Gastroprotective Effect of Geopropolis from Melipona scutellaris Is Dependent on Production of Nitric Oxide and Prostaglandin.

The aim of this study was to evaluate the gastroprotective activity of ethanolic extract of geopropolis (EEGP) from Melipona scutellaris and to investigate the possible mechanisms of action. The gastroprotective activity of the EEGP was evaluated using model ulcer induced by ethanol. To elucidate the possible mechanisms of action, we investigated the involvement of the nonprotein sulfhydryl (NP-SH) groups, nitric oxide and prostaglandins. In addition, the antisecretory activity of EEGP was also evaluated by pylorus ligated model. The EEGP orally administrated (300 mg/kg) reduced the ulcerative lesions induced by the ethanol (P < 0.05). Regarding the mechanism of action, the prior administration of nitric oxide and prostaglandins antagonists suppressed the activity of gastroprotective EEGP (P < 0.05). On the other hand the gastroprotective activity of EEGP was kept in the group pretreated with the antagonist of the NP-SH groups; furthermore the antisecretory activity was not significant (P > 0.05). These results support the alternative medicine use of geopropolis as gastroprotective and the activities observed show to be related to nitric oxide and prostaglandins production.

Omeprazole and misoprostol for preventing gastric mucosa effects caused by indomethacin and celecoxib in rats.

PURPOSE: To evaluate and to compare macro and microscopically the intense injuries of the gastric mucosa of rats which were caused by NSAIDS celecoxib and indomethacin and the gastric cytoprotection with omeprazole and misoprostol. METHODS: The sample is formed by one hundred and fifty Wistar rats with average weight 200 g, distributed in four groups, such as: Group A, subdivided in groups A1 and A2--pre-treatment with omeprazole (20 mg/rat) during seven days and on the 8th day--use of NSAIDS, concerning A1 (20 rats) were given celecoxib (1mg/rat) and A2 (20 rats) were given indomethacin. The Group B, subdivided in group B1 and B2--pre-treatment with misoprostol (20mg/rat) during seven days and on the 8th day use of NSAIDS, concerning B1 (20 rats) were given celecoxib (1 mg/ rat) and B2 (20 rats) were given indomethacin (12.5 mg/rat). The Group C: were not given cytoprotection during seven days, from the 7th to the 8th day--fast of food and water ad libitum, on the 8th day of NSAIDS use, concerning C1 (20 rats) were given celecoxib, C2 (20 rats) were given indomethacin (12.5 mg/ rat), C3 (20 rats) were given celecoxib (200mg/rato), and Group D--control group, concerning 10 rats were observed during seven days ingesting food and water ad libitum. On the 9th day, the stomachs were taken out and were macro and microscopically evaluated for the identification of the gastric injuries. RESULTS: On the macroscopic studies, the groups A2, B2 and C2 presented a remarkable high number of injuries for cm2/animal, respectively 18.55 injuries for cm2/animal, 16.25 injuries for cm2/animal and 13.55 injuries for cm2/animal. On the microscopic studies, the percentage of the injured mucosa, presented expressive difference among the groups A1, B1, C1 when compared to the groups A2, B2, C2 (p<0.0001). The average of the length/injury and the average of the depth of the injuries did not present expressive statistics differences among the groups A2, B2 and C2. The average of the edema presented expressive statistics difference among the groups A2 and D; B2 and C2 and between C2 and D (p < 0.05). CONCLUSIONS: The indomethacin on the applied concentration causes a great number of macroscopic and microscopic injuries to gastric mucosa of rats when compared to celecoxib which does not cause lesions. Omeprazole and misoprostol on the applied concentrations do not present macroscopic and microscopic effectiveness on the gastric cytoprotection when applying indomethacin. Considering the microscopic analysis of the average of the edema, the group of animals, which was given misoprostol as cytoprotection, presented a lower average compared to the group which was given omeprazole.

Omeprazole and misoprostol for preventing gastric mucosa effects caused by indomethacin and celecoxib in rats

OBJETIVO: Avaliar e comparar macro e microscopicamente as lesões agudas da mucosa gástrica de ratos provocadas pelos AINEs celecoxib e indometacina e a citoproteção gástrica com omeprazol e misoprostol. MÉTODOS: A amostragem consistiu 150 ratos machos da raça Wistar, com peso médio de 200g, divididos em quatro grupos, a saber: grupo A, subdividido em grupos A1 e A2 – pré-tratamento com omeprazol (20 mg/rato) durante sete dias, e no oitavo dia receberam o AINEs, sendo A1 (20 ratos) receberam celecoxib (1mg/rato) e A2 (20 ratos) receberam indometacina (12,5mg/rato). O grupo B, subdividido em grupo B1 e B2 – pré-tratamento com misoprostol (20ìg/rato) durante sete dias e no oitavo dia receberam AINEs, sendo B1 (20 ratos) receberam celecoxib (1mg/rato) e B2 (20 ratos) receberam indometacina (12,5mg/rato). O grupo C não recebeu citoproteção durante sete dias e no oitavo dia recebeu AINEs, sendo C1 (20 ratos) receberam celecoxib (1mg/rato) , C2 (20ratos) receberam indometacina (12,5mg/rato), C3 (20 ratos) receberam celecoxib e grupo D – grupo controle, no qual dez ratos foram observados recebendo ração e água ad libitum. A seguir, no 9º dia (de todos os grupos), os estômagos eram removidos e avaliados macro e microscopicamente para a identificação das lesões gástricas. RESULTADOS: Na análise macroscópica, os grupos A2, B2 e C2 apresentaram número de lesões por cm2/animal significativamente elevados, sendo respectivamente 18,55 lesões por cm2/animal, 16,25 lesões por cm2/animal e 13,55 lesões por cm2/animal. Na análise microscópica, a porcentagem da mucosa com lesão mostrou diferença significativa entre os grupos A1, B1, C1 quando comparados com os grupos A2, B2 e C2 (p<0,0001). Os resultados da média da extensão/lesão e da média da profundidade das lesões não mostraram diferenças estatísticas significativas entre os grupos A2, B2 e C2. A média do edema mostrou diferença estatística significativa entre os grupos A2 e D; B2 e C2 e entre C2 e D (p<0,05)...