potential of the Cornus macrophylla. C. macrophylla belongs to the family Cornaceae. It is locally known as khadang and is used for the treatment of different diseases such as analgesic, tonic, diuretic, malaria, inflammation, allergy, infections, cancer, diabetes, and lipid peroxidative. The crude extract and different fractions of C. macrophyll were evaluated by gas chromatography and mass spectroscopy (GC-MS), which identified the most potent bioactive phytochemicals. The antioxidant ability of C. macrophylla was studied by 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and 1,1 diphenyl-2-picryl-hydrazyl (DPPH) methods. The crude and subsequent fractions of the C. macrophylla were also tested against anti-inflammatory enzymes using COX-2 (Cyclooxygenase-2) and 5-LOX (5-lipoxygenase) assays. The molecular docking was carried out using molecular operating environment (MOE) software. The GC-MS study of C. macrophylla confirmed forty-eight compounds in ethyl acetate (Et.AC) fraction and revealed that the Et.AC fraction was the most active fraction. The antioxidant ability of the Et.AC fraction showed an IC₅₀ values of 09.54 μg/mL and 7.8 μg/mL against ABTS and DPPH assay respectively. Among all the fractions of C. macrophylla, Et.AC showed excellent activity against COX-2 and 5-LOX enzyme. The observed IC₅₀ values were 93.35 μg/mL against COX-2 and 75.64 μg/mL for 5-LOX respectively. Molecular docking studies supported these in vitro results and confirmed the anti-inflammatory potential of C. macrophylla. C. macrophylla has promising potential as a source for the development of new drugs against inflammation in the future.

Pro-Oxidant and Cytotoxic Effects of Tucum-Do-Cerrado (Bactris setosa Mart.) Extracts in Colorectal Adenocarcinoma Caco-2 Cells

Colorectal cancer is one of the most common types of cancer. Bioactive natural compounds can act in cancer chemoprevention as tumor growth inhibitors. Tucum-do-cerrado (Bactris setosa Mart.) is a Brazilian fruit that contains several phenolic compounds. This study investigated the effect of tucum aqueous extract in Caco-2 cells in comparison to primary human intestinal organoids and fibroblasts. Cells were exposed to 0.5 and 1 mg/ml of tucum aqueous extract for 24 h. ROS production, mRNA levels for SOD1 and SOD2, CAT, GPX1, NFE2L2, HIF1A and NOS2 were evaluated in Caco-2 cells exposed to tucum extract. Cell viability of Caco-2 cells was decreased upon tucum extract exposure. Mitochondrial ROS levels increased in Caco-2 cells exposed to tucum extract. The mRNA levels of SOD1, SOD2, CAT, GPX, NFE2L2 and HIF1A were downregulated in Caco-2 cells exposed to tucum extract, while NOS2 mRNA levels remained unchanged. Protein levels of SOD2, CAT and NRF2 remained unchanged in Caco-2 cells treated with tucum extract, indicating that catalase and SOD2 cellular functions may be unaffected by the tucum extract at 24 h, of exposure. Aqueous extract of tucum-do-cerrado may induce cellular toxicity in a cancer cell-specific manner, possibly through increased mitochondrial ROS production and gene expression regulation.

Cardiac mitochondrial energetics of the Australasian red spiny lobster, Jasus edwardsii, when exposed to isoeugenol within the commercial anaesthetic AQUI-S

The anaesthetic isoeugenol has been used as metabolic suppressant for commercial transport of live lobsters in order to decrease energy expenditure aand improve survival. Given the central role of mitochondria in metabolism and structural similarities of isoeugenol to the mitochondrial electron carrier coenzyme Q, we explored the influence on mitochondrial function of isoeugenol. Mitochondrial function was measured using high resolution respirometry and saponin permeabilized heart fibres from the Australasian red spiny lobster, Jasus edwardsii. Relative to vehicle (polysorbate), isoeugenol inhibited respiration supported by complex I (CI) and cytochrome c oxidase (CCO). While complex II (CII), which also reduces coenzyme Q was largely unaffected by isoeugenol, respiration supported by CII when uncoupled was depressed. Titration of isoeugenol indicates that respiration through CI has a half inhibition constant (IC50) of 2.4±0.1 µM, and full inhibition constant IC100 of approximately 6.3 µM. These concentrations are consistent with those used for transport and euthanasia of J. edwardsii and indicates that CI is a possible target of isoeugenol like many other anaesthetics with quinone-like structures.

Reactivity vs. selectivity of quinone methides: synthesis of pharmaceutically important molecules, toxicity and biological applications

Quinone methides (QMs) are considered to be highly reactive intermediates because of their aromatization both in chemical and biological systems. Being highly accessible, quinone methides (QMs) have been widely exploited and their concurrent use has been manifested for the synthesis of tertiary and quaternary carbon centers of bioactives, drugs and drug-like molecules. In this feature article, the synthetic routes, structure-reactivity relationships and synthetic applications of quinone methides are discussed. Formation of the intermediates during bioactivation of different chemical entities and possible chemical manifestations leading to their toxicity in biological systems are also covered.

