Endopleura uchi (Huber) Cuatrec. (Humiriaceae), a Brazilian Amazon plant,
commonly known as “uxi”, is used in folk medicine for the treatment of several
pathologies, such as arthritis. Bergenin, one of the chemical constituents of E. uchi,
has several biological activities, including anti-inflammatory and antinociceptive
activities. In order to obtain a more potent derivative than bergenin it has decided to
acetyl this substance. Acetylbergenin was tested in nociception and inflammation
models. Bergenin was isolated from the chromatographic fractionation of aqueous
extract from stem bark of E. uchi and the acetylbergenin was obtained by acetylation
of bergenin. The substances were identified based on spectral analysis of 1H NMR, 13C NMR, DEPT and COSY, and comparison with literature data. For nociception models were carried out the abdominal writhing test, hot plate test and formalin test, while in the inflammation models were carried out the croton oil-induced ear edema,
rat paw edema induced by carrageenan and dextran, carragenin-induced peritonitis
test. Furthermore, the model of gastric ulcer induced by stress was used to assess
the potential ulcerogenic of the substance. In the abdominal writhing test induced by
acetic acid 0.6%, acetilbergenin doses of 1, 5, 10, 15 and 25 mg / kg blocked the
number of writhing in 28.2%, 52.7%, 61.1 %, 68.3% and 95.0%, respectively, and
dose-dependent manner when compared to the control group. The calculated ED50
was 6.8mg/kg. In the hot plate test (55ºC), acetylbergenin (6.8 mg/kg) did not induce
alterations in the latency time when compared to the control group. In the formalin
test, acetylbergenin (6.8mg/kg) inhibited 88.30% the algic stimulus in the second
phase (inflammatory) compared to the control group. Furthermore, naloxone
reversed the effect of acetylbergenin the second phase of this test. In the croton oilinduced
dermatitis, acetylbergenin (6.8 mg/kg) provoked inhibitory effect in 75.60% in
comparison to the control group. In the paw edema induced by carrageenan,
acetylbergenin (6.8 mg/kg) was able to reduce the development of edema from the
2nd to the 5th hours compared to the control group. In the paw edema induced by
dextran, acetylbergenin (6.8 mg/kg) reduced edema at all times. In carragenininduced
peritonitis, acetylbergenin (6.8mg/kg) blocked 70% of the neutrophils
number compared to the control group. In the trial of gastric ulcer, acetylbergenin
blocked 78.55% in the generation of gastric lesions by stress when compared to
indomethacin. The results suggest that acetylbergenin has an antinociceptive and
anti-inflammatory activity which, according to the tests employed, is probably of
peripheral origin.
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