New Medical Herbalism Formulations as a Targeted Therapeutic Strategies Used in Southern Tunisia to Promote Neo-Epithelium, Angiogenesis, and Collagen Biosynthesis and to Impede Scar Formation Post-Third-Degree Burned Skin

The aim of the study is to assess the suitability of the herbal formulation for topical application as a skin burn dressing on the in vivo wound-closure of third-degree wound injuries. Rat wound models were used to prove the in vivo skin burn-healing process. Body weight gain, food and water intake, and behavior were investigated daily during treatment period. Cutaneous biopsies of the burned wound surfaces were monitored at days 4, 13, and 28. Formulation markedly (P < .05) increased wound repair rate and collagen production compared to untreated burnt skin. Macroscopic and histological analysis of the wound of formula (F)-treated group showed significant skin contraction rate and rapid wound healing without scar through regeneration of epidermis that were approved in formula mixed with honey (F-hY)- and Drs-treated wound compared with thymol, and the untreated wound tissues that were not covered by denuded epithelial. Furthermore, the wound healing efficacy of F-hY, F, and Drs cream was proved by decreased the amount of malondialdehyde compared to untreated rats. In conclusion, F and F-hY was found to promote cutaneous wound repair. In all case, the formula alone or mixed with honeybees was even better than thymol in the repair of cutaneous wound.

Unveiling the therapeutic potential of thymol from Nigella sativa L. seed: selective anticancer action against human breast cancer cells (MCF-7) through down-regulation of Cyclin D1 and proliferative cell nuclear antigen (PCNA) expressions

BACKGROUND

Breast adenocarcinoma cells (MCF-7) are characterized by the overexpression of apoptotic marker genes and proliferative cell nuclear antigen (PCNA), which promote cancer cell proliferation. Thymol, derived from Nigella sativa (NS), has been investigated for its potential anti-proliferative and anticancer properties, especially its ability to suppress Cyclin D1 and PCNA expression, which are crucial in the proliferation of cancer cells.

METHODS

The cytotoxicity of thymol on MCF-7 cells was assessed using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release methods. Thymol was tested at increasing concentrations (0-1000 µM) to evaluate its impact on MCF-7 cell growth. Additionally, Cyclin D1 and PCNA gene expression in thymol-treated and vehicle control groups of MCF-7 were quantified using real-time Polymerase Chain Reaction (RT-qPCR). Protein-ligand interactions were also investigated using the CB-Dock2 server.

RESULTS

Thymol significantly inhibited MCF-7 cell growth, with a 50% inhibition observed at 200 µM. The gene expression of Cyclin D1 and PCNA was down-regulated in the thymol-treated group relative to the vehicle control. The experimental results were verified through protein-ligand interaction investigations.

CONCLUSIONS

Thymol, extracted from NS, demonstrated specific cytotoxic effects on MCF-7 cells by suppressing the expression of Cyclin D1 and PCNA, suggesting its potential as an effective drug for MCF-7. However, additional in vivo research is required to ascertain its efficacy and safety in medical applications.

Effect of thymol on antimicrobial susceptibility, and adhesion genes expression of uropathogenic Escherichia coli isolated from pediatric urinary tract infection

BACKGROUND

Uropathogenic Escherichia coli (UPEC) is a common cause of urinary tract infections (UTI) in children and currently is one of the leading medical problems. Due to the increase in antibiotic resistance rate, herbal medicines with lower side effects were considered.

OBJECTIVE

This study aimed to identify the afa, fimH, and sfa genes of UPEC bacteria isolated from pediatric UTI to investigate the effect of the thyme on the expression of fimH gene.

STUDY DESIGN

In this cross-sectional study, 160 UPEC were isolated from pediatric UTIs. An antibiotic susceptibility test was performed on six families of antibiotics, including beta-lactams, quinolones, aminoglycosides, carbapenems, sulfonamides, and nitrofurantoin. The micro-broth dilution method was used to determine MIC of thymol. The biofilm production ability of isolated strains was quantified by the microtiter plate method. The PCR technique was used to detectfimH, afa, and sfa adhesion genes, and real-time PCR was used to measure the fimHgene expression.

RESULTS

The results of the antibiogram showed that the lowest and highest resistance related to meropenem and imipenem (zero), and 72.5% for cephalothin. MIC showed 80.7% of the isolates were sensitive to thymol. The biofilm production results showed that 3.12%, 53.75%, and 43.12% of the isolates were strong, weak, and no-biofilm (Zero) producers, respectively. After thymol treatment, 26.25% and 73.75% of isolates were weak and no-producer (Zero) biofilms, respectively and there was a significant correlation (P-value = 0.042) compared to the control group. The frequency of fimH, sfa, and afa genes was 53.1%, 49.4%, and 29.4%, respectively. The expression of fimHgene after 48 h thymol treatment decreased significantly (P-value< 0.05).

CONCLUSION

Due to the significant effects of thymol in preventing the expression of the adhesion gene (fimH) of UPEC bacteria, our study is a proof-of-concept study evaluating bacterial sensitivity to Thymol and its effect on biofilm production in vitro. Given the demonstrated promising results of Thymol's effectiveness and the increase in bacterial antibiotic resistance, further studies should be undertaken to determine the safety and effectiveness of Thymol use in the clinical treatment of urinary tract infection. We believe that Thymol may prove to be an effective adjunct to the treatment of bacterial urinary tract infections.

Thymol regulates the Endothelin-1 at gene expression and protein synthesis levels in septic rats

Sepsis is a serious systemic inflammatory response to infections. In this study, effects of thymol treatments on sepsis response were investigated. A total of 24 rats were randomly divided into 3 different treatment groups, namely as Control, Sepsis and Thymol. A sepsis model was created with a cecal ligation and perforation (CLP) in the sepsis group. For the treatment group, 100 mg/kg dose of thymol was administered via oral gavage and sepsis was established with a CLP after 1 h. All rats were sacrificed at 12 h post-opia. Blood and tissue samples were taken. ALT, AST, urea, creatinine and LDH were evaluated to assess the sepsis response in separated sera. Gene expression analysis was conducted for ET-1, TNF-α, IL-1 in lung, kidney and liver tissue samples. ET-1 and thymol interactions were determined by molecular docking studies. The ET-1, SOD, GSH-Px and MDA levels were determined by ELISA method. Genetic, biochemical and histopathological results were evaluated statistically. The pro-inflammatory cytokines and ET-1 gene expression revealed a significant decrease in the treatment groups, while there was an increase in septic groups. SOD, GSH-Px and MDA levels of rat tissues were significantly different in the thymol groups as compared to the sepsis groups (p < 0.05). Likewise, ET-1 levels were significantly reduced in the thymol groups. In terms of serum parameters, present findings were consistent with the literature. It was concluded based on present findings that thymol therapy may reduce sepsis-related morbidity, which would be beneficial in the early phase of the sepsis.

