Antibacterial Effect of Ethanolic Extracts of Dodonaea viscosa L. Jacq. and Mammea americana L. against Staphylococci Isolated from Skin Lesions.

Background: The resistance to antibiotics shown by some dermatological pathogenic microorganisms has increased the interest of pharmaceutical and cosmetic industries in developing natural products that possess different biological activities, including antimicrobial effects. Methods: In the present investigation, the antibacterial activity of ethanolic extracts of Dodonaea viscosa aerial part and Mammea americana leaves and seed was evaluated against resistant strains of Staphylococcus isolated from skin lesions and against S. aureus ATCC 25923 (reference strain). Column chromatography (CC) and preparative thin-layer chromatography (PTLC) were used to obtain separate fractions of the seed extract of M. americana. We also determined the antimicrobial resistance of the strains against antibiotics using the agar disc diffusion assay. In addition, phytochemical screening was performed by colorimetric standard techniques. Results: M. americana seed extract showed the highest antibacterial activity with MBC from 2.3 µg/mL to 19.5 µg/mL without differences with gentamicin (p = 0.998). The isolated strain S. epidermidis I showed the highest antimicrobial resistance against the tested antibiotics. PTLC-fractions of M. americana seed extract showed MBC from 3.2 µg/mL to 40.7 µg/mL against S. epidermidis I and S. aureus 25923 (reference), respectively, which suggests a synergistic effect of the secondary metabolites present in the crude ethanolic extract compared to its active PTLC-fractions, where only coumarins and compounds with lactone groups were detected in the phytochemical screening. Conclusion: M. americana seed extract has promising effects that should be considered in further studies as an alternative or adjuvant in treating skin infections caused by staphylococci.

Mammea type coumarins isolated from Calophyllum brasiliense induced apoptotic cell death of Trypanosoma cruzi through mitochondrial dysfunction, ROS production and cell cycle alterations.

Chagas Disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi which affects 6-8 million people, mostly in Latin America. The medical treatment is based on two nitroimidazole compounds, which have limited effectiveness in the chronic phase of the disease and produce several adverse effects; consequently, there is an urgent need to develop new, safe, and effective drugs. Previous reports had shown that natural coumarins, especially mammea A/BA isolated from the tropical tree Calophyllum brasiliense, is a promissory molecule for developing new drugs, due to its potent activity, higher than benznidazole, selectivity, and its low toxicity in mice. However, its mode of action is still unknown. In the present work, we evaluated the mechanism of action of the coumarin mammea A/BA (93.6%), isolated from the tropical tree C. brasiliense on Querétaro strain (Tc1) of T. cruzi. This compound was tested in vitro on epimastigotes and trypomastigotes of T. cruzi for intracellular esterase activity, plasma membrane integrity, phosphatidylserine exposure, ROS production, mitochondrial membrane potential, caspase-like activity, DNA integrity, cell cycle and autophagy. Mammea A/BA showed a 50% lethal concentration (LC50) of 85.8 and 36.9 µM for epimastigotes and trypomastigotes respectively. It affected intracellular esterase activity, produced important plasma membrane damage and induced phosphatidylserine exposure. An increase in reactive oxygen species (ROS) and decrease in mitochondrial membrane potential were detected. Caspase-like activity was present in both parasite forms producing DNA integrity damage. This compound also induced a cell cycle arrest in the G1 phase and the presence of autophagy vacuoles. The above data suggest that mammea A/BA induce cell death of T. cruzi by autophagy and apoptosis-like phenomena and support our suggestion that mammea A/BA could be a promising molecule for the development of new drugs to treat Chagas Disease.

Antimicrobial activity of endophytic fungi from the medicinal plants Mammea americana (Calophyllaceae) and Moringa oleifera (Moringaceae) / [Actividad antimicrobiana de hongos endófitos de las plantas medicinales Mammea americana (Calophyllaceae) y Moringa oleifera (Moringaceae)].

