A comparative study of antibacterial and anti-inflammatory effects of mouthrinse containing tea tree oil

Exploring the antimicrobial efficacy of tea tree essential oil and chitosan against oral pathogens to overcome antimicrobial resistance

BACKGROUND

Considering that antimicrobial resistance among oral pathogens is a significant concern in dental practice, with broader implications for overall health due to the oral microbiota serving as a reservoir for antibiotic resistance genes (ARGs), research into natural products is crucial for addressing this issue.

OBJECTIVE

This study aimed to evaluate tea tree oil (TTO) and chitosan (CH) performance against oral pathogens, including mixed-species biofilm, and its effects on bacteria growth, in addition to chemical characterization and cytotoxicity of TTO.

METHODS

Tea Tree Oil and low molecular weight chitosan were used in this study. The chemical composition of TTO was analyzed using gas chromatography coupled with mass spectrometry (GC-MS). To evaluate TTO's antimicrobial properties, time-kill and cell viability assays were conducted. Additionally, minimum inhibitory concentration (MIC), minimum microbiocidal concentration (MMC), checkerboard, and biofilm assays were performed using TTO and CH alone and in combination.

RESULTS

TTO chromatography peaks found consistent with the standard ISO4730:2017 and literature. TTO and CH exhibited inhibitory activity against all tested microorganisms. The predominantly microbiostatic activity of TTO is probably related to terpinen-4-ol associated with terpinene. The oil at MIC value was able to delay the log phase of Aggregatibacter actinomycetemcomitans growth. Fibroblasts (L929) viability remained above 70 % during 24 h for TTO concentrations ranging from 0.5 to 0.0625 mg/ml. TTO-CH combination showed a synergistic activity (FIC = 0.5) against A. actinomycetemcomitans and Streptococcus sanguinis, at a concentration of 0,25MIC for both species. The compounds at MIC concentration inhibited both monospecies and mixed-species biofilms studied bacteria to the same extent as the azithromycin control.

CONCLUSION

TTO and CH demonstrated efficacy in combating oral pathogens and TTO-CH combination offers a promising approach to confront microbial resistance in the oral environment.

Hydrogel burn dressing effectiveness in burn pain

Severe burns are painful and dramatic injuries. Studies show that pain is underestimated and often not adequately treated. This study aims to evaluate the analgesic efficacy of hydrogel burn dressing and silver sulfadiazine, which are two agents commonly used in first-aid dressings for burn patients. This study, designed as a prospective, observational, and cross-sectional study. Study included 64 pediatric patients admitted to our burn center between 01.03.2020 and 01.09.2020 who were examined by our burn service after their first treatment in the emergency dressing room. Two groups of patients were included in the study. Pain level was assessed in the dressing room before and 10 min after the procedure using the Visual Analog Scale and FLACC (Face, Legs, Activity, Cry, Consolability) pain assessment scales.During the study period, Burnaid® was applied to 62.5% of patients (40 patients) and silver sulfadiazine to 37.5% (24 patients). In terms of pain scores, pre-dressing FLACC values were higher in Group B (p = 0.039); post-dressing VAS and FLACC values were significantly lower in group B (p 0.001; p 0.001). In terms of additional analgesia, we found more patients in Group S received analgesics (p 0.001).We believe that its effect on burn wound pain is superior to that of silver sulfadiazine.

Effects of adding tea tree oil on growth performance, immune function, and intestinal function of broilers