Natural products can be used in therapeutic management of COVID-19: Probable mechanistic insights

The unexpected emergence of the new Coronavirus disease (COVID-19) has affected more than three hundred million individuals and resulted in more than five million deaths worldwide. The ongoing pandemic has underscored the urgent need for effective preventive and therapeutic measures to develop anti-viral therapy. The natural compounds possess various pharmaceutical properties and are reported as effective anti-virals. The interest to develop an anti-viral drug against the novel severe acute respiratory syndrome Coronavirus (SARS-CoV-2) from natural compounds has increased globally. Here, we investigated the anti-viral potential of selected promising natural products. Sources of data for this paper are current literature published in the context of therapeutic uses of phytoconstituents and their mechanism of action published in various reputed peer-reviewed journals. An extensive literature survey was done and data were critically analyzed to get deeper insights into the mechanism of action of a few important phytoconstituents. The consumption of natural products such as thymoquinone, quercetin, caffeic acid, ursolic acid, ellagic acid, vanillin, thymol, and rosmarinic acid could improve our immune response and thus possesses excellent therapeutic potential. This review focuses on the anti-viral functions of various phytoconstituent and alkaloids and their potential therapeutic implications against SARS-CoV-2. Our comprehensive analysis provides mechanistic insights into phytoconstituents to restrain viral infection and provide a better solution through natural, therapeutically active agents.

Neuroprotective role of a monoterpene (thymol) on diazepam induced withdrawal symptoms in rats

Benzodiazepine administration is known to be related to tolerance and a withdrawal syndrome on sudden cessation. Thymol possesses multiple biological properties especially in the pathogenesis of different brain disorders. However, to the best of our knowledge there is no study that relates the use of thymol to benzodiazepine induced withdrawal symptoms. Therefore the aim of the current study was to investigate the usefulness of thymol in the treatment of benzodiazepine withdrawal syndrome in rats. Animals were divided into four groups, thymol (40mg/kg/ml), diazepam (4 mg/kg), thymol + diazepam and vehicle control group. The treatment was given for 14 days and then suddenly ceased. After 24 h animals were tested in different behavioral paradigms such as physical signs for withdrawal, marble burying test, inverted screen test, elevated plus maze, passive avoidance test and open field activity. The results of the present study revealed that co-administration of thymol significantly reduced the withdrawal symptoms induced by diazepam. Our results further suggest that administration of thymol not only ameliorates rebound anxiety associated with diazepam withdrawal but also improves motor and memory impairment in rats.

Control of Rhipicephalus annulatus resistant to deltamethrin by spraying infested cattle with synergistic eucalyptus essential oil-thymol-deltamethrin combination

The current study investigated the synergistic effect of combinations containing deltamethrin (D), Eucalyptus essential oil (E), and the thyme essential oil component thymol (T), against a field population of Rhipicephalus annulatus in Egypt that was characterized to be resistant to D. Solutions of T, E, or TE at concentrations of 1.25-5% were combined with 5% deltamethrin at different dilutions (0.25-2 mL/L). Results of the adult immersion test used to estimate the in vitro acaricidal activity of these combinations at 5% yielded LC₅₀ values for D, E-D, T-D, and TE-D of 3.87 mL/L, 3.89 mL/L, 0.14 mL/L, and 0.05 mL/L, respectively. Biochemical analyses using whole-body homogenate of ticks from the in vitro tests revealed that the lowest acetylcholinesterase and glutathione peroxidase activity, and the maximum lipid peroxidation were recorded in ticks treated with 5% TE-D. Glutathione content significantly decreased (p ≤ 0.05) in all treated ticks. Three groups, each containing five cross breed cattle naturally infested with R. annulatus from the same area where resistance to D was detected, were sprayed twice at two-week intervals using 1 mL/L of 5% solutions of D, T-D, or TE-D. Overall efficacy of the D, T-D, and TE-D sprays by day 30 post-treatment was 21.6, 88.3, and 95 %, respectively. Ticks collected from infested cattle three days after treatment with the D spray deposited egg masses that were able to hatch, deposited small masses of eggs unable to hatch when exposed to the T-D spray, and laid few eggs that didn't hatch when sprayed with the TE-D combination. Values for liver and kidney function parameters were comparable in cattle before and after treatment with the combination sprays tested. The TE-D spray overcame the insensitivity to D of this R. annulatus population in Egypt, which also highlighted the significant synergistic effect of thymol on the acaricidal activity of deltamethrin observed in vitro. Acaricidal activity of the TE-D combination apparently has deleterious effects on multiple tick systems involving inhibition of acetylcholinesterase, increased lipid peroxidation, and oxidative stress. These findings document that combinations of natural and synthetic products can be part of integrated management solutions to the problem with widespread resistance to pyrethroids like deltamethrin in populations of cattle ticks, including R. annulatus, around the world.

A multiorganism pipeline for antiseizure drug discovery: Identification of chlorothymol as a novel γ-aminobutyric acidergic anticonvulsant

OBJECTIVE

Current medicines are ineffective in approximately one-third of people with epilepsy. Therefore, new antiseizure drugs are urgently needed to address this problem of pharmacoresistance. However, traditional rodent seizure and epilepsy models are poorly suited to high-throughput compound screening. Furthermore, testing in a single species increases the chance that therapeutic compounds act on molecular targets that may not be conserved in humans. To address these issues, we developed a pipeline approach using four different organisms.

METHODS

We sequentially employed compound library screening in the zebrafish, Danio rerio, chemical genetics in the worm, Caenorhabditis elegans, electrophysiological analysis in mouse and human brain slices, and preclinical validation in mouse seizure models to identify novel antiseizure drugs and their molecular mechanism of action.

RESULTS

Initially, a library of 1690 compounds was screened in an acute pentylenetetrazol seizure model using D rerio. From this screen, the compound chlorothymol was identified as an effective anticonvulsant not only in fish, but also in worms. A subsequent genetic screen in C elegans revealed the molecular target of chlorothymol to be LGC-37, a worm γ-aminobutyric acid type A (GABAA ) receptor subunit. This GABAergic effect was confirmed using in vitro brain slice preparations from both mice and humans, as chlorothymol was shown to enhance tonic and phasic inhibition and this action was reversed by the GABAA receptor antagonist, bicuculline. Finally, chlorothymol exhibited in vivo anticonvulsant efficacy in several mouse seizure assays, including the 6-Hz 44-mA model of pharmacoresistant seizures.

SIGNIFICANCE

These findings establish a multiorganism approach that can identify compounds with evolutionarily conserved molecular targets and translational potential, and so may be useful in drug discovery for epilepsy and possibly other conditions.

