Chemical composition, antioxidant and antibacterial properties of the essential oils of Etlingera elatior and Cinnamomum pubescens Kochummen

trans-Cinnamaldehyde as a Novel Candidate to Overcome Bacterial Resistance: An Overview of In Vitro Studies

The increasing of drug-resistant bacteria and the scanty availability of novel effective antibacterial agents represent alarming problems of the modern society, which stimulated researchers to investigate novel strategies to replace or assist synthetic antibiotics. A great deal of attention has been devoted over the years to essential oils that contain mixtures of volatile compounds and have been traditionally exploited as antimicrobial remedies. Among the essential oil phytochemicals, remarkable antimicrobial and antibiotic-potentiating activities have been highlighted for cinnamaldehyde, an α,β-unsaturated aldehyde, particularly abundant in the essential oils of Cinnamomum spp., and widely used as a food additive in industrial products. In line with this evidence, in the present study, an overview of the available literature has been carried out in order to define the bacterial sensitizing profile of cinnamaldehyde. In vitro studies displayed the ability of the substance to resensitize microbial strains to drugs and increase the efficacy of different antibiotics, especially cefotaxime, ciprofloxacin, and gentamicin; however, in vivo, and clinical trials are lacking. Based on the collected findings, cinnamaldehyde appears to be of interest as an adjuvant agent to overcome superbug infections and antibiotic resistance; however, future more in-dept studies and clinical investigations should be encouraged to clarify its efficacy and the mechanisms involved.

Sponge-liked Silica Nanoporous Particles for Sustaining Release and Long-Term Antibacterial Activity of Natural Essential Oil

To improve the sustained release and long-term antibacterial activity of Chimonanthus nitens Oliv. essential oil (CEO), novel sponge-liked nanoporous silica particles (SNP) were synthesized via the soft template method, which was employed as a biocompatible carrier to prepare spong-liked nanoporous silica particles loading with CEO (CEO-SNP) through physical adsorption. The structure and properties of the samples were characterized via N2 adsorption/desorption measurements, thermogravimetry (TGA), Fourier transform infrared, SEM and TEM. The result showed that the SNP exhibited an excellent loading capability of CEO up to 76.3%. The thermal stability and release behavior of the CEO were significantly improved via the physical adsorption of the SNP materials. The release profile of CEO was in accordance with the first-order kinetic model, which meant that the release mechanism was drug Fick's diffusion. The antibacterial evaluation results demonstrated that the CEO-SNP exhibited strong antibacterial activity against S. aureus, E. coli and P. aeruginosa. The antibacterial results have shown that the CEO-SNP could destroy the cell structure of bacteria, and result in the generation of oxidative stress and the release of nucleic acid. After storage of 30 d at 25 °C, the CEO-SNP still had the stronger antibacterial activity towards S. aureus, E. coli and P. aeruginosa in comparison with CEO. Therefore, the sponge-like silica nanoporous particles seemed to be a promising carrier for long-term stability and antibacterial delivery of CEO.

Phytochemical analysis and anti-microbial activities of Artemisia spp. and rapid isolation methods of artemisinin

Artemisia species are important traditional medicinal plants of Ethiopia which are used for the treatment of infection and non-infection health problems. The genus Artemisia (Astraceae) consists of about 500 species worldwide. In this study, the main aim was to investigate chemical components of Artemisia spp. (A. abyssinica, A. absinthium and A. annua) and evaluate their antimicrobial activities against bacterial strains. The results indicated that the crude extract of these plants was effective against selected bacterial strains. Here we isolated the well-known antimalarial drug artemisinin (7 mg, 0.004%) from Artemisia annua leaves using a rapid n-hexane fractionation method. The n-hexane extract of A. abyssinica, ethyl acetate extract of A. absinthium and n-hexane of A. annua showed varying degrees of inhibiting effect against bacterial strains such as Staphylococcus aureus ATCC 25923 ^T, Salmonella enteritidis ATCC13076^T, Klebsiella pneumoniae ATCC1053^T, boydii ATCC1233^T, Escherichia coli ATCC 25922 ^T, hospital acquired Acinetobacter baumannii. The ethyl acetate extract of Artemisia absinthium (A.ab_e) showed the maximum inhibiting effect (35 mm) against A. baumannii. The minimum zone of inhibition (< 3 mm) was recorded for test extract of A.ap against Klebsiella pneumoniae ATCC1053^T. Ethyl acetate extract of A, absinthium (A.abe) was more effective against these selected bacterial strains and the zone of inhibition ranged from 5 to 35 mm. The minimum inhibition zone (8 mm) was detected against S. typhimurium ATCC 13311 ^T for both A.ac and n-hexane- EtOAc fraction (8:2) of A, abyssinica. The maximum zone of inhibition (25 mm) for fraction (A.ach F4) of A, abyssinica obtained by column chromatography was recorded against S. pyogen ATCC 19,615. However, there was no zone of inhibition detected for boydii ATCC1233^T due to these test extracts. Significant variations (P ≥ 0.05) were observed between all test extracts of these medicinal plants at 95% of confidence intervals. In this study, clear zones of inhibition were detected for the positive control (standard impregnated disks). Based on our results we recommend that various species of Artemisia spp. seem to have the potential for in-depth investigation for various antimicrobial activities that assisting the effort in searching for antimicrobial lead compounds.

