Chemical composition and antimicrobial activity of the essential oil of Syzygium aromaticum flower bud (Clove) against fish systemic bacteria isolated from aquaculture sites

Microbiological Evaluation of Herbal Extracts against Candida albicans in Early Childhood Caries Patients: An In Vitro Study

Purpose

The current literature proposes a probable role of Candida albicans (C. albicans) in its etiopathogenesis in early childhood caries (ECC). This study aimed to isolate C. albicans species in children with and without ECC and compare the antifungal efficacy of neem, miswak, cinnamon, clove, stevia, and ketoconazole. This study also aimed to assess and compare salivary pH in children with and without ECC.

Materials and methods

A total of 60 children were included in the study, who were divided into two groups-group I (children with ECC) and group II (children without ECC). Plaque samples were collected and streaked on Sabouraud dextrose agar (SDA). C. albicans isolates were evaluated, and their susceptibility to herbal agents was tested and compared. Saliva samples were collected, and salivary pH was tested and compared.

Results

The presence of C. albicans was significantly higher in group I (76.7%) as compared to group II (23.3%). The mean zone of inhibition for neem was 4.9 mm, whereas, for miswak, it was 4.5 mm; for cinnamon, 9.3 mm; for clove, 3.8 mm; for stevia, 10.9 mm; and for ketoconazole it was 21.09 mm. The mean salivary pH for group I was 6.7, and that for group II was 7.3.

Conclusion

Candida albicans (C. albicans) carriage in children with ECC was significantly higher than in children without ECC. All herbal agents showed significant antifungal activity, with stevia showing the highest activity. The average salivary pH of children without ECC was slightly higher than that of children with ECC.

How to cite this article

Siddaiah SB, Sinha S, BR A. Microbiological Evaluation of Herbal Extracts against Candida albicans in Early Childhood Caries Patients: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(1):26-30.

Dietary berberine against intestinal oxidative stress, inflammation response, and microbiota disturbance caused by chronic copper exposure in freshwater grouper (Acrossocheilus fasciatus)

Berberine (BBR) is known for its strong antioxidant, anti-inflammatory, and capacity to preserve intestinal microbiota balance in fish. This study aimed to investigate the protective effects of berberine against copper-induced toxicity in the intestine of freshwater grouper Acrossocheilus fasciatus. The experiment involved four groups: a control group, a Cu group exposed to 0.02 mg/L Cu²⁺, and two BBR groups fed with 100 or 400 mg/kg of berberine diets and exposed to the same Cu²⁺ concentration. Three replicates of healthy fish (initial weight 1.56 ± 0.10 g) were subjected to their respective treatments for 30 days. Results showed that none of the treatments significantly affected the survival rate, final weight, weight gain, and feed intake (P > 0.05). However, supplementation with 100 and 400 mg/kg of BBR significantly lowered the antioxidant activities, and glutathione peroxidase (gpx) and superoxide dismutase (sod) expression levels, as well as reduced malondialdehyde (MDA) content caused by Cu²⁺ exposure (P < 0.05). Berberine inclusion significantly downregulated proinflammatory factors NLR family pyrin domain containing 3 (nlrp3), interleukin 1 beta (il1β), interleukin 6 cytokine family signal transducer (il6st) but upregulated transforming growth factor beta 1 (tgfβ1) and heat shock 70kDa protein (hsp70) expression. Moreover, berberine at both levels maintained the intestinal structural integrity and significantly improved gap junction gamma-1 (gjc1) mRNA level compared to the Cu group (P < 0.05). Based on 16S rDNA sequencing, the richness and diversity of intestinal microbiota in different groups were not significantly influenced. Berberine reduced the Firmicutes/Bacteroidota ratio and stifled the growth of some specific pathogenic bacteria such as Pseudomonas, Citrobacter, and Acinetobacter, while boosting the richness of potential probiotic bacteria, including Roseomonas and Reyranella compared with the Cu group. In conclusion, berberine showed significant protective effects against Cu²⁺-induced intestinal oxidative stress, inflammation response, and microbiota disturbance in freshwater grouper.

