The anti-MMP activity of benzalkonium chloride.
OBJECTIVE
This study evaluated the ability of benzalkonium chloride (BAC) to bind to dentine and to inhibit soluble recombinant MMPs and bound dentine matrix metalloproteinases (MMPs).


METHODS
Dentine powder was prepared from extracted human molars. Half was left mineralized; the other half was completely demineralized. The binding of BAC to dentine powder was followed by measuring changes in the supernatant concentration using UV spectrometry. The inhibitory effects of BAC on rhMMP-2, -8 and -9 were followed using a commercially available in vitro proteolytic assay. Matrix-bound endogenous MMP-activity was evaluated in completely demineralized beams. Each beam was either dipped into BAC and then dropped into 1 mL of a complete medium (CM) or they were placed in 1 mL of CM containing BAC for 30 days. After 30 days, changes in the dry mass of the beams or in the hydroxyproline (HYP) content of hydrolysates of the media were quantitated as indirect measures of matrix collagen hydrolysis by MMPs.


RESULTS
Demineralized dentine powder took up 10-times more BAC than did mineralized powder. Water rinsing removed about 50% of the bound BAC, whilst rinsing with 0.5M NaCl removed more than 90% of the bound BAC. BAC concentrations 0.5wt% produced 100% inhibition of soluble recombinant MMP-2, -8 or -9, and inhibited matrix-bound MMPs between 55 and 66% when measured as mass loss or 76-81% when measured as solubilization of collagen peptide fragments.


CONCLUSIONS
BAC is effective at inhibiting both soluble recombinant MMPs and matrix-bound dentine MMPs in the absence of resins.
Department of Prosthodontics, School of Dentistry, University of Turku, Turku, Finland.
Arzu
A
Tezvergil-Mutluay
M Murat
MM
Mutluay
Li-Sha
LS
Gu
Kai
K
Zhang
Kelli A
KA
Agee
Ricardo M
RM
Carvalho
Adriana
A
Manso
Marcela
M
Carrilho
Franklin R
FR
Tay
Lorenzo
L
Breschi
Byoung-In
BI
Suh
David H
DH
Pashley
D000293:Adolescent; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001548:Benzalkonium Compounds / Q000494:pharmacology*; D002863:Chromogenic Compounds; D003094:Collagen / Q000032:analysis; D003804:Dentin / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D006909:Hydroxyproline / Q000032:analysis; D008422:Materials Testing; D020778:Matrix Metalloproteinase 2; D020784:Matrix Metalloproteinase 8; D061965:Matrix Metalloproteinase Inhibitors; D011485:Protein Binding; D011994:Recombinant Proteins; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors; D055815:Young Adult
D000891:Anti-Infective Agents, Local; D001548:Benzalkonium Compounds; D002863:Chromogenic Compounds; D061965:Matrix Metalloproteinase Inhibitors; D011994:Recombinant Proteins; D003094:Collagen; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; C488762:MMP8 protein, human; D020784:Matrix Metalloproteinase 8; D006909:Hydroxyproline