Medicinal value of Lippia multiflora Mondenke flowers in the fight of oral and dental infections

Oral infections pose a significant global health issue. This study assessed the antibacterial properties of methanol and dichloromethane extracts from Lippia multiflora flowers against Staphylococcus aureus ATCC 43300 and Streptococcus mutans ATCC 2517, two bacteria known to cause oral infections. The study measured the ability of these flower extracts to inhibit the growth and biofilm formation of S. aureus and S. mutans using micro-dilution and crystal violet methods, respectively. Additionally, we analyzed the presence of secondary metabolites in the extracts both qualitatively and quantitatively. The antioxidant properties of the extracts were evaluated using DPPH, ABTS, and FRAP methods. The results indicated that the dichloromethane extract demonstrated a more substantial bactericidal effect than the methanolic extract against S. mutans and S. aureus, with minimal bactericidal concentrations of 0.25 ± 0.02 mg/mL and 3.13 ± 0.30 mg/mL, respectively. Furthermore, the dichloromethane extract at a 100 µg/mL concentration exhibited the highest anti-biofilm activity against both S. aureus and S. mutans. Phytochemical screening revealed the presence of alkaloids, flavonoids, quinones, and tannins in both extracts. The total phenolic content was higher in the methanolic extract (49.57 ± 2.74 mg EAG/100 mg) compared to the dichloromethane extract (25.71 ± 0.39 mg EAG/100 mg). Similarly, the total flavonoid content was more significant in the methanolic extract (2.87 ± 0.049 mg EQ/100 mg) than in the dichloromethane extract (2.24 ± 0.02 mg EQ/100 mg). The methanolic extract also exhibited superior anti-DPPH and anti-ABTS activities, as well as a higher Fe (III) reduction potential than the dichloromethane extract (P < 0.05). These findings suggest that L. multiflora flowers could serve as a potential source of antimicrobial agents for combating oral infections.