In vitro evaluation of the acquisition of resistance, antifungal activity and synergism of Brazilian red propolis with antifungal drugs on Candida spp.

AIMS: To evaluate the ability of Candida parapsilosis and Candida glabrata to develop phenotypic resistance to a benzophenone enriched fraction obtained from Brazilian red propolis (BZP-BRP) as compared to fluconazole (FLC). To investigate possible synergy between BZP-BRP and FLC and anidulafungin (AND). METHODS AND RESULTS: To analyse the development of resistance, isolates susceptible to these antifungals were cultured in increasing concentrations of FLC and BZP-BRP. The increase in FLC minimum inhibitory concentration for all isolates was evident and the majority developed resistance, whereas none isolated became less susceptible to BZP-BRP. Synergism was investigated by checkerboard method. BZP-BRP demonstrated synergy with FLC and indifference with AND for most isolates. CONCLUSIONS: In conclusion, the synergism observed with FLC suggests that BZP-BRP could be a possible therapeutic strategy for the treatment of infections related to FLC-resistant Candida sp. SIGNIFICANCE AND IMPACT OF THE STUDY: The indiscriminate use of antifungals results in the emergence of drug-resistant strains among previously susceptible populations. BZP-BRP can become an alternative for the treatment of persistent infections caused by Candida sp.

Benzopyrans from Hypericum polyanthemum.

From the aerial parts of Hypericum polyanthemum Klotzsch ex Reichardt (Guttiferae), three chromenes, 6-isobutyryl-5,7-dimethoxy-2,2-dimethyl-benzopyran; 7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethyl-benzopyran and 5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethyl-benzopyran were isolated. Their structures were determined by NMR spectroscopic analyses.

The use of complex polysaccharides in the management of metabolic diseases: the case of Solanum lycocarpum fruits.

In the Brazilian cerrado, a preparation obtained from the fruits of Solanum lycocarpum St.-Hil. (Solanaceae), popularly known as 'fruta-de-lobo' (wolf-fruit), have been widely employed for diabetes management, obesity and to decrease cholesterol levels. The medicinal preparation consists of the green fruits which are ground in aqueous solution and filtered. The white 'gum' deposited is decanted and slowly dried providing a powder which is commercialized in capsules with the name of 'polvilho-de-lobeira'. Through phytochemical analysis of this phytomedicine and the fruit of S. lycocarpum we found polysaccharides as the main component. Some polysaccharides slow gastric emptying and act on the endocrinous system affecting the liberation of gastrointestinal hormones, lowering blood glucose levels. The hypocholesterolemic activity could be due to the increased fecal bile acid excretion as well as to the action of the short-chain fatty acids, coming from fermentation, on the synthesis of delta-aminolevulinate and by the increase of the cholesterol 7-alpha-hydroxylase and 3-hydroxy-3-methylglutaryl CoA reductase synthesis.

The distribution of iridoids in Bignoniaceae.

The distribution of iridoids among the tribes of Bignoniaceae is shown. In the present work, 18 species from the tribes Bignonieae and Tecomeae as well as one from Eccremocarpeae have been investigated. These data combined with those obtained through a literature review were analysed and showed that iridoids occur predominantly in the tribe Tecomeae. In this tribe, a chemical distintion between the genera Tabebuia and Tecoma was observed: The iridoids in Tabebuia are decarboxylated whereas in Tecoma they are C-4 formylated. The species from Bignonieae are poorly investigated and only few reports have been published, however, the iridoids found are mainly C-4 carboxylated. The only exception, Dolichandra cynanchoides (=Macfadyena cynanchoides), with decarboxylated iridoids, is also morphologically abnormal in Bignonieae.