Concentrations Of Eugenol Research Articles

Efficacy of Benzocaine, Eugenol, and Menthol as Anesthetics for Freshwater Angelfish

For the production and commercialization of ornamental fish species, it is indispensable to collect biometric data that facilitate the selection of animals for trade and genetic improvement of the stock. However, during the handling process, fish receive more stress if proper anesthetics are not used. Thus, application of appropriate anesthetics is an important tool for minimizing stress in animals. The objective of this study was to determine the effective concentrations of benzocaine, eugenol, and menthol for achieving anesthesia in Freshwater Angelfish Pterophyllum scalare and to develop induction and recovery response curves for different concentrations of these anesthetics. In total, 75 fish were exposed to five concentrations of the three anesthetics in a completely randomized design: benzocaine at 60, 85, 110, 135, and 160mg/L; eugenol at 40, 80, 120, 160, and 200mg/L; and menthol at 50, 75, 150, 200, and 250mg/L. Each concentration (5fish/concentration) consisted of five replicates, with each replicate represented by a single fish. The results indicated that the tested substances met the criteria of anesthetic efficiency. The effective concentrations of benzocaine, eugenol, and menthol for the anesthesia of Freshwater Angelfish were identified as 89.25, 90.6, and 92.1mg/L, respectively.

Anaesthetic Effects of Eugenol on Grass Shrimp (Palaemonetes sinensis) of Different Sizes at Different Concentrations and Temperatures

Essential oil derivatives are widely used for anaesthetising aquatic animals. However, the effectiveness of anaesthesia often varies according to the anaesthetic agent, species, temperature, dosage, and interactions among these factors. This study evaluated the effects of eugenol on three sizes of the shrimp Palaemonetes sinensis at different concentrations and temperatures. Eugenol dose, water temperature, and shrimp size were found to significantly influence anaesthesia in P. sinensis. Induction time decreased linearly with increasing water temperature and eugenol concentration, while it increased with body weight. However, recovery times lengthened with increasing concentration and temperature, and shortened with lower body size. At 100 and 200 μL/L eugenol concentrations, the survival rates of medium and large shrimps were maintained at over 80% at all temperatures studied over 72 h recovery. However, the survival rates of small shrimps were below 60% at 24 °C and 28 °C over 5 days of recovery. These results suggest that eugenol is an effective and rapid anaesthetic for P. sinensis, but it might have disadvantages such as slow recovery and possible mortality in small shrimps and at higher temperatures and dosages.

Trans-Cinnamaldehyde and Eugenol Increase Acinetobacter baumannii Sensitivity to Beta-Lactam Antibiotics.

Multi-drug resistant (MDR) Acinetobacter baumannii is a major nosocomial pathogen causing a wide range of clinical conditions with significant mortality rates. A. baumannii strains are equipped with a multitude of antibiotic resistance mechanisms, rendering them resistant to most of the currently available antibiotics. Thus, there is a critical need to explore novel strategies for controlling antibiotic resistance in A. baumannii. This study investigated the efficacy of two food-grade, plant-derived antimicrobials (PDAs), namely trans-cinnamaldehyde (TC) and eugenol (EG) in decreasing A. baumannii’s resistance to seven β-lactam antibiotics, including ampicillin, methicillin, meropenem, penicillin, aztreonam, amoxicillin, and piperacillin. Two MDR A. baumannii isolates (ATCC 17978 and AB 251847) were separately cultured in tryptic soy broth (∼6 log CFU/ml) containing the minimum inhibitory concentration (MIC) of TC or EG with or without the MIC of each antibiotic at 37°C for 18 h. A. baumannii strains not exposed to the PDAs or antibiotics served as controls. Following incubation, A. baumannii counts were determined by broth dilution assay. In addition, the effect of PDAs on the permeability of outer membrane and efflux pumps in A. baumannii was measured. Further, the effect of TC and EG on the expression of A. baumannii genes encoding resistance to β-lactam antibiotics (blaP), efflux pumps (adeABC), and multi-drug resistant protein (mdrp) was studied using real-time quantitative PCR (RT-qPCR). The experiment was replicated three times with duplicate samples of each treatment and control. The results from broth dilution assay indicated that both TC and EG in combination with antibiotics increased the sensitivity of A. baumannii to all the tested antibiotics (P < 0.05). The two PDAs inhibited the function of A. baumannii efflux pump, (AdeABC), but did not increase the permeability of its outer membrane. Moreover, RT-qPCR data revealed that TC and EG down-regulated the expression of majority of the genes associated with β-lactam antibiotic resistance, especially blaP and adeABC (P < 0.05). The results suggest that TC and EG could potentially be used along with β-lactam antibiotics for controlling MDR A. baumannii infections; however, their clinical significance needs to be determined using in vivo studies.

