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Molecular mechanisms of action of herbal antifungal alkaloid berberine, in Candida albicans.

Dhamgaye S, Devaux F, Vandeputte P, Khandelwal NK, Sanglard D, Mukhopadhyay G, Prasad R - PLoS ONE (2014)

Bottom Line: However, unlike BER, HSF1 effect on CW appeared to be independent of MAP kinase and Calcineurin pathway genes.Additionally, unlike hsf1 strain, BER treatment of Candida cells resulted in dysfunctional mitochondria, which was evident from its slow growth in non-fermentative carbon source and poor labeling with mitochondrial membrane potential sensitive probe.Together, our study not only describes the molecular mechanism of BER fungicidal activity but also unravels a new role of evolutionary conserved HSF1, in MDR of Candida.

View Article: PubMed Central - PubMed

Affiliation: School of Life Sciences, Jawaharlal Nehru University, New Delhi, India; Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India.

ABSTRACT
Candida albicans causes superficial to systemic infections in immuno-compromised individuals. The concomitant use of fungistatic drugs and the lack of cidal drugs frequently result in strains that could withstand commonly used antifungals, and display multidrug resistance (MDR). In search of novel fungicidals, in this study, we have explored a plant alkaloid berberine (BER) for its antifungal potential. For this, we screened an in-house transcription factor (TF) mutant library of C. albicans strains towards their susceptibility to BER. Our screen of TF mutant strains identified a heat shock factor (HSF1), which has a central role in thermal adaptation, to be most responsive to BER treatment. Interestingly, HSF1 mutant was not only highly susceptible to BER but also displayed collateral susceptibility towards drugs targeting cell wall (CW) and ergosterol biosynthesis. Notably, BER treatment alone could affect the CW integrity as was evident from the growth retardation of MAP kinase and calcineurin pathway mutant strains and transmission electron microscopy. However, unlike BER, HSF1 effect on CW appeared to be independent of MAP kinase and Calcineurin pathway genes. Additionally, unlike hsf1 strain, BER treatment of Candida cells resulted in dysfunctional mitochondria, which was evident from its slow growth in non-fermentative carbon source and poor labeling with mitochondrial membrane potential sensitive probe. This phenotype was reinforced with an enhanced ROS levels coinciding with the up-regulated oxidative stress genes in BER-treated cells. Together, our study not only describes the molecular mechanism of BER fungicidal activity but also unravels a new role of evolutionary conserved HSF1, in MDR of Candida.

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Related in: MedlinePlus

Antifungal potential of BER (a) Growth curve of WT C. albicans cells at 100, 150 and 200 µg/ml, (b) serial dilution assays in solid (left panel) and liquid medium for testing BER susceptibility of C. albicans and non albicans species.(c) Serial dilution assays of CDR1 (Gu5) and MDR1 (F5) overexpressing and (d) their deletions strains in presence of BER.
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pone-0104554-g001: Antifungal potential of BER (a) Growth curve of WT C. albicans cells at 100, 150 and 200 µg/ml, (b) serial dilution assays in solid (left panel) and liquid medium for testing BER susceptibility of C. albicans and non albicans species.(c) Serial dilution assays of CDR1 (Gu5) and MDR1 (F5) overexpressing and (d) their deletions strains in presence of BER.

Mentions: For an in depth analysis of mechanism of action of antifungal potentials of an herbal alkaloid BER, we have examined the growth pattern of C. albicans and observed that BER maximally retarded cell growth at 200 µg/ml (Figure 1(a)). In serial dilution assays, BER at 200 µg/ml was also effective against all the tested non-albicans species with variable susceptibilities (Figure 1(b)). For instance, C. utilis, C. kefyr and C. krusei were relatively hypersusceptible to BER and their MIC50 ranged between 25 µg/ml and >50 µg/ml, while C. glabrata and C. tropicalis were the least susceptible species with MIC50 of 200 µg/ml in contrast to C. albicans. Notably, BER has reported to be non-toxic to human cells [26].


