Sodium fluoride inhibits MMP-2 and MMP-9

The importance of fluoride (f) in preventing dental caries by favorably interfering in the demineralization-remineralization processes is well-established,but its ability to inhibit matrix metalloproteinases (mmps),which could also help to prevent dentin caries,has not been investigated. this study assessed the ability of f to inhibit salivary and purified human gelatinases mmps-2 and -9. saliva was collected from 10 healthy individuals. pooled saliva was centrifuged,and supernatants were incubated for 1 hr at 37 c and subjected to zymography. sodium fluoride (50-275 ppm f) was added to the incubation buffer. the reversibility of the inhibition of mmps-2 and -9 by naf was tested by the addition of naf (250-5,000 ppm f) to the incubation buffer,after which an additional incubation was performed in the absence of f. f decreased the activities of pro- and active forms of salivary and purified human mmps in a dose-response manner. purified gelatinases were completely inhibited by 200 ppm f (ic50 = 100 and 75 ppm f for mmps-2 and -9,respectively),and salivary mmp-9 by 275 ppm f (ic50 = 200 ppm f). inhibition was partially reversible at 250-1,500 ppm f,but was irreversible at 5,000 ppm f. this is the first study to describe the ability of naf to inhibit mmps completely. © international & american associations for dental research.