Oral Phyto-thymol ameliorates the stress induced IBS symptoms

Physical stressors play a crucial role in the progression of irritable bowel syndrome (IBS). Here we report a heterogeneous physical stress induced IBS rat model which shows depression and subsequent modulation of IBS by oral treatment of thymol. Oral administration of Thymol reduces the stress induced IBS significantly altering the stress induced gastrointestinal hypermotility, prolonged the whole gut transit time, and increased abdominal withdrawal reflex suggesting gastrointestinal hypermotility and visceral discomfort caused the onset of depression. Immunohistochemical analysis in small intestine and colon of rats shows the decreased 5-HT3AR expression level while thymol treatment normalized the 5-HT3AR expression in the stressed rats. Molecular docking studies showed that thymol competes with endogenous serotonin and an antagonist, Tropisetron and all have similar binding energies to 5-HT3AR. Molecular dynamics simulations revealed that thymol and tropisetron might have similar effects on 5-HT3AR. Our study suggest that thymol improves IBS symptoms through 5-HT3AR, could be useful for the treatment of IBS.

Impact of sublethal exposure to synthetic and natural acaricides on honey bee (Apis mellifera) memory and expression of genes related to memory

Acaricides are used by beekeepers in honey bee (Apis mellifera L.) colonies to control parasitic mites, but may also have adverse effects to honey bees. In this study, five commonly used acaricides were tested for their sublethal effects on memory and expression of neural-related genes in honey bees. Memory measured with the proboscis extension reflex (PER) assay was significantly reduced by topical treatment of bees with a single LD₀₅ dose of formic acid at 2 and 24 h post treatment (hpt). However, tau-fluvalinate, amitraz, coumaphos, and formic acid, but not thymol, resulted in memory loss at 48 hpt. The LD₀₅ doses of the acraricides did not affect expression of neuroligin-1, related to memory, or expression of major royal jelly protein-1, related to both memory and development, although expression of both genes was affected at LD₅₀ doses. The LD₀₅ doses of thymol, formic acid, amitraz and coumaphos increased defensin-1 expression, which is related to both memory and immunity. The effect of thymol, however, may have been due to its impact on the immune response rather than memory. This study demonstrates that acaricides vary in their effects on bee's memory, and that the widely used acaricide, formic acid, is particularly damaging.

Neuroprotective Effects of Thymol, a Dietary Monoterpene Against Dopaminergic Neurodegeneration in Rotenone-Induced Rat Model of Parkinson's Disease

Parkinson’s disease (PD), a multifactorial movement disorder that involves progressive degeneration of the nigrostriatal system affecting the movement ability of the patient. Oxidative stress and neuroinflammation both are shown to be involved in the etiopathogenesis of PD. The aim of this study was to evaluate the therapeutic potential of thymol, a dietary monoterpene phenol in rotenone (ROT)-induced neurodegeneration in rats that precisely mimics PD in humans. Male Wistar rats were injected ROT at a dose of 2.5 mg/kg body weight for 4 weeks, to induce PD. Thymol was co-administered for 4 weeks at a dose of 50 mg/kg body weight, 30 min prior to ROT injection. The markers of dopaminergic neurodegeneration, oxidative stress and inflammation were estimated using biochemical assays, enzyme-linked immunosorbent assay, western blotting and immunocytochemistry. ROT challenge increased the oxidative stress markers, inflammatory enzymes and cytokines as well as caused significant damage to nigrostriatal dopaminergic system of the brain. Thymol treatment in ROT challenged rats appears to significantly attenuate dopaminergic neuronal loss, oxidative stress and inflammation. The present study showed protective effects of thymol in ROT-induced neurotoxicity and neurodegeneration mediated by preservation of endogenous antioxidant defense networks and attenuation of inflammatory mediators including cytokines and enzymes.

Thymol, eugenol and lactobacilli in a medical device for the treatment of bacterial vaginosis and vulvovaginal candidiasis

The aim of this non-interventional, observational, multicentre, open-label study was to assess the effectiveness of a vaginal gel containing extracts of Thymus vulgaris and Eugenia caryophyllus in conjunction with two specific lactobacilli strains (Lactobacillus fermentum LF10 and Lactobacillus plantarum LP02) specifically formulated in slow-release vaginal capsules, in treating bacterial vaginosis (BV), vulvovaginal candidiasis (VVC) or recurrent vulvovaginal candidiasis disease (RVVC) [Estromineral Probiogel (EPB) in Italy, or Saugella Probiogel; Meda Pharma - Mylan Group]. There was a statistically significant improvement in pruritus, burning, vulvovaginal oedema and erythema, dyspareunia and vaginal secretions in all diagnostic groups. At the end of the study, the microbiological evaluation was normal in 80.0% of cases with BV, 62.5% of cases with VVC and 100.0% with RVVC. The clinical data allow EPB to be recommended in the acute treatment of VVC and BV, suggesting that EPB is a useful maintenance treatment if there are recurrent episodes. Controlled studies are needed to confirm the efficacy of EPB in the treatment of recurrences and to identify the most appropriate dosage regimen.

Hepatoprotective effect of thymol against subchronic toxicity of titanium dioxide nanoparticles: Biochemical and histological evidences

The study was aimed to investigate the protective action of thymol against nano titanium dioxide (nano-TiO₂) induced hepatotoxicity in rats. To achieve this purpose, the rats were divided into four groups (n = 6) including control, nano-TiO₂ (100 mg/kg), nano-TiO₂ + thymol (10 mg/kg) and nano-TiO₂ + thymol (30 mg/kg). Intragastric (IG) administration of nano-TiO₂ for 60 consecutive days caused widespread histological changes and significantly induced oxidative stress in the liver tissues as manifested by the rise in serum transaminase activities accompanied by marked decline of enzymatic (catalase, superoxide dismutase and glutathione peroxidase) and non-enzymatic (ferric reducing antioxidant power and glutathione) antioxidant levels, and rise of malondialdehyde levels in liver tissue. Pretreatment with thymol (IG) prior to nano-TiO₂ administration significantly ameliorated all of biochemical and histopathological alterations in a dose-dependent manner. In conclusion, thymol effectively protects against nano-TiO₂-induced hepatotoxicity in rats by its antioxidant properties.

[Bronchipret TE® in therapy of acute infections of the respiratory tract]

Bronchipret TE® exhibits multidirectional anti-inflammatory effects as demonstrated in vitro and in vivo studies. It has been disclosed that the drug has the ability to activate the bronchial cleaning mechanism, inhibit the respiratory tract remodeling process by reducing the number of goblet cells, inhibiting enzyme activity and proinflammatory mediators. These mechanisms cause the administration of medication to cause acute bronchitis patients to shorten and alleviate the course of the disease with rapid cough elimination. Use of Bronchipret TE® is in accordance with the recommendations of the European Guideline Committee's and the German Respiratory Society.