The aim of this study was to investigate the effects of adding tea tree oil (TTO) in the basal diet on growth performance, immune function, and intestinal function in broilers. This study utilized 1,650 one-day-old broilers with good health and similar body weight. Subjects were randomized into 5 groups with 6 replicates each: the control group (CON, basal diet), positive control group (PCG, basal diet + 100 mg/kg oregano oil in diet), low-dose TTO group (TTO-L, 50 mg/kg TTO added in the basal diet), medium-dose TTO group (TTO-M, 100 mg/kg TTO added in the basal diet), and high-dose TTO group (TTO-H, 200 mg/kg TTO added in the basal diet). The whole test period lasted 28 d. The results showed that the broilers fed with TTO supplemented diet had significantly higher body weight and average daily gain (ADG) (P = 0.013), and had a lower feed conversion ratio (F/G) (P = 0.010) throughout the trial period. The index of thymus in TTO-M increased significantly compared to CON (P = 0.015) on d 28. On d 14 and 28, C3, IFN-γ, TNF-α, and IL-2 levels in TTO-L serum were significantly increased (P < 0.001); the 3 test groups supplemented with TTO had significantly higher titers of avian influenza H9 subtype in their serum (P < 0.05). Tea tree oil supplement in the diet also had a positive and significant effect on the intestinal morphology of broilers throughout the experiment (P < 0.05). These results indicate that TTO has the ability to promote broiler growth, regulate immunity, and improve intestinal morphology. The proposed dosage of adding 50 mg/kg in broiler basal diets provides a theoretical basis for its subsequent use in livestock feeds.

Mouthwashes: Alternatives and Future Directions

This narrative review summarises "alternative" or "natural" over-the-counter (OTC) mouthwashes not covered elsewhere in this supplement and newly emerging products, as potential mouthwashes of the future. The "natural" mouthwashes reviewed include saltwater, baking soda, coconut oil, charcoal, propolis, seaweeds, and probiotics. Other than essential oils, it is apparent that their clinical effectiveness is still under debate, but there is some evidence to suggest that propolis reduces plaque and gingivitis. This review also covers the host immune response, via novel anti-inmmunomodulant mouthwashes, such as erythropoietin to reduce inflammation with oral mucositis (OM) after radiotherapy. The emerging concept of nanoparticle-containing mouthwashes, such as iron oxide, is further discussed for OM, this agent having the potential for more targeted delivery of chemical antimicrobials. Unfortunately, there are impacts on the environment of widening mouthwash use with more new products, including increased use of packaging, antimicrobial resistance, and possible detrimental effects on marine life. Further, there are roadblocks, relating to regularly approvals and side effects, that still need to be overcome for any OTC deivered immunomodulant or nanoformulation mouthwashes. Despite these caveats, there are many new mouthwashes under development, which could help manage major oral diseases such as caries, gingivitis, and periodontal disease.

Efficacy and safety of Melaleuca alternifolia (tea tree) oil for human health-A systematic review of randomized controlled trials

Introduction: Leaves of the Australian tea tree plant Melaleuca alternifolia were used traditionally by First Nations Australians for treating wounds, burns, and insect bites. Tea tree oil, the essential oil steam-distilled from M. alternifolia, is well-known for its medicinal properties, the evidence for most applications however is limited. This review aimed to critically appraise evidence from clinical trials examining the therapeutic efficacy and safety of tea tree oil on outcomes. Methods: Randomized controlled trials with participants of any age, gender, or health status, comparing tea tree oil to any control were included, without limit on publication date. Electronic databases were searched on 12 August 2022 with additional records sourced from article reference sections, reviews, and industry white papers. Risk of bias was assessed by two authors independently using the Cochrane risk-of-bias 1.0 tool. Results were summarized and synthesized thematically. Results: Forty-six articles were eligible from the following medical fields (Dentistry n = 18, Dermatology n = 9, Infectious disease n = 9, Ophthalmology n = 6, Podiatry n = 3; and Other n = 1). Results indicate that oral mouthwashes with 0.2%-0.5% tea tree oil may limit accumulation of dental plaque. Gels containing 5% tea tree oil applied directly to the periodontium may aid treatment of periodontitis as an adjunctive therapy to scaling and root planing. More evidence is needed to confirm the benefits of tea tree oil for reducing acne lesions and severity. Local anti-inflammatory effects on skin, if any, also require further elucidation. Topical tea tree oil regimens show similar efficacy to standard treatments for decolonizing the body from methicillin-resistant Staphylococcus aureus, although intra-nasal use of tea tree oil may cause irritation to mucous membranes. Tea tree oil with added iodine may provide an effective treatment for molluscum contagiosum lesions in young children. More evidence on efficacy of tea tree oil-based eyelid wipes for Demodex mite control are needed. Side effects were reported in 60% of included studies and were minor, except where tea tree oil was applied topically in concentrations ≥ 25%. Discussion: Overall, the quality of research was poor to modest and higher quality trials with larger samples and better reporting are required to substantiate potential therapeutic applications of tea tree oil. Systematic Review Registration: PROSPERO, identifier [CRD42021285168].