A Mini-Review: Effect of Medium on the Activity of Eugenol

Abstract:

The role of essential fatty acids is vital in the life of a human being. The lack of essential fatty acids causes various diseases such as cardiovascular, inflammatory bowel and obesity. Although synthetic antioxidants have already been used, nowadays, the demand for natural antioxidants has increased mainly because of the adverse effects of synthetic antioxidants. Spices are widely used in this context as a source of natural antioxidants. It has been observed that they also act as pro-oxidant. This review aims to evaluate the fundamental reason for the different activities of the spices by studying the example of Eugenol, a principal phenolic constituent of clove oil. The chemistry concerning the mechanism to display antioxidant and pro-oxidant activity is currently being reviewed. The isomerization of Eugenol to Isoeugenol plays a key role in exhibiting dissimilar behaviour of the Eugenol. Under the polar medium, isomerization of Eugenol does not take place and it acts as an antioxidant. However, in the non-polar medium, Eugenol isomerizes to Isoeugenol and displays a pro-oxidant effect. In a basic medium, Eugenol isomerizes to Isoeugenol undergoing degradation. Hence, to utilize the beneficial activity of Eugenol, it should be present in a polar or acidic medium. It can be concluded from this review article that the structural form of any molecule plays a major role in utilizing its activity and is also dependent on the medium. Hence, the medium also performs a vital role to influence the activity of any molecule.

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.

Integrated Metabolomics and Proteomics Dynamics of Serum Samples Reveals Dietary Zeolite Clinoptilolite Supplementation Restores Energy Balance in High Yielding Dairy Cows

Dairy cows can suffer from a negative energy balance (NEB) during their transition from the dry period to early lactation, which can increase the risk of postpartum diseases such as clinical ketosis, mastitis, and fatty liver. Zeolite clinoptilolite (CPL), due to its ion-exchange property, has often been used to treat NEB in animals. However, limited information is available on the dynamics of global metabolomics and proteomic profiles in serum that could provide a better understanding of the associated altered biological pathways in response to CPL. Thus, in the present study, a total 64 serum samples were collected from 8 control and 8 CPL-treated cows at different time points in the prepartum and postpartum stages. Labelled proteomics and untargeted metabolomics resulted in identification of 64 and 21 differentially expressed proteins and metabolites, respectively, which appear to play key roles in restoring energy balance (EB) after CPL supplementation. Joint pathway and interaction analysis revealed cross-talks among valproic acid, leucic acid, glycerol, fibronectin, and kinninogen-1, which could be responsible for restoring NEB. By using a global proteomics and metabolomics strategy, the present study concluded that CPL supplementation could lower NEB in just a few weeks, and explained the possible underlying pathways employed by CPL.

Development of Eugenol-Embedded Calcium Citrate Nanoparticles as a Local Anesthetic Agent

Eugenol is a major phenolic component derived from clove oil with potential medical applications. Of particular interest, it has been used as a therapeutic agent in topical applications because of its analgesic and local anesthetic properties. However, topical formulations of eugenol produce skin irritation, which limits its clinical applications. One promising strategy to overcome this disadvantage is by using a biocompatible material that could be an appropriate topical vehicle for eugenol. Researchers have recently focused on the development of eugenol-embedded calcium citrate nanoparticles (Eu-CaCit NPs) without adverse effects. The Eu-CaCit NPs were developed as a topical delivery system and their biocompatibility and penetration ability were evaluated. Eu-CaCit NPs at 1.2 mg/mL did not show cytotoxicity effects in human cells. Moreover, the Eu-CaCit NPs presented the ability to penetrate the dermis layer of the human intact skin following 12 h exposure. All the results concluded that Eu-CaCit NPs have shown a potential as a carrier for topical delivery of eugenol. These novel nanoparticles represent a promising alternative for topical application of local anesthetic with natural pain relievers.

Molecular Interaction Analysis of COX-2 Against Aryl Amino Alcohol Derivatives from Isoeugenol as Anti Breast Cancer using Molecular Docking

Breast cancer occurs due to uncontrolled cells proliferation. The Proliferation causes severe inflammatory which can be the initial stages of cancer symptoms. Aryl amino alcohol compounds from isoeugenol derivatives are proposed for the potential drugs of breast cancer. This study was conducted on iso-eugenol derivatives by adding carbonyl groups, hydroxyl groups, halide compounds and amines to determine the effect on anticancer activity through molecular docking studies. The molecular docking approach is carried out to see the interaction of ligands with protein compounds by using the minimized ligand energy bind with protein active site using protein data bank ID 5GMN. The docking result show that IE-Benzanilide-Cl (11) and IE-Benzanilide-OH (10) have the lowest binding energy (−8.3 kcal/mol and −8.6 kcal/mol) compare to another compounds. AdmetSAR computer simulations show that all compounds have very few toxic effects. The use of aryl amino alcohol derivatives (10 and 11) may be suggested as anti-breast cancer drugs. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

A chemical genetic approach using genetically encoded reporters to detect and assess the toxicity of plant secondary metabolites against bacterial pathogens

