Effects of extracts from Bacteroides gingivalis, Bacteroides intermedius, and Bacteroides asaccharolyticus on the growth of fibroblast lines obtained from healthy and inflamed human gingiva

Abstract

The effect of sonicates from Bacteroides gingivalis, Bacteroides intermedius, and Bacteroides asaccharolyticus on the uptake of (3H)‐thymidine by different gingival fibroblast cell lines was studied. Extracts from B. intermedius stimulated thymidine uptake by as much as 150% over that of controls. This effect varied according to both the fibroblast line and the concentration of the bacterial extract. B. asaccharolyticus extracts inhibited the thymidine uptake of all fibroblast cell lines at high concentrations, but in low doses the thymidine uptake was stimulated in some fibroblast lines by up to 200%. B. gingivalis extract caused a strong, dose‐dependent inhibition of thymidine uptake in all of the fibroblast lines tested. Low concentrations of B. gingivalis extract (10 μg protein/ml) inhibited DNA‐synthesis by 12‐60%, and high concentrations (100 μg protein/ml) by 70‐90%. The results suggest that the response of periodontal fibroblasts to oral Bacteroides varies considerably depending on the Bacteroides species, as well as on the individual characteristics of the cell lines being tested.