Chemical composition, antioxidant and antimicrobial activity of essential oils from tangerine (Citrus reticulata L.), grapefruit (Citrus paradisi L.), lemon (Citrus lemon L.) and cinnamon (Cinnamomum zeylanicum Blume)

The phytochemical and biological properties of tangerine (Citrus reticulata L.), grapefruit (Citrus paradisi L.), lemon (Citrus lemon L.) and cinnamon (Cinnamomum zeylanicum Blume) essential oils were examined. The chemical composition of the essential oils determined using chromatography analysis revealed that D-limonene and cis-cinnamaldehyde were the main components. The antioxidant and antimicrobial activities of the essential oils have been studied by the DPPH radical-scavenging assay and the disc-diffusion method, respectively. All essential oils had antimicrobial activity against saprophytic (Bacillus subtilis, Penicillium chrysogenum, Fusarium moniliforme, Aspergillus niger, Aspergillus flavus, Saccharomyces cerevisiae) and pathogenic microorganisms (Escherichia coli, Salmonella abony, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans), with the highest inhibitory activity being observed in cinnamon oil, followed by grapefruit zest oil, tangerine zest oil and lemon zest oil; the MIC ranging from 6 to 60 ppm. In addition, they exhibited high antioxidant activity with the highest antioxidant activity being determined for the grapefruit zest essential oil, followed by the lemon zest essential oil, the tangerine zest essential oil and the cinnamon essential oil. The demonstrated promising results for the antioxidant and antimicrobial activity of the studied essential oils would give reason for their inclusion in the development of bio-preservation strategies for food emulsion preservation.

Cinnamomum Species: Bridging Phytochemistry Knowledge, Pharmacological Properties and Toxicological Safety for Health Benefits

The genus Cinnamomum includes a number of plant species largely used as food, food additives and spices for a long time. Different traditional healing systems have used these plants as herbal remedies to cure diverse ailments. The aim of this comprehensive and updated review is to summarize the biodiversity of the genus Cinnamomum, its bioactive compounds, the mechanisms that underlie the pharmacological activities and molecular targets and toxicological safety. All the data in this review have been collected from databases and recent scientific literature including Web of Science, PubMed, ScienceDirect etc. The results showed that the bioactive compounds of Cinnamomum species possess antimicrobial, antidiabetic, antioxidant, anti-inflammatory, anticancer and neuroprotective effects. The preclinical (in vitro/in vivo) studies provided the possible molecular mechanisms of these action. As a novelty, recent clinical studies and toxicological data described in this paper support and confirm the pharmacological importance of the genus Cinnamomum. In conclusion, the obtained results from preclinical studies and clinical trials, as well as reduced side effects provide insights into future research of new drugs based on extracts and bioactive compounds from Cinnamomum plants.

The Phytochemical Analysis and Synergistic Antifungal Effect of Etlingera elatior Jack. Flowers and Murraya koenigii Spreng. Leaves against Candida albican

Traditional medicinal plant possessed antimicrobial properties. Candidiasis is an infection of Candida albicans which has developed resistance towards antifungal drugs. The extracts of Murraya koenigii Spreng leaves and Etlingera elatior Jack flowers were used as antifungal agents individually and in combination against C. albicans. Both extracts were tested for the presence of phytochemicals (alkaloids, tannins, flavonoids, glycosides and saponins). Individual extracts were examined for antifungal activity using Kirby-Bauer test. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) were evaluated using microdilution broth assay and checkerboard assay. The extracts of both plants were positive for the presence of phytochemicals flavonoids, alkaloids, tannins, glycosides and saponins. The inhibition zone of M. koenigii leaf and E. elatior flower extracts were 8.33 mm and 8.17 mm respectively. The MIC of M. koenigii and E. elatior ranged from 200 mg/mL to 400 mg/mL and in combination, the extracts were indifferent towards C. albicans (FIC=1.0). MFC revealed there was no visible growth of C. albicans on SDA plate. M. koenigii and E. elatior have potential to be used individually or in combination as antifungal agents against C. albicans.