Plant secondary metabolites are emerging as attractive alternatives in the development of therapeutics against infectious and chronic diseases. Due to the present pandemic, therapeutics showing toxicity against bacterial pathogens and viruses are gaining interest. Plant metabolites of terpenoid and phenylpropanoid categories have known antibacterial and antiviral properties. These metabolites have also been associated with toxicity to eukaryotic cells in terms of carcinogenicity, hepatotoxicity, and neurotoxicity. Sensing methods that can report the exact antibacterial dosage, formation, and accumulation of these antibacterial compounds are needed. The whole-cell reporters for such antibacterial metabolites are cost-effective and easy to maintain. In the present study, battery of toxicity sensors containing fluorescent transcriptional bioreporters was constructed, followed by fine-tuning the response using gene-debilitated E. coli mutants. This study shows that by combining regulatory switches with chemical genetics strategy, it may be possible to detect and elucidate the mode of action of effective antibacterial plant secondary metabolites - thymol, cinnamaldehyde, eugenol, and carvacrol in both pure and complex formats. Apart from the detection of adulteration of pure compounds present in complex mixture of essential oils, this approach will be useful to detect authenticity of essential oils and thus reduce unintended harmful effects on human and animal health.

Pharmacological Properties and Health Benefits of Eugenol: A Comprehensive Review

The biologically active phytochemicals are sourced from edible and medicinally important plants and are important molecules being used for the formulation of thousands of drugs. These phytochemicals have great benefits against many ailments particularly the inflammatory diseases or oxidative stress-mediated chronic diseases. Eugenol (EUG) is a versatile naturally occurring molecule as phenolic monoterpenoid and frequently found in essential oils in a wide range of plant species. EUG bears huge industrial applications particularly in pharmaceutics, dentistry, flavoring of foods, agriculture, and cosmeceutics. It is being focused recently due to its great potential in preventing several chronic conditions. The World Health Organization (WHO) has declared EUG as a nonmutant and generally recognized as safe (GRAS) molecule. The available literature about pharmacological activities of EUG shows remarkable anti-inflammatory, antioxidant, analgesic, and antimicrobial properties and has a significant effect on human health. The current manuscript summarizes the pharmacological characteristics of EUG and its potential health benefits.

Mechanical Nociceptive Threshold, Tissue Alterations and Horn Growth in Calves after Injection of Isoeugenol or Clove Oil under the Horn Bud

Disbudding of calves is a common, painful intervention. Due to cytotoxic and anesthetic properties, the injection of clove oil or its component isoeugenol may be less detrimental to animal welfare. We investigated mechanical nociceptive threshold (MNT), possible tissue alterations and horn growth for up to 12 weeks after injection of 1.5 mL clove oil (CLOV), isoeugenol (ISO) or saline (CON) or after hot-iron disbudding (BURN; with local anesthesia and sedation, n = 10/treatment). MNT was measured using von Frey filaments and a pressure algometer at four locations around the horn bud. There was a treatment*time point interaction (linear mixed model, p < 0.05). MNT decreased most strongly and for the longest time for BURN in most calves at least for 3 weeks. For ISO, the decrease was less distinct and most calves' values returned to baseline after 1-2 weeks. MNT in CLOV was intermediate, with decreased values up to 3 weeks in some animals. 12 weeks after the treatment, horn growth was prevented in about 50% of the horns in CLOV and ISO. Tissue alterations such as swellings of the eyelids often occurred in CLOV, but less so in ISO. Our results suggest that injection of isoeugenol causes less pain and thus seems to be beneficial compared to hot-iron disbudding, while clove oil was not advantageous. Regarding the effectiveness of isoeugenol to prevent horn growth, more studies are needed.

Influence of Piper betle L. extract on umbilical cord cells in vitro and potential treating cutaneous wound

This research aimed to test the effects of Piper betle L. from Vietnam on fibroblasts and UC-derived mesenchymal stem cells (UC-MSCs) from human umbilical cord (UC) on the scratch assay. We tested the extract at different concentrations and then assessed the level of expression of the factors involved in the inflammatory process on fibroblasts including IL-33, VCAM, CD248 by assay real time qPCR. At the concentrations of 0.025 μL/mL and 0.03 μL/mL, the extracts positively affected fibroblast proliferation and UC-MSCs. By contrast, the concentration of 0.058 μL/mL, the extract was toxic to UC-MSCs and fibroblast cell lines, the cells were no longer able to survive. qPCR results show that Piper betle L. extract has the ability to reduce the expression levels of IL-33 (50.8%), VCAM (32.1%), CD248 (46.13%) which trigger inflammatory processes, thereby reducing cellular stress and promoting the process of healing scratches. Our study revealed the proliferation capabilities of Piper betle L. extract from Vietnam In vitro. Hence, Piper betle L. could be recommended as a potential source of wound healing agents.

