Abstract
BACKGROUND: Periodontitis is common in dogs. It is characterized by destruction of the supporting tissues of the teeth due to the host-immune response triggered by plaque. Magnoliae cortex and Zea mays L. extract showed anti-inflammatory and anti-microbial effects, respectively. This study aimed to evaluate improvement in periodontitis following the administration of Magnoliae cortex and Zea mays L. extract in dogs. Periodontitis was experimentally induced in 10 beagle dogs. Five dogs were administered 40 mg of Magnoliae cortex extract and 20 mg of Zea mays L. extract orally once per day for 2 months (MZ group), whereas the other group received empty gelatin capsules (control group). Periodontal clinical parameters, complete blood count, serum chemistry parameters, and tissue inflammatory cytokines and chemokine expression were assessed before and after combined oral extracts administration. RESULTS: The complete blood count and serum chemistry results of all dogs were within normal ranges. Gingival inflammation in MZ group was significantly better than that in the control group at 4 and 8 weeks post-medication (PM; p < 0.05). The periodontal pocket depth and clinical attachment loss at 8 weeks PM in the MZ group were significantly lower than the baseline values (p < 0.05). The incidence of bleeding on probing in the MZ group was significantly lower than that in the control group at 4 weeks PM (p < 0.05). Throughout the medication period, the percentages of CD4 + and CD8 + T cells were higher and lower, respectively, in the MZ group. However, these differences were only significant at 8 weeks PM. The expression of the inflammatory cytokines IL-1β, IL-6, IL-17, and TNF-α and the chemokine IL-8 in the inflamed tissues was lower in the MZ group, and the two groups showed a significant difference in TNF-α expression. CONCLUSIONS: Combined administration of Magnoliae cortex and Zea mays L. extract improved the clinical symptoms of periodontal disease in dogs. This beneficial effect may be partly due to the inhibitory effects of these extracts on the inflammatory response.