Modulatory antimicrobial activity of Piper arboretum extracts (Zingiberaceae)

The side effects of certain antibiotics have been a recent dilemma in the medical arena. Due this fact, the necessity of natural product discovery could provide important indications against several pharmacological targets and combat many infectious agents. Piper arboreum Aub. (Piperaceae) has been used by Brazilian traditional communities against several illnesses including rheumatism, bronchitis, sexually transmitted diseases and complaints of the urinary tract. Medicinal plants are a source of several remedies used in clinical practice to combat microbial infections. In this study, ethanol extract and fractions of Piper arboreum leaves were used to assay antimicrobial and modulatory activity. The minimum inhibitory concentration (MIC) was determined using microdilution method of ethanol extract and fractions from the leaves of P. arboreum ranging between 8 and 1024 mgmL–1. The capacity of these natural products to enhance the activity of antibiotic and antifungal drugs was also assayed. In these tests, natural products were combined with drugs. The natural products assayed did not demonstrate any clinically relevant antimicrobial activity (MIC ³ 1024 mg mL–1). However, the modulation of antibiotic activity assay observed a synergistic activity of natural products combined with antifungal (such as nystatin and amphotericin B) and antibiotic drugs (such as amikacin, gentamicin and kanamycin). According to these results, these natural products can be an interesting alternative not only to combat infectious diseases caused by bacteria or fungi, but also to combat enhanced resistance of microorganisms to antibiotic and antifungal drugs

Isolation of phytosterols of Dalbergia ecastophyllum (L.) Taub. (Leguminosae) and modulation of antibiotic resistance by a possible membrane effect

AbstractGlobally there are a larger number of strains of microorganisms resistant to multiple drugs mainly due to misuse and indiscriminate, resulting in increased morbidity, costs inherent benefits of health care, as well as mortality rates for infections. As a result of this a large number of researches have been conducted emphasizing the antimicrobial properties of plant products. In this study, the ethanol extract and hexane fraction of Dalbergia ecastophyllum (L.) Taub. (Leguminosae) have been used to evaluate the antibacterial and antifungal activity and for modulating the resistance of antimicrobials against bacterial strains of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans and fungal strains of Candida krusei, Candida tropicalis. The antibacterial and modulatory activity was determined by microdilution. Inhibition of the growth of bacteria and fungi tested extract was ⩾1024. The activity was enhanced when aminoglycosides were associated with sub-inhibitory concentrations of the ethanol extract and hexane fraction of Dalbergia ecastophyllum. Therefore, it is suggested that the ethanol extract and hexane fraction of Dalbergia ecastophyllum (L.) Taub. (Leguminosae) can be used as a source of natural products with a view to changing the resistance of these microorganisms to antimicrobials

Herbs in association with drugs: Enhancement of the aminoglycoside- antibiotic activity by Pityrogramma calomelanos (L.) Link

a b s t r a c t Aims: In this work, the ethyl acetate and hexane fractions of Pityrogramma calomelanos (L.) were evaluated to antibacterial and antifungal activity against strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, Candida krusei and Candida tropicalis. Methods: The study was performed aiming to assess the antimicrobial effect with the method of dilution in HIA. The hexane and ethyl acetate fractions were named HFPC and EAFPC, respectively. Results: Both fractions of specie P. calomelanos displayed good activity against S. aureus when associated with gentamicin. When associated with the antifungal, the fractions did not exhibit relevant activity against species of Candida. Conclusions: These results indicate that this specie can be used as a possible source of natural products of antibacterial interest, mainly when combined with aminoglycosides

Estudo mesoscópico da valva mitral e do seu anel fibroso Mesoscopic study of the mitral valve and its fibrous ring

