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Year : 2015  |  Volume : 5  |  Issue : 3  |  Page : 182-186

Antibacterial efficacy of Melaleuca alternifolia (Tea tree oil), Curcuma longa (Turmeric), 2% chlorhexidine, and 5% sodium hypochlorite against Enterococcus faecalis: An in vitro study

1 Department of Conservative Dentistry and Endodontics, Moradabad, Uttar Pradesh, India
2 Department of General Pathology, Kothiwal Dental College and Research Centre, Moradabad, Uttar Pradesh, India

Date of Web Publication26-Aug-2015

Correspondence Address:
Agrima Vasudeva
Department of Conservative Dentistry and Endodontics, Kothiwal Dental College and Research Centre, Moradabad, Uttar Pradesh - 244 001
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Source of Support: Nil., Conflict of Interest: None

DOI: 10.4103/1658-5984.163623

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Aim: To evaluate and compare the antibacterial efficacy of Melaleuca alternifolia (tea tree oil), Curcumalonga (turmeric), 2% chlorhexidine (CHX), and 5% sodium hypochlorite (NaOCl) against Enterococcus faecalis.
Materials and Methods: Agar plates were prepared using tryptone soya agar. Cultures of E. faecalis were grown in tryptone soya broth. Agar well diffusion method was performed and the plates were incubated at 37΀C for 24 h. The zones of inhibition were recorded. The readings were subjected to statistical analysis using analysis of variance (ANOVA) and Tukey's post hoc test. P-value was considered significant at P < 0.05.
Results: Maximum antibacterial efficacy was exhibited by 2% CHX, followed by 5% NaOCl and C. longa with no statistically significant difference between them. It was followed by M. alternifolia (Tea tree oil). Ethanol and saline showed the least antibacterial action.
Conclusion: According to the results of this study, C. longa and M. alternifolia can be used as an alternative root canal irrigant, although long-term in vivo studies are warranted.

Keywords: Antibacterial efficacy, chlorhexidine, curcuma longa, enterococcus faecalis, sodium hypochlorite

How to cite this article:
Sinha DJ, Vasudeva A, Jaiswal N, Garg P, Tyagi SP, Singh J. Antibacterial efficacy of Melaleuca alternifolia (Tea tree oil), Curcuma longa (Turmeric), 2% chlorhexidine, and 5% sodium hypochlorite against Enterococcus faecalis: An in vitro study. Saudi Endod J 2015;5:182-6

How to cite this URL:
Sinha DJ, Vasudeva A, Jaiswal N, Garg P, Tyagi SP, Singh J. Antibacterial efficacy of Melaleuca alternifolia (Tea tree oil), Curcuma longa (Turmeric), 2% chlorhexidine, and 5% sodium hypochlorite against Enterococcus faecalis: An in vitro study. Saudi Endod J [serial online] 2015 [cited 2022 Oct 3];5:182-6. Available from: https://www.saudiendodj.com/text.asp?2015/5/3/182/163623

  Introduction Top

The ultimate goal of endodontic treatment is either to prevent the development of apical periodontitis or to create adequate conditions for periapical healing in presence of disease. Thus, the rationale of endodontic treatment is to eradicate the infection present and/or prevent the microorganisms from infecting or reinfecting the root canal system.[1]

Enterococcus faecalis is a gram positive facultative anaerobe. It is found in 4–40% of primary endodontic infections.[2] The frequency of E. faecalis found in persistent periradicular lesions has been shown to be much higher. In fact, failed root canal treatment cases are nine times more likely to contain E. faecalis than primary endodontic infections.[2] Studies have investigated its occurrence in root-filled teeth with the prevalence ranging from 24 to 77%.[3],[4] E. faecalis possesses high resistance and ability to inactivate antimicrobial agents, survival capacity in harsh environmental conditions with scarce nutrient supply and extreme alkaline pH, and has the capacity to grow as a biofilm on root canal walls.[5],[6]

Several irrigants are used during the root canal treatment to eliminate the microorganisms and to remove the pulp tissue. The use of conventional irrigants, especially sodium hypochlorite (NaOCl) is highly efficient in eliminating E. faecalis biofilm. But, the disadvantages of NaOCl is its tissue toxicity, unpleasant taste and odor, corrosion of instruments, inability to remove the smear layer,[7] reduction in the elastic modulus, and flexural strength of dentin.[8]