Inhibitory effects of eugenol on putative nociceptive response in spinal cord preparation isolated from neonatal rats.

Eugenol is contained in several plants including clove and is thought to exert an analgesic effect. It has been suggested that the slow ventral root potential induced by ipsilateral dorsal root stimulation in the isolated (typically lumbar) spinal cord of newborn rats reflects the nociceptive response, and this in vitro experimental model is useful to assess the actions of analgesics. To further elucidate neuronal mechanisms of eugenol-induced analgesia, we examined the effects of extracellularly applied eugenol on the nociceptive spinal reflex response. To evaluate the effects of eugenol on putative nociceptive responses, the ipsilateral fifth lumbar (L5) dorsal root was stimulated using a glass suction electrode, and the induced reflex responses were recorded from the L5 and twelfth thoracic (Th12) ventral roots in spinal cord preparations (Th10-L5) from newborn rats (postnatal day 0-3). We found that eugenol (0.25-1.0mM) caused dose-dependent attenuation of the reflex response and also depressed spontaneous ventral root activity. We also found that the slow ventral root potential was further divided into two components: initial and late components. A lower concentration of eugenol selectively depressed the late component. The inhibitory effects by 1.0mM eugenol were not reversed by 10µM capsazepine (TRPV1 antagonist) or 40µM HC-030031 (TRPA1 antagonist). The depressive effect of eugenol on the reflex response was also confirmed by optical recordings using voltage-sensitive dye. Our report provides additional evidence on the basic neuronal mechanisms of eugenol to support its clinical use as a potential analgesic treatment.

Electroanalytical determination of eugenol in clove oil by voltammetry of immobilized microdroplets

The determination of eugenol employing voltammetry of immobilized microdroplets (VIM) is reported in this work. The construction of the electrode was based on a glassy carbon substrate modified with carbon black nanoparticles and eugenol standard or clove oil sample within a dihexadecyl hydrogen phosphate (DHP) film. The different experimental parameters related to this proposed procedure, i.e., supporting electrolyte composition, pH, ionic strength, and square-wave voltammetry (SWV) parameters (amplitude, frequency, and step potential) were optimized. By doing that, the SWV measurements were performed on the following optimum experimental conditions: 0.2 mol L−1 phosphate buffer solution (pH 2.0), amplitude 90 mV, frequency 30 Hz, and step potential 5 mV. The analytical curve for eugenol was linear in the wide range from 0.03 to 26 μg (r = 0.999) with limits of detection (LOD) and quantification (LOQ) of 0.13 and 0.42 ng, respectively. Three commercial clove oil samples were successfully immobilized and analyzed using the proposed VIM procedure showing eugenol concentrations ranging from 14.0 to 68.3%. Comparing the results obtained by the proposed and comparative procedure (spectrophotometric), relative standard deviations (RSDs) lower than 5.0% were verified, demonstrating the concordance of the results obtained by both methods.