Introduction: Infectious diseases represent one of the leading causes of death worldwide. Considering the growing global challenge of antimicrobial resistance, research into new sources of potentially effective antimicrobial agents from natural origins is of great importance for world health. Objective: To evaluate the antimicrobial activity of endophytic fungi from Mammea americana and Moringa oleifera upon Staphylococcus aureus (ATCC 29213), S. aureus (resistant strain USb003), Escherichia coli (ATCC 25922), and E. coli (resistant strain USb007). Materials and methods: We isolated endophytic fungi from the leaves, seeds, and stems of the two plants under study. We evaluated their antimicrobial activity through the formation of sensitivity haloes in dual tests in vitro, as well as in trials using crude ethanolic extracts from the endophytes. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and cytotoxicity o the substances were analyzed. Results: Three ethanolic extracts of Penicillium sp., Cladosporium (001), and Cladosporium (002) exhibited the greatest inhibition halos in sensitive and resistant strains of E. coli and S. aureus. The MIC and CBM found were statistically significant (p≤0.05) compared with the gentamicin control. Furthermore, the cytotoxicity test results of CC50>1,000 demonstrated that the endophytic fungi studied exhibit bactericidal characteristics without causing unintended damage. Conclusion: The endophytic fungi M. oleifera and M. americana represent a source of active secondary metabolites with antimicrobial and non-toxic properties. In light of these findings, further research should proceed with chemical identification of the compounds and the study of their mechanisms of action, especially given the paucity of current scientific knowledge concerning the isolation of endophytes in these plants.

Introducción. Las enfermedades infecciosas son una causa importante de muertes en el mundo. La resistencia antimicrobiana es un problema global, por lo que es conveniente la investigación de nuevas fuentes de agentes antimicrobianos de origen natural potencialmente efectivos. Objetivo. Evaluar la actividad antimicrobiana de hongos endófitos de Mammea americana y Moringa oleifera en la cepa sensible (ATCC 29213) y en la cepa resistente (USb003) de Staphylococcus aureus, así como en la cepa sensible (ATCC 25922) y la cepa resistente (USb007) de Escherichia coli. Materiales y métodos. Se aislaron 14 hongos endófitos de las hojas, semillas y tallos de las dos plantas en estudio. Se evaluó su actividad antimicrobiana mediante la formación de halos de sensibilidad por ensayo dual in vitro y pruebas con extractos etanólicos crudos provenientes de los endófitos a los que se les evaluó la concentración mínima inhibitoria (CMI), la concentración bactericida mínima (CBM) y la citotoxicidad. Resultados. Tres extractos etanólicos de Penicillium sp., Cladosporium sp. (001) y Cladosporium sp. (002) presentaron mayores halos de inhibición en cepas sensibles y resistentes de E. coli y S. aureus. La CMI y la CBM halladas fueron estadísticamente significativas (p≤0,05), comparadas con el control de gentamicina. Las pruebas de citotoxicidad (concentración citotóxica, CC50>1.000) demostraron que los hongos endófitos poseen características bactericidas y no ocasionan daño alguno. Conclusión. Se halló una fuente de metabolitos secundarios activos con propiedades antimicrobianas y no tóxicas en los hongos endófitos de M. oleifera y M. americana; estos hallazgos son importantes para continuar con la identificación química de los compuestos y el estudio de sus mecanismos de acción en estas plantas en las que el aislamiento de endófitos ha sido escaso.

Metabolite Profiling by UPLC-MSE, NMR, and Antioxidant Properties of Amazonian Fruits: Mamey Apple (Mammea Americana), Camapu (Physalis Angulata), and Uxi (Endopleura Uchi).

The metabolite profiling associated with the antioxidant potential of Amazonian fruits represents an important step to the bioactive compound's characterization due to the large biodiversity in this region. The comprehensive bioactive compounds profile and antioxidant capacities of mamey apple (Mammea americana), camapu (Physalis angulata), and uxi (Endopleura uchi) was determined for the first time. Bioactive compounds were characterized by ultra-performance liquid chromatography coupled to high resolution mass spectrometry (UPLC-MSE) in aqueous and ethanolic extracts. Globally, a total of 293 metabolites were tentatively identified in mamey apple, campau, and uxi extracts. The main classes of compounds in the three species were terpenoids (61), phenolic acids (58), and flavonoids (53). Ethanolic extracts of fruits showed higher antioxidant activity and total ion abundance of bioactive compounds than aqueous. Uxi had the highest values of phenolic content (701.84 mg GAE/100 g), ABTS (1602.7 µmol Trolox g-1), and ORAC (15.04 µmol Trolox g-1). Mamey apple had the highest results for DPPH (1168.42 µmol TE g-1) and FRAP (1381.13 µmol FSE g-1). Nuclear magnetic resonance (NMR) spectroscopy results showed that sugars and lipids were the substances with the highest amounts in mamey apple and camapu. Data referring to chemical characteristics and antioxidant capacity of these fruits can contribute to their economic exploitation.