Tanshinone IIA loaded bioactive nanoemulsion for alleviation of lipopolysaccharide induced acute lung injury via inhibition of endothelial glycocalyx shedding

Acute lung injury (ALI) and its more serious form; acute respiratory distress syndrome are major causes of COVID-19 related mortality. Finding new therapeutic targets for ALI is thus of great interest. This work aimed to prepare a biocompatible nanoformulation for effective pulmonary delivery of the herbal drug; tanshinone-IIA (TSIIA) for ALI management. A nanoemulsion (NE) formulation based on bioactive natural ingredients; rhamnolipid biosurfactant and tea-tree oil, was developed using a simple ultrasonication technique, optimized by varying oil concentration and surfactant:oil ratio. The selected TSIIA-NE formulation showed 105.7 nm diameter and a PDI ∼ 0.3. EE exceeded 98 % with biphasic sustained drug release and good stability over 3-months. In-vivo efficacy was evaluated in lipopolysaccharide (LPS)-induced ALI model. TSIIA-NE (30 µg/kg) was administered once intratracheally 2 h after LPS instillation. Evaluation was performed 7days post-treatment. Pulmonary function assessment, inflammatory, oxidative stress and glycocalyx shedding markers analysis in addition to histopathological examination of lung tissue were performed. When compared to untreated rats, in-vivo efficacy study demonstrated 1.4 and 1.9-fold increases in tidal volume and minute respiratory volume, respectively, with 32 % drop in wet/dry lung weight ratio and improved levels of arterial blood gases. Lung histopathology and biochemical analysis of different biomarkers in tissue homogenate and bronchoalveolar lavage fluid indicated that treatment may ameliorate LPS-induced ALI symptoms thorough anti-oxidative, anti-inflammatory effects and inhibition of glycocalyx degradation. TSIIA-NE efficacy was superior to free medication and blank-NE. The enhanced efficacy of TSIIA bioactive nanoemulsion significantly suggests the pharmacotherapeutic potential of bioactive TSIIA-NE as a promising nanoplatform for ALI.

Reduced-Pressure Process for Fabricating Tea Tree Oil-Polyvinylpyrrolidone Electrospun Fibers

Electrospun fibers containing tea tree oil (TTO) can be explored for practical applications due to the antimicrobial and anti-inflammatory activities of TTO. Considering that there are potentially toxic components in TTO, it is necessary to eliminate or reduce its content in the preparation process of TTO-doped electrospun fibers. In this work, electrospun TTO-PVP (polyvinylpyrrolidone) fibers containing an 18.18 wt.% decreased content of 1,8-Cineole were successfully fabricated by intense evaporation of a self-made reduced-pressure electrospinning (RP-ES) setup (as low as 94.4 kPa). In addition, such intense evaporation led to a morphology change, where a typical average fiber diameter increased from 0.831 to 1.148 μm, fewer and smaller beads in fibers, along with a rougher and grooves fiber surface. These morphology changes allowed Terpinen-4-ol to remain in the fiber for a more extended period. In addition, RP-ES proved the possibility for intense evaporation and continuous vapor removal by continuously environmental vacuum pumping of electrospinning.