Comparison of Syzygium Aromaticum (clove) and Punica Granatum (Pomegranate) extracts with 2% chlorhexidine in dentinal tubule disinfection against faecalis by using real-time PCR: an in-vitro study

Background: A vital and significant goal in treating a tooth with an apical infection is getting rid of the germs in the pulp space. Recurrent root canal infections are most frequently linked to Enterococcus faecalis and can happen even after endodontic therapy. E. faecalis can resist routine endodontic disinfectants and can also survive the nutrient-deprived conditions in the root filled tooth. So, an attempt has been made to eliminate the microorganisms using the herbal extracts which have antimicrobial properties and comparing it with the well accepted and excellent antimicrobial agent 2% chlorhexidine. Aim: To compare Syzygium aromaticum (Clove) and Punica granatum (Pomegranate) extracts with 2% chlorhexidine in dentinal tubule disinfection with Real-time polymerase chain reaction which was used to detect E. faecalis. Methods: Thirty-six extracted premolar teeth were selected, access cavity was prepared and cleaning and shaping was done. With the help of a rotating diamond disc bur, the middle part of the root was sliced. E. faecalis was applied to the tooth specimens and left on them for 21 days. Group 1 specimens had pomegranate extract, Group 2 contained clove extract, and Group 3 contained 2% CHX. After being watered by the corresponding groups, the specimens were incubated for 5 days. A Gates-Glidden drill was used to collect the dentinal shavings, which were then subjected to DNA isolation before being subjected to real-time PCR analysis. Statistical analysis used: The results were statistically analyzed using one way ANOVA and Post hoc Tukey's analysis. Results: Threshold cycle (Ct) values showed greater inhibition of bacterial load with pomegranate extracts followed by 2% chlorhexidine. Lesser reduction of bacterial load was found with clove extract. Conclusion: Pomegranate extract, an herbal extract with therapeutic potential which can be utilised as an efficient substitute for 2% CHX for treating E. fecalis.  Keywords: Clove; Pomegranate; E. Fecalis; Real-time PCR.  

Chemical Composition and Evaluation of Antifungal and Insecticidal Activities of Essential Oils Extracted from Jambosa caryophyllus (Thunb.) Nied: Clove Buds

Jambosa caryophyllus has been used in traditional phytotherapy as a treatment against infections. In the present work, essential oils extracted from clove buds (Jambosa caryophyllus ) (EO-JC) were investigated for their composition, antifungal, and insecticidal properties. Extraction of EO-JC was performed by use of hydrodistillation using a Clevenger-type apparatus, and the EOs were analyzed by gas chromatography coupled with mass spectrometry (GC-MS). Antifungal activity of EO-JC was evaluated by the use of solid-state diffusion (disc method) and microdilution to determine the minimum inhibitory concentration (MIC), against three strains of fungus, Aspergillus niger, Aspergillus flavus, and Fusarium oxysporum. Insecticidal activity of EO-JC against the cowpea weevil, Callosobruchus maculatus, was determined to assess utility of EO-JC to control this pest. Several exposures including inhalation and contact were used to determine lethality, as well as the repulsion test was conducted at concentrations of 4, 8, 16, and 32 μL EO-JC. Characterization of EO-JC by GC/MS revealed 34 compounds accounting for 99.98% of the mass of the extract. The predominant compound was eugenol (26.80%) followed by β-caryophyllene (16.03%) and eugenyl acetate (5.83%). The antifungal activity of EO-JC on solid media exhibited inhibitions in the range of 49% to 87%, and MIC was between 3.125 and 7.80 μg EO-JC/mL. Insecticidal activity, as determined by the use of the inhalation test, and expressed as the LD₅₀ and LD₉₅ after 96 hours of exposure was 2.32 and 21.92 μL/L air, respectively. In the contact test, a 96-hour exposure resulted in LD₅₀ and LD₉₅ of 5.51 and 11.05 μL/L of air, respectively. EO-JC exhibited insecticidal activity against fungi and pest chickpea weevil.

Modulation of Antioxidant Defense in Farmed Rainbow Trout (Oncorhynchus mykiss) Fed with a Diet Supplemented by the Waste Derived from the Supercritical Fluid Extraction of Basil (Ocimum basilicum)

Phytotherapy is based on the use of plants to prevent or treat human and animal diseases. Recently, the use of essential oils and polyphenol-enriched extracts is also rapidly increasing in the aquaculture sector as a means of greater industrial and environmental sustainability. Previous studies assessed the antibacterial and antiparasitic effects of these bioactive compounds on fish. However, studies on the modulation of oxidative stress biomarkers are still scant to date. Thus, in this study, the modulation of antioxidant defense against oxidative stress exerted by fish diets supplemented with a basil supercritical extract (F1-BEO) was assessed in rainbow trout Oncorhynchus mykiss. The F1-BEO extracted with supercritical fluid extraction was added to the commercial feed flour (0.5, 1, 2, 3% w/w) and mixed with fish oil to obtain a suitable compound for pellet preparation. Fish were fed for 30 days. The levels of stress biomarkers such as superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase, glyoxalase I, glyoxalase II, lactate dehydrogenase, glutathione and malondialdehyde showed a boost in the antioxidant pathway in fish fed with a 0.5% F1-BEO-supplemented diet. Higher F1-BEO supplementation led to a failure of activity of several enzymes and the depletion of glutathione levels. Malondialdehyde concentration suggests a sufficient oxidative stress defense against lipid peroxidation in all experimental groups, except for a 3% F1-BEO-supplemented diet (liver 168.87 ± 38.79 nmol/mg prot; kidney 146.86 ± 23.28 nmol/mg prot), compared to control (liver 127.76 ± 18.15 nmol/mg prot; kidney 98.68 ± 15.65 nmol/mg prot). Our results suggest supplementing F1-BEO in fish diets up to 0.5% to avoid potential oxidative pressure in farmed trout.

Essential Oils Improve the Survival of Gnotobiotic Brine Shrimp (Artemia franciscana) Challenged With Vibrio campbellii

The halophilic aquatic bacterium Vibrio campbellii is an important aquatic pathogen, capable of causing vibriosis in shrimp and fish resulting in significant economic losses. In a previous work, essential oils (EOs) extracts from Melaleuca alternifolia, Litsea citrata, and Eucalyptus citriodora were found to inhibit the growth of V. campbellii in vitro. This study aimed to determine in vivo EOs’ potential protective effect towards gnotobiotic brine shrimp Artemia franciscana, challenged with V. campbellii. The study showed that brine shrimp larvae supplemented with EOs of M. alternifolia (0.0008%) and L. citrata (0.002%) displayed significantly increased survival against V. campbellii. The results indicated that supplementation of these EOs increased the expression of immune-related genes (either in the presence or absence of the pathogen), probably contributing to enhanced protection. Furthermore, in vitro studies indicated that some EOs modulated the expression of virulence factors including swimming motility, biofilm formation, and gelatinase and lipase activity, while flow cytometry data and regrowth assay indicated that these EOs do not exhibit antimicrobial activity as V. campbellii grew at the tested concentrations [M. alternifolia (0.0008%) and L. citrata (0.002%)]. Our findings suggest that EOs extracted from M. alternifolia and L. citrata, can modulate virulence factor production and immunological responses and might hence become part of an intervention strategy to control vibriosis in a fish or shrimp aquaculture setting, a hypothesis that needs to be validated in the future.

Chemical Composition, In Vitro and In Situ Antimicrobial and Antibiofilm Activities of Syzygium aromaticum (Clove) Essential Oil

The essential oil of Syzygium (S.) aromaticum (CEO) is known for its good biological activity. The aim of the research was to evaluate in vitro and in situ antimicrobial and antibiofilm activity of the essential oil produced in Slovakia. The main components of CEO were eugenol 82.4% and (E)-caryophyllene 14.0%. The antimicrobial activity was either weak or very strong with inhibition zones ranging from 4.67 to 15.78 mm in gram-positive and gram-negative bacteria and from 8.22 to 18.56 mm in yeasts and fungi. Among the tested bacteria and fungi, the lowest values of MIC were determined for Staphylococcus (S.) aureus and Penicillium (P.) expansum, respectively. The vapor phase of CEO inhibited the growth of the microscopic filamentous fungi of the genus Penicillium when tested in situ on bread. The strongest effect of mycelia inhibition in a bread model was observed against P. expansum at concentrations of 250 and 500 μL/mL. The best antimicrobial activity of CEO in the carrot model was found against P. chrysosenum. Differences between the mass spectra of Bacillus (B.) subtilis biofilms on the tested surfaces (wood, glass) and the control sample were noted from the seventh day of culture. There were some changes in mass spectra of Stenotrophomonas (S.) maltophilia, which were observed in both experimental groups from the fifth day of culture. These findings confirmed the impact of CEO on the protein structure of older biofilms. The findings indicate that, besides being safe and sensorially attractive, S. aromaticum has antimicrobial activity, which makes it a potential substitute for chemical food preservatives.