Antiviral effect of compounds derived from the seeds of Mammea americana and Tabernaemontana cymosa on Dengue and Chikungunya virus infections.

BACKGROUND: The transmission of Dengue virus (DENV) and Chikungunya virus (CHIKV) has increased worldwide, due in part to the lack of a specific antiviral treatment. For this reason, the search for compounds with antiviral potential, either as licensed drugs or in natural products, is a research priority. The objective of this study was to identify some of the compounds that are present in Mammea americana (M. americana) and Tabernaemontana cymosa (T. cymosa) plants and, subsequently, to evaluate their cytotoxicity in VERO cells and their potential antiviral effects on DENV and CHIKV infections in those same cells. METHODS: Dry ethanolic extracts of M. americana and T. cymosa seeds were subjected to open column chromatographic fractionation, leading to the identification of four compounds: two coumarins, derived from M. americana; and lupeol acetate and voacangine derived from T. cymosa.. The cytotoxicity of each compound was subsequently assessed by the MTT method (at concentrations from 400 to 6.25 µg/mL). Pre- and post-treatment antiviral assays were performed at non-toxic concentrations; the resulting DENV inhibition was evaluated by Real-Time PCR, and the CHIKV inhibition was tested by the plating method. The results were analyzed by means of statistical analysis. RESULTS: The compounds showed low toxicity at concentrations ≤ 200 µg/mL. The compounds coumarin A and coumarin B, which are derived from the M. americana plant, significantly inhibited infection with both viruses during the implementation of the two experimental strategies employed here (post-treatment with inhibition percentages greater than 50%, p < 0.01; and pre-treatment with percentages of inhibition greater than 40%, p < 0.01). However, the lupeol acetate and voacangine compounds, which were derived from the T. cymosa plant, only significantly inhibited the DENV infection during the post-treatment strategy (at inhibition percentages greater than 70%, p < 0.01). CONCLUSION: In vitro, the coumarins are capable of inhibiting infection by DENV and CHIKV (with inhibition percentages above 50% in different experimental strategies), which could indicate that these two compounds are potential antivirals for treating Dengue and Chikungunya fever. Additionally, lupeol acetate and voacangine efficiently inhibit infection with DENV, also turning them into promising antivirals for Dengue fever.

Tamizaje fitoquímico y actividad antibacteriana de los extractos secos de tinturas al 20 por ciento de Mammea americana L / Phytochemical screening and antibacterial activity of dry extracts of 20 por ciento tinctures from Mammea americana L

Introducción: el mamey amarillo (Mammea americana L.) se utiliza ampliamente en la curación de diversos tipos de enfermedades producidas por parásitos e insectos. Objetivo: realizar el tamizaje fitoquímico y determinar la actividad antibacteriana de los extractos secos de la tintura al 20 por ciento de las hojas y corteza del fuste de esta planta. Métodos: se recolectaron hojas y corteza del fuste de la planta objeto de estudio, que fueron lavadas, desinfectadas, secadas y pulverizadas. Luego se procedió a la elaboración de las tinturas al 20 por ciento por el método de maceración de la droga. Los extractos secos de las partes estudiadas de la planta se obtuvieron a partir de las tinturas al 20 por ciento y se emplearon para los ensayos del tamizaje fitoquímico y la evaluación de la actividad antibacteriana. Resultados: se comprobó la existencia de una alta diversidad de metabolitos secundarios, con predominio de los alcaloides, coumarinas, fenoles o taninos, quinonas y flavonoides. Los extractos secos mostraron actividad antibacteriana in vitro frente a la cepa de Staphylococcus aureus (ATCC 29737). Conclusiones: se destacan, por su significativa presencia, flavonoides, alcaloides, taninos y cumarinas, los cuales resultan de interés biológico y farmacológico por sus posibles aplicaciones terapéuticas