The Physico-Mechanical Properties and Release Kinetics of Eugenol in Chitosan-Alginate Polyelectrolyte Complex Films as Active Food Packaging

A study of eugenol release and its kinetics model from chitosan-alginate polyelectrolyte complex (PEC) films has been conducted. Some factors that affected the eugenol release were also studied, including the composition of chitosan-alginate PEC and the concentration of eugenol. The chitosan-alginate-eugenol PEC films were synthesized at pH ± 4.0, then the PEC films were characterized using a Fourier-transform infrared spectroscopy (FTIR) spectrophotometer. An investigation of the films’ properties was also conducted, including morphology analysis using a scanning electron microscope (SEM), differential thermal analysis (DTA) / thermogravimetric analysis (TGA), mechanical strength, transparency testing, water absorption, and water vapor permeability. The release of eugenol was investigated through in vitro assay in ethanol 96% (v/v) for four days, and the concentration of eugenol was measured using an ultraviolet-visible (UV-Vis) spectrophotometer. The characterization of the films using FTIR showed that the formation of PEC occurred through ionic interaction between the amine groups (–NH3+)of the chitosan and the carboxylate groups (–COO–) of the alginate. The result showed that the composition of chitosan-alginate PEC and the concentration of eugenol can affect the release of eugenol from PEC films. A higher concentration of alginate and eugenol could increase the concentration of eugenol that was released from the films. The mechanism for the release of eugenol from chitosan-alginate PEC films followed the Korsmeyer-Peppas model with an n value of &lt; 0.5, which means the release mechanism for eugenol was controlled by a Fickian diffusion process. The antioxidant activity assay of the films using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method resulted in a high radical scavenging activity (RSA) value of 55.99% in four days.

Rainbow trout (Oncorhynchus mykiss) anesthesia with myrcene: efficacy and physiological responses in comparison with eugenol.

The aim of the present study was to investigate anesthetic efficacy of myrcene in rainbow trout (Oncorhynchus mykiss) along with the fish biochemical response to anesthesia in comparison with eugenol. In the first experiment, 240 fish were stocked in 12 tanks and acclimatized to experimental conditions for 2weeks. Then, the fish of each tank were subjected to one concentration of either eugenol (12, 20, 30, 50, 80, and 130μL/L) or myrcene (100, 150, 200, 300, 400, and 500μL/L) concentrations. Induction time of and recovery time from anesthesia were recorded for each fish separately. Using these results, desired concentrations to induce anesthesia within 60, 180, 300, and 600s were determined, being 81, 30, 19, and 10μL/L eugenol and 531, 251, 177, and 111μL/L myrcene. In the second experiment, 96 fish were stocked in 8 tanks. Six fish were netted from each tank and exposed to the calculated eugenol or myrcene concentrations. Blood samples were taken after the fish reached anesthesia. The results showed that there was no significant difference in serum lactate, alanine transaminase, and alkaline phosphatase. Increase in the induction time of anesthesia resulted in increased serum glucose with no significant difference between the anesthetics. Increase in induction time of anesthesia led to increase in serum lactate dehydrogenase activity in the eugenol-anesthetized fish and aspartate transaminase activity in myrcene-anesthetized fish. In conclusion, myrcene is capable to anesthetize rainbow trout, but at higher concentrations compared to eugenol. In addition, biochemical analysis showed that increase in induction time of anesthesia leads to hyperglycemia and increase in AST and LDH activities depending on anesthetic type.

Evaluating Antioxidant Eugenol on Oxidation Stability of Biodiesel Synthesized from Used Frying Oil

Due the environmental appeal, the demand of new processes and inputs has been increasing considerably in the last decade. Biodiesel is a biodegradable fuel obtained from vegetable oils or animal fats, including those discarded after use. The methyl and ethyl transesterification routes for biodiesel production were tested by using residual frying oil as raw material through the homogeneous basic catalyst, such as sodium hydroxide. In present work, it was evaluated the efficiency of the eugenol on the oxidation stability of the methyl and ethyl biodiesels synthesized from residual frying oil. The chromatographic analysis determined that the conversion of the yield to the methyl and ethylic esters (biodiesel) was 90.6 % and 87.3 %(m/m) respectively. For both biodiesel samples a rise of the eugenol concentration added resulted in an increase of the induction period (oxidation stability parameter evaluated by Rancimat method), with a consequent reduction of the acid number. Taking these results into account, it can be concluded that the samples obtained after eugenol addition can be used as biodiesel. DOI: http://dx.doi.org/10.17807/orbital.v10i1.1030

