title: Endogenous nitric oxide accumulation is involved in the antifungal activity of Shikonin against Candida albicans.
abstract: The aim of the present study was to investigate the role of nitric oxide (NO) in the antifungal activity of Shikonin (SK) against Candida albicans (C. albicans) and to clarify the underlying mechanism. The results showed that the NO donors S-nitrosoglutathione (GSNO) and L-arginine could enhance the antifungal activity of SK, whereas the NO production inhibitor Nω-nitro-L-arginine methyl ester (L-NAME) attenuated antifungal action. Using the fluorescent dye 3-amino,4-aminomethyl-2', 7-difluorescein, diacetate (DAF-FM DA), we found that the accumulation of NO in C. albicans was increased markedly by SK in a time- and dose-dependent manner. In addition, the results of real-time reverse transcription-PCR (RT-PCR) demonstrated that the transcription level of YHB1 in C. albicans was greatly increased upon incubation of SK. Consistently, the YHB1-null mutant (yhb1Δ/Δ) exhibited a higher susceptibility to SK than wild-type cells. In addition, although the transcription level of CTA4 in C. albicans was not significantly changed when exposed to SK, the CTA4-null mutant (cta4Δ/Δ) was more susceptible to SK. Collectively, SK is the agent found to execute its antifungal activity directly via endogenous NO accumulation, and NO-mediated damage is related to the suppression of YHB1 and the function of CTA4.
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, China.
authors.forename: Zebin
authors.initials: Z
authors.lastname: Liao
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yan
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, China.
authors.forename: Huaihuai
authors.initials: H
authors.lastname: Dong
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, China.
authors.forename: Yuanying
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: School of Pharmacy, Second Military Medical University, Shanghai 200433, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Cao
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D001120:Arginine / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D008826:Microbial Sensitivity Tests; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009285:Naphthoquinones / Q000737:chemistry / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction; D026422:S-Nitrosoglutathione / Q000494:pharmacology
chemical_list: D000935:Antifungal Agents; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D009285:Naphthoquinones; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; C016101:shikonin; D026422:S-Nitrosoglutathione; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester