OBJECTIVETo explore the mechanism of injurious effect of succinic acid on human fibroblast and it's role in bacteroides fragilis infection.

METHODSIn vitro cultured human fibroblasts were challenged by succinic acid in concentrations of 5, 10, 20 and 30 mmol/L (pH5.5), respectively. The cellular activity, apoptosis rate, the collagen synthesis in the supernatant of the cell culture, and the activity of caspase-3 were determined 24 hours after challenge. Isotonic saline challenged fibroblast were employed as control and the changes in the indices before and after succinic acid challenge were observed.

RESULTSAlong with the increase in the concentration of succinic acid, the fibroblast proliferation rate was decreased and so was the collagen synthesis. But the apoptosis rate and caspase-3 activity were increased. The activity of caspase-3 was markedly higher than that in normal control when the succinic acid concentration was 10-30 mmol/L. The cellular activity and collagen synthesis were significantly lower and the apoptosis rate was obviously higher than those in control group when the succinic acid concentration was 20 or 30 mmol/L (P < 0.05).

CONCLUSIONThe proliferation and collagen synthesis in fibroblast culture could be significantly inhibited and the cellular apoptosis could be promoted by succinic acid. The process of wound healing of the wounds infected by bacteroides fragilis would be delayed due to the production of succinic acid by the bacteria.