TY - JOUR
T1 - Mycological and electron microscopic study of Solanum chrysotrichum saponin SC-2 antifungal activity on Candida species of medical significance
AU - Herrera-Arellano, Armando
AU - Martínez-Rivera, María De Los Angeles
AU - Hernández-Cruz, Maribel
AU - López-Villegas, Edgar Oliver
AU - Rodríguez-Tovar, Aída Verónica
AU - Alvarez, Laura
AU - Marquina-Bahena, Silvia
AU - Navarro-García, Víctor Manuel
AU - Tortoriello, Jaime
PY - 2007/12
Y1 - 2007/12
N2 - Solanum chrysotrichum is utilized in traditional Mexican medicine for the treatment of mycotic skin infections. Several microbiological studies have provided evidence of its antifungal activity against dermatophytes and yeasts. S. chrysotrichum saponins have been identified as a group of compounds with antifungal activity and saponin SC-2 has demonstrated to be the most active. Previous clinical studies have shown the therapeutic effectiveness of S. chrysotrichum-derived saponin-standardized herbal products in the treatment of Tinea pedis and Pityriasis capitis. There is no previous evidence of the activity of these saponins against Candida non-albicans species, or fluconazole- and ketoconazole-resistant Candida strains. The present study reports the biological activity of the SC-2 saponin (inhibitory concentration [IC 50] and minimum fungicide concentration [MFC]), against 12 Candida strains of clinical significance (C. albicans, five strains; C. glabrata and C. parapsilosis, two; C. krusei, C. lusitaniae and C. tropicalis, one), including some fluconazole (Fluco)- and ketoconazole (Keto)-resistant clinical isolates. In addition, SC-2-associated microstructural alterations were reported in four of the above-mentioned Candida species. Seven strains had IC50 of 200 μg/mL for SC-2, 400 μg/mL was found in four strains, and 800 μg/mL for a sole C. glabrata strain. Susceptibility to SC-2 saponin was as follows: C. albicans = C. lusitaniae > C. krusei > C. glabrata. The MFC was 800 μg/mL for the majority of strains (nine), 400 μg/mL for C. albicans (two strains) and C lusitaniae. The ultrastructural Candida changes originated by SC-2 included the following: 1) damage on cytoplasmic membrane and organelles; 2) changes in cell wall morphology and density, with separation of cytoplasmatic membrane from cell wall and disintegration of the latter; and 3) total degradation of cellular components and death. Changes were manifested from 6 h of incubation, reaching their maximum effect at 48 h. In conclusion, the saponin SC-2 possesses fungicide and fungistatic activity on different Candida albicans and non-albicans species (including some azole-resistant strains) with IC 50 values of 200 μg/mL (in Fluco-susceptible strains) and of 400 - 800 μg/mL (in Fluco-resistant strains). Additionally, we observed by transmission electron microscopy (TEM) that saponin SC-2 causes severe changes in all fungal cell membranes, and to a lesser degree on the cell wall.
AB - Solanum chrysotrichum is utilized in traditional Mexican medicine for the treatment of mycotic skin infections. Several microbiological studies have provided evidence of its antifungal activity against dermatophytes and yeasts. S. chrysotrichum saponins have been identified as a group of compounds with antifungal activity and saponin SC-2 has demonstrated to be the most active. Previous clinical studies have shown the therapeutic effectiveness of S. chrysotrichum-derived saponin-standardized herbal products in the treatment of Tinea pedis and Pityriasis capitis. There is no previous evidence of the activity of these saponins against Candida non-albicans species, or fluconazole- and ketoconazole-resistant Candida strains. The present study reports the biological activity of the SC-2 saponin (inhibitory concentration [IC 50] and minimum fungicide concentration [MFC]), against 12 Candida strains of clinical significance (C. albicans, five strains; C. glabrata and C. parapsilosis, two; C. krusei, C. lusitaniae and C. tropicalis, one), including some fluconazole (Fluco)- and ketoconazole (Keto)-resistant clinical isolates. In addition, SC-2-associated microstructural alterations were reported in four of the above-mentioned Candida species. Seven strains had IC50 of 200 μg/mL for SC-2, 400 μg/mL was found in four strains, and 800 μg/mL for a sole C. glabrata strain. Susceptibility to SC-2 saponin was as follows: C. albicans = C. lusitaniae > C. krusei > C. glabrata. The MFC was 800 μg/mL for the majority of strains (nine), 400 μg/mL for C. albicans (two strains) and C lusitaniae. The ultrastructural Candida changes originated by SC-2 included the following: 1) damage on cytoplasmic membrane and organelles; 2) changes in cell wall morphology and density, with separation of cytoplasmatic membrane from cell wall and disintegration of the latter; and 3) total degradation of cellular components and death. Changes were manifested from 6 h of incubation, reaching their maximum effect at 48 h. In conclusion, the saponin SC-2 possesses fungicide and fungistatic activity on different Candida albicans and non-albicans species (including some azole-resistant strains) with IC 50 values of 200 μg/mL (in Fluco-susceptible strains) and of 400 - 800 μg/mL (in Fluco-resistant strains). Additionally, we observed by transmission electron microscopy (TEM) that saponin SC-2 causes severe changes in all fungal cell membranes, and to a lesser degree on the cell wall.
KW - Antifungal activity
KW - Solanaceae
KW - Solanum chrysotrichum
KW - Spirostan saponin
UR - http://www.scopus.com/inward/record.url?scp=38149136580&partnerID=8YFLogxK
U2 - 10.1055/s-2007-993744
DO - 10.1055/s-2007-993744
M3 - Artículo
C2 - 18058612
SN - 0032-0943
VL - 73
SP - 1568
EP - 1573
JO - Planta Medica
JF - Planta Medica
IS - 15
ER -