Green and efficient extraction of Aurantii Fructus Immaturus flavonoids by natural deep eutectic solvents: Component identification, extraction mechanism and biological activity

Dental caries is a global epidemic, but the next weapon against it might come from a Mediterranean herb—and the solvent used to extract it changes everything.

The fight against tooth decay is getting a green upgrade. Scientists tested extracts of Teucrium polium L., a plant from the Lamiaceae family, against seven bacteria that cause dental caries. They used three solvents—ethanol, hydroethanol, and water—at concentrations from 0.1 to 1000 ppm. The results were striking: the hydroethanolic extract hit Streptococcus mutans hardest, with a minimum inhibitory concentration (MIC) of just 1.24 mg/mL. The ethanolic extract proved most potent against S. sanguinis (MIC 1.55 mg/mL) and S. sobrinus (MIC 1.52 mg/mL). For S. salivarius, the hydromethanolic extract led at 1.52 mg/mL, while S. aureus fell to the ethanolic extract at 1.9 mg/mL. The aqueous extract was the best against S. epidermidis (MIC 2.03 mg/mL), and the ethanolic extract dominated L. fermentum at 1.36 mg/mL. Overall, the ethanolic extract showed the broadest efficacy, followed by the hydroethanolic version, while aqueous extracts lagged behind. This means solvent choice is a strategic decision—matching the right extract to the right bacterium maximizes the punch. The study also found that mouthwashes containing ethanolic and hydroethanolic extracts at 2.44 mg/L inhibited all tested oral bacteria. Future work should dive into the mechanisms of action and compare these extracts with conventional treatments, paving the way for innovative, plant-based dental therapies.

Key Points

• Hydroethanolic extract best against S. mutans (MIC 1.24 mg/mL).
• Ethanolic extract most effective overall across seven bacteria.
• Mouthwash at 2.44 mg/L inhibited all oral bacteria tested.