Assessment of Antimicrobial Activity, Mode of Action and Volatile Compounds of Etlingera pavieana Essential Oil

Etlingera pavieana (Pierre ex Gagnep.) R.M.S. is a rhizomatous plant in the Zingiberaceae family which could be freshly eaten, used as a condiment or as a traditional remedy. Our work investigated the chemical composition and antimicrobial activity of the E. pavieana essential oils extracted from the rhizome (EOEP). We extracted the EOEP from the rhizome by hydrodistillation and analyzed the chemical composition by headspace solid-phase microextraction coupled with gas chromatography/mass spectrometry (HS-SPME-GC/MS). A total of 22 volatile compounds were identified where trans-anethole (78.54%) and estragole (19.36%) were the major components in the EOEP. The antimicrobial activity of EOEP was evaluated based on the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values using the broth dilution method and enumerating cell death overtime. Our work shows that the EOEP exhibits potent antibacterial activity against foodborne pathogenic Gram-positive bacteria, namely Bacillus cereus, Staphylococcus aureus and Listeria monocytogenes in the range of 0.1–0.3% (v/v). We further investigated the mechanism of EOEP inhibition using Synchrotron Fourier transformation infrared (FTIR) microspectroscopy. Here, we show significant differences in DNA/nucleic acid, proteins and cell membrane composition in the bacterial cell. To conclude, EOEP exhibited antimicrobial activity against foodborne pathogens, especially the Gram-positive bacteria associated with ready-to-eat (RTE) food and, thus, has the potential to serve as a natural preservative agent in RTE products.

Antibacterial Activity and Metabolomics Profiling of Torch Ginger (Etlingera elatior Jack) Flower Oil Extracted Using Subcritical Carbon Dioxide (CO2)

The aim of this study was to identify the bioactive compound and evaluate the antibacterial activity of torch ginger flower oil extracted using subcritical carbon dioxide. The antibacterial activity was evaluated in agar diffusion assay, while MIC and MBC were determined using the microdilution broth assay. The essential oil was subjected to metabolomics profiling using GC-MS and 1H-NMR techniques. The results demonstrated strong antibacterial activity towards Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli. The MIC values were 0.0625, 0.25, and 0.25 mg/mL, and the MBC values were 0.25, 0.5, and 1 mg/mL towards S. typhimurium, S. aureus, and E. coli, respectively. A total of 33 compounds were identified using GC-MS including 15 compounds (45%) known for their antimicrobial activity. In addition, sixteen metabolites were identified using NMR analysis and 8 out of the sixteen metabolites (50%) have antibacterial activity. The extracted oil demonstrated broad range for antibacterial activity and has high potential for applications in pharmaceutical and food industries. Practical Applications. The oil extracted from the torch ginger flower was found very stable and has promising applications as antibacterial agent for food and pharmaceutical industries.

Pepper fragrant essential oil (PFEO) and functionalized MCM-41 nanoparticles: formation, characterization, and bactericidal activity

BACKGROUND

It is well known that plant essential oils have good antimicrobial activity. However, their strong volatility and intense odor limit their application. Mesoporous silica (MCM-41), a non-toxic mesoporous material with excellent loading capability, is a promising delivery system for different types of food ingredients in the food industry.

