ROLE OF PGE2 IN THE (-)-MENTHOL GASTROPROTECTIVE ACTIVITY
Rozza, A.L., de-Faria, F.M., Souza-Brito, A.R.M. and Pellizzon, C.H.
Morphology Department, UNESP Botucatu/SP Brazil
Abstract:
(-)-Menthol (ME) demonstrated significant gastroprotective properties in our previous studies. The present study aimedto evaluate if the gastroprotection conferred by ME is related to PGE2, which can activate K+ATP channels, inhibiting
neutrophil activation and myeloperoxidase (MPO) production. Wistar rats (n=7) were orally treated with vehicle or ME
50 mg/kg and submitted or not to treatment with indomethacin (30 mg/kg s.c), PGE2 in the stomach mucosa was
measured by ELISA. The involvement of K+ATP channels in gastroprotection was determined by administration of the
antagonist glibenclamide (3 mg/kg i.p) before the oral treatments administration (vehicle or ME 50 mg/kg). The ulcer
area was measured and samples of these stomachs were destined to MPO measurement by ELISA and to confection of
histological slides to neutrophil counting. Unpaired t test, p<0.01. ME maintained high PGE2 level, even with
indomethacin administration. The gastroprotective effect of ME was reversed when the K+ATP channels were blocked.
The level of MPO and the neutrophils counting were decreased in the ME treated group. The gastroprotective effect of
ME is related to the maintenance of PGE2 levels, subsequent activation of K+ATP channels and inhibiting of neutrophil
recruitment and MPO releasing.