Topical Eugenol Successfully Treats Experimental Candida albicans-Induced Keratitis

Purpose: To determine the efficacy of eugenol for the treatment of Candida keratitis in an experimental model. Methods: The in vitro antifungal activity of eugenol and fluconazole was tested against C. albicans strains via the microbroth dilution method. An experimental model of Candida albicans keratitis was used. Rabbits were classified into those that received no treatment (control; group 1) and those that started eugenol treatment immediately (group 2) or after 4 days (group 3) of keratitis induction (n = 12–16 rabbits/group). The 2 treatment groups were assigned to 50 μL of 4 mg/mL eugenol drops hourly for 15 days, while the control group received saline. Corneal penetration of eugenol was measured using HPLC, and corneal toxicity was evaluated clinically and histopathologically. Results: The in vitro minimum inhibitory concentrations of eugenol and fluconazole against C. albicans were 2 and > 0.4 mg/mL, respectively. A 4-mg/mL preparation of eugenol in propylene glycol was the maximum nontoxic dose on rabbit corneas as suggested by clinical and histopathologic findings. At least 75% of all eugenol-treated eyes recovered from keratitis, with improvement in the remaining 25% of the eyes compared to controls. Conclusions: Eugenol can act as a natural, safe, and effective treatment for fungal keratitis, regardless of whether treatment is started immediately or after 4 days of keratitis induction.

Determination of eugenol in plants and pharmaceutical form by HPLC with amperometric detection at graphene-modified carbon paste electrode

Eugenol is an important natural compound derived from various plants, mainly in clove, and used for healthy benefits, cosmetics and as flavoring agent. A high-performance liquid chromatography (HPLC) coupled to electrochemical detection method was developed for determination eugenol in several methanol extract of plants and pastille. The separation was carried out on a RP-HPLC C18 column, isocratically in 1% acetic acid–acetonitrile–methanol (43:17:40 v/v) mobile phase system with amperometric detection at carbon paste electrode modified with graphene, versus Ag/AgCl at 0.9 V. The range of eugenol concentration varied from 0.16 to 16.42 µg/mL with good coefficient of determination (r 2 = 0.9994). The limit of detection and limit of quantification values of eugenol were 0.052 and 0.157 µg/mL, respectively.

Eugenol enhances proliferation and migration of mouse bone marrow-derived mesenchymal stem cells in vitro

Mesenchymal stem cells (MSCs) have received considerable attention in regenerative medicine during the past decade. Eugenol is a natural and versatile vegetable molecule, which has a wide variety of therapeutic effects. Although different biological and pharmaceutical functions of Eugenol are well known, its effect on MSCs has not been studied yet. Therefore, this study was focused on investigating the effect of Eugenol on the proliferation and migration of bone marrow (BM)-derived MSCs in vitro. To do so, BM-MSCs were isolated from 4 to 8 weeks old NMRI mice. Cytotoxicity of Eugenol on MSCs was evaluated by MTT assay at 24, 48 and 72 h after treatment. In addition, its effect was assessed on the proliferation and migration of MSCs using wound healing assay in vitro and quantitative gene expression analysis for Oct4, Sox2, Cyclin-D1, Rex1, Tex10, Cxcr4, Vla4 and c-Met. Results showed that Eugenol reduced the number of MSCs in a dose- and time-dependent manner. The median inhibition concentration of Eugenol on MSCs was 400 μg/ml at 24 and 48 h and 200 μg/ml at 72 h after treatment. Moreover, about 90% viability of MSCs was detected at concentrations ≤12.5 μg/ml. The wound healing assay and gene expression analysis demonstrated that Eugenol promoted the migratory potential of MSCs through up-regulation of c-Met. Moreover, Eugenol has enhanced the proliferation of MSCs via over-expression of Sox2, Rex1 and Tex10. In conclusion, this study revealed that Eugenol enhances the proliferation and migration of MSCs, and thus this will be beneficial to the field of regenerative medicine.