Antiparasitic and Antibacterial Functionality of Essential Oils: An Alternative Approach for Sustainable Aquaculture

Using synthetic antibiotics/chemicals for infectious bacterial pathogens and parasitic disease control causes beneficial microbial killing, produces multi-drug resistant pathogens, and residual antibiotic impacts in humans are the major threats to aquaculture sustainability. Applications of herbal products to combat microbial and parasitic diseases are considered as alternative approaches for sustainable aquaculture. Essential oils (EOs) are the secondary metabolites of medicinal plants that possess bioactive compounds like terpens, terpenoids, phenylpropenes, and isothiocyanates with synergistic relationship among these compounds. The hydrophobic compounds of EOs can penetrate the bacterial and parasitic cells and cause cell deformities and organelles dysfunctions. Dietary supplementation of EOs also modulate growth, immunity, and infectious disease resistance in aquatic organisms. Published research reports also demonstrated EOs effectiveness against Ichthyophthirius multifiliis, Gyrodactylus sp., Euclinostomum heterostomum, and other parasites both in vivo and in vitro. Moreover, different infectious fish pathogenic bacteria like Aeromonas salmonicida, Vibrio harveyi, and Streptococcus agalactiae destruction was confirmed by plant originated EOs. However, no research was conducted to confirm the mechanism of action or pathway identification of EOs to combat aquatic parasites and disease-causing microbes. This review aims to explore the effectiveness of EOs against fish parasites and pathogenic bacteria as an environment-friendly phytotherapeutic in the aquaculture industry. Moreover, research gaps and future approaches to use EOs for sustainable aquaculture practice are also postulated.

Impact of essential oil from plants on migratory activity of Sitophilus granarius and Tenebrio molitor

Measures against pests should be performed in the context of integrated management of agricultural crops and complex control of pests. Therefore, use of ecologically safe approaches is the best option. Essential oils of plants can make an impact on the main metabolic, biochemical, physiological and behavioural functions of insects. We evaluated the effect of 18 essential oils and 18 dried plants on migratory activity of Sitophilus granarius (Linnaeus, 1758) and Tenebrio molitor Linnaeus, 1758 in conditions of laboratory experiment. Notable repellent activity against S. granarius was exhibited by Citrus sinensis and Picea abies. Repellent action against T. molitor was displayed by dried and cut leaves of Origanum vulgare and Eucalyptus globulus, and also essential oils from Juniperus communis, Р. abies, Pterocarpus santalinus, C. sinensis and C. aurantiifolia. Therefore, out of 18 studied essential oils, only two samples had a notable biological effect on migratory activity of S. granarius and five samples – on T. molitor. These data indicate a possibility of using essential oils or their main components as ecologically safe natural repellents against pests of stored wheat and products of its processing.

Essential oils as alternatives to antibiotics in swine production

This review article summarizes the efficacy, feasibility and potential mechanisms of the application of essential oils as antibiotic alternatives in swine production. Although there are numerous studies demonstrating that essential oils have several properties, such as antimicrobial, antioxidative and anti-inflammatory effects, feed palatability enhancement and improvement in gut growth and health, there is still a need of further investigations to elucidate the mechanisms underlying their functions. In the past, the results has been inconsistent in both laboratory and field studies because of the varied product compositions, dosages, purities and growing stages and conditions of animals. The minimal inhibitory concentration (MIC) of essential oils needed for killing enteric pathogens may not ensure the optimal feed intake and the essential oils inclusion cost may be too high in swine production. With the lipophilic and volatile nature of essential oils, there is a challenge in effective delivery of essential oils within pig gut and this challenge can partially be resolved by microencapsulation and nanotechnology. The effects of essential oils on inflammation, oxidative stress, microbiome, gut chemosensing and bacterial quorum sensing (QS) have led to better production performance of animals fed essential oils in a number of studies. It has been demonstrated that essential oils have good potential as antibiotic alternatives in feeds for swine production. The combination of different essential oils and other compounds (synergistic effect) such as organic acids seems to be a promising approach to improve the efficacy and safety of essential oils in applications. High-throughput systems technologies have been developed recently, which will allow us to dissect the mechanisms underlying the functions of essential oils and facilitate the use of essential oils in swine production.

