Cresol is a well-known
environmental pollutant,
toluene metabolite, uremic toxicant and accidental
poisoning product.
Formocresol, a preparation of
formalin and
cresol, is also used as a
root canal medicament and for
pulpotomy of primary teeth. However, little is known about its effect on cardiovascular system. In this study,
m-cresol inhibited the AA-induced platelet aggregation by 43-97% at concentrations ranging from 0.25 to 1 mM.
Collagen-induced platelet aggregation was also inhibited by 0.25-1 mM of
m-cresol by 47-98%. Accordingly,
o-cresol (0.1-0.5 mM) also inhibited the AA-induced platelet aggregation by 46-96% and the
collagen-induced platelet aggregation by 35-88% at concentrations of 0.1-1 mM. AA- and
collagen-induced platelet
thromboxane B(2) (TXB(2)) production was inhibited by even 0.1 mM of
m-cresol with 88 and 54% of inhibition, respectively. The
o-cresol (0.1 mM) also inhibited the AA- and
collagen-induced platelet TXB(2) production with 91 and 97% respectively. Although m- and
o-cresol (<1 mM) showed little effect on
thrombin-induced platelet aggregation, they effectively inhibited the
thrombin-induced platelet TXB(2) production. The
m-cresol (2 and 5 mM) inhibited the COX-1 activity by 55-99%, but showed little effect on COX-2
enzyme activity. Moreover,
o-cresol (0.5 and 1 mM) inhibited the COX-1 activity by 40-95%. COX-2
enzyme activity was inhibited by 68% at a concentration of 5 mM
o-cresol. These results indicate that acute
cresol-
poisoning, direct root canal medication with
formocresol or long-term occupational exposure to
cresol and
toluene may potentially suppress
blood clot formation and lead to tissue
hemorrhage via inhibition of platelet aggregation, TXB(2) production and COX
enzyme activity.