Molecular mechanisms of action of herbal antifungal alkaloid berberine, in Candida albicans.

Dhamgaye S, Devaux F, Vandeputte P, Khandelwal NK, Sanglard D, Mukhopadhyay G, Prasad R - PLoS ONE (2014)

Antifungal potential of BER (a) Growth curve of WT C. albicans cells at 100, 150 and 200 µg/ml, (b) serial dilution assays in solid (left panel) and liquid medium for testing BER susceptibility of C. albicans and non albicans species.(c) Serial dilution assays of CDR1 (Gu5) and MDR1 (F5) overexpressing and (d) their deletions strains in presence of BER.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126717&req=5

pone-0104554-g001: Antifungal potential of BER (a) Growth curve of WT C. albicans cells at 100, 150 and 200 µg/ml, (b) serial dilution assays in solid (left panel) and liquid medium for testing BER susceptibility of C. albicans and non albicans species.(c) Serial dilution assays of CDR1 (Gu5) and MDR1 (F5) overexpressing and (d) their deletions strains in presence of BER.
Mentions: For an in depth analysis of mechanism of action of antifungal potentials of an herbal alkaloid BER, we have examined the growth pattern of C. albicans and observed that BER maximally retarded cell growth at 200 µg/ml (Figure 1(a)). In serial dilution assays, BER at 200 µg/ml was also effective against all the tested non-albicans species with variable susceptibilities (Figure 1(b)). For instance, C. utilis, C. kefyr and C. krusei were relatively hypersusceptible to BER and their MIC50 ranged between 25 µg/ml and >50 µg/ml, while C. glabrata and C. tropicalis were the least susceptible species with MIC50 of 200 µg/ml in contrast to C. albicans. Notably, BER has reported to be non-toxic to human cells [26].

Bottom Line: However, unlike BER, HSF1 effect on CW appeared to be independent of MAP kinase and Calcineurin pathway genes.Additionally, unlike hsf1 strain, BER treatment of Candida cells resulted in dysfunctional mitochondria, which was evident from its slow growth in non-fermentative carbon source and poor labeling with mitochondrial membrane potential sensitive probe.Together, our study not only describes the molecular mechanism of BER fungicidal activity but also unravels a new role of evolutionary conserved HSF1, in MDR of Candida.

View Article: PubMed Central - PubMed

Affiliation: School of Life Sciences, Jawaharlal Nehru University, New Delhi, India; Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India.

ABSTRACT
Candida albicans causes superficial to systemic infections in immuno-compromised individuals. The concomitant use of fungistatic drugs and the lack of cidal drugs frequently result in strains that could withstand commonly used antifungals, and display multidrug resistance (MDR). In search of novel fungicidals, in this study, we have explored a plant alkaloid berberine (BER) for its antifungal potential. For this, we screened an in-house transcription factor (TF) mutant library of C. albicans strains towards their susceptibility to BER. Our screen of TF mutant strains identified a heat shock factor (HSF1), which has a central role in thermal adaptation, to be most responsive to BER treatment. Interestingly, HSF1 mutant was not only highly susceptible to BER but also displayed collateral susceptibility towards drugs targeting cell wall (CW) and ergosterol biosynthesis. Notably, BER treatment alone could affect the CW integrity as was evident from the growth retardation of MAP kinase and calcineurin pathway mutant strains and transmission electron microscopy. However, unlike BER, HSF1 effect on CW appeared to be independent of MAP kinase and Calcineurin pathway genes. Additionally, unlike hsf1 strain, BER treatment of Candida cells resulted in dysfunctional mitochondria, which was evident from its slow growth in non-fermentative carbon source and poor labeling with mitochondrial membrane potential sensitive probe. This phenotype was reinforced with an enhanced ROS levels coinciding with the up-regulated oxidative stress genes in BER-treated cells. Together, our study not only describes the molecular mechanism of BER fungicidal activity but also unravels a new role of evolutionary conserved HSF1, in MDR of Candida.

Show MeSH
Related in: MedlinePlus