Towards green oviposition deterrents? Effectiveness of Syzygium lanceolatum (Myrtaceae) essential oil against six mosquito vectors and impact on four aquatic biological control agents

Essential oils (EOs) from plants may be alternative sources of molecules toxic against mosquito vectors of public health relevance. Most of researches in this field focused on EOs as larvicides or ovicides, while limited efforts focused on the exploitation of EOs as oviposition deterrents. In the present study, the larvicidal and oviposition deterrent activity of Syzygium lanceolatum leaf EO was evaluated against six mosquito species, Anopheles stephensi, An. subpictus, Aedes aegypti, Ae. albopictus, Culex quinquefasciatus, and Cx. tritaeniorhynchus. The chemical composition of the S. lanceolatum EO was analyzed by GC-MS analysis, showing the presence of phenyl propanal, β-caryophyllene, α-humulene, and caryophyllene oxide as major constituents. S. lanceolatum EO showed high acute toxicity on An. stephensi (LC₅₀ = 51.20 μg/ml), Ae. aegypti (LC₅₀ = 55.11 μg/ml), Cx. quinquefasciatus (LC₅₀ = 60.01 μg/ml), An. subpictus (LC₅₀ = 61.34 μg/ml), Ae. albopictus (LC₅₀ = 66.71 μg/ml), and Cx. tritaeniorhynchus (LC₅₀ = 72.24 μg/ml) larvae. Furthermore, the EO was effective as oviposition deterrent against the six tested mosquito species, with OAI on An. stephensi, An. subpictus, Ae. aegypti, Ae. albopictus, Cx. quinquefasciatus, and Cx. tritaeniorhynchus reaching -0.83, -0.81, -0.84, -0.83, -0.84, and -0.86, respectively. The toxicity of S. lanceolatum EO against several biological control agents of mosquitoes, including water bugs (Anisops bouvieri and Diplonychus indicus) and fishes (Gambusia affinis and Poecilia reticulata), was extremely low, with LC₅₀ ranging between 4148 and 15,762 μg/ml. Overall, our results pointed out the promising potential of the S. lanceolatum leaf EO as a source of environmental-friendly oviposition deterrents and larvicides effective against a wide number of mosquito species of importance for parasitology.

Peperomia pellucida leaf extract as immunostimulator in controlling motile aeromonad septicemia due to Aeromonas hydrophila in red hybrid tilapia, Oreochromis spp. farming

Aim:

This study was revealed the potential of Peperomia pellucida leaf extract as an immunostimulator agent in controlling motile aeromonad septicemia due to Aeromonas hydrophila in red hybrid tilapia, Oreochromis sp.

Materials and Methods:

In the present study, minimum inhibitory concentration (MIC) of P. pellucida leaf extract against A. hydrophila was determined through two-fold microbroth dilution method. The plant extract was screening for its active compound using a gas chromatograph mass spectrometer, and the effectiveness of P. pellucida leaf extract as an immunostimulator agent was evaluated. The experimental fish were fed with medicated feed at three different concentrations (25 mg/kg, PP-25; 50 mg/kg, PP-50; and 100 mg/kg, PP-100) of P. pellucida leaf extract for 1 week before they were intraperitoneally exposed to A. hydrophila. Enzyme-linked immunosorbent assay was carried out to determine the value of antibody response to A. hydrophila in fish from a group of fish that received medicated feed, and the percentage of total cumulative mortality of the experimental fish were observed at the end of the experiment.

Results:

The results showed that the major bioactive compound is phytol (40%), and the MIC value was 31.5 mg/L. The value of antibody response to A. hydrophila in fish from a group of fish which received medicated feed (PP-25, 0.128±0.014 optical density [OD]; PP-50, 0.132±0.003 OD; and PP-100, 0.171±0.02 OD) was found significantly higher (p<0.05) compared to fish did not receive medicated feed (0.00 OD). Whereas, percentage cumulative mortality of fish from all groups of fish received medicated feed (PP-25, 18.0±3.2%; PP-50, 18.2±2.8%; and PP-100, 17.7±1.8%) were found significantly lower (p<0.05) compared to a group of fish did not receive medicated feed (83.2±1.4%).

Conclusion:

The findings of the present study indicated the huge potential of P. pellucida leaf extract as natural immunostimulator agent for aquaculture uses.