Alignment Layer of Liquid Crystal Using Plant-Based Isoeugenol-Substituted Polystyrene

We synthesized a series of renewable and plant-based isoeugenol-substituted polystyrenes (PIEU#, # = 100, 80, 60, 40, and 20, where # is the molar percent content of isoeugenol moiety), using polymer modification reactions to study their liquid crystal (LC) alignment behavior. In general, the LC cells fabricated using polymer film with a higher molar content of isoeugenol side groups showed vertical LC alignment behavior. This alignment behavior was well related to the surface energy value of the polymer layer. For example, vertical alignments were observed when the polar surface energy value of the polymer was smaller than approximately 3.59 mJ/m2, generated by the nonpolar isoeugenol moiety with long and bulky carbon groups. Good alignment stability at 100 °C and under ultraviolet (UV) irradiation of 15 J/cm2 was observed for the LC cells fabricated using PIEU100 as a LC alignment layer. Therefore, renewable isoeugenol-based materials can be used to produce an eco-friendly vertical LC alignment system.

Essential oil of Ocimum gratissimum (Linnaeus, 1753): efficacy for anesthesia and transport of Oreochromis niloticus

This study aimed to evaluate the essential oil of Ocimum gratissimum L. (EOOG) for anesthesia and in the transport of Oreochromis niloticus. Experiment I determined the time of anesthesia induction and recovery during anesthesia of O. niloticus exposed to different concentrations of EOOG (0, 30, 90, 150, and 300 mg L^-1). Based on data from Experiment I, Experiment II evaluated the effect of 0, 30, and 90 mg L^-1 EOOG on blood parameters and oxidative stress immediately after anesthesia induction and 1 h after recovery. Experiment III evaluated the effect of 0, 5, and 10 mg L^-1 EOOG on blood variables immediately after 4.5 h of transport of juveniles. Concentrations between 90 and 150 mg L^-1 EOOG were efficient for anesthesia and recovery. The use of 90 mg L^-1 of EOOG prevented an increase in plasma glucose. Other changes in blood parameters and oxidative stress are discussed. The use of 10 mg L^-1 EOOG in transport increased plasma glucose and decreased hematocrit values immediately after transport. It is concluded that the use of 90 and 150 mg L^-1 EOOG causes anesthesia and recovery in O. niloticus within the time intervals considered ideal. The use of 90 mg L^-1 EOOG favored stable plasma glucose soon after anesthesia induction and 1 h after recovery, but caused changes in the antioxidant defense system by increasing hepatic and kidney ROS. The transport of 12 g O. niloticus for 4.5 h can be performed with concentration of 5 mg L^-1 of EOOG.

Encapsulation of essential oil components with methyl-β-cyclodextrin using ultrasonication: Solubility, characterization, DPPH and antibacterial assay

Essential oils derived from medicinal plants are prosperous sources of active components having high biological potential. Cuminaldehye and isoeugenol, are hydrophobic essential oil components (EOC), are showing drastic limitations in their applications by low water solubility and the respective volatility. Methyl-β-cyclodextrin inclusion complexes (MβCD-ICs) were prepared in aqueous solution and in solid state with the EOC via the ultrasonication method, an energy saving, high efficiency and eco-friend technique, aim to extend their aqueous solubility and biological properties. UV-Vis absorption, fluorescence, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), proton nuclear magnetic resonance (¹H NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD) and computational simulations confirmed the formation of EOC/MβCD-ICs. Result of solubility studies proved the enhanced solubilization of EOC in the presence of MβCD in aqueous and double reciprocal profiles substantiated the guest/host stoichiometry of 1:1. TGA and DSC studies indicated the improved stability of EOC in MβCD-ICs. The efficiency of ICs in terms of the antioxidant activity was verified and the IC displayed higher antioxidant activity compared to that of free EOC, as determined by free radical scavenging assay. Finally, the antibacterial effect of EOC/MβCD-ICs against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria was demonstrated. Overall results not only revealed the potential of MβCD on the bioavailability, solubility and stability, but also that the intensification caused by the IC may be greater that the antioxidant and antibacterial effects of the selected EOC for this study.

Essential Oils as a Feed Additives: Pharmacokinetics and Potential Toxicity in Monogastric Animals

Essential oils (EOs) are now a hot topic in finding modern substitutes for antibiotics. Many studies have shown positive results and confirmed their high antibacterial activity both in vitro and in vivo. Deservedly, there is an attempt to use EOs as a substitute for antibiotics, which are currently limited by legislation in animal breeding. Given the potential of EOs, studies on their fate in the body need to be summarized. The content of EO's active substances varies depending on growing conditions and consequently on processing and storage. Their content also changes dynamically during the passage through the gastrointestinal tract and their effective concentration can be noticeably diluted at their place of action (small intestine and colon). Based on the solubility of the individual EO's active substances, they are eliminated from the body at different rates. Despite a strong antimicrobial effect, some oils can be toxic to the body and cause damage to the liver, kidneys, or gastrointestinal tissues. Reproductive toxicity has been reported for Origanum vulgare and Mentha arvensis. Several publications also address the effect on the genome. It has been observed that EOs can show both genoprotective effects (Syzygium aromaticum) and genotoxicity, as is the case of Cinnamomum camphor. This review shows that although oils are mainly studied as promising antimicrobials, it is also important to assess animal safety.