Introduction: the yellow mammee (Mammea americana L.) is widely used to cure different diseases caused by parasites and insects. Objective: to perform a phytochemical screening and to determine antibacterial activity of dry extracts of 20 percent tincture from the leaves and the bark of this plant. Methods: the leaves and stem bark of the plant were harvested, washed, disinfected, dried and crushed. Then it proceeded to the preparation of 20 percent tinctures through drug maceration. The dried extracts of the studied parts were obtained from the 20 percent tinctures and used to evaluate the phytochemical screening tests and the antibacterial activity. Results: the existence of a high diversity of secondary metabolites, predominantly alkaloids, coumarins, phenols and / or tannins, quinones, and flavonoids were confirmed. The dried extracts showed antibacterial activity in vitro against Staphylococcus aureus (ATCC 29737). Conclusions: flavonoids, alkaloids, tannins and coumarins, which are of biological and pharmacological interest for their potential therapeutic applications, were significantly present in these extracts

Typhoid fever outbreak associated with frozen mamey pulp imported from Guatemala to the western United States, 2010.

BACKGROUND: Fifty-four outbreaks of domestically acquired typhoid fever were reported between 1960 and 1999. In 2010, the Southern Nevada Health District detected an outbreak of typhoid fever among persons who had not recently travelled abroad. METHODS: We conducted a case-control study to examine the relationship between illness and exposures. A case was defined as illness with the outbreak strain of Salmonella serotype Typhi, as determined by pulsed-field gel electrophoresis (PFGE), with onset during 2010. Controls were matched by neighborhood, age, and sex. Bivariate and multivariate statistical analyses were completed using logistic regression. Traceback investigation was completed. RESULTS: We identified 12 cases in 3 states with onset from 15 April 2010 to 4 September 2010. The median age of case patients was 18 years (range, 4-48 years), 8 (67%) were female, and 11 (92%) were Hispanic. Nine (82%) were hospitalized; none died. Consumption of frozen mamey pulp in a fruit shake was reported by 6 of 8 case patients (75%) and none of the 33 controls (matched odds ratio, 33.9; 95% confidence interval, 4.9). Traceback investigations implicated 2 brands of frozen mamey pulp from a single manufacturer in Guatemala, which was also implicated in a 1998-1999 outbreak of typhoid fever in Florida. CONCLUSIONS: Reporting of individual cases of typhoid fever and subtyping of isolates by PFGE resulted in rapid detection of an outbreak associated with a ready-to-eat frozen food imported from a typhoid-endemic region. Improvements in food manufacturing practices and monitoring will prevent additional outbreaks.

Natural and semisynthetic mammea-type isoprenylated dihydroxycoumarins uncouple cellular respiration.

In an effort to identify natural product-based molecular-targeted antitumor agents, mammea-type coumarins from the tropical/subtropical plant Mammea americana were found to inhibit the activation of HIF-1 (hypoxia-inducible factor-1) in human breast and prostate tumor cells. In addition to the recently reported mammea E/BB (15), bioassay-guided fractionation of the active extract yielded 14 mammea-type coumarins including three new compounds, mammea F/BB (1), mammea F/BA (2), and mammea C/AA (3). The absolute configuration of C-1' in 1 was determined by the modified Mosher's method on a methylated derivative. These coumarins were evaluated for their effects on mitochondrial respiration, HIF-1 signaling, and tumor cell proliferation/viability. Acetylation of 1 afforded a triacetoxylated product (A-2) that inhibited HIF-1 activation with increased potency in both T47D (IC(50) 0.83 µM for hypoxia-induced) and PC-3 cells (IC(50) 0.94 µM for hypoxia-induced). Coumarins possessing a 6-prenyl-8-(3-methyloxobutyl) substituent pattern exhibited enhanced HIF-1 inhibitory effects. The O-methylated derivatives were less active at inhibiting HIF-1 and suppressing cell proliferation/viability. Mechanistic studies indicate that these compounds act as anionic protonophores that potently uncouple mitochondrial electron transport and disrupt hypoxic signaling.

Mammea E/BB, an isoprenylated dihydroxycoumarin protonophore that potently uncouples mitochondrial electron transport, disrupts hypoxic signaling in tumor cells.

