Ameliorating Effects of Jixueteng in a Mouse Model of Porphyromonas gingivalis-Induced Periodontitis: Analysis Based on Gingival Microcirculatory System

Abstract

Jixueteng, the dried stem of Spatholobus suberectus Dunn (Leguminosae), is a traditional Chinese herbal medicine that promotes blood circulation and can be used to treat blood stasis. In this study, we aimed to investigate the potential of Jixueteng as a preventive and therapeutic drug for periodontitis. We investigated the inhibitory effects of Jixueteng on Porphyromonas gingivalis ( P. gingivalis)-induced gingival circulatory disturbances in mice. Seventy-two male C57BL/6N mice (4-week-old) were randomly divided into the following four groups of 12 mice each. Group 1 served as the P. gingivalis noninfected control (control group). Group 2 was administered Jixueteng extract in drinking water to P. gingivalis noninfected control mice. Group 3 was infected orally with P. gingivalis; and group 4 was administered Jixueteng extract in drinking water and then infected with P. gingivalis. To evaluate the effect of Jixueteng on gingival microcirculation systems, we examined gingival blood flow (GBF) in oral microcirculation in vivo in a mouse model of periodontitis. Gingival reactive hyperemia (GRH) was determined using laser Doppler flowmetry. GRH was elicited by the release of occlusive gingival compression by the laser Doppler probe (diameter 1.0 mm) for 1 min. GRH was estimated by basal blood flow, maximum response (Peak), the time taken for the maximum response to fall to one half (T1/2) and increased total amount of blood flow (Mass). Furthermore, to determine the effect of an oral application of P. gingivalis and/or Jixueteng on GBF and gingival microvessel ultrastructure, morphological analysis of gingival microvessels was performed by using a vascular resin cast model. Administration of Jixueteng to P. gingivalis-infected animals significantly reduced GRH, especially T1/2 and Mass, compared to that in P. gingivalis-infected animals. Alternatively, in the morphological analysis, reduction of the gingival capillary network which resulted from P. gingivalis-infection was improved by Jixueteng administration. Since Jixueteng ameliorates P. gingivalis infection-induced gingival circulatory disturbance, it may be useful in the treatment of P. gingivalis-induced periodontitis.