Anesthetic Agents of Plant Origin: A Review of Phytochemicals with Anesthetic Activity

The majority of currently used anesthetic agents are derived from or associated with natural products, especially plants, as evidenced by cocaine that was isolated from coca (Erythroxylum coca, Erythroxylaceae) and became a prototype of modern local anesthetics and by thymol and eugenol contained in thyme (Thymus vulgaris, Lamiaceae) and clove (Syzygium aromaticum, Myrtaceae), respectively, both of which are structurally and mechanistically similar to intravenous phenolic anesthetics. This paper reviews different classes of phytochemicals with the anesthetic activity and their characteristic molecular structures that could be lead compounds for anesthetics and anesthesia-related drugs. Phytochemicals in research papers published between 1996 and 2016 were retrieved from the point of view of well-known modes of anesthetic action, that is, the mechanistic interactions with Na⁺ channels, γ-aminobutyric acid type A receptors, N-methyl-d-aspartate receptors and lipid membranes. The searched phytochemicals include terpenoids, alkaloids and flavonoids because they have been frequently reported to possess local anesthetic, general anesthetic, antinociceptive, analgesic or sedative property. Clinical applicability of phytochemicals to local and general anesthesia is discussed by referring to animal in vivo experiments and human pre-clinical trials. This review will give structural suggestions for novel anesthetic agents of plant origin.

Thymol improves high-fat diet-induced cognitive deficits in mice via ameliorating brain insulin resistance and upregulating NRF2/HO-1 pathway

The impaired insulin signaling has been recognized as a common pathogenetic mechanism between diabetes and Alzheimer's disease (AD). In the progression of AD, brain is characterized by defective insulin receptor substrate-1 (IRS-1) and increased oxidative stress. Thymol, a monoterpene phenol isolated from medicinal herbs, has exhibited robust neuroprotective effects. The present study was designed to investigate the protective effect of thymol on HFD-induced cognitive deficits, and explore the possible mechanisms. C57BL/6 J mice were fed for 12 weeks with either HFD or normal diet. The mice fed with HFD were dosed with metformin (200 mg/kg) or thymol (20, 40 mg/kg) daily. It was observed that thymol treatment significantly reversed the gain of body weight and peripheral insulin resistance induced by HFD. Meanwhile, thymol improved the cognitive impairments in the Morris Water Maze (MWM) test and decreased HFD-induced Aβ deposition and tau hyperphosphorylation in the hippocampus, which may be correlated with the inhibition of hippocampal oxidative stress and inflammation. In addition, thymol down-regulated the level of P-Ser307 IRS-1, and hence enhancing the expression of P-Ser473 AKT and P-Ser9 GSK3β. We further found that the protective effects of thymol on cognitive impairments were associated with the up-regulation of nuclear respiratory factor (Nrf2)/heme oxygenase-1(HO-1) pathway. In conclusion, thymol exhibited beneficial effects on HFD-induced cognitive deficits through improving hippocampal insulin resistance, and activating Nrf2/HO-1 signaling.

The effect of chlorhexidine in reducing oral colonisation in geriatric patients: a randomised controlled trial

INTRODUCTION

Inadequate oral care has been implicated in the development of aspiration pneumonia in frail geriatric patients and is a major cause of mortality, due to the colonisation of microbes in vulnerable patients. This type of pneumonia has been associated with an increase in respiratory pathogens in the oral cavity. The aim of this study was to evaluate the effects of chlorhexidine compared to routine oral care in edentulous geriatric inpatients.

METHODS

A double-blind, parallel-group randomised controlled trial was carried out. The intervention group received oral care with chlorhexidine 0.2%, while the control group received routine oral care with thymol. Nurses provided oral care with assigned solutions of 20 mL once daily over seven days. Oral cavity assessment using the Brief Oral Health Status Examination form was performed before each oral care procedure. Data on medication received and the subsequent development of aspiration pneumonia was recorded. An oral swab was performed on Day 7 to obtain specimens to test for colonisation.

RESULTS

The final sample consisted of 35 (control) and 43 (intervention) patients. Chlorhexidine was effective in reducing oral colonisation compared to routine oral care with thymol (p < 0.001). The risk of oral bacterial colonisation was nearly three times higher in the thymol group compared to the chlorhexidine group.

CONCLUSION

The use of chlorhexidine 0.2% significantly reduced oral colonisation and is recommended as an easier and more cost-effective alternative for oral hygiene.

Evaluation of the efficacy of a new oral gel containing carvacrol and thymol for home oral care in the management of chronic periodontitis using PCR analysis: a microbiological pilot study

The use of chemical devices for domestic oral hygiene in periodontal patients has led to new treatment strategies aiming primarily at a control of infection. Over the last few years, carvacrol and thymol (CT) have been subjected to many scientific and medical studies. The purpose of the present study was to assess the effect of CT on the red complex bacteria using Polymerase Chain Reaction (PCR) for microbiological analysis. Five patients with a diagnosis of chronic periodontitis in the age group >25 years, were selected. None of these patients had received any surgical or non-surgical periodontal therapy and demonstrated radiographic evidence of moderate bone loss. After scaling and root planning, patients received a CT gel to be used at home. Four non-adjacent sites in separate quadrants were selected in each patient for monitoring, based on criteria that the sites localize chronic periodontitis. Microbial analysis (MA) was analyzed at baseline and at day 15. SPSS program was used for statistical purposes and a paired samples correlation was performed at the end of the observation period. Although an absolute reduction was observed among the studied bacteria (i.e. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Campylobacter rectus and Total bacteria loading) none reach a statistical significant value. The present study demonstrated that CT gel has a small impact on oral biofilm. Additional studies are needed to detect the efficacy of CT gel.

[Treatment of cough in respiratory tract infections - the effect of combining the natural active compounds with thymol]

Cough is one of the characteristic symptoms of upper respiratory tract infections (URI). Herbal medicines are often used in the treatment of the cough associated with infection and to accelerate recovery or support the immune system. An example of such products are extracts of thyme and primrose, and also their combination with thymol. Thymus vulgaris is a spasmolytic, antimicrobial, anti-inflammatory, immunomodulatory and antioxidant agent. The most important component responsible for the activity of thyme is thymol contained in the volatile thyme oil. Primrose is, most of all, a saponine agent with expectorant and secretolytic activity, showing also spasmolytic, anti-inflammatory and antimicrobial effects. Because of the additive effects of the mentioned extracts and their wide activity profile they are often used as a combination drug. The use of this combination was assessed in the URI with the effects of alleviation of cough and dyspnea, and shortening the length of the disease. The effectiveness of the drug containing the extracts of thyme and primrose with the addition of thymol (Bronchosol®) was comparable to synthetic ambroxol and its safety has been proved. Moreover, the in-vitro antibacterial and antifungal effects of this drug have been evaluated.

