RESUMO
Withanolides are steroidal lactones commonly found in plants of the Solanaceae family that have significant medicinal value. In this study, three withanolides extracted from Iochroma arborescens leaves were isolated and characterized. These included withaphysalin F (3: ) and two newly identified epimeric compounds: 18R- and 18S-O-methyl-withaphysalin F (1: and 2: ). Their structures were elucidated by NMR, IR, MS, CD, and X-ray diffraction analysis, and their potential against cell proliferation and migration was investigated. The cytotoxic assay revealed activity against different tumor and non-tumor cell lines. (18S)-O-methyl-withaphysalin F (2: ) presented cell death effects after at least 6 hours of exposure. MDA-MB-231 cells were exposed to 0.06 and 0.6 µM of (18S)-O-methyl-withaphysalin F (2: ), and reductions in cell adhesion, migration, and clonogenicity were observed. Morphological analysis revealed negative regulation in filopodia, salience, and roughness, as well as alterations in cellular microarchitecture. These results provide clues as to the effects of (18S)-O-methyl-withaphysalin F (2: ), allowing new molecular modifications to improve potency and selectivity and increase our antineoplastic arsenal.
Assuntos
Antineoplásicos Fitogênicos , Movimento Celular , Proliferação de Células , Humanos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Vitanolídeos/farmacologia , Vitanolídeos/isolamento & purificação , Vitanolídeos/química , Solanaceae/química , Estrutura Molecular , Folhas de Planta/químicaRESUMO
Candida albicans is a major cause of human infections, ranging from relatively simple to treat skin and mucosal diseases to systemic life-threatening invasive candidiasis. Fungal infections treatment faces three major challenges: the limited number of therapeutic options, the toxicity of the available drugs, and the rise of antifungal resistance. In this study, we demonstrate the antifungal activity and mechanism of action of peptides ToAP2 and NDBP-5.7 against planktonic cells and biofilms of C. albicans. Both peptides were active against C. albicans cells; however, ToAP2 was more active and produced more pronounced effects on fungal cells. Both peptides affected C. albicans membrane permeability and produced changes in fungal cell morphology, such as deformations in the cell wall and disruption of ultracellular organization. Both peptides showed synergism with amphotericin B, while ToAP2 also presents a synergic effect with fluconazole. Besides, ToAP2 (6.25 µM.) was able to inhibit filamentation after 24 h of treatment and was active against both the early phase and mature biofilms of C. albicans. Finally, ToAP2 was protective in a Galleria mellonella model of infection. Altogether these results point to the therapeutic potential of ToAP2 and other antimicrobial peptides in the development of new therapies for C. albicans infections.