Periodontal disease (PD) is one of the most prevalent and severe oral inflammatory conditions in dogs. PD’s cause is the microbial plaque of the smooth surfaces of the teeth and affects the tissues that support the teeth, leading to inflammation, destruction, and loss of tooth support.
PD encompasses a range of specific diagnoses, including gingivitis and periodontitis, with the term used to describe the presence of at least one of these conditions. Data show that PD affects between 44.0% and 63.6% of dogs. In efforts to prevent the disease, various pharmaceutical and herbal substances have been used to limit the growth of bacteria in dental plaque, typically in combination with mechanical removal through brushing. Luteolin, a plant compound belonging to the flavonoid family, has been isolated from various plants such as chamomile, celery, and artichoke. It demonstrates antioxidant, antimicrobial, anti-inflammatory, anti-allergic, and anti-cancer properties both in vitro and in vivo, primarily by suppressing the production of pro-inflammatory cytokines and mediators. The aim of the whole project was to develop a luteolin-based dental paste for the prevention and treatment of PD, based on luteolin’s antimicrobial activity and its lack of antimicrobial resistance. The aim of the animal study was to clinically evaluate the results of the luteolin based dental cream in reducing the accumulation of dental microbial plaque in Beagle dogs teeth. Six Beagle dogs underwent professional tooth scaling and polishing on day 0 of the experiment under general anesthesia. For one month after the procedure the dogs were fed with a commercial dry dog diet and a cream containing 20 ppm luteolin was applied once daily on their teeth. At the end of the one-month period, under general anesthesia, the dental microbial plaque was identified by two different non-toxic stains (FD&C blue #1 and D&C red #28, Young 2Tone, Young Dental Company) and the teeth were photographed. Then, professional scaling and polishing of the teeth was performed again. In the next phase of the experiment, while the dogs were fed with the same dry diet for one month, a cream containing only excipients (without luteolin) was applied daily to their teeth. After 30 days, again under general anaesthesia, the microbial plaque was identified using the same dye preparation and the teeth were photographed. The teeth evaluated during the study included: 104, 107, 108, 204, 207, 208, 304, 308, 308, 309, 404, 408 and 409. The plaque coverage area on the teeth was then evaluated using the program QuPath.

Statistical analysis using a t-test and the Wilcoxon test revealed a statistically significant difference between the two groups in terms of the reduction of dental plaque formation when luteolin dental cream was used compared to a cream containing only excipients. Therefore, the incorporation of luteolin into dental care products may represent a promising, natural approach for the prevention and management of periodontal disease in dogs. Further research could investigate the effect of luteolin on microbiological plaque deposition, with larger sample sizes, as well as the long-term effects.