Antimitotic and antimutagenic action of the Hymenaea stigonocarpa bark on dividing cells / Ação antimitótica e antimutagênica do ritidoma de Hymenaea stigonocarpa Mart ex Hayne na divisão celular

Abstract The objective of this study was to evaluate the action of Hymenaea stigonocarpa bark hydroalcoholic extract against a mutagenic compound using A. cepa meristematic root cells as a test system. The treatment groups were: Negative Control (NC) – distilled water; Positive Control (PC) – paracetamol at a concentration of 0.008 mg/mL, Jatoba Control (JC) – aqueous fraction jatobá-do-cerrado at 0.5 or 1.0 or 1.5 mg/mL, and Simultaneous Treatment (ST) - jatobá-do-cerrado aqueous fraction at a concentration of 0.5 or 1.0 or 1.5 mg/mL associated with paracetamol solution at a concentration of 0.008 mg/mL. All groups were analyzed at 24 and 48 h. Five onion bulbs (five replications) were used for each treatment group. The root tips were fixed in Carnoy and slides prepared by the crush technique. Cells were analyzed throughout the cell cycle, totaling 5,000 for each treatment group at each exposure time. Mitotic indices were subjected to statistical analysis using the chi-square test (p<0.05). From the results it was found that the ST group, at the three concentrations, significantly potentiated the antiproliferative effect of the test system cells when compared to PC, NC and TJ at the three concentrations. Furthermore, the three ST concentrations significantly reduced the number of cell aberrations when compared to the number of aberrant cells obtained for the PC, demonstrating antimutagenic action on the A. cepa test system cells.

Resumo O objetivo do presente trabalho foi avaliar a ação do extrato hidroalcólico do ritidoma de Hymenaea stigonocarpa frente a um composto mutagênico, utilizando como sistema teste as células meristemáticas de raízes de A. cepa. Os grupos tratamentos avaliados foram: Controle Negativo (CN) – água destilada; Controle Positivo (CP) – paracetamol na concentração de 0,008 mg/mL, Controle Jatobá (CJ) – fração aquosa de jatobá-do-cerrado na concentração de 0,5 ou 1,0 ou 1,5 mg/mL, e Tratamento Simultâneo (TS) – fração aquosa de jatobá-do-cerrado na concentração de 0,5 ou 1,0 ou 1,5 mg/mL associada a solução de paracetamol na concentração de 0,008 mg/mL. Todos os grupos foram analisados nos tempos de 24 e 48 h. Para cada grupo tratamento cinco bulbos de cebolas (cinco repetições) foram utilizados. As radículas foram fixadas em Carnoy e as lâminas preparadas pela técnica de esmagamento. Analisaram-se células em todo ciclo celular, totalizando 5.000 para cada grupo tratamento em cada tempo de exposição. Os índices mitóticos obtidos foram submetidos à análise estatística do Qui-quadrado (p<0,05). A partir dos resultados verificou-se que o grupo TS, nas três concentrações, potencializou o efeito antiproliferativo significativo as células do sistema teste quando comparado ao CP, CN e TJ nas três concentrações. Ainda, o TS nas três concentrações reduziu de forma significativa o número de aberrações celulares quando comparado com o número de células aberrantes obtidas para o CP, demonstrando ação antimutagênica as células do sistema teste A. cepa.

Antimitotic and antimutagenic action of the Hymenaea stigonocarpa bark on dividing cells.

The objective of this study was to evaluate the action of Hymenaea stigonocarpa bark hydroalcoholic extract against a mutagenic compound using A. cepa meristematic root cells as a test system. The treatment groups were: Negative Control (NC) - distilled water; Positive Control (PC) - paracetamol at a concentration of 0.008 mg/mL, Jatoba Control (JC) - aqueous fraction jatobá-do-cerrado at 0.5 or 1.0 or 1.5 mg/mL, and Simultaneous Treatment (ST) - jatobá-do-cerrado aqueous fraction at a concentration of 0.5 or 1.0 or 1.5 mg/mL associated with paracetamol solution at a concentration of 0.008 mg/mL. All groups were analyzed at 24 and 48 h. Five onion bulbs (five replications) were used for each treatment group. The root tips were fixed in Carnoy and slides prepared by the crush technique. Cells were analyzed throughout the cell cycle, totaling 5,000 for each treatment group at each exposure time. Mitotic indices were subjected to statistical analysis using the chi-square test (p<0.05). From the results it was found that the ST group, at the three concentrations, significantly potentiated the antiproliferative effect of the test system cells when compared to PC, NC and TJ at the three concentrations. Furthermore, the three ST concentrations significantly reduced the number of cell aberrations when compared to the number of aberrant cells obtained for the PC, demonstrating antimutagenic action on the A. cepa test system cells.

Gastroprotective activity of Cenostigma macrophyllum Tul. var. acuminata Teles Freire leaves on experimental ulcer models.

