Mycological and Electron Microscopic Study of Solanum chrysotrichum Saponin SC-2 Antifungal Activity on Candida Species of Medical Significance

Abstract

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 IC (50) of 200 microg/mL for SC-2, 400 microg/mL was found in four strains, and 800 microg/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 microg/mL for the majority of strains (nine), 400 microg/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 microg/mL (in Fluco-susceptible strains) and of 400 - 800 mug/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.

Handbook of Integrative Dermatology

“…It was shown to have a similar clinical effectiveness to that of ketoconazole, but obtained a smaller percentage of mycological effectiveness and 100% tolerability (Herrera-Arellano et al 2013 ) . An additional study found the Saponin SC to be effective against candida non-albicans species, or fluconazole and ketoconazole resistant strains of yeast (Herrera-Arellano et al 2007 …”

Advances in the mechanisms of Hibiscus sabdariffa L. on hypertension

“…The rigid planar structure of delphinidin-3-O-sambubioside and cyanidin-3-O-sambubioside and the presence of ortho-dihydroxylation on the aromatic ring probably contributed to the inhibition of ACE [12] . Another clinical trial, conducted on 193 patients with hypertension stages I and II, carried out by Herrera-Arellano et al also confirmed the inhibition of ACE activity through using watery infusions of HS [42] . The trial showed that HS calyxes could significantly reduce plasma ACE activity.…”

“…Daily consumption of 500 mg of HS calyx powder could reduce systolic blood pressures and serum triglycerides in metabolic syndrome patients [17] . Another clinical trial showed that the experimental treatment decreased blood pressure from 146.48/97.77 to 129.89/85.96 mmHg, reaching an absolute reduction of 17.14/11.97 mmHg by using HS calyx watery infusions [6] . Notably, this experimental treatment showed a therapeutic effectiveness of 65.12% and a tolerability and safety up to 100%.…”

“…They are abundant in HS flower and responsible for its red color [5]. Anthocyanins, particularly delphinidin-3-sambubioside and cyanidin-3-sambubioside, are regarded as important nutraceuticals since they play a potential role in the prevention of various diseases associated with oxidative stress [6][7][8][9] . Early reports have proved that polyphenol-rich foods could protect and improve endothelial function with vascular relaxation through the NO-cGMP pathway and ACE inhibition, resulting in a decrease of blood pressure [10][11].…”

Oral mycoses and other opportunistic infections in HIV: therapy and emerging problems – a workshop report

“…Alternative medicine is practiced in China, Tanzania, Kenya, South Africa, Pakistan, France, Iran, India, USA, Turkey, Rumania, Mexico, and several other countries (de Boer et al , ; Zaidi and Crow, ; Herrera‐Arellano et al , ; Hancianu et al , ; Ndhlala et al , ; Altuner et al , ; Farahnejad et al , ; Liu et al , ; Zheng et al , ; Kitonde et al , ; Vediyappan et al , ).…”