Chlorhexidine (CHX) has a broad spectrum of antimicrobial activity and demonstrates substantivity.[9] It counteracts the disadvantages of NaOCl, but its inability to dissolve the organic matter is a drawback. It may also discolor the teeth.[10]

In spite of significant development in the field of dentistry, there is no ideal root canal irrigant and the search for an alternative irrigant is ongoing. Due to the constant increase in the antibiotic resistant strains and the side effects caused by synthetic drugs, the trend has now shifted to the age old herbal products.[11] India is a country rich in medicinal plants. Studies have shown that herbal products have a promising role as root canal irrigants. The major advantages of herbal irrigants are safety, easy availability, increased shelf-life, cost effectiveness, and lack of microbial resistance so far.[12]

Melaleuca alternifolia (tea tree oil) is a native Australian plant with good antimicrobial properties. It also holds mild solvent action, and hence could hold potential applications in root canal treatment for dissolving the necrotic pulp tissue. Tea tree oil's major active component is terpinen-4-ol, which is responsible for its antibacterial and antifungal properties.[13]

Curcuma longa, commonly called as turmeric belongs to Zingiberaceae family. It is a native of southeast Asia and cultivated mainly in India. It has been shown to have a wide spectrum of actions like anti-inflammatory, antioxidant, antibacterial, antifungal, antiprotozoal, and antiviral activities. The main yellow bioactive component of C. longa is curcumin (diferuloylmethane). It is a natural polyphenolic flavonoid and a known cyclooxygenase-2 inhibitor.[13]

As there is no study reported till date comparing the antimicrobial efficacy of M. alternifolia and C. longa with NaOCl and CHX, this in vitro study was undertaken to evaluate the antibacterial efficacy of M. alternifolia (tea tree oil), C. longa (turmeric), 2% CHX, and 5% NaOCl against E. faecalis.

  Materials and Methods Top

Procurement of the microorganism

A pure culture of E. faecalis (ATCC 29212; HiMedia, Mumbai) was inoculated on Tryptone soya agar plates, incubated at 37°C overnight for 24 h

Preparation of extracts

The available form of M. alternifolia (RYM exports, Mumbai) was prepared to have miscibility in 85% (v/v) ethanol, to get a concentration of 2% by volume.[14]

Ethanolic extract of C. longa was prepared by adding 20 mg of C. longa powder (having more than 95%curcumin; RYM exports, Mumbai) in 1 ml of absolute ethanol.[15]

2%CHX solution was obtained from Basic Pharma, Gujarat

5% NaOCl (Prime Dental Limited) was used

Absolute ethanol and saline were taken as negative controls

The cultured E. faecalis was suspended in 5 ml tryptone soya broth (Hi Media, Mumbai) and incubated for 4 h at 37°C. The turbidity was adjusted to 0.5 Mac Farland standard and 50 μl of the inoculum was spread over petri plates with the help of L-arm loop

Antibacterial assay

Wells of 5 mm diameter were punched using a sterile cork borer and 50 μl of the irrigants were added to the wells with the help of a micropipette as follows:

  • Group A: 5% NaOCl
  • Group B: 2% CHX
  • Group C: M. alternifolia (tea tree oil)
  • Group D: C. longa (turmeric)
  • Group E: Absolute ethanol
  • Group F: Saline (negative control).

The plates were then incubated at 37°C for 24 h. After 24 h, the diameter of bacterial inhibition zones was recorded to the nearest size in millimeters using vernier calipers. The experiment was done four times and the mean values were calculated

Statistical analysis

The results were tabulated and statistically analyzed using one-way analysis of variance (ANOVA) followed by post-hoccomparison using Tukey&#39;s t-test. P < 0.05 was considered statistically significant

  Results Top

[Table 1] shows the mean zone of inhibition in millimeters. Well-defined zones were seen around all the groups taken, but no zone of inhibition was seen by ethanol and normal saline (negative control) [Figure 1]. There was significant difference between the different groups. The highest zone of inhibition against E. faecalis was seen by 2% CHX, followed by 5% NaOCl and C. longa which showed similar activity. M. alternifolia had the least activity followed by ethanol and saline, which did not show any statistically significant zones of inhibition
Figure 1: Zones of inhibition. C = 2% chlorhexidine, H = 5% sodium hypochlorite, T = Melaleuca Alternifolia, CL = Curcuma longa, E = ethanol, S = saline

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Table 1: Mean zones of inhibition (mm)

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Results can be condensed as:

2% CHX> 5% NaOCl = C. longa > M. alternifolia > absolute ethanol = saline

  Discussion Top

E. faecalis is the most commonly isolated microorganism from the root canals of failed endodontic cases. It possesses various virulence factors which enables it to survive and persist as a pathogen in the root canals. It can survive in the root canal as a single organism or as a major component of the flora. Hence, E. faecalis was chosen as the test organism for this study

Phytotherapeutics or ethnopharmacology is the preferred approach these days due to the harmful effects and safety concerns of the conventional therapy. The major advantages of herbal irrigants are safety, easy availability, increased shelf-life, cost effectiveness, and lack of microbial resistance so far.[12]

The agar diffusion method was used in the study for antimicrobial activity assessment. It is the most accepted method for antibacterial activity of various dental materials, medicaments, and root canal irrigants. The advantage of this method is that it allows direct comparison of the materials against the organisms, indicating the potential of the test materials to eliminate microorganisms in the local microenvironment of the root canal system. However, there are certain disadvantages of using this method, the most important being that the results may be variable depending upon the ability of the material to diffuse across the medium and not only on the toxicity of the material for the particular organism.[16] In this study, experiment was repeated four times according to a study by Balakrishnan et al.,[16] thereby making the results more reliable

CHX exhibited antibacterial efficacy in our study, which is in support of previously published studies

Onc¸ag˘ et al., (2003) evaluated the antibacterial properties of 5.25% NaOCl, 2% CHX,0.2% CHX, and 0.2% CHX plus 0.2% cetrimide; 2% CHX was more effective than 5.25% NaOCl against E. faecalis in both the conditions.[17]

Study by Vianna et al., in 2004 had investigated the ex vivo antimicrobial activity against endodontic pathogens of three concentrations (0.2, 1, and 2%) of two forms of CHX (geland liquid) and compared them with five concentrations of NaOCl. Both the 2% gel and 2% liquid formulations of CHX eliminated Staphylococcus aureus and Candida albicans within 15 s, whereas the gel formulation killed E. faecalis within 1 min.[18]

NaOCl was used in our study as it is considered to be the gold standard for irrigation. Results of the study showed that it had good antimicrobial action against E. faecalis, which is in support of the study by Arslan et al.[19]

Ethanolic extract of C. longa was taken in this study since curcumin, which is the active ingredient, is insoluble in aqueous media as stated in the study by Harit et al.[15] Our study has shown good antibacterial efficacy of C. longa against E. faecalis. The mechanism behind this could be bacterial cell perturbation.[20]

Neelakantan et al., found that curcumin had significant antibacterial activity against E. faecalis. They concluded that the antibacterial activity of curcumin was similar to NaOCl, which is in support of our study.[21]

However in a study by Suvarna et al., in 2014, ethanolic extract of turmeric did not show any antimicrobial activity against E. faecalis at various tested concentrations.[22] The results are in contradiction with our study, but the authors did not give any explanation for the nonefficacy of C. longa, even though this action was in contrast to various studies published stating that C. longa has good antibacterial action against E. faecalis

M. alternifolia (tea tree oil) causes lysis and the loss of membrane integrity and function by leakage of ions and the inhibition of respiration in microbes. Tea tree oil exhibits broad-spectrum antimicrobial activity which can be principally attributed to terpinen-4-ol.[13] Results of our study showed that tea tree oil exhibits good antibacterial efficacy, which is in support of the study by Kamath et al., in 2013.[14]

Absolute ethanol Extra has been striked through as C. longa was prepared using it as a solvent. The result of the present study showed that it did not exhibit significant antimicrobial efficacy against the tested microorganism, which was similar to the result obtained with saline taken as the negative control

  Conclusion Top

Under the limitations of this in vitro study, it can be concluded that 2% CHX showed the maximum antibacterial activity and herbal products demonstrated significant antibacterial activity against E. faecalis. C. longa and M. alternifolia can be employed as an alternative to NaOCl

Since herbal products are easily extracted and arecost effective, this study opens new avenues for use of herbal products as root canal irrigants. In future they can be explored further for other parameters such as toxicity, inhibition of biofilm formation before recommending their usage as root canal irrigants

Further preclinical and clinical trials are required to highlight the antimicrobial activity of many such herbal products available in nature and to promote the discovery of new natural compounds