Chemical Composition, Antiradical and Antifungal Activities of Essential Oil of the Leaves of Cinnamomum Zeylanicum Blume from Cameroon

The aim of the present study was to investigate the essential oil of Cinnamomum zeylanicum from Cameroon for its chemical composition, antiradical and antifungal activities against some common fungi causing spoilage of stored food product. The essential oil, obtained by hydrodistillation of fresh leaves, was analysed by GC and GC/MS. The oil contains 11 components among which eugenol (89.1%), linalool (4.3%), benzoate benzyl (3.1%) and cinnamaldehyde (1.5%) were the main components. Determination of antiradical activity of the oil was studied by the DPPH (diphenyl picryl hydrazyl) method. The antiradical activity of Cinnamomum essential oil (SC50 = 4.5 mg/L) was higher than that of butylated hydroxy toluene (BHT), which was used as the reference compound (SC50 = 7 mg/L). The growth inhibitory effect of C. zeylanicumn essential oil on Aspergillus flavus and Fusarium moniliforme was determined on potato dextrose agar. After 9 days of incubation on essential oil-supplemented medium, the growth of A. flavus and Fusarium was totally inhibited by 500 ppm of Cinnamommum zeylanicum oil. Results obtained in the present study indicate the possibility of exploiting C. zeylanicum essential oil to prevent diseases such as diabetes and cancer, to slow down ageing, and also to combat strains of A. flavus and Fusarium moniliforme responsible for biodeterioration of stored food products.

Determination of kinetic parameters of the enzymatic reaction between soybean peroxidase and natural antioxidants using chemometric tools

The oxidation of eugenol, isoeugenol and vanillin natural antioxidants catalyzed by the soybean peroxidase enzyme was studied using uv-vis spectroscopy. An experimental design was used to optimize the different variables. The multivariate curve resolution method was used to obtain the profiles of antioxidant absorbance's as a function of time due to uv-vis absorption bands of both antioxidants and the enzymatic reaction product/s show a strong overlap. From these results, apparent Michaelis-Menten constants as well as the kinetic parameters k1 and k3 involved in the catalytic cycle of peroxidases were calculated. The antioxidant apparent acidity constants were also determined at different pH's from uv-vis spectrophotometric measurements. Values of k1 were (0.6 ± 0.1) × 105 M-1 s-1, (2.0 ± 0.2) × 105 M-1 s-1 and (7.0 ± 0.5) × 106 M-1 s-1 and k3 (4.0 ± 0.2) × 105 M-1 s-1, (6.0 ± 0.6) × 105 M-1 s-1 and (6.0 ± 0.9) × 106 M-1 s-1 for eugenol, isoeugenol and vanillin, respectively.

Formation and biological targets of botanical o-quinones

The formation of o-quinones from direct 2-electron oxidation of catechols and/or two successive one electron oxidations could explain the cytotoxic/genotoxic and/or chemopreventive effects of several phenolic botanical extracts. For example, poison ivy contains urushiol, an oily mixture, which is oxidized to various o-quinones likely resulting in skin toxicity through oxidative stress and alkylation mechanisms resulting in immune responses. Green tea contains catechins which are directly oxidized to o-quinones by various oxidative enzymes. Alternatively, phenolic botanicals could be o-hydroxylated by P450 to form catechols in vivo which are oxidized to o-quinones. Examples include, resveratrol which is oxidized to piceatannol and further oxidized to the o-quinone. Finally, botanical o-quinones can be formed by O-dealkylation of O-alkoxy groups or methylenedioxy rings resulting in catechols which are further oxidized to o-quinones. Examples include safrole, eugenol, podophyllotoxin and etoposide, as well as methysticin. Once formed these o-quinones have a variety of biological targets in vivo resulting in various biological effects ranging from chemoprevention - > no effect - > toxicity. This U-shaped biological effect curve has been described for a number of reactive intermediates including o-quinones. The current review summarizes the latest data on the formation and biological targets of botanical o-quinones.

Molecular interactions of active constituents of essential oils in zwitterionic lipid bilayers

Eugenol and its related compounds are major active constituents of essential oils and have been extensively used as food flavoring agents with significant lipid peroxidation inhibition activity, highlighting the importance of understanding detailed molecular mechanisms behind their interactions with lipid bilayer. For this, we studied antioxidant activity of essential oils rich extract of Cinnamomum tamala leaves and molecular dynamics simulations of eugenol, isoeugenol, methyleugenol, acetyleugenol and eugenol oxide in POPC and PLPC lipid bilayers. All the compounds penetrated into bilayer however, isoeugenol showed highest affinity for the pure POPC and PLPC bilayers with lowest free energy profiles, formed more H-bonds with bilayer oxygen atoms and more pronounced changes in area per lipid and thickness of the bilayer, thus more efficient for scavenging radicals coming from outside as well as centrally located lipid peroxyl radicals. These molecular interactions rationalize the difference in inhibition activities of lipid peroxidation by eugenol and its related compounds.