RESULTS

In this study, we first performed component analysis of pepper fragrant essential oil (PFEO) by gas chromatography - mass spectrometry (GC-MS), then the MCM-41 host was prepared, and the essential oil functionalized nanoparticles (EONs) were formed by embedding PFEO into mesoporous silica particles. Further analysis indicated that the particle size and zeta potential of EONs were 717 ± 13.38 nm and - 43.90 ± 0.67 mV, respectively. Transmission electron microscopy (TEM) images showed that EONs had an inerratic morphology and stable structure. The bactericidal activities of PFEO and EONs against Escherichia coli (E. coli), Salmonella enterica (S. enterica), Staphylococcus aureus (S. aureus) and Listeria monocytogenes (L. monocytogenes) were subsequently tested using the twofold dilution method. Results indicated that, after 48 h incubation, minimum bactericidal concentrations (MBC) of EONs used against gram-negative bacteria were decreased to a greater degree than those of PFEO, suggesting that nanoencapsulation by MCM-41 can improve antimicrobial activity. Atomic force microscopy (AFM) observation also confirmed that EONs showed a notable inhibitory effect against E. coli by disrupting cell membrane structure.

CONCLUSION

Pepper fragrant essential oil nanoencapsulation could be a very promising organic delivery system in food industry for antimicrobial activity enhancement. © 2019 Society of Chemical Industry.

Chemical compound identification and antibacterial activity evaluation of cinnamon extracts obtained by subcritical n-butane and ethanol extraction

Four important Cinnamomum species in China including C. cassia, C. loureiroi, C. wilsonii, and C. burmannii were chosen to be extracted by subcritical n-butane and ethanol. The chemical compounds of extracts were identified by GC-MS and HPLC-MS, and the antibacterial activities were evaluated by agar-well diffusion assay and twofold microdilution broth method. There were 47 compounds identified in n-butane extracts and 11 compounds in ethanol extracts totally. The major compounds in n-butane extracts varied significantly among different Cinnamomum species, and (E)-cinnamaldehyde and coumarin were major compounds for C. cassia with area percentage of 74.32%; (E)-cinnamaldehyde and α-copaene for C. loureiroi with area percentage of 67.83%; linalool, (E)-cinnamaldehyde, and citral for C. wilsonii with area percentage of 58.74%; and eugenol, (E)-cinnamaldehyde, and coumarin for C. burmannii with area percentage of 76.43%. The maximum compounds in ethanol extracts were (E)-cinnamaldehyde and (Z)-cinnamaldehyde, and others varied among the Cinnamomum species. All cinnamon extracts showed antibacterial activities that n-butane extracts were much more sensitive than ethanol extracts. The inhibition zone for N-butane extracts against Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella anatum was from 18.98 to 37.45 mm while for ethanol extracts from 7.11 to 10.11 mm. The minimum bactericidal concentrations for n-butane extracts were ranged from 0.31 to 2.50 mg/ml and for ethanol extracts ranged from 20.00 to 160.00 mg/ml. N-butane extracts of C. cassia and C. loureiroi processed much higher antibacterial activities than C. wilsonii and C. burmannii. N-butane extracts of C. cassia and C. loureiroi have the potential to be used as food biopreservative.

Screening of Chemical Composition, in vitro Antioxidant, α-Amylase and α-Glucosidase Inhibitory Activities of the Leaf Essential Oils of Cinnamomum wightii from Different Populations

Cnnamomum wightii is an endemic species of the Western Ghats, India and is used in Ayurveda and Siddha systems of medicine. Its bark and leaves are adulterated with commercial cinnamon in southern India. Despite its medicinal and commercial importance, the species remains underexplored. The objective of the present work was to screen the chemical composition, in vitro antioxidant, α-amylase and α-glucosidase inhibitory activities of the leaf essential oil of C. wightii collected from different populations. GC-FID and GC-MS analyses of the leaf essential oils from seven accessions enabled the identification of a total of 70 constituents, of which only 16 compounds were present in all samples. Eleven major constituents (> 5%) were identified, of which only linalool and spathulenol were present in all accessions as major constituents. Among seven accessions, essential oil from Parson's valley, Nilgiris exhibited better antioxidant activity with IC50 values of 2.552 ± 0.13 and 3.485 ± 0.09 mg/mL for ABTS and DPPH respectively. The essential oil from Korakundah, Nilgiris showed better hypoglycemic activity with IC50 values of 1.617 ± 0.02 and 1.146 ± 0.02 mg/mL for α-amylase and α-glucosidase inhibitory activities respectively. The leaf essential oils of C. wightii may be used in nutraceutical products focusing diabetes mellitus as the moderate inhibition of the metabolic enzymes has the advantage of slow release of glucose.