Protective effect of thymol on high fat diet induced diabetic nephropathy in C57BL/6J mice

Obesity is one of several factors implicated in chronic kidney disease (CKD). Thymol, a monoterpene phenolic compound found in the oils of thyme with multiple biological properties especially antidiabetic activity. The present study was undertaken to evaluate the thymol against diabetic nephropathy by high fat diet (HFD)-induced diabetic C57BL/6J mice. After 10 weeks of continuous dietary intervention, HFD (fat- 35.2%) to mice presented characteristic features of progressive nephropathy by significant increased in kidney weight, blood, and urinary parameters, glomerulosclerosis, oxidative stress, hyperlipidemia and subsequent renal injuries. After intragastric administration of thymol (40 mg/kg BW) daily for the subsequent 5 weeks significantly decreased the blood, urinary parameters and kidney weight. Thymol inhibited the activation of transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor (VEGF). Also, significantly increased the antioxidants and suppresses the lipid peroxidation markers in erythrocytes and kidney tissue compared to the diabetic mice. Thymol downregulated the expression level of sterol regulatory element binding protein-1c (SREBP-1c) and reduced the lipid accumulation in renal. Histopathological study of kidney tissues showed that extracellular mesangial matrix expansion, glomerulosclerosis in diabetic mice were suppressed by thymol. Further, our results indicate that administration of thymol afforded remarkable protection against HFD-induced diabetic nephropathy.

Antibacterial effects of fluoride varnish compared with chlorhexidine plus fluoride in disabled children

PURPOSE

To evaluate the effects of fluoride varnish vs a combination of chlorhexidine-thymol varnish plus a gel containing chlorhexidine and fluoride on oral hygiene and caries prevention in disabled children.

MATERIALS AND METHODS

Ninety patients aged 3-17 years who were treated under general anaesthesia were randomly assigned into three groups as follows: group 1: Fluor Protector (0.1% fluoride varnish); group 2: Cervitec Plus (1% chlorhexidine- 1% thymol varnish) + Cervitec Gel (0.2% chlorhexidine-0.2% sodium fluoride); group 3: control (toothbrushing only). Mutans streptococci (MS) and lactobacilli (LB) levels, visible plaque index (VPI) and gingival bleeding index (GBI) were evaluated at four stages: T0, before general anaesthesia; T1, one month after treatment; T2, six months after treatment; T3, twelve months after treatment. The data were evaluated using Kruskal-Wallis and Mann-Whitney U-tests (P < 0.05).

RESULTS

Groups 1 and 2 showed significantly lower scores than group 3 for all parameters at T1 and T2. No statistically significant difference was detected among any of the the groups at T3 (P > 0.05).

CONCLUSION

The use of materials that include both fluoride and chlorhexidine as routine treatment of children with disability may increase the success of restorations by improving oral hygiene, reduce the need for future restorative treatments and thus the need for general anaesthesia.

New Miticides for Integrated Pest Management of Varroa destructor (Acari: Varroidae) in Honey Bee Colonies on the Canadian Prairies

Varroa destructor Anderson and Trueman 2000 (Acari: Varroidae) is an ectoparasitic mite of the honey bee, Apis mellifera L. (Hymenoptera: Apidae). Honey bee colonies require extensive management to prevent mortality caused by varroa mites and the viruses they vector. New miticides (Thymovar and HopGuard) to manage varroa mites were evaluated during the spring and fall treatment windows of the Canadian prairies to determine their effectiveness as part of an integrated management strategy. Thymovar and HopGuard were evaluated alongside the currently used industry standards: Apivar and formic acid. Results demonstrated that Apivar and formic acid remain effective V. destructor management options under spring and fall conditions. Applications of Thymovar during spring were associated with a reduction in brood area, and therefore should be limited to the fall season. The miticide HopGuard was not effective in managing V. destructor, and alteration of the current delivery system is necessary. This study demonstrates the potential for new effective treatment options to supplement currently used V. destructor integrated pest management systems.

Thymol and eugenol derivatives as potential antileishmanial agents

In Northeastern Brazil visceral leishmaniasis is endemic with lethal cases among humans and dogs. Treatment is toxic and 5-10% of humans die despite treatment. The aim of this work was to survey natural active compounds to find new molecules with high activity and low toxicity against Leishmania infantum chagasi. The compounds thymol and eugenol were chosen to be starting compounds to synthesize acetyl and benzoyl derivatives and to test their antileishmanial activity in vitro and in vivo against L. i. chagasi. A screening assay using luciferase-expressing promastigotes was used to measure the growth inhibition of promastigotes, and an ELISA in situ was performed to evaluate the growth inhibition of amastigote. For the in vivo assay, thymol and eugenol derivatives were given IP to BALB/c mice at 100mg/kg/day for 30 days. The thymol derivatives demonstrated the greater activity than the eugenol derivatives, and benzoyl-thymol was the best inhibitor (8.67 ± 0.28 μg/mL). All compounds demonstrated similar activity against amastigotes, and acetyl-thymol was more active than thymol and the positive control drug amphotericin B. Immunohistochemistry demonstrated the presence of Leishmania amastigote only in the spleen but not the liver of mice treated with acetyl-thymol. Thus, these synthesized derivatives demonstrated anti-leishmanial activity both in vitro and in vivo. These may constitute useful compounds to generate new agents for treatment of leishmaniasis.

Superiority of essential oils versus 0.075% CPC-containing mouthrinse: a two-week randomized clinical trial

OBJECTIVE

The objective of this randomized, examiner-blind, parallel, controlled clinical study was to compare the antiplaque/antigingivitis efficacy of an essential oil-containing mouthrinse (EO) to a new 0.075% cetylpyridinium chloride mouthrinse (CPC) using a two-week experimental gingivitis model with a 5% hydroalcohol rinse serving as the negative control.

METHODS

After signing informed consents and completing baseline examinations, 185 subjects were randomized into three groups. Subjects began supervised/recorded rinsing with 20 ml of their assigned rinse for 30 seconds twice daily for two weeks, with no mechanical oral hygiene permitted. Baseline and two-week assessments were conducted as follows: Turesky Modification of the Quigley-Hein Plaque Index (PI), Modified Gingival Index (MGI), and the Gingival Bleeding Index (BI). Analysis of efficacy variables (i.e., mean PI, mean MGI, mean BI, and proportion of bleeding sites derived from the BI) was performed using a one-way analysis of covariance (ANCOVA).

RESULTS

Among the 182 subjects who completed the study, the EO rinse showed statistically significant reductions compared to the negative control within the range previously reported in this model; PI = 36.5% (p < 0.001) and MGI = 17.5% (p < 0.001). A 43.2% reduction in proportion of bleeding sites (p < 0.001) was demonstrated. Mean PI, MGI, and proportion of bleeding sites at two weeks were statistically significantly lower for the EO rinse compared to the CPC rinse (p < 0.001), showing 27.7%, 11.9%, and 30.0% reductions, respectively.