Efficacy of Melaleuca alternifolia and chlorhexidine mouth rinses in reducing oral malodor and Solobacterium moorei levels. A 1 week, randomized, double-blind, parallel study

OBJECTIVES

The objective is to evaluate the association of Solobacterium moorei (S. moorei) to halitosis and to also check for the effects of two different mouth rinses on levels of S. moorei in saliva and tongue coating and its impact on oral halitosis.

MATERIALS AND METHODS

This was a placebo-controlled parallel study of 160 individuals who were randomized and the study was performed using double-blinded protocol. Enrolled individuals filled a structured questionnaire regarding demographic data, oral hygiene habits, and dietary habits. Full mouth organoleptic odor scores (OLR), volatile sulfur compounds levels, Miyazaki's tongue coating index, and Plaque scores were recorded before intervention (baseline) and after 1-week post treatment. Microbiological samples obtained from the tongue and saliva was investigated for S. moorei levels using real time polymerase chain reaction. Participants were randomly assigned for two test mouth rinses (Melaleuca alternifolia and Chlorhexidine) and placebo groups.

RESULTS

All salivary and tongue coating samples were tested positive for S. moorei in the halitosis group. One week post-treatment S. moorei counts in saliva and tongue coating samples of test group showed a significant reduction at P < 0.001. Paired t-test results showed that Melaleuca alternifolia was comparable with chlorhexidine in reduction of OLR, and VSC scores (P < 0.001). Salivary levels of S. moorei in Melaleuca alternifolia group showed a higher reduction (5.67 log¹⁰ copies/mL) than chlorhexidine group (5.1log¹⁰ copies/mL).

CONCLUSION

S. moorei showed a positive correlation with oral halitosis scores. Both Melaleuca alternifolia and chlorhexidine were equally effective in reducing S. moorei levels and halitosis score.

Intrapocket application of tea tree oil gel in the treatment of stage 2 periodontitis

BACKGROUND

The gold standard in treatment of periodontitis is mechanical removing of dental biofilm but using local delivery drugs as adjunctive to SRP is widely used to modulate inflammatory host and eradicate microbes. Tea tree oil (TTO) has a broad-spectrum antimicrobial, anti-inflammatory, antifungal, antiviral, antioxidant effect. This study aimed to assess clinically and biochemically the effect of intrapocket application of TTO (Melaleuca alternifolia) gel adjunctive to scaling and root planing (SRP) in the treatment of stage 2 (moderate) periodontitis and to correlate the biochemical levels with clinical response.

METHODS

A randomized, controlled clinical trial was conducted on thirty patients with stage 2 periodontitis. Patients were equally divided into two groups: Control Group treated with (SRP) alone and Test Group treated with SRP and locally delivered 5% TTO gel. Clinical assessment included pocket probing depth (PPD), clinical attachment loss (CAL), gingival index (GI) and bleeding on probing (BOP) measured at baseline and after 3 and 6 months. The level of matrix metalloproteinase-8 (MMP-8), in the gingival crevicular fluid (GCF) was also assessed at baseline and after1, 3 and 6 months by Enzyme-linked immunosorbent assay (ELISA) kit. Chi-square, Student t- tests, Mann-Whitney U test and Spearman correlation were the statistical tests used in the study.

RESULTS

An improvement of all clinical and biochemical parameters was observed (at p < 0.001) in both groups. A significant difference between the two groups was found in both clinical and biochemical parameters.

CONCLUSION

The local delivery of TTO gel adjunctive to SRP proved to be effective in the treatment of stage II periodontitis. Trial registration The study was retrospectively registered at clinicaltrials.gov NCT04769271, on 24/2/2021.

Effect of essential oils on oral halitosis treatment: a review

Halitosis is a very common condition which may affect up to 30% of the population. In about 90% of the cases, halitosis originates in the mouth due to inadequate plaque control, periodontal disease, dry mouth, faulty restorations, and in particular due to excessive bacterial growth. Oral malodor is mainly caused by a microbial degradation of amino acids into volatile, bad-smelling gases (volatile sulfur compounds - VSCs). Management of oral malodor is directed primarily at managing and reducing the VSC-producing bacteria count as well as masking the odor. Essential oils have been used for this purpose in traditional medicine for centuries. In the present review, data on the antimicrobial activity of essential oils against relevant oral VSC-producing bacteria are compiled and compared. Additionally, other positive aspects of essential oils with regard to oral odor are considered.