Plant-Derived Anticancer Agents: Lessons from the Pharmacology of Geniposide and Its Aglycone, Genipin

For centuries, plants have been exploited by mankind as sources of numerous cancer chemotherapeutic agents. Good examples of anticancer compounds of clinical significance today include the taxanes (e.g., taxol), vincristine, vinblastine, and the podophyllotoxin analogues that all trace their origin to higher plants. While all these drugs, along with the various other available therapeutic options, brought some relief in cancer management, a real breakthrough or cure has not yet been achieved. This critical review is a reflection on the lessons learnt from decades of research on the iridoid glycoside geniposide and its aglycone, genipin, which are currently used as gold standard reference compounds in cancer studies. Their effects on tumour development (carcinogenesis), cancer cell survival, and death, with particular emphasis on their mechanisms of actions, are discussed. Particular attention is also given to mechanisms related to the dual pro-oxidant and antioxidant effects of these compounds, the mitochondrial mechanism of cancer cell killing through reactive oxygen species (ROS), including that generated through the uncoupling protein-2 (UCP-2), the inflammatory mechanism, and cell cycle regulation. The implications of various studies for the evaluation of glycosidic and aglycone forms of natural products in vitro and in vivo through pharmacokinetic scrutiny are also addressed.

Impact of Storage Conditions on the Stability of Predominant Phenolic Constituents and Antioxidant Activity of Dried Piper betle Extracts

The phenolic constituents in Piper betle are well known for their antioxidant potential; however, current literature has very little information on their stability under the influence of storage factors. Present study evaluated the stability of total phenolic content (TPC) and antioxidant activity together with individual phenolic constituents (hydroxychavicol, eugenol, isoeugenol and allylpyrocatechol 3,4-diacetate) present in dried Piper betle's extract under different storage temperature of 5 and 25 °C with and without light for a period of six months. Both light and temperature significantly influenced TPC and its corresponding antioxidant activity over time. More than 95% TPC and antioxidant activity was retained at 5 °C in dark condition after 180 days of storage. Hydroxychavicol demonstrated the best stability with no degradation while eugenol and isoeugenol displayed moderate stability in low temperature (5 °C) and dark conditions. 4-allyl-1,2-diacetoxybenzene was the only compound that underwent complete degradation. A new compound, 2,4-di-tert-butylphenol, was detected after five weeks of storage only in the extracts exposed to light. Both zero-order and first-order kinetic models were adopted to describe the degradation kinetics of the extract's antioxidant activity. Zero-order displayed better fit with higher correlation coefficients (R² = 0.9046) and the half-life was determined as 62 days for the optimised storage conditions (5 °C in dark conditions).

Microcystin-LR increases genotoxicity induced by aflatoxin B1 through oxidative stress and DNA base excision repair genes in human hepatic cell lines

Aflatoxin B1 (AFB1) and microcystin-LR (MC-LR) simultaneously exist in polluted food and water in humid and warm areas, and each has been reported to be genotoxic to liver and associated with hepatocellular carcinoma (HCC). However, the genotoxic effects of the two biotoxins in combination and potential mechanism remain unknown. We treated the human hepatic cell line HL7702 with AFB1 and MC-LR together at different ratios, examined their genotoxic effects using micronuclei and comet assays, and evaluated the possible mechanism by measuring oxidative stress markers and DNA base excision repair (BER) genes. Our data show that co-exposure to AFB1 and MC-LR significantly increased DNA damage compared with AFB1 or MC-LR alone as measured by the levels of both micronuclei and tail DNA. Meanwhile, AFB1 and MC-LR co-exposure showed biphasic effects on ROS production, and a gradual trend towards increased Glutathione (GSH) levels and activity of Catalase (CAT) and Superoxide Dismutase (SOD). Furthermore, MC-LR, with or without AFB1, significantly down-regulated the expression of the base excision repair (BER) genes 8-oxoguanine glycosylase-1 (OGG1) and X-ray repair cross complementing group 1 (XRCC1). AFB1 and MC-LR in combination upregulated the expression of the BER gene apurinic/apyrimidinic endonuclease 1 (APE1), whereas either agent alone had no effect. In conclusion, our studies show that MC-LR exacerbates AFB1-induced genotoxicity and we report for the first time that this occurs through effects on oxidative stress and the deregulation of DNA base excision repair genes.

The Dual Antioxidant/Prooxidant Effect of Eugenol and Its Action in Cancer Development and Treatment

The formation of reactive oxygen species (ROS) during metabolism is a normal process usually compensated for by the antioxidant defense system of an organism. However, ROS can cause oxidative damage and have been proposed to be the main cause of age-related clinical complications and diseases such as cancer. In recent decades, the relationship between diet and cancer has been more studied, especially with foods containing antioxidant compounds. Eugenol is a natural compound widely found in many aromatic plant species, spices and foods and is used in cosmetics and pharmaceutical products. Eugenol has a dual effect on oxidative stress, which can action as an antioxidant or prooxidant agent. In addition, it has anti-carcinogenic, cytotoxic and antitumor properties. Considering the importance of eugenol in the area of food and human health, in this review, we discuss the role of eugenol on redox status and its potential use in the treatment and prevention of cancer.