CONCLUSION

An EO rinse provided superior antigingivitis/antiplaque efficacy compared to a 0.075% CPC rinse in this short-term clinical trial, and demonstrated efficacy within the range shown in previous studies using this model.

Effect of thymol on peripheral blood mononuclear cell PBMC and acute promyelotic cancer cell line HL-60

Thymol, a naturally occurring phenolic compound, has been known for its antioxidant, anti microbial, and anti inflammatory activity. Thymol has also been reported as anti-cancer agent, but its anti-cancer mechanism has not yet been fully elucidated. Thus, we aimed to investigate anticancer activity of thymol on HL-60 (acute promyelotic leukemia) cells. In our study, thymol demonstrated dose dependent cytotoxic effects on HL-60 cells after 24h of exposure. However, thymol did not show any cytotoxic effect in normal human PBMC. The cytotoxic effect of thymol on HL-60 cells appears to be associated with induction of cell cycle arrest at sub G0/G1 phase, and apoptotic cell death based on genomic DNA fragmentation pattern. Thymol also showed significant increase in production of reactive oxygen species (ROS) activity, increase in mitochondrial H(2)O(2) production and depolarization of mitochondrial membrane potential. On performing Western Blot analysis, thymol showed increase in Bax protein level with a concomitant decrease in Bcl2 protein expression in a dose dependent manner. Our study also showed activation of caspase -9, -8 and -3 and concomitant PARP cleavage, which is the hallmark of caspase-dependent apoptosis. Moreover, to rule out the involvement of other mechanisms in apoptosis induction by thymol, we also studied its effect on apoptosis inducing factor (AIF). Thymol induced AIF translocation from mitochondria to cytosol and to nucleus, thus indicating its ability to induce caspase independent apoptosis. We conclude that, thymol-induced apoptosis in HL-60 cells involves both caspase dependent and caspase independent pathways.

MYCOTOX® and aflatoxicosis in quails

1. This study was to evaluate the toxic effects of aflatoxin (AF) on growth performance of quail, and to determine the preventive efficacy of MYCOTOX (oxicinol, tymol, micronised yeast). 2. One hundred and eighty 1-d-old quail (Coturnix coturnix japonica) of both sexes were weighed and randomly divided into 4 experimental groups each with 5 replicates of 9 birds. 3. There were 4 dietary treatments: (1) control with 0 mg AF/kg diet and 0% MYCOTOX; (2) 0 mg AF/kg diet and 0.5% MYCOTOX; (3) 2.5 mg AF/kg diet and 0% MYCOTOX; (4) 2.5 mg AF/kg diet plus 0.5% MYCOTOX. The chicks were maintained on these treatments to 3 weeks of age. Quail consumed the diets and water ad libitum. 4. Body weight (BW) gains in groups receiving AF alone were the lowest at all periods. Feed intake was lowest in the group consuming the AF diet. The addition of MYCOTOX to the AF diet did not prevent or reduce the toxic effects of AF on feed intake at any time period. Feeding diets containing MYCOTOX alone did not change feed intake significantly. With the exception of the 1 to 7 d period, feed conversion of chicks fed the AF diet was similar to those of the other experimental groups. 5. Bursa of Fabricius weight decreased, whereas the relative weights of liver, kidney and spleen increased in quail consuming diets containing AF and AF plus MYCOTOX. Liver colour was normal in the control and MYCOTOX alone group, but was lighter in groups fed AF. 6. The results indicated that MYCOTOX was not effective in preventing the deleterious effects of AF.

Antinociceptive effect of extracts and compounds from Hofmeisteria schaffneri

ETHNOPHARMACOLOGICAL RELEVANCE

Hofmeisteria schaffneri (Asteraceae) is a medicinal plant widely commercialized in the most important Markets of Mexico City for the treatment of gastro-intestinal complaints and skin afflictions.

AIM OF THE STUDY

The main goals of this study were to establish the potential acute toxicity and the antinociceptive activity in animal models of several preparations and compounds from Hofmeisteria schaffneri.

MATERIALS AND METHODS

The aqueous and organic extracts as well as the essential oil of Hofmeisteria schaffneri were prepared by infusion, maceration and hydrodistillation, respectively. Investigation of the acute toxicity was accomplished by the Lorke method. The antinociceptive effect was assessed using the writhing and the hot plate tests. Natural compounds were isolated by standard phytochemical procedures. In addition, a few thymol esters were prepared by chemical synthesis. The stability of natural and synthetic esters was qualitatively analyzed by measuring their susceptibility to hydrolysis by pig liver estearase and mouse plasma at 37 degrees C.

RESULTS

The LD(50) for each preparation tested was higher than 5000 mg/kg revealing that they were not toxic to mice after exposure for short space of time. On the other hand, the extracts showed significant antinociceptive effect when tested in the hot plate model. The most active natural product as antinociceptive agent was hofmeisterin III (1) which also was the most stable in the stability study. Its pharmacological effect seems to be partially mediated by an opioid mechanism since naloxone inhibits its action. Using compound 1 as a lead molecule, several synthetic thymol esters were prepared and only compounds 13, 15 and 17 were antinoceptive at the dose of 1 mg/kg.

CONCLUSIONS

The present investigation provided evidence of the efficacy of several preparations of Hofmeisteria schaffneri as antinociceptive agents. The most active preparation was the essential oil which contained large amount of hofmeisterin III (1) and other thymol derivatives. Some novel synthetic analogs of hofmeisterin III with antinociceptive properties were discovered. The nature of the ester chain of these analogs did not have a clear impact on the antinociceptive activity. The phyto-preparations analyzed in this study were not toxic to mice according to the Lorke's test; therefore considering their long term use of the plant they might be secure for human consumption.

Effectiveness of 2-year application of school-based chlorhexidine varnish, sodium fluoride gel, and dental health education programs in high-risk adolescents

OBJECTIVE

To compare the caries preventive effects of 2-year application of school-based chlorhexidine varnish, sodium fluoride gel, and dental health education programs among a high-risk group of 11- to 13-year-olds with low caries activity.

METHOD AND MATERIALS

A total of 149 subjects who had previous caries experience in the primary dentition and Streptococcus mutans levels higher than 10(5) at baseline with 0 DMFS index were selected for this randomized clinical trial. Subjects were allocated to one of 3 groups for treatment with chlorhexidine varnish (n = 50), sodium fluoride gel (n = 50), or a dental health education program (n = 49), which were repeated throughout the 2-year study. The outcomes examined at the end of the study were the caries increment (DMFS index), dental plaque scores, and salivary S mutans counts.