Benzocaí­­na, MS-222, eugenol e mentol como anestésicos para juvenis de tainha Mugil liza

A anestesia tem sido utilizada em aquicultura como técnica para facilitar a manipulação dos animais e amenizar o estresse causado pelos procedimentos de manejo. O presente estudo teve como objetivo determinar a eficiência de quatro fármacos como anestésico em juvenis de tainha Mugil liza. Os peixes (6,9 ± 1,4 g) foram submetidos individualmente (N=10 por concentração) í­Â anestesia utilizando-se quatro concentrações de benzocaí­­na (30, 40, 50 e 60 mg L-1), MS-222 (100, 125, 150 e 175 mg L-1), eugenol (50, 70, 90 e 110 mg L-1) e mentol (175, 200, 225 e 250 mg L-1). O critério utilizado para avaliação das melhores concentrações foi a faixa de tempo máximo de três e cinco minutos para anestesia e recuperação dos peixes respectivamente. As concentrações mais eficientes foram: benzocaí­­na, 50 mg L-1; MS-222, 150 mg L-1; eugenol, 70 mg L-1; e mentol, 225 mg L-1.

Essential oil of Syringa oblata Lindl. as a potential biocontrol agent against tobacco brown spot caused by Alternaria alternata

Alternaria alternata causes serious brown spot disease in tobacco. To effectively control the disease, we tested the antifungal effects of the essential oil from the buds of Syringa oblata Lindl. Twelve different compounds were identified by gas chromatography–mass spectrometry. The major constituents were eugenol (40.426%), eugenol acetate (28.784%), β-caryophyllene (21.989%), and α-caryophyllene (3.456%). Among these, the most active antifungal component was eugenol, exhibiting complete inhibition of mycelial growth. The minimum inhibitory concentration of eugenol against A. alternata was 150 μg/mL, and the minimum fungicidal concentration was 250 μg/mL. The effect of eugenol on the surface morphology and membrane integrity of A. alternata was studied by scanning electron microscopy (SEM) and fluorescent microscopy (FSM). SEM observations revealed shriveled hyphae, while FSM observations revealed a disrupted membrane in eugenol-treated samples. Further experiments confirmed that eugenol activated a membrane-active mechanism that increased the membrane permeability, as evidenced by extracellular conductivity measurements. Under field conditions, an in vivo assay indicated that eugenol emulsion was effective in protecting tobacco from brown spot infection. This study suggests that eugenol has the potential to be used as a fungicide to control tobacco brown spot disease caused by A. alternata.

Tumor suppressive roles of eugenol in human lung cancer cells.

BackgroundEugenol, a natural compound available in Syzigium aromaticum (cloves), is exploited for various medicinal applications. Eugenol induces apoptosis and functions as an anti‐cancer drug in several types of tumors. We investigated the tumor suppressive role and potential mechanisms of eugenol in human lung cancer cells.MethodsHuman embryonic lung fibroblast MRC‐5 and lung cancer adenocarcinoma A549 cells were incubated with or without various concentrations of eugenol for 24 hours. Cell counting kit 8 and crystal violet staining assays were performed to detect cell viability. The cell migration and invasion abilities were also determined by wound healing and transwell assays. Finally, Western blotting assay was performed to examine the changes in lung cancer cell viability and invasion of downstream targets after treatment with eugenol.ResultsEugenol could inhibit cell viability in lung cancer cells. Furthermore, eugenol obviously impaired cell migration and invasion. Finally, the expression levels of phosphate‐Akt and MMP‐2 in lung cancer cells were reduced after treatment with eugenol.ConclusionOur results demonstrated the tumor suppressive roles of eugenol on lung cancer cell proliferation, migration, and invasion partially through the PI3K/Akt pathway and MMP activity in vitro. These results suggest eugenol as a potential chemotherapeutic agent against human lung cancer.

