Comparison of Antimicrobial Activity of Commercially Available Herbal Toothpastes - An In Vitro Microbiological Study

Introduction

Oral health is a cornerstone of overall well-being, encompassing practices and habits that maintain the health of the mouth and its components, including teeth, gums and tongue.¹ A healthy smile contributes to social confidence and is also considered as an indicator of potential health issues.²

Toothpaste represents the most widely used form of dentifrice, serving to remove plaque, prevent dental caries, and maintain periodontal health.³ The shift from chemical based to herbal formulations reflects an increasing preference for natural alternatives in oral care.⁴ Consumers are increasingly drawn to herbal options, prioritizing ingredients like neem, clove, and aloe vera for their perceived benefits, such as antimicrobial properties and reduced environmental impact.⁵ This transition aligns with a broader trend towards embracing holistic and eco-friendly approaches to personal hygiene.

Comparison of the action of herbal toothpastes against various microorganisms in the oral cavity is crucial for several reasons. Firstly, it helps assess the effectiveness of herbal ingredients in combating oral bacteria, which plays a major role in sustaining a good oral hygiene and preventing dental issues. Additionally, such compari­sons contribute to scientific validation, establishing the credibility of herbal toothpaste formulations and en­couraging their adoption by consumers.⁶ Furthermore, understanding the antimicrobial properties allows for in­formed choices in oral care, especially for individuals seeking natural alternatives or those with specific dental health concerns. Comparative studies also aid in refining formulations, ensuring that herbal toothpastes meet or exceed the antimicrobial standards set by conventional counterparts. Overall, this comparison serves as a valu­able benchmark for the efficacy of herbal toothpastes in promoting oral health.⁷

Thus the current study aimed to evaluate and compare the antimicrobial activity of five commercially available herbal toothpastes (Dabur Red, Colgate Vedshakti, Meswak, Patanjali Dantkant and Vicco Vajradanti) at varying dilutions.

Materials and Methods

Methodology: An in vitro study employing a double-blind design.

Microorganisms

The pure cultures of Streptococcus mutans (MTCC 497) and Candida albicans (MTCC 183) were obtained from the Institute of Microbial Technology, Chandigarh, India. Escherichia coli was obtained from the microbiology department of A J Institute of Medical Sciences.

Candida albicans (MTCC 183) was cultured in yeast peptone dextrose broth (HiMedia Laboratories Pvt. Ltd.) at 37°C for 24 hours. Streptococcus mutans (MTCC 497) was cultured in brain-heart infusion broth (HiMedia Laboratories Pvt. Ltd.) for 48 hours at 37°C, and Escherichia coli was cultured in Luria-Bertani broth (HiMedia Laboratories Pvt. Ltd.) for 24 hours at 37°C.

Evaluation of the dentifrices

Based on a survey conducted among patients visiting A J Institute of Dental Sciences, five herbal toothpastes were chosen for the assessment of their microbicidal action. They were purchased from local markets in Mangalore, Karnataka, India. Each toothpaste was masked and assigned a code (A-E). The composition of the selected dentifrices is presented in Table 1.

Solutions of the selected dentifrices were prepared by blending the computed quantity of toothpastes (2.0 gm) in measured volume (2 mL) of sterile pyrogen-free distilled water, to obtain a dilution of 1:1. The solution thus made (1:1) was further serially diluted with sterile distilled water to prepare 1:2, 1:4, 1:8, and 1:16 dilutions.

Antimicrobial assay

The antimicrobial activity of the dentifrice dilutions was assessed using a modified agar well diffusion method. Briefly, agar plates were seeded with 0.2 mL of 24-h broth cultures of each isolate and allowed to dry for one hour. Wells of 8 mm diameter were prepared using a sterile cork-borer, with one central well and six peripheral wells equidistantly placed in each plate. Into the peripheral wells, 0.2 mL of dentifrice dilutions were dispensed, beginning with 1:2 in one plate, followed by 1:4, 1:8, and 1:16 in separate agar plates. Each plate contained samples A-E and a positive control (fluoridated toothpaste, coded as F) at the corresponding dilution. The central well was filled with 0.2 mL of sterile distilled water to serve as a negative control. Plates were incubated at 37°C for 24 hours, after which the anti-microbial activity was evaluated by measuring the diameter of the zones of inhibition. All experiments were performed in triplicate.

Results

Assessment of antimicrobial activity revealed that toothpaste formulations B and D exhibited greater efficacy compared to the other formulations tested. Formulation B demonstrated zones of inhibition against Candida albicans (up to 1:4 dilution), Streptococcus mutans (up to 1:2 dilution), and Escherichia coli (up to 1:4 dilution). Formulation D, although active only against Candida albicans (up to 1:2 dilution) and Streptococcus mutans (up to 1:2 dilution), produced the largest zones of inhibition among all formulations. The detailed results are presented in Table 2 and Figure 1.

Discussion

The current study aimed to assess and compare the antimicrobial action of five commercially available herbal toothpaste formulations against common oral pathogens, Candida albicans, Escherichia coli, and Streptococcus mutans. The selected formulations, sourced from diverse commercial brands, contained various herbal ingredients purported to have properties detrimental to these organisms.

The results revealed substantial differences in the antimicrobial effectiveness of the tested herbal toothpaste formulations. Certain formulations exhibited notable inhibition zones and reduced colony-forming units, indicating promising activity against the target microorganisms.

This investigation concluded that toothpaste formu­lations B and D exhibited better antimicrobial activi­ty compared to the other formulations tested. These findings provide valuable information for consumers, professionals pertaining to the stream of oral health, and the dental industry, regarding the relative efficacy of commercially available herbal toothpaste formula­tions. Understanding the diverse antimicrobial profiles and mechanisms of action may guide consumers make informed choices tailored to their oral health require­ments and preferences. Further research is warranted to investigate additional microbial strains, optimize formulations, and address safety considerations, to enhance the overall understanding and acceptance of herbal alternatives in oral care.

Conclusion

In conclusion, this study compared the antimicrobial activity of five herbal toothpaste formulations against Candida albans, Streptococcus mutans, and Escherichia coli at four dilutions (1:2, 1:4, 1:8, and 1:16). The findings highlight the potential benefits of herbal alternatives in promoting oral health and provide an insight into the effectiveness of these formulations in controlling specific microbial strains associated with oral and systemic conditions. These results may also assist consumers in selecting effective herbal toothpaste brands for maintaining oral hygiene.

Conflict of Interest

The authors declare no conflict of interest.

Acknowledgment

We thank Laxmi Memorial Education Trust®, A J Institute of Dental Sciences and A J Institute of Medical Sciences and Research centre for providing the facility and infrastructure to carry out the study.