Tea Tree Oil versus Chlorhexidine Mouthwash in Treatment of Gingivitis: A Pilot Randomized, Double Blinded Clinical Trial

Objective  The study evaluated the efficacy of tea tree oil for the treatment of gingivitis.

Materials and Methods  The tea tree oil was administered in the form of mouthwash and then compared with a mouthwash with chlorhexidine 0.12%. Both treatments were domestic and lasted for 14 days. Patients were chosen according to random criteria, aged between 18 and 60 years, and who showed a clinically evident gingivitis. In clinical evaluation, the following clinical criteria were taken into consideration: gingival index (GI), plaque index (PI), bleeding index (BI), probing depth (PD), the presence of dental dyschromia, and the presence of taste alteration. The subjects were evaluated before (T0) and after the treatment (T1), and the data collected for each patient were recorded on a periodontal chart.

Results  The comparison showed that tea tree oil offered a better improvement in the evaluation of PI, BOP, and PD; furthermore, it did not cause dental dyschromia and taste alteration. In group A, treated with tea tree oil, PI decreased from 53.25 to 5.50% and BI from 38.41 to 4.22%. In group B, treated with chlorhexidine PI decreased from 47.69 to 2.37% and BI from 32.93 to 6.28%. Instead, the subjects using chlorhexidine 0.12% blamed a distaste for the product that caused a slight taste alteration; 20% of them showed iatrogenic dental dyschromia.

Conclusions  The collected data showed the efficacy of both treatments. Although further research works will be necessary, this study showed that tea tree oil could be an effective nontoxic substitute for the therapy of gingivitis.

Essential oils as topical anti-infective agents: A systematic review and meta-analysis

OBJECTIVE

This study summarized evidence on the efficacy and safety of essential oils (EOs) in the treatment of topical infections.

DESIGN AND SETTING

Systematic review of clinical trials conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guideline. Electronic databases of the Cochrane, PubMed, EMBASE, Web of Science, and Scopus were searched from inception to November 2018.

INTERVENTION

Essential oil of any type, standard treatment and placebo.

MAIN OUTCOME MEASURES

Outcomes of the study include total acne count, acne severity index, reduction in total acne surface area, number of non-inflammatory acne lesions and inflammatory acne lesions, microbial cure rate, microbial decolonization rate, and new microbial emergence.

RESULTS

Non-significant but higher proportion of MRSA was cleared in EOs group (69% [95%CI: 34%, 96%]) compared to routine care (45% [95%CI: 36%, 53%]). Essential oils significantly lowered level of new MRSA emergence (9% [95% CI: 5%, 14%], I² = 86.59%) compared to routine care (53% [95%CI: 30%, 75%], I² = 86.59%). Four of the five studies on acne treatment showed equal or superior efficacy of EOs and the remaining one showed inferior efficacy to a control. In treatment of topical fungal infections, efficacy of essential oils were non-inferior compared to a standard treatment but superior to a placebo.

CONCLUSION

Essential oils could be considered as alternative treatment for acne, decolonization of MRSA, and topical fungal infections, yet the low quality and heterogeneity among the studies calls for further studies.

Improvement in ocular symptoms and signs in patients with Demodex anterior blepharitis using a novel terpinen-4-ol (2.5%) and hyaluronic acid (0.2%) cleansing wipe

Purpose: To evaluate the clinical improvement in ocular symptoms and signs in patients suffering from Demodex anterior blepharitis after using a novel cleansing wipe impregnated with 2.5% terpinen-4-ol and 0.2% hyaluronic acid.

Study design: This was an exploratory, multicenter, open, randomized, two-parallel group comparative study.