  References Top

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Rôças IN, Siqueira JF Jr, Santos KR. Association of Enterococcus faecalis with different forms of periradicular diseases. J Endod 2004;30:315-20.  Back to cited text no. 2
Hancock HH 3rd, Sigurdsson A, Trope M, Moiseiwitsch J. Bacteria isolated after unsuccessful endodontic treatment in a North American population. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91:579-86.  Back to cited text no. 3
Garg P, Tyagi SP, Sinha DJ, Singh UP, Malik V, Maccune ER. Comparison of antimicrobial efficacy of propolis, Morindacitrifolia, Azadirachtaindica, triphala, green tea polyphenols and 5.25% sodium hypochlorite against Enterococcus faecalis biofilm. Saudi Endod J 2014;4:122-7.  Back to cited text no. 4
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Sedgley C, Nagel A, Dahlén G, Reit C, Molander A. Real-time quantitative polymerase chain reaction and culture analyses of Enterococcus faecalis in root canals. J Endod 2006;32:173-7.  Back to cited text no. 5
Martina LP, Ebenezar AV, Ghani MF, Narayanan A, Sundaram M, Mohan AG. An in vitro comparative antibacterial study of different concentrations of green tea extracts and 2% chlorhexidine on Enterococcus faecalis. Saudi Endod J 2013;3:120-4.  Back to cited text no. 6
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Vaghela DJ, Kandaswamy D, Venkateshbabu N, Jamini N, Arathi G. Disinfection of dentinal tubules with two different formulations of calcium hydroxide as compared to 2% chlorhexidine: As intracanal medicaments against Enterococcus faecalis and Candida albicans: An in vitro study. J Conserv Dent 2011;14:182-6.  Back to cited text no. 9
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Yamashita JC, Tanomaru Filho M, Leonardo MR, Rossi MA, Silva LA. Scanning electron microscope study of the cleaning ability of chlorhexidine as a root-canal irrigant. Int Endod J 2003;36:391-4.  Back to cited text no. 10
Prabhakar J, Senthilkumar M, Priya MS, Mahalakshmi K, Sehgal PK, Sukumaran VG. Evaluation of antimicrobial efficacy of herbal alternatives (Triphala and green tea polyphenols), MTAD, and 5% sodium hypochlorite against Enterococcus faecalis biofilm formed on tooth substrate: An in vitro study. J Endod 2010;36:83-6.  Back to cited text no. 11
Pratishta J, Ranjan M. Role of herbs in root canal irrigation-A review. IOSR J Pharm Biol Sci 2014;9:6-10.  Back to cited text no. 12
Neelakantan P, Jagannathan N, Nazar N. Ethnopharmacological approach in endodontic treatment: A focused review. Int J Drug Dev Res 2011;3:68-77.  Back to cited text no. 13
Kamath U, Sheth H, Ramesh S, Singla K. Comparison of the antibacterial efficacy of tea tree oil with 3% sodium hypochlorite and 2% chlorhexidine against E. faecalis: An in vitro study. J Contemp Dent 2013;3:117-20.  Back to cited text no. 14
Harit J, Barapatre A, Prajapati M, Aadil KR, Senapati S. Antimicrobial activity of rhizome of selected curcuma variety. Int J Life Sci Bt Pharm Res 2013;2:183-9.  Back to cited text no. 15
Balakrishnan R, Dhole TK, Dubey S, Boruah L, Langde SP. Comparative antimicrobial and antifungal efficacy of Bio-pure MTAD, Metapex and Aztreonam on Enterococcus faecalis and Candida albicans. ENDO 2013;47-51.  Back to cited text no. 16
Oncag˘ O, Hosgor M, Hilmioglu S, Zekioglu O, Eronat C, Burhanoglu D. Comparison of antibacterial and toxic effects of various root canal irrigants. Int Endod J 2003;36:423-32.  Back to cited text no. 17
Vianna ME, Gomes BP, Berber VB, Zaia AA, Ferraz CC, de Souza-Filho FJ. In vitro evaluation of the antimicrobial activity of chlorhexidine and sodium hypochlorite. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;97:79-84.  Back to cited text no. 18
Arslan S, Ozbilge H, Kaya EG, Er O.In vitro antimicrobial activity of propolis, BioPure MTAD, sodium hypochlorite, and chlorhexidine on Enterococcus faecalis and Candida albicans. Saudi Med J 2011;32:479-83.  Back to cited text no. 19
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Suvarna R, Bhat SS, Hegde KS. Antibacterial activity of turmeric against Enterococcus faecalis- An in vitro study. Int J Curr Microbiol App Sci 2014;3:498-504.  Back to cited text no. 22


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