ETHNOPHARMACOLOGICAL RELEVANCE: Cenostigma macrophyllum Tul. var. acuminata Teles Freire (Leguminosae-Caesalpinioideae), popularly known in Brazil as "caneleiro", is widely used in folk medicine against gastrointestinal diseases. In previous studies, the ethanol extract of leaves from Cenostigma macrophyllum Tul. var. acuminata Teles Freire had shown antinociceptive, anti-inflammatory, antibacterial, antioxidant and antiulcerogenic activities. AIM OF THE STUDY: The aim of this study was to assess the gastroprotective effect of the hydroalcoholic fraction of leaves of Cenostigma macrophyllum Tul. var. acuminata Teles Freire (Cm-FHA), as well as to elucidate the possible underlying mechanisms of action. MATERIALS AND METHODS: Mice were used for the evaluation of the acute toxicity, and mice and rats to study the gastroprotective activity. The potential gastroprotective of Cm-FHA was assessed on different gastric ulcer models in rodents, such as absolute ethanol, HCl/ethanol, ischemia-reperfusion, cold restraint stress and indomethacin. The participation of prostaglandins, NO-synthase pathway and ATP-sensitive potassium channels (KATP) in gastroprotective activity of Cm-FHA were evaluated after treatment with a cyclooxygenase inhibitor (indomethacin), a NO-synthase inhibitor (L-NAME) and a KATP channel blocker (glibenclamide 5mg/kg), respectively. Likewise, the catalase activity was determinated in order to assess the possible participation of antioxidant mechanisms. RESULTS: No signs of acute toxicity was observed after oral acute administration of Cm-FHA, considering the analyzed parameters. Likewise, Cm-FHA promoted a protective effect against gastric ulcers induced by absolute ethanol (lesion inhibition by 40% at both 100 and 200mg/kg), HCl/ethanol (lesion inhibition by 50 or 48% at 100 or 200mg/kg, respectively), ischemia-reperfusion (lesion inhibition by 49 or 90% at 100 or 200mg/kg, respectively) and cold restraint stress (lesion inhibition by 63 or 76% at 100 or 200mg/kg, respectively), as well as a increase of catalase activity was observed. Otherwise, Cm-FHA was not able to protect gastric mucosa against indomethacin-induced lesions. Nitric oxide release, the of KATP channels opening and antioxidant activity are the possibly involved in the Cm-FHA-induced gastroprotective activity. CONCLUSION: This study corroborates the folk medicine use of Cenostigma macrophyllum for treatment of gastric ulcers, as well as reinforces this species as a valuable source of promising natural drugs with gastroprotective activity.

Gastroprotective activity of Zanthoxylum rhoifolium Lam. in animal models.

ETHNOPHARMACOLOGICAL RELEVANCE: The stem barks of Zanthoxylum rhoifolium Lam. (Rutaceae), locally known as "mamica de cadela", are popularly used in dyspepsies, stomachic, tonic, antitumoral, antipyretic and are used in treating flatulence and colic. The objective of this study was to evaluate the gastroprotective effect of the ethanolic extract of Zanthoxylum rhoifolium (EEZR) stem barks in acute gastric lesion models, investigating their possible mechanisms. MATERIALS AND METHODS: Mice were used for the evaluation of the acute toxicity, and mice and rats to study the gastroprotective activity. The gastroprotective action of EEZR was analyzed in the absolute ethanol, HCl/ethanol and indomethacin-induced gastric lesion models in mice, hypothermic-restraint stress, and ischemia/reperfusion in rats. In the investigation of the gastroprotective mechanisms of EEZR, the participation of the NO-synthase pathway, ATP-sensitive potassium channels (K(ATP)), the levels of the non-protein sulfhydril groups (NP-SH) and the catalase activity using the ethanol-induced gastric mucosa lesion model and the quantification of the gastric mucus and the antisecretory activity through pylorus ligature model in rats were analyzed. RESULTS: The animals did not present any signs of acute toxicity for the EEZR (up to the 4 g/kg dose, po), and it was not possible to calculate the DL(50). EEZR (125-500 mg/kg) exhibited a significant gastroprotective effect in absolute ethanol, HCl/ethanol, hypothermic-restraint stress, and ischemia/reperfusion-induced gastric lesion models. EEZR (250 and 500 mg/kg) exhibited still a gastroprotective activity in the indomethacin-induced ulcer model. Gastroprotection of EEZR was significantly decreased in pre-treated mice with l-NAME or glibenclamide, the respective nitric oxide synthase and K(ATP) channels inhibitors. Our studies revealed that EEZR (500 mg/kg) prevented the decrease of the non-protein sulfhydril groups (NP-SH) and increased the catalase levels in ethanol-treated animals. Furthermore, the extract (500 mg/kg) significantly increased the mucus production, however, the gastric secretion parameters (volume, [H(+)], pH) did not show any alteration. CONCLUSIONS: Our results indicate that the ethanolic extract of Zanthoxylum rhoifolium exhibits a significant gastroprotection, because it inhibits the formation of gastric lesions using different models. The release of the nitric oxide, the opening of the K(ATP) channels, the participation of the non-protein sulfhydril groups (NP-SH), catalase and the increase of mucous secretion seem to be involved in the gastroprotection activity of the EEZR. Nevertheless, this activity does not seem to be related to antisecretory mechanisms.