The mammea-type coumarin mammea E/BB (1) was found to inhibit both hypoxia-induced and iron chelator-induced hypoxia-inducible factor-1 (HIF-1) activation in human breast tumor T47D cells with IC(50) values of 0.96 and 0.89 µM, respectively. Compound 1 suppressed the hypoxic induction of secreted VEGF protein (T47D cells) and inhibited cell viability/proliferation in four human tumor cell lines. Compound 1 (at 5 and 20 µM) inhibited human breast tumor MDA-MB-231 cell migration. While the mechanisms that underlie their biological activities have remained unknown, prenylated mammea coumarins have been shown to be cytotoxic to human tumor cells, suppress tumor growth in animal models, and display a wide variety of antimicrobial effects. Mechanistic studies revealed that 1 appears to exert an assemblage of cellular effects by functioning as an anionic protonophore that potently uncouples mitochondrial electron transport and disrupts mitochondrial signaling in human tumor cell lines.

Observações sobre abelhas sem ferrão (Hymenoptera: meliponini) coletoras de látex em Abricó do Pará Mammea americana (L.) Jacq. (Clusiaceae), Manaus, Amazonas, Brasil / Observations on stingless bees (Hymenoptera: meliponini) collecting of latex in mammy Mammea americana (L.) Jacq. (Clusiaceae), Manaus, state of Amazonas, Brazil

O conhecimento das espécies de plantas utilizadas pelas abelhas sem ferrão é primordial para a manutenção das mesmas. O objetivo deste trabalho foi verificar a coleta de látex em Mammea americana (Clusiaceae) e os padrões de abundância dos visitantes. O estudo foi conduzido no Bosque da Ciência, Instituto Nacional de Pesquisas da Amazônia, em Manaus-AM. A comunidade de abelhas foi representada por Trigona williana e T. recursa. A espécie presente em maior abundância foi T. recursa (89,4%). Estas abelhas coletam o látex para proteger o ninho contra possíveis inquilinos e predadores, devido a sua ação antimicrobiana.

The knowledge regarding the plant species used by the stingless bees for their survival is a fundamental factor for their maintenance. The objective of this study is to observe collecting latex in Mammea americana tree (Clusiaceae) and abundance patterns of visitors. The study was carried out in the “Bosque da Ciência,” Instituto Nacional de Pesquisas da Amazônia, Manaus-AM. The bee communities were represented by Trigona williana and Trigona recursa. The latter presented the highest abundance (89.4%). These bees probably collect this substance in order to protect their nest against other possible tenants and predators, since it acts as an antimicrobial agent.

Vasodilator and antioxidant effect of xanthones isolated from Brazilian medicinal plants.

Vasorelaxant and antioxidant activities are important in the therapy for cardiovascular diseases. We aimed at investigating the vasorelaxant and antioxidant activities of six xanthones isolated from Brazilian medicinal plants. Xanthone ( 1), 1-hydroxyxanthone ( 2), 4-hydroxyxanthone ( 3), 1-hydroxy-8-methoxyxanthone ( 4), 1,3-dihydroxy-7-methoxyxanthone ( 5) and 2,6,8-trihydroxy-1-methoxyxanthone ( 6) induced concentration-dependent vasorelaxant effects in endothelium-intact mice aortic rings. The presence of a hydroxy group in position 1 seemed to decrease the vasodilator effect while a hydroxy in position 4 and an increased number of hydroxy groups improved the vasorelaxatory potential of xanthones. All xanthones showed antioxidant activity but their potencies did not correlate with the vasodilator effect. Our results suggest that the tested xanthones are potentially vasorelaxant and antioxidant compounds but the two activities are not interrelated.

Trypanocidal constituents in plants: 7. Mammea-type coumarins.

Calophyllum brasiliense and Mammea americana (Clusiaceae) are two trees from the tropical rain forests of the American continent. A previous screening showed high trypanocidal activity in the extracts of these species. Several mammea-type coumarins, triterpenoids and biflavonoids were isolated from the leaves of C. brasiliense. Mammea A/AA was obtained from the fruit peels of M. americana. These compounds were tested in vitro against epimastigotes and trypomastigotes of Trypanosoma cruzi, the etiologic agent of Chagas disease. The most potent compounds were mammea A/BA, A/BB, A/AA, A/BD and B/BA, with MC100 values in the range of 15 to 90 microg/ml. Coumarins with a cyclized gamma,gamma-dimethylallyl substituent on C-6, such as mammea B/BA, cyclo F + B/BB cyclo F, and isomammeigin, showed MC100 values > 200 microg/ml. Several active coumarins were also tested against normal human lymphocytes in vitro, which showed that mammea A/AA and A/BA were not toxic. Other compounds from C. brasiliense, such as the triterpenoids, friedelin, canophyllol, the biflavonoid amentoflavone, and protocatechuic and shikimic acids, were inactive against the epimastigotes. The isopropylidenedioxy derivative of shikimic acid was inactive, and its structure was confirmed by X-ray diffraction. Our results suggest that mammea-type coumarins could be a valuable source of trypanocidal compounds.

