Abstract
Ashitaba (Angelica keiskei) is a perennial herb native to Japan, traditionally consumed as a health-promoting food and herbal medicine. This study evaluated the antimicrobial, anti-halitosis, and anti-inflammatory effects of Ashitaba extract on canine periodontal disease (PD) caused by Porphyromonas gulae (P. gulae). In vitro, Ashitaba extract (0.006-0.1%) significantly inhibited P. gulae viability by up to 80% and reduced biofilm formation by approximately 10% at 0.1%. The extract also suppressed the production of volatile sulfur compounds-hydrogen sulfide and methyl mercaptan-by over 80% and 40%, respectively, within 10 min. Furthermore, Ashitaba extract markedly decreased P. gulae-induced pro-inflammatory cytokine secretion (IL-1β, IL-6, TNF-α) by up to 90% in murine, canine, and human macrophage and gingival cell lines. In vivo, daily oral application of 0.05% Ashitaba-extract gel for four weeks, with or without tooth brushing, significantly improved gingivitis scores (by 40-60%), reduced halitosis levels, and decreased P. gulae DNA detection and enzymatic activity in dogs with PD. These findings demonstrate that Ashitaba extract possesses potent bactericidal, anti-halitosis, and anti-inflammatory properties, supporting its potential as a natural adjunctive therapy for the prevention and management of canine periodontal disease.