Lack of postexposure analgesic efficacy of low concentrations of eugenol in zebrafish

ObjectiveTo test the postexposure analgesic efficacy of low doses of eugenol in zebrafish. Study designProspective experimental study. AnimalsA total of 76 large adult zebrafish (Danio rerio). MethodsFish swimming behavior (median velocity, freeze time, high-speed swimming and distance moved in the vertical direction) was recorded in a 1.6 L video arena before and after exposure to eugenol (0, 1, 2, 5, 10 and 20 mg L−1). In a second experiment, fish were anesthetized with 2-phenoxy-ethanol and treated with an injection of 5% acetic acid (noxious stimulus), and then exposed to 0, 1, 2 and 5 mg L−1 eugenol. The fish swimming behavior was also recorded. ResultsThe higher doses (10 and 20 mg L−1) reduced the median velocity, high-speed swimming and distance moved in the vertical direction, and increased the freeze time. Zebrafish behavior was not altered by eugenol (1, 2 and 5 mg L−1) after noxious stimulation. Conclusions and clinical relevanceThe change in the behavior of zebrafish associated with a noxious stimulus can be monitored and is a good model for studying analgesia in fish. Eugenol (10 and 20 mg L−1) induced zebrafish sedation. The response after a noxious stimulus was not affected by postexposure to lower doses, and thus we cannot recommend its use as an analgesic.

Inhibitory effect of eugenol on seed germination and pre-harvest sprouting of hybrid rice (Oryza sativa L.)

Pre-harvest sprouting (PHS) is a constrain problem in hybrid rice production. The present study was conducted to investigate the inhibitory effect of eugenol on seed germination and PHS of hybrid rice variety (Qian You 1). The results showed that seed germination speed and the activities of α-amylase were inhibited by eugenol pre-soaking and these effects enhanced with the increasing of eugenol concentrations; while seedling growth was not negatively affected. In field trials, eugenol application caused a significant decline in PHS as compared with control, whereas no sustained inhibition in post-harvested seed germination was observed. The HPLC analysis indicated that eugenol raised the internal ABA content by 1–4 times more than control, and seeds treated with eugenol had relatively lower OsABA8OH2 and higher transcript levels of OsNCED2 expression during early stages of seed imbibitions. In addition, seed germinated faster after GA3 application than eugenol alone, and seed endogenous ABA content decreased obviously. It suggested that eugenol strongly delayed seed germination and the PHS in the field, which might be mainly due to the increased ABA contents caused by eugenol. However, the phenomenon of delayed germination and high ABA content caused by eugenol could be effectively recovered by exogenous GA3.

Study of the Encapsulations of the Eugenol in β-Cyclodextrin in Low Concentrations Conditions

Essential oils, their antimicrobial properties due to arouse interest in the food industry for use as antimicrobial additives. However, due to their low thermal and oxidative stability its application is limited. Among the essential oils, eugenol is a compound already used studied due to their numerous properties. To minimize the degradative effects resulting from environmental factors or thermal processing, one possibility is the formation of inclusion complexes with β-CD in order to increase their thermal stability and provide controlled release. The objective of this study was to obtain and characterize β-CD-eugenol microcapsules obtained in solutions containing low concentrations of Eugenol compound. The result showed the formation of the microcapsules but with low antibacterial actions due the low concentration of Eugenol in the complexes. The encapsulations constant (Kc) determined is 27.62 M-1 and the FTIR spectra indicated the microencapsulation.