Trypanocidal constituents in plants: 7. Mammea-type coumarins

Calophyllum brasiliense and Mammea americana (Clusiaceae) are two trees from the tropical rain forests of the American continent. A previous screening showed high trypanocidal activity in the extracts of these species. Several mammea-type coumarins, triterpenoids and biflavonoids were isolated from the leaves of C. brasiliense. Mammea A/AA was obtained from the fruit peels of M. americana. These compounds were tested in vitro against epimastigotes and trypomastigotes of Trypanosoma cruzi, the etiologic agent of Chagas disease. The most potent compounds were mammea A/BA, A/BB, A/AA, A/BD and B/BA, with MC100 values in the range of 15 to 90 g/ml. Coumarins with a cyclized ,-dimethylallyl substituent on C-6, such as mammea B/BA, cyclo F + B/BB cyclo F, and isomammeigin, showed MC100 values > 200 g/ml. Several active coumarins were also tested against normal human lymphocytes in vitro, which showed that mammea A/AA and A/BA were not toxic. Other compounds from C. brasiliense, such as the triterpenoids, friedelin, canophyllol, the biflavonoid amentoflavone, and protocatechuic and shikimic acids, were inactive against the epimastigotes. The isopropylidenedioxy derivative of shikimic acid was inactive, and its structure was confirmed by X-ray diffraction. Our results suggest that mammea-type coumarins could be a valuable source of trypanocidal compounds.

Preliminary studies of Mammea americana L. (Guttiferae) bark/latex extract point to an effective antiulcer effect on gastric ulcer models in mice.

Plant extracts are some of the most attractive sources of new drugs and have shown promising results for the treatment of gastric ulcers. Several folk medicinal plants and herbs have been used to treat gastrointestinal disorders, including gastric ulcers. Mammea americana L. (Guttiferae) fruit is very common in the diet of the population of northern South America. Our research interest in this plant arose because of its potential medicinal value as a tonic and against stomachache, as used in folk medicine. In this paper we evaluated three different extracts (ethanolic/EtOH, methanolic/MeOH and dichloromethane/DCM) obtained from M. americana L., for their ability to protect the gastric mucosa against injuries caused by necrotizing agents (0.3 M HCl/60% EtOH), hypothermic restraint stress, nonsteroidal anti-inflammatory drugs (NSAID, indomethacin) and pylorus ligation. In the HCl/EtOH-induced gastric-ulcer model, EtOH and DCM extracts demonstrated significant inhibition of the ulcerative lesion index by 54% (12.0 +/- 2.6 mm) and 86% (3.7 +/- 1.8 mm), respectively, in relation to the control value (26.0 +/- 1.4 mm) (p<0.0001). In the NSAID/cholinomimetic-induced lesion model, both EtOH and DCM extracts showed antiulcerogenic effects with significant reduction in the damage to these gastric lesions of 36% (8.3 +/- 2.0 mm) and 42% (7.5 +/- 1.4 mm), respectively, as compared to the control group (13.0 +/- 0.9 mm) (p<0.0001). In the gastric ulcer induced by hypothermic-restraint stress, both extracts also showed significant activity, and inhibited the gastric lesion index by 58% and 75%, respectively. The EtOH and DCM extracts also changed gastric juice parameters as well as those of cimetidine, decreased gastric acid secretion significantly (p<0.0001), increased pH values and promoted reduced acid output (p<0.0001). In all gastric-ulcer-induced models, MeOH extract did not show any significant antiulcerogenic activity, nor did it change gastric-juice parameters (p>0.05). The results suggest that EtOH and DCM extracts obtained from M. americana possess excellent antisecretory and/or gastrotective effect in all gastric ulcer models. These results suggest that the antiulcerogenic compound(s) present in M. americana may be clustered in the apolar fraction, which will be investigated by our group for the probable mechanisms of action.