RESULTS

The subjects in the education group showed a significant increase in the salivary levels of S mutans in comparison with the other groups (P = .004), but there was no significant difference among the groups in the caries increment after 2 years, with mean DMFS +/- SD as 0.95 +/- 1.33, 0.88 +/- 1.47, and 1.05 +/- 2.01 in the chlorhexidine varnish, sodium fluoride gel, and education groups, respectively. There were also no significant differences in the pre- and posttreatment plaque scores between the groups.

CONCLUSION

Although all 3 preventive programs in this high-caries-risk group of children with low caries activity resulted in similar plaque and caries values after 2 years, longer follow-up studies are needed to clarify the effect of reduction in S mutans growth by chemotherapeutic agents in caries incidence.

The Role of Chlorhexidine in Caries Prevention

Chlorhexidine rinses should not be recommended for use in caries prevention due to the current lack of evidence for their effectiveness.

Eugenol and thymol, alone or in combination, induce morphological alterations in the envelope of Candida albicans

The envelope of Candida albicans, with its outermost array of macromolecules protruding towards the environment, is pivotal to the expression of major virulence factors such as adhesiveness, and the morphological transition to hyphal form. We tested the anticandidal activity of eugenol, main component of clove oil, and thymol, main component of thyme oil, alone or in combination, by investigating their ability to interfere with the architecture of the envelope of C. albicans. Both molecules alterated the morphogenesis of the envelope, but the effects of thymol were more pronounced than those of eugenol. Certain combinations of the two molecules led to a synergistic effect, which is interesting in the view of potentiating their inhibition of C. albicans colonisation and infectiousness.

[Treatment of acute bronchitis in children and adolescents. Non-interventional postmarketing surveillance study confirms the benefit and safety of a syrup made of extracts from thyme and ivy leaves]

OBJECTIVE

For the investigation of the benefits and tolerability of a syrup made of extracts from thyme and ivy (Bronchipret Saft) in children and adolescents (ages: 2-17 years) with acute bronchitis and productive cough, a non-interventional postmarketing surveillance study was carried out.

METHODS

Prerequisites for participation in the surveillance study were productive cough for a maximum of two days, at least ten coughing fits per day prior to the initiation of treatment (estimation of the parents or adolescent) and a Bronchitis Severity Score (BSS) of at least five points. The primary outcome measure was the change in the clinical symptoms based on the BSS. Treatment was carried out using age-appropriate dosages prescribed by the doctor on a case-by-case basis in accordance with the summary of product characteristics. Documentation of the course of treatment for the surveillance study was to be taken on treatment days 0, 4 and 10.

RESULTS

For the descriptive, statistical evaluation of the surveillance study, the data from 1234 children and adolescents (623 boys and 611 girls) in the age groups < 2 years (N = 12), 2-5 years (N = 372), 6-11 years (N = 438) and 12-17 years (N = 412) were available. The correspondence of the dosages to the age-specific recommendations of the valid summary of product characteristics varied from 81.7% to 93.9% in the different age groups. The average BSS value decreased from 8.8 points to 4.8 on treatment day 4 and to 1.3 points after about ten days of treatment. Compared to that of the initial examination, the number of documented coughing fits had decreased on the average by 18.7 (81.3%) on day 10. The responder rates of the various age groups were 92.0% to 96.5%. The tolerability was rated as very good to good by the physicians in 96.5% of the cases. Two female patients had temporary, not serious adverse drug reactions (stomache ache, mild nausea).

CONCLUSION

Acute bronchitis with productive cough in (young) children and adolescents can be treated safely and effectively with the thyme and ivy syrup. A ten-day treatment using age-appropriate dosages led to a clear improvement in the symptoms or cure with very good tolerability.

The efficacy of techniques for the disinfection of artificial sub-surface dentinal caries lesions and their effect on demineralization and remineralization in vitro

OBJECTIVES

The efficacy of three techniques for the disinfection of artificial sub-surface root caries lesions and their response to subsequent episodes of de- and remineralization was investigated quantitatively in vitro.

METHODS

Sub-surface dentinal lesions (n=20), cut into four experimental blocks and deliberately contaminated with Streptococcus mutans, were subject to either steam autoclaving (121 degrees C, 5min), gamma irradiation (4100Gy), immersion in 0.1% (w/v) thymol-distilled water solution (24h) or reserved as a control. Next, the lesions were incubated aerobically in sterile nutrient broth for 24h at 37 degrees C and resultant cultures plated onto blood agar and neutralisation agar. Ten blocks from each experimental group were then immersed in an acidic buffer solution or exposed to artificial saliva for 5 days. Baseline changes in the mineral content and distribution of the lesions were assessed by transverse microradiography (TMR).

RESULTS

Micro-organisms were recovered from each control block and one block treated by gamma irradiation. Steam autoclaving and immersion in a thymol solution significantly decreased (p<0.05) the amount of mineral lost from the body of lesions subject to a further acid challenge. Mineral ion uptake by lesions exposed to artificial saliva was significantly increased (p<0.05) through disinfection by steam autoclaving.

CONCLUSIONS

Gamma irradiation proved the most acceptable method for the disinfection of sub-surface root dentine lesions having the least adverse effect on demineralization and remineralization.

Effect of a 40% chlorhexidine varnish on demineralization of dentin surfaces in situ

PURPOSE

To evaluate the effect of varnish with different chlorhexidine concentrations on the demineralization of dentin surfaces in situ.

METHODS

An intraoral model was used to study the ability of chlorhexidine to prevent demineralization. Dentin specimens from extracted human teeth were treated with chlorhexidine varnish and exposed to the oral environment of 47 subjects. The dentin specimens were prepared from the cervical regions of 47 third molars, sterilized by irradiation with 60 GY and mounted in intraoral appliances worn by the subjects. Before the delivery of the appliance, the specimens and participants were treated once with one of the three different varnishes (according to the manufacturer's instructions). All participants were randomly assigned to one of the three groups: (1) EC 40 (n=16), (2) Cervitec (n=15), or (3) ChemFil Varnish (control group, n=16). The appliances were worn day and night for 3 weeks. At mealtimes, the appliance was stored in 10% sucrose solution. After exposure to demineralization, the dentin surface was evaluated by microradiography to assess the depth of the lesion (microm) and the loss of mineral (Vol% microm). Data analysis was accomplished using one-way ANOVA plus LSD testing (P< 0.05).

RESULTS

Both chlorhexidine varnishes EC 40 and Cervitec resulted in significantly decreased mineral loss and lesion depth in dentin than the control. In addition, EC 40 treated specimens demonstrated significantly reduced lesion depth compared to Cervitec and the control (109.22 microm vs. 139.23 microm and 178.21 microm).

In vitro sealing ability of two materials at five different implant-abutment surfaces

BACKGROUND

The aim of the present study was to test the sealing ability of two materials at five different implant-abutment surfaces.