Phytogenic compounds as alternatives to in-feed antibiotics: potentials and challenges in application

This article summarizes current experimental knowledge on the efficacy, possible mechanisms and feasibility in the application of phytogenic products as feed additives for food-producing animals. Phytogenic compounds comprise a wide range of plant-derived natural bioactive compounds and essential oils are a major group. Numerous studies have demonstrated that phytogenic compounds have a variety of functions, including antimicrobial/antiviral, antioxidative and anti-inflammation effects and improvement in the palatability of feed and gut development/health. However, the mechanisms underlying their functions are still largely unclear. In the past, there has been a lack of consistency in the results from both laboratory and field studies, largely due to the varied composition of products, dosages, purities and growing conditions of animals used. The minimal inhibitory concentration (MIC) of phytogenic compounds required for controlling enteric pathogens may not guarantee the best feed intake, balanced immunity of animals and cost-effectiveness in animal production. The lipophilic nature of photogenic compounds also presents a challenge in effective delivery to the animal gut and this can partially be resolved by microencapsulation and combination with other compounds (synergistic effect). Interestingly, the effects of photogenic compounds on anti-inflammation, gut chemosensing and possible disruption of bacterial quorum sensing could explain a certain number of studies with different animal species for the better production performance of animals that have received phytogenic feed additives. It is obvious that phytogenic compounds have good potential as an alternative to antibiotics in feed for food animal production and the combination of different phytogenic compounds appears to be an approach to improve the efficacy and safety of phytogenic compounds in the application. It is our expectation that the recent development of high-throughput and "omics" technologies can significantly advance the studies on the mechanisms underlying phytogenic compounds' functions and, therefore, guide the effective use of the compounds.

Clove (Syzygium aromaticum) ingredients affect lymphocyte subtypes expansion and cytokine profile responses: An in vitro evaluation

Clove (Syzygium aromaticum) has been used in folk medicine in many disorders. The present work aimed to investigate effects of clove essential oil as eugenol and water soluble ingredients on mouse splenocytes. Clove extracts were harvested and in different concentrations (0.001–1000 μg/mL) were affected to splenocytes and also phytohemagglutinin (PHA = 5 μg/mL) and lipopolysaccharide (LPS = 10 μg/mL) activated splenocytes; then splenocytes proliferation assayed using the MTT ([3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyl tetrazolium bromide]) method were done. On the culture supernatant interferon (IFN)-γ, interleukin (IL)-4, IL-10, and transforming growth factor (TGF)-β cytokines were measured. Clove ingredients (100 μg/mL and 1000 μg/mL) reduced PHA stimulated splenocytes proliferation and enhanced LPS stimulated cells expansion. Treated splenocytes showed suppression of IFN-γ release and induction of IL-4, IL-10, and TGF-β secretion (in the range of 0.1–1000 μg/mL). The results of this study suggest clove extracts could suppress the T cell cellular immunity and enhance humoral immune responses. In clove affection cytokine pattern shifted toward modulatory and Th2 responses and accelerator of humoral immunity cytokines.

Immunomodulatory effects of clove (Syzygium aromaticum) constituents on macrophages: in vitro evaluations of aqueous and ethanolic components

The present work sought to investigate potential suppressive effects on mouse macrophages by in vitro treatment with clove (Syzygium aromaticum) ethanolic extracted essential oil (containing eugenol) or its water-soluble extract. Using doses (ranging from 0.001-1000 µg/ml) of each material freshly prepared in the laboratory, cell survival and production of nitric oxide (NO), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-12 by the treated cells (that in all cases also had received LPS stimulation) were measured. Results indicated that, except at doses ≥100 µg/ml, viability was unaffected in all groups. NO release by LPS-stimulated macrophages was generally significantly suppressed by either material; in contrast, low (i.e. 0.001-1 µg/ml) doses of either extract class appeared to enhance NO release by non-LPS (unstimulated)-treated macrophages. Among LPS-stimulated cells, TNFα release was also significantly affected by each extract; the ethanolic extract was suppressive at all doses tested, while the aqueous material was so up to 1 µg/ml and then became stimulatory. In contrast, nearly every dose of either extract appeared to stimulate IL-6 release from the LPS-treated cells. Effects on IL-12 production were overall inconsistent; in general, the ethanolic extract tended to be stimulatory of production by the LPS-treated cells. The data for the aqueous material showed no discernable pattern of effect. The results suggest that clove extracts do not have a distinct cytotoxic activity, but do impart potential anti- and pro-oxidant effects in cells, depending on their concentrations and on the activation state of the macrophages themselves at the time of exposure to the extracts. The impact of the extracts on macrophage cytokine release also displays a pattern of dose-relatedness.