In this study the leaf ethanol extract of Byrsonima sericea DC. (BSLE), known as
murici of the beach, and two diterpenes, barbatusin (BB) and 3β-hydroxy-3-
deoxobarbatusin, (OHBB), isolated from Plectranthus grandis, popularly called big
boldo, were evaluated in experimental models of gastric lesions induced by ethanol.
Dose of 500 and 1000 mg / kg, p.o. were not toxic. Dose of 1000 mg / kg of BSLE
reduced the intestinal transit compared with the control (atropine 1 mg / kg), showing an
anti effect. BSLE at doses of 125, 250, 500 and 1000 mg / kg, po significantly
attenuated the gastric lesions induced by ethanol in 58, 86, 80 and 90% respectively. In
the model of indomethacin, dose of 250, 500 and 1000 mg / kg, p.o. significantly
attenuated the gastric damage, inhibiting in 53, 51 and 53% respectively. BSLE (250
mg / kg) had a significant effect on gastric mucosal protective factors, the concentration
of the gastric mucous concentration of non-protein sulfhydryl groups (GSH), and the
levels of malonaldehyde, as well as the activity of enzymes, superoxide dismutase and
catalase. The characterization of the mechanism of action was taken through biological
tests in order to assess the action via the activation of nerve endings sensitive to
capsaicin, the role of nitric oxide and also the participation of potassium channels. The
pre-treatment with the TRPV1 receptor antagonist capsazepina, L-NAME and
glibenclamide was able to reverse the effect gastroprotetor of BSLE. The results of this
study indicate an action cytoprotectant gastroprotetor giving effect against gastric injury
induced by ethanol and indomethacin, demonstrating a possible participation of this
statement, the activation of TRPV1 receptor vanilloid, release of nitric oxide, opening
of potassium channels and sensitive to ATP action antioxidant. The analysis of BSLE
by high performance liquid chromatography revealed the presence of flavonoids rutin,
isoquercitrin, kaempferol-3-O-rutinoside and quercetin. Dose of 2.5, 5.0 and 10 mg / kg,
po, were used to assess OHBB and BB. OHBB (2.5, 5.0 and 10 mg / kg, po)
significantly attenuated the gastric lesions induced by ethanol (53, 55, and 96%
reduction) and BB only at doses of 5.0 and 10 mg / kg , (31, and 76% reduction),
respectively. OHBB (5 mg / kg) and BB (10 mg / kg) were able to significantly reduce
the depletion of GSH and increased levels of malonaldehyde. The pre-treatment
capsazepine, and L-NAME were not able to reverse the effect gastroprotective of
OHBB while the pre-treatment with glibenclamide gastroprotective reversed the effect
of OHBB front of lesions induced by ethanol. Additionally, the effect of BB was
significantly reduced in mice pre-treated with capsazepine and L-NAME. OHBB was
capable of causing depletion of catalase, while the administration of BB did not alter the
amount of this enzyme in stomach tissue. OHBB preserved the amount of the enzyme
superoxide dismutase and BB was able to increase the amount of the same fabric. The
results of this study indicate an action cytoprotectant of OHBB and BB gastroprotective
giving effect against gastric injury induced by ethanol. The diterpenes act by different
mechanisms, as shown in the results.
Keywords: Byrsonima sericea. Plectranthus grandis. Barbatusin. 3-β-hydroxy-3-
deoxibarbatusina. Gastroprotection. Flavonoids