Possible involvement of nitric oxide in estrogen-induced uterine edema in the immature rat

We examined whether nitric oxide mediates estrogen-induced uterine edema in the immature rat. Immature Wistar rats (19-21 days) received estradiol-17 beta (E2) in a single sc dose of 10 micrograms/animal and 6 h later the animals were sacrificed and the changes in uterine wet and dry weights were determined. E2 treatment caused a 93 per cent increase in uterine wet weight (control, N = 6, 39.88 +/- 3.2 mg; E2 treated, N = 6, 76.8 +/- 4.9 mg), but not in dry weight, suggesting that it induces uterine edema. Pretreatment with L-nitroarginine methyl ester (L-NAME), a competitive antagonist of nitric oxide synthetase, at doses of 10 and 20 mg/kg, ip, caused a dose-related reduction (59 and 86 per cent ) in the uterine wet weight increase induced by E2. Furthermore, L-arginine (300-600 mg/kg, sc), the nitric oxide precursor, was able to reverse L-NAME (20 mg/kg)-induced decreases in uterine weight by 47 and 62 per cent , respectively. The results suggest that nitric oxide is the principal mediator involved in estrogen-induced uterine edema in the immature rat

Involvement of PAF-acether and eicosanoids in adrenaline-induced pulmonary edema in mice

The participation of platelet-activating factor (PAF,PAF-acether) in a mouse model of pulmonary edema was studied using specific antagonists.Mice were treated before induction of edema with the PAF antagonists BN52021 (10mg/kg, ip), PCA 4248 (10 mg/kg, po) or WEB2170 (10mg/kg, ip),the lipoxygenase inhibitor EP10161 (10 mg/kg,ip),the cyclo-oxygenase inhibitor aspirin (250 mg/kg,po), or with the mixed cyclo-lipoxygenase inhibitor BW755C(50 mg/kg, ip).The test drugs were administered to animals either 30 min (When the ip route was used) or 60 min (when given po) prior to the induction of pulmonary edema.Pulmonary edema was induced by intravenous administration of adrenaline (2 mg/kg). When the lung-body index was usedas thecriterion for comparision between groups,BN52021, PCA4248 and WEB2170 were found to have no significant effect on pulmonary edema. In contrast, EP10161, aspirinand BW755C significantly inhibited pulmonary edemaby 49%,30% and 27%,respectively. The results suggest that arachidonate metabolites are likely to play a major roe in adrenaline-induced pulmonary edema in mice, whereas PAF-acether does not seem to play an important role in this model

Evaluation of the purified fraction of Wilbrandia (c. f. ) verticillata for antitumour activity

Cucurbatacins are known to produce cytotoxic and anticancer activities. Two novel norcucurbitacin glucosides (Wvl and Wv2) have recently been isolated from a purified fraction obtained from the rhizome of Wilbrandia verticillata. The present study evaluates the cytotoxic and anti-tumour activities of the norcucurbitacins. We have found a regular cytotoxicity in KB cells (Cy50 = 12µg/ml) as well as a significant inhibition in the Walker 256 carcinosarcoma growth (approximately 75%).

Inhibition of formaldehyde-induced arthritis by a purified fraction prepared from Wilbrandia (cf) verticillata which contains novel norcucurbitacin glucosides

The anti-inflammatory activity of a purified fraction of the rhizome of Wilbrandia (cf) verticillata, which contains two novel norcucurbitacin glucosides, is reported. The increase of vascular permeability induced by acetic acid in mice (N = 5) was inhibited 69% and 90% by 50 and 100 mg/kg of the purified fraction, po (P<0.01). Acetylsalicylic acid (200 mg/kg), po, inhibited the response by 62% under the same conditions (P<0.05). The purified fraction (100 mg/kg, po) also significantly inhibited paw swelling in the rat formaldehyde-induced arthritis model on 8 of 10 days and reduced the swelling by 63% on day 10. Dexamethasone (1 mg/kg, ip) was more effective than the extract under the same conditions. These data partially characterize the anti-inflammatory activity of the purified fraction from this plant which is used in Brazilian folk medicine for the treatment of arthritis and related disorders