Torch Ginger (<I>Etlingera elatior</I>): A Review on its Botanical Aspects, Phytoconstituents and Pharmacological Activities

In order to propose a prospective candidate for novel complementary phytopharmaceuticals, one of Zingiberaceae family plant, Etlingeraelatior or torch ginger, was being evaluated. The aim of this review was to provide a comprehensive literature research focused on the botanical aspects, nutritional quality, phytoconstituents and pharmacological activities of E. elatior. Researches on this particular plant were conducted in Malaysia (55.5%), Indonesia (33.3%), Thailand (8.3%) and Singapore (2.7%). This review article has revealed that the most prominent pharmacological activities were anti-microbial, anti-oxidant and anti-tumor activities in consistent with the dominated levels of flavonoids, terpenoids and phenols. However, extended and integrated research should be converged towards intensive investigations concerning to isolated phytoconstituents and its bioactivities, pharmacokinetics, bioavailability, molecular mechanism of its specific pharmacological activities, safety and efficacy studies for further development.

Inhibition of methicillin-resistant Staphylococcus aureus (MRSA) by antimicrobial peptides (AMPs) and plant essential oils

CONTEXT

Drug-resistant bacterial infections cause considerable patient mortality and morbidity. The annual frequency of deaths from methicillin-resistant Staphylococcus aureus (MRSA) has surpassed those caused by human immunodeficiency virus/acquired immune deficiency syndrome. The antimicrobial peptides (AMPs), plant essential oils (EOs) and their combinations have proven to be quite effective in killing a wide selection of bacterial pathogens including MRSA.

OBJECTIVES

This review summarizes the studies in the use of AMPs, plant EOs and their combinations for coping with MRSA bacteria, and to formulate new prospects for future studies on this topic.

METHODS

The sources of scientific literature such as PubMed, library search, Google Scholar, Science Direct and electronic databases such as 'The Antimicrobial Peptide Database', 'Collection of Anti-Microbial Peptides' and 'YADAMP'. Physicochemical data of anti-MRSA peptides were determined by Scientific DataBase Maker software.

RESULTS

Of the 118 peptides, 88 exhibited an activity against MRSA with the highest activity of minimum inhibitory concentration values. Various plant EOs have been effective against MRSA. Remarkably, lemongrass EOs completely inhibited all MRSA growth on the plate. Lemon myrtle, Mountain savory, Cinnamon bark and Melissa EOs showed a significant inhibition.

CONCLUSION

Several of these AMPs, EOs and their combinations were effective against MRSA. Their activities have implications for the development of new drugs for medical use.

GC×GC-TOFMS Analysis of Essential Oils Composition from Leaves, Twigs and Seeds of Cinnamomum camphora L. Presl and Their Insecticidal and Repellent Activities

Interest in essential oils with pesticidal activity against insects and pests is growing. In this study, essential oils from different parts (leaves, twigs and seeds) of Cinnamomum camphora L. Presl were investigated for their chemical composition, and insecticidal and repellent activities against the cotton aphid. The essential oils, obtained by hydrodistillation, were analyzed by GC×GC-TOFMS. A total of 96 components were identified in the essential oils and the main constituents found in the leaves and twigs were camphor, eucalyptol, linalool and 3,7-dimethyl-1,3,7-octatriene. The major components found in the seeds were eucalyptol (20.90%), methyleugenol (19.98%), linalool (14.66%) and camphor (5.5%). In the contact toxicity assay, the three essential oils of leaves, twigs and seeds exhibited a strong insecticidal activity against cotton aphids with LC50 values of 245.79, 274.99 and 146.78 mg/L (after 48 h of treatment), respectively. In the repellent assay, the highest repellent rate (89.86%) was found in the seed essential oil at the concentration of 20 μL/mL after 24 h of treatment. Linalool was found to be a significant contributor to the insecticidal and repellent activities. The results indicate that the essential oils of C. camphora might have the potential to be developed into a natural insecticide or repellent for controlling cotton aphids.

Linalool, derived from Cinnamomum camphora (L.) Presl leaf extracts, possesses molluscicidal activity against Oncomelania hupensis and inhibits infection of Schistosoma japonicum

BACKGROUND

Schistosomiasis japonicum remains a considerable economic and public health concern in China, the Philippines and Indonesia. Currently available measures to control the unique intermediate host Oncomelania hupensis are frequently associated with severe side effects. Previous studies have demonstrated that linalool-rich extracts from various plants exhibited promising biological activities including cytotoxic, anti-microbial and anti-parasitic properties.

