RESUMEN
Liquidambar styraciflua L. is an aromatic species, popularly used in traditional Chinese medicine to treat diarrhea, dysentery, coughs, and skin sores. The present study was designed to investigate the chemical composition and biological potential of extracts obtained from the fruits of this plant. For the chemical evaluation, it was used mainly liquid and gas chromatography, plus NMR, and colorimetric methods. The aqueous extract (EA) originated two other fractions: an aqueous (P-EA) and an ethanolic (S-EA). The three extracts were composed of proteins, phenolic compounds, and carbohydrates in different proportions. The analyses showed that the polysaccharide extract (P-EA) contained pectic polysaccharides, such as acetylated and methyl esterified homogalacturonans together with arabinogalactan, while the fraction S-EA presented phenolic acids and terpenes such as gallic acid, protocathecuic acid, liquidambaric acid, combretastatin, and atractyloside A. EA, P-EA, and S-EA showed antioxidant activity, with IC50 values of 4.64 µg/mL, 16.45 µg/mL, and 3.67 µg/mL, respectively. The cytotoxicity followed the sequence S-EA > EA > P-EA, demonstrating that the toxic compounds were separated from the non-toxic ones by ethanol precipitation. While the fraction S-EA is very toxic to any cell line, the fraction P-EA is a promising candidate for studies against cancer due to its high toxicity to tumoral cells and low toxicity to normal cells.
Asunto(s)
Antineoplásicos , Liquidambar , Frutas , Extractos Vegetales/farmacología , Extractos Vegetales/química , Liquidambar/química , Antioxidantes/farmacología , Antioxidantes/química , Antineoplásicos/farmacologíaRESUMEN
Scedosporium apiospermum is an emerging fungal pathogen that causes both localized and disseminated infections in immunocompromised patients. Glucosylceramides (CMH, GlcCer) are the main neutral glycosphingolipids expressed in fungal cells. In this study, glucosylceramides (GlcCer) were extracted and purified in several chromatographic steps. Using high-performance thin layer chromatography (HPTLC) and electrospray ionization mass spectrometry (ESI-MS), N-2'-hydroxyhexadecanoyl-1-ß-D-glucopyranosyl-9-methyl-4,8-sphingadienine was identified as the main GlcCer in S. apiospermum. A monoclonal antibody (Mab) against this molecule was used for indirect immunofluorescence experiments, which revealed that this CMH is present on the surface of the mycelial and conidial forms of S. apiospermum. Treatment of S. apiospermum conidia with the Mab significantly reduced fungal growth. In addition, the Mab also enhanced the phagocytosis and killing of S. apiospermum by murine cells. In vitro assays were performed to evaluate the CMHs for their cytotoxic activities against the mammalian cell lines L.929 and RAW, and an inhibitory effect on cell proliferation was observed. Synergistic in vitro interactions were observed between the Mab against GlcCer and both amphotericin B (AmB) and itraconazole. Because Scedosporium species develop drug resistance, the number of available antifungal drugs is limited; our data indicate that combining immunotherapy with the available drugs might be a viable treatment option. These results suggest that in S. apiospermum, GlcCer are most likely cell wall components that are targeted by antifungal antibodies, which directly inhibit fungal development and enhance macrophage function; furthermore, these results suggest the combined use of monoclonal antibodies against GlcCer and antifungal drugs for antifungal immunotherapy.
Asunto(s)
Glucosilceramidas/metabolismo , Macrófagos/microbiología , Scedosporium/crecimiento & desarrollo , Scedosporium/metabolismo , Anfotericina B/farmacología , Animales , Anticuerpos Monoclonales/inmunología , Línea Celular , Medios de Cultivo Condicionados/metabolismo , Glucosilceramidas/química , Glucosilceramidas/inmunología , Itraconazol/farmacología , Masculino , Ratones , Scedosporium/efectos de los fármacos , Scedosporium/fisiologíaRESUMEN
Brown, red and green algae from the Southeastern coast of Brazil were successively extracted with chloroform/methanol 2:1 and 1:2 (v/v). The crude lipid extract was partitioned according to Folch and the lower phase enriched in glycolipids was fractionated on a silica gel column chromatography eluted with chloroform, acetone and methanol. Three major orcinol-reactive bands present in the acetone and methanol fractions were detected by thin-layer chromatography with chromatographic mobilities corresponding to sulfoglycolipids and glycosyldiacylglycerols. These fractions exhibited potent antiviral activity against HSV-1-ACVs and HSV-1-ACVr and present low toxicity for cell cultures. Purification and identification of these bioactive glycolipids will be necessary in order to elucidate their primary structures and mechanism of action.