Inhibitory activity of a green and black tea blend on Streptococcus mutans

Comparative Evaluation of the Antimicrobial Efficacy of Elettaria cardamomum (0.5%) Mouthwash, Camellia sinensis (0.5%) Mouthwash, and 0.12% Chlorhexidine Gluconate Mouthwash against Streptococcus mutans: An In Vitro Study

Aim

The in vitro study aimed to evaluate and compare the antimicrobial efficacy of Elettaria cardamomum (0.5%) mouthwash, Camellia sinensis (0.5%) mouthwash, and 0.12% chlorhexidine gluconate mouthwash against Streptococcus mutans.

Materials and methods

A total of 60 samples of the five mouthwash preparations were prepared to check for their antimicrobial efficacy. The zone of inhibition (ZOI) against S. mutans was measured as a diameter in mm, and the minimum inhibitory concentration (MIC) of mouthwash preparations was measured as μg/mL. All the groups were compared statistically using the Mann-Whitney U test and the Kruskal-Wallis test.

Results

The highest ZOI was observed in group V chlorhexidine gluconate [mean: 20.8, standard deviation (SD): 0.58], followed by group III C. sinensis (alcohol-free) (mean: 15.5, SD: 0.67), group IV C. sinensis (alcohol-based) (mean: 14.08, SD: 0.66), and group II E. cardamomum (alcohol-based) (mean: 13.2, SD: 0.45). The least ZOI was observed in group I E. cardamomum (alcohol-free) (mean: 10.7, SD: 0.45). This difference was statistically significant (p < 0.01). The MIC was similar in all the groups (p = 0.13).

Conclusion

Chlorhexidine gluconate 0.12% mouthwash showed the best antimicrobial action; however, C. sinensis mouthwash showed potential against S. mutans. E. cardamomum mouthwash exhibited limited antimicrobial activity.

How to cite this article

Deolikar S, Jawdekar A, Saraf T, et al. Comparative Evaluation of the Antimicrobial Efficacy of Elettaria cardamomum (0.5%) Mouthwash, Camellia sinensis (0.5%) Mouthwash, and 0.12% Chlorhexidine Gluconate Mouthwash against Streptococcus mutans: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(4):461-466.

Natural Inhibitors of Mammalian α-Amylases as Promising Drugs for the Treatment of Metabolic Diseases

α-Amylase is a generally acknowledged molecular target of a distinct class of antidiabetic drugs named α-glucosidase inhibitors. This class of medications is scarce and rather underutilized, and treatment with current commercial drugs is accompanied by unpleasant adverse effects. However, mammalian α-amylase inhibitors are abundant in nature and form an extensive pool of high-affinity ligands that are available for drug discovery. Individual compounds and natural extracts and preparations are promising therapeutic agents for conditions associated with impaired starch metabolism, e.g., diabetes mellitus, obesity, and other metabolic disorders. This review focuses on the structural diversity and action mechanisms of active natural products with inhibitory activity toward mammalian α-amylases, and emphasizes proteinaceous inhibitors as more effective compounds with significant potential for clinical use.

Antibacterial Effects of Steeped White Tea, Black Tea, and Green Tea against Streptococcus mutans and Plaque Accumulation

BACKGROUND: Tea is the most consumed beverage in the world after water. Tea (Camellia sinensis) is native to Southeast Asia and is now available in more than 30 countries. Tea has various health properties. Tea has an active component, namely catechins, which can inhibit the growth of Streptococcus mutans as a component of dental plaque formation. AIM: This study aims to determine the antibacterial effect of steeped white tea, black tea, and green tea on S. mutans and plaque accumulation. METHODS: The research used a quasi-experimental design with pre-test and post-test group design. The population was students of the Department of Dental Nursing. Purposive sampling technique is used with a sample size of 48 students who were divided into three parts of the sample group for the 2.5% concentration of tea mouthwash treatment. The analysis used paired t-test to see the antibacterial effect and differences in three-variable test followed by Kruskal–Wallis test. RESULTS: The results showed that the mouth rinses of steeped white tea, black tea, and green tea were effective in reducing S. mutans and plaque accumulation on teeth. There is a significant difference in the inhibition zone of S. mutans against the three types of tea, and white has the largest inhibition zone. As for plaque accumulation, there is no difference between the three types of tea. CONCLUSIONS: It can be concluded that mouth rinsing with steeping white tea, black tea, and green tea with a concentration of 2.5% has antibacterial properties that can inhibit S. mutans and plaque accumulation.

Interactions of dextransucrase purified from Streptococcus mutans 890 with plant polyphenols

Plant polyphenols have been extensively studied for their chemopreventive properties for human health. Dextransucrase plays an essential role in synthesizing exopolysaccharides from its exclusive substrate sucrose in Streptococcus mutans. In the present study, the effect of polyphenols gallic acid and tannic acid was investigated on the dextransucrase activity. The enzyme was purified by ethanol precipitation followed by column chromatography by Sephadex G-200 gel chromatography, followed by PEG-400 treatment. The purified enzyme exhibited 52 fold enrichment with 17.5% yield and specific activity of 3.54 Units/mg protein. On SDS-PAGE enzyme protein gave a single band with a molecular weight of 160 kDa. Dextransucrase activity was inhibited 80–90% by 0.04 mM tannic acid (TA) or 0.4 mM gallic acid (GA) suggesting that tannic acid has 10- fold more inhibitory potential than gallic acid on the activity of dextransucrase. CD/ORD studies revealed modifications in the tertiary structure of enzyme protein in presence of tannic acid and gallic acid, which were further confirmed by fluorescence spectra of the protein in presence of tannic acid. These results suggest that inhibition of dextransucrase activity in S. mutans by polyphenols may have potential applications in the prevention and control of dental caries.