Methods: Forty-eight patients with Demodex anterior blepharitis were randomly assigned to apply the sterile wipe T1172 (Blephademodex^®), either once daily (n=24, Group 1) or twice daily (n=24, Group 2) for 29 days. Overall ocular discomfort and other individual symptoms were measured using a 0–10 numeric rating scale at Day 8 and Day 29. Ocular signs, including eyelid margin hyperemia and number of cylindrical dandruff, were examined at slit lamp. Overall treatment performance by investigator, patient satisfaction and tolerance were evaluated with questionnaires.

Results: Overall ocular discomfort was significantly reduced from baseline (p<0.0001) in both groups at Day 8 (−3.6±0.3 in Group 1 and −4.0±0.4 in Group 2) and Day 29 (−5.7±0.4 and −6.8±0.7, respectively), with no difference between groups (D8: p=0.718; D29: p=0.505). Each ocular symptom associated with Demodex blepharitis was improved in both groups. Eyelid margin hyperemia was significantly reduced at Day 8 (−0.7±0.7; p<0.001) and Day 29 (−1.1±0.7; p<0.0001) in Group 1. Similar results were observed in Group 2 (Day 8: p<0.001; Day 29: p<0.0001). Total disappearance of cylindrical dandruff was reported in 30.4% of patients in Group 1 and 43.5% in Group 2. Improvements in other ocular signs were observed in both groups. The product was well tolerated. All patients were satisfied or very satisfied and would continue using it.

Conclusion: Daily eyelid hygiene using this cleansing wipe impregnated with 2.5% terpinen-4-ol and 0.2% hyaluronic acid during a 4-week period led to a rapid and marked reduction in ocular symptoms and signs associated with Demodex anterior blepharitis and was well tolerated.

Essential Oils as Antimicrobial Agents-Myth or Real Alternative?

Herbs and the essential oils derived from them have been used from the beginning of human history for different purposes. Their beneficial properties have been applied to mask unpleasant odors, attract the attention of other people, add flavor and aroma properties to prepared dishes, perfumes, and cosmetics, etc. Herbs and essential oils (EOs) have also been used in medicine because of their biological properties, such as larvicidal action, analgesic and anti-inflammatory properties, antioxidant, fungicide, and antitumor activities, and many more. Many EOs exhibit antimicrobial properties, which is extremely important in fields of science and industry, such as medicine, agriculture, or cosmetology. Among the 250 EOs which are commercially available, about a dozen possess high antimicrobial potential. According to available papers and patents, EOs seem to be a potential alternative to synthetic compounds, especially because of the resistance that has been increasingly developed by pathogenic microorganisms. In this review we summarize the latest research studies about the most-active EOs that are known and used because of their antimicrobial properties. Finally, it is noteworthy that the antimicrobial activities of EOs are not preeminent for all strains. Further investigations should, thus, focus on targeting EOs and microorganisms.

The Antiplaque Efficacy of Two Herbal-Based Toothpastes: A Clinical Intervention

Aims

This study is the first of its kind in the United Arab Emirates, where these herbal plant extracts are commonly incorporated into toothpaste. The present study compares two herbal toothpastes (Meswak extract and tea tree oil [TTO]) and analyses their efficiency in reducing plaque accumulation.

Materials and Methods

A total of 25 patients were examined for plaque and assigned a plaque score. They were then randomly assigned to use either Meswak-based toothpaste or TTO-based toothpaste. After 24 h, a new plaque score was recorded, and the patients used their regular brand for 2 weeks. The patients were then instructed to use the second of the two study toothpastes for 24 h, and a third set of plaque scores was obtained. Statistical data were analyzed using the SPSS software with a significance of P < 0.05 and Kruskal-Wallis test.

Results

Analysis of plaque scores showed a reduction in plaque index after using either of the two herbal-based toothpastes; however, when compared with TTO, Meswak-based toothpaste resulted in significantly less plaque.

Conclusions

Brushing with Meswak-based toothpaste gave a significant drop in plaque score when compared with TTO-based paste.