Effects of Phellodendron Bark Extract Containing Toothpaste on Gingival Tissues

Objectives: Phellodendron bark extract (PBE), one of the herbal medicines, has been widely used as an anti-inflammatory agent for gastroenteritis, diarrhea, rheumatoid arthritis, etc. It has been also added to toothpastes for preventing periodontal disease due to its anti-inflammatory and antibacterial effects. Furthermore, since berberine, one of the main components of PBE, has been reported to have effects on osteoclast differentiation, it may be highly effective in preventing alveolar bone resorption associated with periodontal disease. However, the effects of PBE on osteoclastogenesis and its permeability upon toothpaste application have not been studied. In this study, we analyzed the effects of PBE-containing toothpaste on gingival tissues.
Methods: The effects of PBE on osteoclastogenesis were examined in mouse primary osteoclast precursor cells. The cells were cultured with α-MEM containing RANKL (100 ng/mL) and M-CSF (100 ng/mL) in the presence or absence of PBE (10 μg/mL). Osteoclasts were identified as TRAP positive cells with 3 or more nuclei. The PBE permeability to gingival tissues was evaluated by porcine lower jaws. A toothpaste containing 0.05% PBE was diluted 3 times with artificial saliva. The jaws were immersed in the toothpaste solution and incubated at 37C°. Gingival tissues were collected with biopsy trepans after 3 minutes, 1 and 6 hours. PBE permeability to gingival connective tissue were measured by berberine concentration.
Results: PBE significantly suppressed RANKL-induced osteoclast formation. In addition, porcine jaw model analysis showed that PBE penetrated into connective tissue after 3 minutes, 1 and 6 hours in a time-dependent manner and reached the effective concentration for inhibiting osteoclastogenesis after 6 hours.
Conclusions: It was suggested that PBE contained in toothpaste can penetrate into gingival connective tissues leading to osteoclastogenesis suppression. We suppose that these effects of PBE-containing toothpaste might lead to a new approach to prevent periodontal disease as daily care.