Antinflammatory and anticancer effects of terpenes from oily fractions of Teucruim alopecurus, blocker of IκBα kinase, through downregulation of NF-κB activation, potentiation of apoptosis and suppression of NF-κB-regulated gene expression

Teucrium alopecurus is an endemic plant limited to southern Tunisia. In the present study, the chemical composition, anticancer and nuclear factor-κB (NF-κB) inhibitory effects of Teucrium alopecurus leaf essential oil was investigated. The analysis of Teucrium alopecurus (TA-1) with Gas Chromatography-Mass Spectrometry (GC/MS) showed that α-Bisabolol, (+)-epi-Bicyclosesquiphellandrene and α-Cadinol, were found in relatively high amounts (16.16%, 15.40% and 8.52%, respectively). Cell viability was determined by 3-(4-5-dimethylthiazol-2-yl) 2-5-diphenyl-tetrazolium (MTT) assay. Cell cycle and apoptosis assay were determined by flow cytometry. TA-1 functions as an anticancer agent by triggering apoptosis potentiated by chemotherapeutic agents and TNF in human myeloid leukemia cells (KBM5) through a mechanism involving poly(ADP-ribose) polymerase (PARP) cleavage and initiator and effector caspases activation. Moreover, electrophoretic mobility shift assay (EMSA) revealed that TA-1 downregulated nuclear localization of NF-κB and its phosphorylation induced by TNF-α and this, allows the suppression of the degradation and phosphorylation of IκB and the inhibition of the phosphorylation of p65 phosphorylation and the p50-p65 heterodimer nuclear translocation, causing attenuation of NF-κB-regulated antiapoptotic (Survivin, Bcl-2, c-IAP1/2, Bcl-xL, Mcl-1, and cFLIP), invasion (ICAM1), metasatsis (MMP-9), and angiogenesis (VEGF) gene expression in KBM5; and finally reporter gene expression. Furthermore, treatment with essential oil and TNF-α suppressed the NF-κB DNA binding activity. Finally, the activation of nuclear factor-κB induced by different plasmids (TNFR1, TRADD, TRAF2, NIK, TAK1/TAB1, and IKKβ) was inhibited following treatment with TA-1. Overall, TA-1 inhibits NF-κB activation and further growth and proliferation of cancer cells.

Mechanism underlying methyl eugenol attenuation of intestinal ischemia/reperfusion injury

Intestinal ischemia/reperfusion (I/R) injury is associated with a high risk of mortality in the clinical situation. Many factors are involved in I/R, including reactive oxygen species, cytokine release, and apoptosis. We aimed to determine whether a pure methyl eugenol (ME) given before intestinal ischemia, protects against intestinal I/R injury and the possible mechanism involved in this protection. Rat received ME (100 mg/kg) for 30 days then underwent intestinal I/R with 30 min ischemia and 60 min reperfusion. Serum lactate dehydrogenase (LDH) level, tissue malondialdehyde (MDA), as well as some antioxidant biomarkers were assessed, while the serum level of tumor necrosis factor alpha (TNF-α) was determined by ELISA. The change in TNF-α and interleukin 6 (IL-6) gene expressions were evaluated and confirmed by assessing protein level of TNF-α in the intestinal tissue by immunohistochemistry. Apoptosis was evaluated using DNA-laddering assay and by detecting caspase-3 immunohistochemically. Administration of ME prior to I/R injury resulted in a modulation of the production of MDA, LDH, and nitric oxide and restoration of the tested oxidative stress biomarkers. Pretreatment with ME downregulated messenger RNA of TNF-α and IL-6 inflammatory cytokines and their protein expressions in I/R rats. Marked inhibition of the apoptotic DNA and improvement of the architectures of small intestine were observed after pretreatment with ME. ME exhibits a protective effect against intestinal I/R via amelioration of the oxidative stress and inflammatory cytokines gene expression. Therefore, the supplementation of ME prior to intestinal I/R might be helpful in the attenuation of I/R complications.

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.

Comparison study on antioxidant, DNA damage protective and antibacterial activities of eugenol and isoeugenol against several foodborne pathogens

Eugenol and its isomer isoeugenol are both used as flavouring agents or food additives in food products, and have both some similar biological properties. However, the difference in biological activities between eugenol and isoeugenol is rarely studied. In this study, the profiles of antioxidant, DNA-protective effects and antibacterial activities of eugenol and isoeugenol against several common foodborne pathogens were investigated and compared under various experiment conditions. Results showed that eugenol and isoeugenol had strong antioxidant activity, the protective effect against DNA damage and antibacterial activity. In addition, it was found that isoeugenol exhibited the higher biological activities mentioned above than eugenol, which was because isoeugenol had a carbon–carbon double bond closer to the benzene ring compared with eugenol. However, the specific reason needs to be further studied.

