A lyophilized aqueous extract of Maytenus ilicifolia leaves inhibits histamine-mediated acid secretion in isolated frog gastric mucosa

Abstract

Lyophilized aqueous extract of Maytenus ilicifolia leaves (LAEMIL) is commonly used in Brazilian folk medicine in the treatment of dyspepsia as well as gastric ulcers. We have investigated the effect and the possible mechanism of action of the LAEMIL on acid secretion in isolated frog gastric mucosa incubated in an Ussing chamber. It was observed that LAEMIL (7-28 mg%) as well as cimetidine (125-4,000 microM), a well-known histamine H2 receptor antagonist, decreased basal acid secretion in a concentration-dependent manner. Similarly to cimetidine (190 microM), LAEMIL (21 mg%) also inhibited gastric acid secretion induced by increasing concentrations of histamine (50-800 microM). The EC50 values for histamine alone and histamine in the presence of LAEMIL or cimetidine were 94.6 microM (71.1-125.9 microM), 244.9 microM (209.4-286.4 microM) and 142.2 microM (23.6-855.0 microM), respectively. LAEMIL, histamine and cimetidine were effective on acid secretion only when added to the serosal surface of the mucosa. Furthermore, simultaneous addition of LAEMIL and cimetidine at concentrations, per se, ineffective, caused a 16% reduction in the basal acid secretion [from 8.3 +/- 0.3 to 6.9 +/- 0.2 microEq g(-1) (15 min)(-1), n=4]. Although effects such as inhibition of histamine biosynthesis and/or histamine release can not be ruled out, our data suggest that LAEMIL, like cimetidine, reduces acid secretion in the isolated frog gastric mucosa by antagonising histamine H2 receptors.

Anti-ulcerogenic Action Mechanism of <i>Maytenus ilicifolia</i> Detected by mRNA RT-PCR and Free Radical Scavenging Activity Evaluated by ESR

“…In this acute experiment, the lesion areas of rats undergoing Tween 80 treatment were 7.42±0.40 mm 2 and animals undergoing Maytenus ilicifolia (300 and 500 mg/kg) treatment showed smaller lesion areas: 3.12 ±0.80 mm 2 and 5.34 mm 2 (p<0.05 and p<0.001, respectively), when compared with the negative control tween 80. The oral administration of ethanol solution on the negative control group (pre-treated with tween) caused necrotizing gastric mucosa lesions, observed by the tissue disorganization, lack of continuous glandular epithelium and own lamina formed by connective tissue (Figure 3 A and B).…”

“…It is used in folk medicine for the treatment of dyspepsia as well as gastric ulcers and potentially on cancer treatment [2]- [4] Cipriani et al demonstrated, after several purification steps, that the tea (infusion) of M. ilicifolia leaves releases a polysaccharide (arabinogalactan). The pre-treatment with arabinogalactan practically abolished the ethanol-induced gastric damage, suggesting a potential ability to bind to the surface mucosa and function as a protective coating, antisecretory activity, and mucosal protection by increased mucus synthesis, and radical scavenging [5].…”

Antiulcer Agents from Higher Plants

“…The drug cimetidine was used as control. The results of this study suggest that the extract of M. ilicifolia reduces gastric acid secretion in isolated frog gastric mucosa, by acting in a manner similar to the drug cimetidine, antagonizing the histamine H 2 receptor [26].…”

Nitric oxide-dependent vasorelaxation induced by extractive solutions and fractions of Maytenus ilicifolia Mart ex Reissek (Celastraceae) leaves

“…The antiulcer effectiveness of M. ilicifolia extracts have been experimentally proven (Souza-Formigoni et al, 1991;Tabach and Oliveira, 2003;Ferreira et al, 2004;Jorge et al, 2004). Moreover, cytotoxicity (Shirota et al, 1994), antioxidation (Melo et al, 2001), antimutagenicity (Horn and Vargas, 2003), and contraception (Montanari and Bevilacqua, 2002) are among the other biological activities attributed to M. ilicifolia preparations in preclinical experiments.…”