Pharmacokinetics of Eugenol in Japanese Flounder, Paralichthys olivaceus

AbstractEugenol, which has been used as an anesthetic for fish, was administered to Japanese flounder, Paralichthys olivaceus (127 ± 50.8 g), by bath treatment at concentrations of 0.025, 0.125, and 0.25 mL/L seawater for 10 min and intramuscular injection at 40 μL/fish to investigate the pharmacokinetic characteristics of eugenol in the plasma of Japanese flounder. In the bath treatment test, plasma eugenol concentration increased with increasing eugenol concentration up to 0.125 mL/L and reached steady state within 5 min. After a 10‐min bath treatment in 0.25 mL/L eugenol, plasma eugenol concentration was about 58.4 µg/mL. After transfer into running seawater, plasma eugenol concentration decreased biphasically with half‐lives of 0.0296 h (α‐phase) and 0.289 h (β‐phase). The AUC0000→0800 was about 16.5 µg h/mL. In administration by intramuscular injection, plasma eugenol concentration increased rapidly after administration and decreased biphasically with half‐lives of 0.0329 h (α‐phase) and 8.08 h (β‐phase). The AUC0000→0800 was about 52.5 µg h/mL. In both methods of administration, Japanese flounder with average weight of 127 g were effectively anesthetized when plasma eugenol concentrations were between 2.19 and 4.88 µg/mL.

Biochemical parameters of silver catfish (Rhamdia quelen) after transport with eugenol or essential oil of Lippia alba added to the water.

The transport of live fish is a routine practice in aquaculture and constitutes a considerable source of stress to the animals. The addition of anesthetic to the water used for fish transport can prevent or mitigate the deleterious effects of transport stress. This study investigated the effects of the addition of eugenol (EUG) (1.5 or 3.0 µL L-1) and essential oil of Lippia alba (EOL) (10 or 20 µL L-1) on metabolic parameters (glycogen, lactate and total protein levels) in liver and muscle, acetylcholinesterase activity (AChE) in muscle and brain, and the levels of protein carbonyl (PC), thiobarbituric acid reactive substances (TBARS) and nonprotein thiol groups (NPSH) and activity of glutathione-S-transferase in the liver of silver catfish (Rhamdia quelen; Quoy and Gaimard, 1824) transported for four hours in plastic bags (loading density of 169.2 g L-1). The addition of various concentrations of EUG (1.5 or 3.0 µL L-1) and EOL (10 or 20 µL L-1) to the transport water is advisable for the transportation of silver catfish, since both concentrations of these substances increased the levels of NPSH antioxidant and decreased the TBARS levels in the liver. In addition, the lower liver levels of glycogen and lactate in these groups and lower AChE activity in the brain (EOL 10 or 20 µL L-1) compared to the control group indicate that the energetic metabolism and neurotransmission were lower after administration of anesthetics, contributing to the maintenance of homeostasis and sedation status.

OPTIMATION OF ETHANOL CONCENTRATION IN EXTRACTION OF EUGENOL FROM GALANGAL RHIZOME

Objective: The main objective of this study was to determine the optimal ethanol concentration as solvent for extracting eugenol from galangal.Methods: Galangal rhizome extraction was conducted with kinetic maceration at 50°C with various ethanol concentration as solvent (0%, 30%, 50%, 70%, and 96%). A 1:10 ratio of rhizome and ethanol was applied. The extract was obtained, then its eugenol concentration was analyzed qualitatively and quantitatively by thin-layer chromatography-densitometer with n-hexane:ethyl acetate (4:1) by using mobile phase and silica gel 60 F254 as stationary phase and applying a wavelength of 283 nm.Results: The result of qualitative analysis showed that extract of 70% and 96% ethanol had a spot with Rf value 0.63, which was equal to the Rf value of standard eugenol. Standard curve equation for the 70% ethanol extract was y=89318x+656.07 (r=0.9993) and for the 96% ethanol extract was y=8658x+1743 (r=0.9999). The result of the quantitative analysis showed that the 70% and 96% ethanol extract contained 4.85% and 4.79% eugenol, respectively.Conclusion: Extraction of galangal rhizome in 70% and 96% ethanol was positively containing eugenol. Highest eugenol concentration (4.85%) was obtained from galangal rhizome extraction in 70% ethanol.