Inhibitory Effects of Oenothera biennis (Evening Primrose) Seed Extract on Streptococcus mutans and S. mutans-Induced Dental Caries in Rats

Abstract

Background: Oenothera biennis (evening primrose) seed extract (OBSE) is known to contain polyphenols, which may possess antioxidant activities. Polyphenols extracted from several plants are reported to exhibit cariostatic activities by inhibiting mutans streptococcus growth and glucosyltransferase activities. The purpose of the present study was to examine the inhibitory effects of OBSE on the development of dental caries, both in vitro and in vivo. Methods: OBSE was investigated for its inhibitory effects on cellular aggregation, hydrophobicity, sucrose-dependent adherence and insoluble glucan synthesis. Furthermore, biofilm formation was examined in the presence of OBSE, using confocal microscopic imaging. An animal experiment was also performed to examine the in vivo effects. Results: OBSE induced a strong aggregation of Streptococcus mutans MT8148 cells, while cell surface hydrophobicity was decreased by approximately 90% at a concentration of 0.25 mg/ml. The sucrose-dependent adherence of the MT8148 cells was also reduced by addition of OBSE, with a reduction rate of 73% seen at a concentration of 1.00 mg/ml. Additionally, confocal microscopic observations revealed the biofilm development phase to be remarkably changed in the presence of OBSE. Furthermore, insoluble glucan synthesis was significantly reduced when OBSE was present at concentrations greater than 0.03 mg/ml. In an animal experiment, the caries scores in rats given OBSE (0.05 mg/ml in drinking water) were significantly lower than those in rats given water without OBSE. Conclusion: Our results indicate that OBSE has inhibitory activity on dental caries.

Binding Forces of Streptococcus mutans P1 Adhesin

“…Patients with high dental caries scores demonstrated a higher prevalence of hydrophobic bacteria than low caries patients. 66 In addition, compounds that diminish the surface hydrophobicity of S. mutans are now being reported to inhibit bacterial adherence in vitro 67–69 and cariogenicity in an animal model. 67 …”

Dental Caries

“…Polymeric polyphenols are synthesized from monomeric polyphenols (the main components of green tea polyphenols) by partial fermentation due to oxidases/peroxidases present in the leaves (Hamada et al, 1996). Also, some other plants, such as the cacao bean, the main constituent of chocolate, and Oenothera biennis (evening primrose) seed extracts contain some polyphenols that have been demonstrated to exhibit anti-GTF activities and inhibit caries induced in specific-pathogen-free rats infected with S. mutans MT8148R (Ooshima et al, 2000;Matsumoto-Nakano et al, 2011).…”

Ganzheitsmedizinische Behandlungsmöglichkeiten zur Förderung der Mundgesundheit und bei Erkrankungen im Mund – Teil 1

“…Ein Extrakt aus den Samen der Nachtkerze hemmte bei Ratten die experimentell mit S. mutans induzierte Karies [18].…”