OBJETIVO: Estudar o arranjo espacial dos elementos fibrosos que constituem os folhetos da valva mitral e do seu anel fibroso. MÉTODOS: Foram utilizados 20 corações adultos, de ambos os sexos, fixados em formol a 10%. Isolaram-se a valva mitral, juntamente com o anel fibroso, e uma pequena quantidade de tecido muscular ao seu redor. Parte desse material foi incluído em parafina, submetido a cortes seriados de 40µm de espessura e corados pelo tricrômio de Azan e pela resorcina-fucsina, e o restante das peças dissecadas sob lupa estereoscópica, com ajuda de delicadas pinças e agulhas, para se observar a disposição dos feixes miocárdicos ao nível do anel mitral. RESULTADOS: Observou-se que o anel fibroso mitral era constituído por feixes colágenos de trajetória semicircular, envolvendo de forma incompleta o óstio atrioventricular, uma vez que era ausente na região ântero-medial do óstio. Verificou-se que os feixes miocárdicos ventriculares inseriam-se de forma oblíqua, na borda externa do anel, sendo que na região ântero-medial assumiam uma trajetória semicircular. Os folhetos da valva mitral eram constituídos de feixes colágenos dispostos, paralelamente, no sentido do maior eixo da válvula, recobertos pelo endocárdio atrial e ventricular. Os feixes colágenos, presentes na base dos folhetos valvares, praticamente se continuavam com os do anel fibroso. Observou-se, em alguns casos, a existência de delgados feixes miocárdios atriais no folheto valvar anterior, que praticamente eram restritos à região central das válvulas. CONCLUSÃO: Os folhetos da valva mitral e seu anel fibroso possuem uma continuidade estrutural, que demonstra que estes elementos funcionam de forma integrada no fechamento do óstio atrioventricular esquerdo durante a sístole ventricular, no que seria auxiliado pela redução do diâmetro do anel fibroso, através da contração dos feixes miocárdicos semicirculares que nele se inserem.<br>PURPOSE: To study the spatial arrangement of the fibrous elements that form the leaflets of the mitral valve and its fibrous ring. METHODS: The study of 20 human adult hearts, of both sexes, fixed in 10% formaldehyde solution was made. The mitral valves with their fibrous rings and small parts of the adjacent atrial and ventricular muscles were removed. Part of this material was embedded in paraffin and cut serially at a thickness of 40µm and stained by Azan's trichrome and by resorcin-fuccin and another was dissected under stereoscope in order to verify the arrangement of the myocardial bundles at the level of the fibrous ring. RESULTS: It was observed that the fibrous ring is consisted of collagenous fibers which involved in an incomplete form the atrioventricular ostium, as they were absent in the anteromedial region of the ostium. The leaflets were made of collagenous fibers disposed parallel to the long axis of the valve. This collagenous fibers were covered by atrial and ventricular endocardium. The collagenous fibers of the leaflets were continuous, by their base, into the fibrous ring. It was observed, in a few cases, the presence of atrial muscle fibers into the anterior leaflet of the mitral, mainly in its central area. CONCLUSION: The leaflets of the mitral valve and its fibrous ring have a structural continuity suggesting that elements would act synchronously in the closure of the atrioventricular ostium during ventricular systole. The contraction of the myocardial bundles fixed in the fibrous ring contributes to decrease the diameter of the mitral ring

Evaluación de las actividades antimicrobianas y moduladoras de resistencia de extractos y fracciones de Piper mollicomum (Piperaceae)

Este estudio tuvo como objetivo evaluar las actividades antimicrobianas de diferentes extractos de Piper mollicomum Kunth ex Steud. contra cepas estándar y resistentes a múltiples fármacos de bacterias y hongos, así como analizar su potencial para modular la resistencia a los antimicrobianos. Los datos obtenidos en este trabajo demostraron una actividad potenciadora de antibióticos prometedora por parte de P. mollicomum, alentando el desarrollo de nuevas investigaciones para caracterizar las propiedades toxicológicas y farmacológicas de los extractos y compuestos aislados de esta especie, que pueden contribuir al desarrollo de nuevos agentes terapéuticos para combatir la resistencia a los antimicrobianos.This study aimed to evaluate the antimicrobial activities of different extracts of Piper mollicomum Kunth ex Steud. against standard and multidrug resistant strains of bacteria and fungi, as well as to analyze their potential to modulate antimicrobial resistance. The data obtained in this work demonstrated promising antibiotic-enhancing activity by P. mollicomum, encouraging the development of further research to characterize the toxicological and pharmacological properties of the extracts and isolated compounds of this species, which may contribute to the development of new therapeutic agents to combat antibacterial resistance