Green tea extract inhibits the onset of periodontal destruction in rat experimental periodontitis.

BACKGROUND AND OBJECTIVE: Green tea extract exerts a variety of biological effects, including anti-inflammatory activities. However, there has been no report on the effect of green tea extract on loss of attachment, which is an important characteristic of periodontitis. Here, we examined the inhibitory effects of green tea extract on the onset of periodontitis in a rat model. MATERIAL AND METHODS: Rats were immunized intraperitoneally with Escherichia coli lipopolysaccharide (LPS). The LPS group (n = 12) received a topical application of LPS onto the palatal gingival sulcus every 24 h. The green tea extract group (n = 12) received a topical application of LPS mixed with green tea extract, sunphenon BG, every 24 h. The phosphate-buffered saline (PBS) group (n = 6) received a topical application of PBS every 24 h. The levels of anti-LPS immunoglobulin G (IgG) in serum were determined using ELISA. Rats in the LPS and green tea extract groups were killed after the 10th and 20th applications. Rats in the PBS group were killed after the 20th application. Loss of attachment, level of alveolar bone and inflammatory cell infiltration were investigated histopathologically and histometrically. RANKL-positive cells and the formation of immune complexes were evaluated immunohistologically. RESULTS: There was no significant difference in the serum levels of anti-LPS IgG between the LPS group and the green tea extract group. In contrast, loss of attachment, level of alveolar bone, inflammatory cell infiltration and RANKL expression in the green tea extract group were significantly decreased compared with those in the LPS group. CONCLUSION: These findings demonstrate that green tea extract suppresses the onset of loss of attachment and alveolar bone resorption in a rat model of experimental periodontitis.

Serological survey of selected pathogens of free-ranging foxes in southern Argentina, 1998--2001.

A serological survey was conducted in the Patagonia region of Argentina to estimate the prevalence of nine disease agents within the populations of free-ranging culpeo (Dusicyon culpaeus) and grey (Dusicyon griseus) foxes. The disease agents were Aujeszky's disease virus (ADV), Brucella, canine adenovirus (CAV), canine distemper virus (CDV), canine parvovirus (CPV), Encephalitozoon cuniculi, Leptospira, Neospora caninum, and Toxoplasma gondii. A total of 84 foxes were sampled (28 culpeo and 56 grey), and 73% of the sera had antibodies against one or more pathogens. Among these seropositive sera, 47% of them reacted to only one antigen, while the other 53% reacted to multiple antigens. The presence of antibodies to Toxoplasma (20%), Neospora (44%), Leptospira (30%) and Brucella (18%) suggests that these organisms actively circulate in the area. Antibodies against CDV, CAV and CPV were detected in 2%, 5% and 5% of foxes, respectively. Regarding Encephalitozoon cuniculi and ADV, no evidence of either was found.