METHODS

We identified the components of leaf extracts from Cinnamomum camphora by gas chromatography coupled to mass spectrometry (GC-MS) and investigated molluscicidal and larvicidal effects of linalool against O. hupensis and Schistosoma japonicium. The ultrastructural alterations in gills, salivary gland, stomach and hepatopancreas of snails were observed under the light microscope and transmission electron microscope, and lesions to tegument of cercaria were examined under a light microscope and fluorescence microscope. We then evaluated the effects of linalool on skin penetration and migration of schistosomula and adult survival by measurement of worm burden and egg counts in Balb/C mice infected with linalool-treated cercariae.

RESULTS

In the present work, 44 components were identified from the leaf extracts of C. camphora, of which linalool was the most abundant constituent. Linalool exhibited the striking molluscicidal and larvicidal effects with LC50 = 0.25 mg/L for O. hupensis and LC50 = 0.07 mg/L for cercaria of S. japonicium. After exposure to linalool, damage to the gills and hepatopancreas of the snails, and to the tegument and body-tail joint of cercariae was apparent. In addition, linalool markedly reduced the recovered schistosomulum from mouse skin after challenge infection, and therefore decreased the worm burden in infected animals, but not fecundity of female adults of the parasite.

CONCLUSIONS

Our findings indicated that linalool might be a novel chemotherapeutic agent against S. japonicium and the snail intermediate host.

Plant essential oils and their constituents in coping with multidrug-resistant bacteria

Antibiotic resistance is documented to be a serious problem that affects the choice of appropriate antibiotic therapy and increases the probability of unfavorable infection outcome. One of the proposed methods to cope with multidrug-resistant (MDR) bacteria is the use of alternative antibacterial treatments, which include natural antimicrobial substances such as plant essential oils (EOs). The aim of the present article is to review published studies on the activity of EOs and their constituents against MDR bacteria and to formulate perspectives for the future. In general, published studies indicate that EOs can be used as effective antiseptics against many species, including MDR bacteria, such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, resistant isolates of Pseudomonas aeruginosa, Klebsiella pneumoniae and others; certain EOs may potentiate the effectiveness of antibiotics against MDR bacteria; EOs can be synergistic with bacteriophages; and polymeric nanoparticles can be used for delivery of EOs and enhancement of their activity at the site of infection.

A procyanidin type A trimer from cinnamon extract attenuates glial cell swelling and the reduction in glutamate uptake following ischemia-like injury in vitro

Dietary polyphenols exert neuroprotective effects in ischemic injury. The protective effects of a procyanidin type A trimer (trimer 1) isolated from a water soluble cinnamon extract (CE) were investigated on key features of ischemic injury, including cell swelling, increased free radical production, increased intracellular calcium ([Ca(2+)](i)), mitochondrial dysfunction, and the reduction in glutamate uptake. Astrocyte (glial) swelling is a major component of cytotoxic brain edema in ischemia and, along with vasogenic edema, may contribute to increased intracranial pressure, brain herniation, and additional ischemic injuries. C6 glial cultures were exposed to oxygen-glucose deprivation (OGD) for 5 h, and cell swelling was determined at 90 min after the end of OGD. OGD-induced increases in glial swelling were significantly blocked by trimer 1, but not by the major nonpolyphenol fractions of CE including cinnamaldehyde and coumarin. Increased free radical production, a contributing factor in cell swelling following ischemic injury, was also significantly reduced by trimer 1. Mitochondrial dysfunction, another key feature of ischemic injury, is hypothesized to contribute to glial swelling. Depolarization of the inner mitochondrial membrane potential (ΔΨ(m)) was assessed using a fluorescent dye (tetramethylrhodamine ethyl ester [TMRE]), and was significantly attenuated by trimer 1 as was OGD-induced increased [Ca(2+)](i). Taken together with our previous observation that blockers of [Ca(2+)](i) reduce cell swelling, our results indicate that trimer 1 may attenuate cell swelling by regulating [Ca(2+)](i). Trimer 1 also significantly attenuated the OGD-induced decrease in glutamate uptake. In addition, cyclosporin A, a blocker of the mitochondrial permeability pore (mPT), but not FK506 (that does not block the mPT), reduced the OGD-induced decline in glutamate uptake indicating a role of the mPT in such effects. Thus, the effects of trimer 1 in attenuating the reduction in glutamate uptake are likely mediated through their action on the mitochondria.