Antibacterial and Antivirulence Effects of Kale (Brassica oleracea var. sabellica) on Streptococcus intermedius

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Original Article

Author Details : Chaiyakorn Songsangwattanakij, Kathawut Tachasuttirut, Surawut Pongsiriwet, Jitjiroj Ittichaicharoen, Sunee Chansakaow, Kittipong Laosuwan*

Volume : 10, Issue : 1, Year : 2024

Article Page : 36-42

https://doi.org/10.18231/j.jooo.2024.007

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Abstract

Background: Persistent odontogenic infections caused by resistant bacterial species, such as Streptococcus intermedius, have consistently been associated with deep-seated infections. This in vitro study aimed to evaluate the antibacterial and antivirulence effects of kale (Brassica oleracea var. sabellica) on S.intermedius.
Materials and Methods: S. intermedius was freshly incubated in tryptic soy broth media. Three experiments per concentration of kale were conducted under aseptic conditions (i.e., disc diffusion, broth microdilution, and reverse-transcription polymerase chain reaction) to evaluate the antibacterial and
antivirulence effects. The samples were then treated with 1000, 500, 250, 125, 65, 30, 15, 7, and 3 mg/mL kale; ampicillin (positive control); and tryptic soy broth (negative control). After 24-h incubation, the inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and relative gene expression of the virulence factor (intermedilysin [ily]) were measured. All assays were conducted in triplicate. The findings were reported and analyzed as means ± standard deviations. The agar disc diffusion and relative gene expression were statistically analyzed using one-way analysis of variance and Tukey’s test, with the significance level set at P < 0> Results: Kale showed antibacterial effects S. intermedius on by significantly inhibiting bacterial growth and reducing expression only at a concentration of 1000 mg/mL; it yielded an inhibition zone of 11.12 ± 1.59 mm, which was smaller than that with ampicillin. The MIC and MBC ranged from 15 to 65 mg/mL and from 500 mg/mL, respectively. Conversely, the highest concentration of kale yielded significantly less inhibition than did ampicillin.
Conclusions: The antibacterial effects of kale may be dose-dependent. Kale can inhibit bacterial growth and suppress ily expression under in vitro conditions of S. intermedius, which is mainly involved in deepseated odontogenic infections. The overall rate of survival and amount of residual bacteria increase with biofilm aging.
 

Keywords: Kale, Antibacterial, Antivirulence, Streptococcus intermedius, Odontogenic infections, Intermedilysin gene.

How to cite : Songsangwattanakij C, Tachasuttirut K, Pongsiriwet S, Ittichaicharoen J, Chansakaow S, Laosuwan K, Antibacterial and Antivirulence Effects of Kale (Brassica oleracea var. sabellica) on Streptococcus intermedius. J Oral Med Oral Surg Oral Pathol Oral Radiol 2024;10(1):36-42

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