Regeneration of β-Carotene from Radical Cation by Eugenol, Isoeugenol, and Clove Oil in the Marcus Theory Inverted Region for Electron Transfer

The rate of regeneration of β-carotene by eugenol from the β-carotene radical cation, an initial bleaching product of β-carotene, was found by laser flash photolysis and transient absorption spectroscopy to be close to the diffusion limit in chloroform/methanol (9:1, v/v), with a second-order rate constant (k₂) of 4.3 × 10⁹ L mol^-1 s^-1 at 23 °C. Isoeugenol, more reducing with a standard reduction potential of 100 mV lower than eugenol, was slower, with k₂ = 7.2 × 10⁸ L mol^-1 s^-1. Regeneration of β-carotene following photobleaching was found 50% more efficient by eugenol, indicating that, for the more reducing isoeugenol, the driving force exceeds the reorganization energy for electron transfer significantly in the Marcus theory inverted region. For eugenol/isoeugenol mixtures and clove oil, kinetic control by the faster eugenol determines the regeneration, with a thermodynamic backup of reduction equivalent through eugenol regeneration by the more reducing isoeugenol for the mixture. Clove oil, accordingly, is a potential protector of provitamin A for use in red palm oils.

Low electro-synthesis potentials improve permselectivity of polymerized natural phenols in biosensor applications

First-generation amperometric biosensors are often based on the electro-oxidation of oxidase-generated H₂O₂. At the applied potential used in most studies, other molecules such as ascorbic acid or dopamine can be oxidized. Phenylenediamines are commonly used to avoid this problem: when these compounds are electro-deposited onto the transducer surface in the form of poly-phenylenediamine, a highly selective membrane is formed. Although there is no evidence of toxicity of the resulting polymer, phenylenediamine monomers are considered carcinogenic. An aim of this work was to evaluate the suitability of natural phenols as non-toxic alternatives to the ortho isomer of phenylenediamine. Electrosynthesis over Pt-Ir electrodes of 2-methoxy phenols (guaiacol, eugenol and isoeugenol), and hydroxylated biphenyls (dehydrodieugenol and magnolol) was achieved. The potentials used in the present study are significantly lower than values commonly applied during electro-polymerization. Polymers were obtained by means of constant potential amperometry, instead of cyclic voltammetry, in order to achieve multiple polymerizations, hence decreasing the time of realization and variability. Permselective properties of natural phenols were significantly improved at low polymerization potentials. Among the tested compounds, isoeugenol and magnolol, polymerized respectively at +25mV and +170mV against Ag/AgCl reference electrode, proved as permselective as poly-ortho-phenylenediamine and may be considered as effective polymeric alternatives. The natural phenol-coated electrodes were stable and responsive throughout 14 days. A biosensor prototype based on acetylcholine esterase and choline oxidase was electro-coated with poly-magnolol in order to evaluate the interference-rejecting properties of the electrosynthesized film in an amperometric biosensor; a moderate decrease in ascorbic acid rejection was observed during in vitro calibration of biosensors.

Eugenol and Its Role in Chronic Diseases

The active components in cloves are eugenol and isoeugenol. Eugenol has recently become a focus of interest because of its potential role in alleviating and preventing chronic diseases such as cancer, inflammatory reactions, and other conditions. The radical-scavenging and anti-inflammatory activities of eugenol have been shown to modulate chronic diseases in vitro and in vivo, but in humans, the therapeutic use of eugenol still remains to be explored. Based on a review of the recent literature, the antioxidant, anti-proliferative, and anti-inflammatory activities of eugenol and its related compounds are discussed in relation to experimentally determined antioxidant activity (stoichiometric factor n and inhibition rate constant) and theoretical parameters [phenolic O-H bond dissociation enthalpy (BDE), ionization potential (IP according to Koopman's theorem), and electrophilicity (ω)], calculated using a density functional theory method. Dimers of eugenol and its related compounds showed large antioxidant activities and high ω values and also exerted efficient anti-inflammatory activities. Eugenol appears to possess multiple antioxidant activities (dimerization, recycling, and chelating effect) in one molecule, thus having the potential to alleviate and prevent chronic diseases.

Regulation effect of Aspirin Eugenol Ester on blood lipids in Wistar rats with hyperlipidemia

Background

Aspirin eugenol ester (AEE) is a promising drug candidate for treatment of inflammation, pain and fever and prevention of cardiovascular diseases with less side effects. The experiment will be conducted to investigate the efficacy of AEE on curing hyperlipidemia in Wistar rats. The rats were fed with high fat diet (HFD) for 8 weeks to induce hyperlipidemia.

Results

Compared with the model group, the results showed that AEE at 54 mg/kg dosage could significantly decrease the hyperlipidemia indexes including triglyceride (TG), low density lipoprotein (LDL) and total cholesterol (TCH) (p < 0.01), increase high density lipoprotein (HDL) (p < 0.05) for five weeks drug administration. Meanwhile, simvastatin had same effect on hyperlipidemia indexes such as TG, LDL, TC, but no significant increase in HDL.

Conclusion

AEE was effective against hyperlipidemia and had better anti-hyperlipidemic effect than its component, acetylsalicylic acid (Aspirin, ASA), eugenol and integration of ASA and eugenol. Under the experimental circumstance, the optimal dose of AEE to cure hyperlipidemia is 54 mg/kg for five weeks in Wistar rats.