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Dextransuccrase an important enzyme of S. mutans is involved in the metabolism of sucrose.

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Purified enzyme is inhibited (80-90%) by plant polyphenols. Observed inhibition is due to change in teritary structure.

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S. mutans is an important cariogenic agent.

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Plant polyphenols are good anticariogenic agents.

Tea extracts differentially inhibit Streptococcus mutans and Streptococcus sobrinus biofilm colonization depending on the steeping temperature

This study aimed to evaluate the effects of tea extracts on oral biofilm colonization depending on steeping temperature. S. mutans and S. sobrinus were cultured and treated with green or black tea extracts prepared under different steeping conditions. Biofilm formation, glucosyltransferase (GTF) levels, bacterial growth, and acidogenicity were evaluated. Biofilms were also assessed by gas chromatography-mass spectrometry and confocal laser scanning microscopy. All extracts with hot steeping showed higher inhibitory effects on biofilm formation and cell viability and lower GTF levels compared with those with cold steeping (p < 0.05). Hot steeping significantly reduced bacterial growth (p < 0.05) and maintained the pH. Catechins were only identified from hot steeping extracts. Within the limits of this study, extracts with cold steeping showed lower inhibitory effects on oral biofilms. The different effects between steeping extracts may be attributed to the difference in catechins released from tea extracts under the different steep conditions.

Health Functions and Related Molecular Mechanisms of Tea Components: An Update Review

Tea is widely consumed all over the world. Generally, tea is divided into six categories: White, green, yellow, oolong, black, and dark teas, based on the fermentation degree. Tea contains abundant phytochemicals, such as polyphenols, pigments, polysaccharides, alkaloids, free amino acids, and saponins. However, the bioavailability of tea phytochemicals is relatively low. Thus, some novel technologies like nanotechnology have been developed to improve the bioavailability of tea bioactive components and consequently enhance the bioactivity. So far, many studies have demonstrated that tea shows various health functions, such as antioxidant, anti-inflammatory, immuno-regulatory, anticancer, cardiovascular-protective, anti-diabetic, anti-obesity, and hepato-protective effects. Moreover, it is also considered that drinking tea is safe to humans, since reports about the severe adverse effects of tea consumption are rare. In order to provide a better understanding of tea and its health potential, this review summarizes and discusses recent literature on the bioactive components, bioavailability, health functions, and safety issues of tea, with special attention paid to the related molecular mechanisms of tea health functions.

Magnificamide, a β-Defensin-Like Peptide from the Mucus of the Sea Anemone Heteractis magnifica, Is a Strong Inhibitor of Mammalian α-Amylases

Sea anemones’ venom is rich in peptides acting on different biological targets, mainly on cytoplasmic membranes and ion channels. These animals are also a source of pancreatic α-amylase inhibitors, which have the ability to control the glucose level in the blood and can be used for the treatment of prediabetes and type 2 diabetes mellitus. Recently we have isolated and characterized magnificamide (44 aa, 4770 Da), the major α-amylase inhibitor of the sea anemone Heteractis magnifica mucus, which shares 84% sequence identity with helianthamide from Stichodactyla helianthus. Herein, we report some features in the action of a recombinant analog of magnificamide. The recombinant peptide inhibits porcine pancreatic and human saliva α-amylases with Ki’s equal to 0.17 ± 0.06 nM and 7.7 ± 1.5 nM, respectively, and does not show antimicrobial or channel modulating activities. We have concluded that the main function of magnificamide is the inhibition of α-amylases; therefore, its functionally active recombinant analog is a promising agent for further studies as a potential drug candidate for the treatment of the type 2 diabetes mellitus.

Theaflavin-3,3'-Digallate Suppresses Biofilm Formation, Acid Production, and Acid Tolerance in Streptococcus mutans by Targeting Virulence Factors

As one of the most important cariogenic pathogens, Streptococcus mutans has strong abilities to form biofilms, produce acid and tolerate acid. In present study, we found that theaflavin-3,3′-digallate (TF3) had an inhibitory effect on S. mutans UA159 in vitro. Visualized by field emission-scanning electron microscopy, the suppressed formation of S. mutans biofilms grown with TF3 at sub-inhibitory concentrations could be attributed to the reduced biofilm matrix, which was proven to contain glucans and extracellular DNA (eDNA). Glucan-reduced effect of TF3 was achieved by down-regulating expression levels of gtfB, gtfC, and gtfD encoding glucosyltransferases. Besides, TF3 reduced eDNA formation of S. mutans by negatively regulating lrgA, lrgB, and srtA, which govern cell autolysis and membrane vesicle components. Furthermore, TF3 also played vital roles in antagonizing preformed biofilms of S. mutans. Bactericidal effects of TF3 became significant when its concentrations increased more than twofold of minimum inhibitory concentration (MIC). Moreover, the capacities of S. mutans biofilms to produce acid and tolerate acid were significantly weakened by TF3 at MIC. Based on real-time PCR (RT-PCR) analysis, the mechanistic effects of TF3 were speculated to comprise the inhibition of enolase, lactate dehydrogenase, F-type ATPase and the agmatine deiminase system. Moreover, TF3 has been found to downregulate LytST, VicRK, and ComDE two component systems in S. mutans, which play critical roles in the regulatory network of virulence factors. Our present study found that TF3 could suppress the formation and cariogenic capacities of S. mutans biofilms, which will provide new strategies for anti-caries in the future.