METHODS

In the first phase, 2 mul brain-heart infusion (BHI) broth was deposited into the implant wells and glass culture tubes. A varnish or silicon sealant was applied at the cervical implant portion of experimental groups. The control group remained unexposed. The abutments were torque-tightened to 20 Ncm with a manual torque driver. Implants were immersed in 4 ml BHI broth at 37 degrees C for 2 hours to exclude contamination. In the second phase, 100 mul Enterococcus faecalis American Type Culture Collection (ATCC) strain 29212 was deposited into the glass culture tubes. After periods of 7, 14, 21, 35, 49, and 63 days, the sealing capacity was checked. Abutments were removed, and a sterile paper cone collected material inside implant bodies. This material was transferred to new tubes with BHI to verify the presence of cloudy broths within 24 to 48 hours.

RESULTS

There were no statistically significant differences between the two materials for each time period (Fisher exact test; P >0.05). Group E showed the least level of sealing ability (six implants contaminated), whereas group T showed the highest level (only two implants).

CONCLUSIONS

1) Materials tested were not able to prevent contamination over 63 days. 2) Bacterial contamination was verified after 14 and 35 days in the control and experimental groups, respectively. 3) Although materials tested had demonstrated similar sealing capacities, dental implants showed bacterial contamination regardless of their external or internal hexagonal configurations.

In Vitroacetylcholinesterase inhibitory properties of thymol, carvacrol and their derivatives thymoquinone and thymohydroquinone

The aim of this study was to examine in vitro the inhibitory activity exerted by the main constituents of essential oil obtained from the aromatic plant Thymus vulgaris L. on acetylcholinesterase (AChE). The total essential oil and selected compounds, specifically linalool and thymol, carvacrol and their derivatives thymoquinone and thymohydroquinone, were tested for AChE inhibition. Thymohydroquinone exhibited the strongest AChE inhibitory effect over the range of concentrations. The AChE inhibitory potential decreased in the following order: thymohydroquinone > carvacrol > thymoquinone > essential oil > thymol > linalool. It is interesting that the AChE inhibitory effect exerted by carvacrol was 10 times stronger than that exerted by its isomer thymol, although thymol and carvacrol have a very similar structure.

Effect of Thymol on the spontaneous contractile activity of the smooth muscles

Effects of Thymol on the spontaneous contractile activity (SCA) have been found in in vitro experiments with circular smooth-muscle strips (SMAs) from guinea pig stomach and vena portae. Thymol was found to possess an agonistic effect on the alpha(1)-, alpha(2)- and beta-adrenergic receptors. Its spasmolytic effect is registered at doses higher than 10(-6)M. Thymol in a dose of 10(-4)M inhibits 100% the SCA of the SMAs and reduces the excitatory effect of 10(-5)M ACH to 35%. It is assumed that Thymol has an analgesic effect through its action on the alpha(2)-adrenergic receptors of the nerve cells. By influencing the beta-adrenergic receptors in the adipose cells, it is possible to induce increased synthesis of fatty acids and glycerol, which is a prerequisite for increased heat release.

Efficacy of chlorhexidine-thymol varnish (CervitecR) against plaque accumulation and gingival inflammation in a geriatric population

OBJECTIVES

To determine whether the 3-monthly application of chlorhexidine (CHX)-thymol varnish is an effective method of controlling plaque and gingivitis in a group of institutionalised elderly as a complement to their usual oral hygiene practices.

DESIGN

A 6-month double-blind clinical trial.

SETTING

Two residential homes in Almería (Spain).

PARTICIPANTS

Fifty-six dentate subjects aged above 64 years who completed the 6-month study.

INTERVENTION

The study subjects were randomly assigned to one of two groups (Cervitec or placebo). Varnishes were applied twice in the first week of the study and were applied again a month later and every 3 months until the end of the study. The patients continued with their usual oral hygiene practices throughout the study.

MEASUREMENT

Plaque index and gingival index scores were determined at baseline and after 1, 3 and 6 months.

RESULTS

Treatment with Cervitec varnish had a statistically significant effect overtime on the gingival index score (p = 0.029), but not on the plaque index score (p = 0.651). The groups did not significantly differ in reductions in plaque or gingival index scores between baseline and 1, 3 or 6 months.

CONCLUSION

According to these results, Cervitec, a CHX-thymol varnish, does not appear to reduce plaque and gingivitis by a 3-monthly application in the institutionalised elderly with poor oral hygiene. Wider studies are required to investigate different varnishing protocols in geriatric populations.

In vitro inhibitory effects of thymol and quinones of Nigella sativa seeds on cyclooxygenase-1- and -2-catalyzed prostaglandin E2 biosyntheses

Dithymoquinone, thymohydroquinone, thymol and thymoquinone, compounds derived from N. sativa seeds, were investigated for their in vitro anti-inflammatory activities using cyclooxygenase-1 (COX-1) and -2 (COX-2) assays. Our results show that all substances tested possess significant inhibitory activity against at least one COX form at concentrations comparable to the active one of indomethacin. Thymol was the most active against COX-1 with an IC (50) value of 0.2 microM while thymohydroquinone and thymoquinone exhibited the strongest inhibitory effect on COX-2 with IC (50) values of 0.1 and 0.3 microM, respectively. Moreover, dithymoquinone and thymoquinone showed a limited COX-2-specific inhibition. We conclude that dithymoquinone, thymohydroquinone, thymol and thymoquinone can participate in the general anti-inflammatory activity of N. sativa and suggest that these agents should be further studied for possible use as non-steroidal anti-inflammatory drugs.

Short-term anti-plaque effect of two chlorhexidine varnishes

BACKGROUND

Chlorhexidine (CHX) varnishes have been mainly used for the prevention of caries in high-risk populations. Reports regarding their anti-plaque effect on a clinical level are limited to non-existing as opposed to their microbiological impact on plaque formation.

AIM

The aim of this preliminary investigation was to evaluate the anti-plaque effect of two CHX varnishes applied on sound enamel in relation to a positive control, a negative control and to one another.

METHODS

Sixteen healthy subjects volunteered for this randomized-controlled, single-blind, four-treatment-four-period crossover-designed clinical trial. A 3-day plaque re-growth model was used to determine de novo plaque accumulation following CHX rinsing, Cervitec application, EC40 application and no therapy. The amount of plaque was measured using the Quigley and Hein plaque index and "automatic image analysis" (AIA).

RESULTS AND CONCLUSIONS

Varnish treatment resulted in significantly higher plaque levels than CHX rinsing irrespective of the varnish that was used (p< or =0.002), implying that the latter is likely to remain the gold standard as an anti-plaque agent. However, highly significant differences were also found in favour of both varnish systems when compared with no therapy (p<0.001), which indicates that varnish treatment is an effective means of inhibiting plaque formation in a short time span. Cervitec exhibited slightly, yet significantly, higher plaque levels in comparison with EC40 as determined by AIA (p=0.006). Large-scale trials with a longer observation period are necessary to substantiate these results.