title: Synergistic antifungal activity of berberine derivative B-7b and fluconazole.
abstract: Our previous study demonstrated berberine (BBR) and fluconazole (FLC) used concomitantly exhibited a synergism against FLC-resistant Candida albicans in vitro. We also suggested BBR played a major antifungal role in the synergism of FLC and BBR, while FLC increased intracellular BBR concentrations. Our following systematic structural modification and reconstruction of BBR core identified the novel scaffold of N-(2-(benzo[d][1,3]dioxol-5-yl)ethyl)-2-(substituted phenyl)acet-amide derivatives 7a-i, including B-7b and B-7d exhibiting remarkable synergistic antifungal activity and low cytotoxicity. Here, the study mainly investigated the synergistic activity of FLC and B-7b and the underlying mechanism. In vitro interaction of FLC and B-7b was investigated against 30 FLC-resistant clinical isolates of C. albicans and non-C. albicans species, including Candida tropicalis, Candida parapsilosis, Candida glabrata, Candida krusei and Cryptococcus neoformans. The potent synergistic activity of B-7b in combination with FLC against FLC-resistant C. albicans was found through the checkerboard microdilution assay. The findings of agar diffusion tests and time-kill curves confirmed its better synergism with FLC. And as expected, B-7b exhibited much lower cytotoxicity than BBR to human umbilical vein endothelial cells. In contrast to BBR, we found that endogenous ROS augmentation was not involved in the synergism of FLC and B-7b. According to the results from our present comparative proteomic study, it seemed that the disruption of protein folding and processing and the weakening of cells' self-defensive ability contributed to the synergism of FLC and B-7b. Together, these results suggested novel scaffold BBR derivative B-7b could be a promising synergist in combination with FLC for the treatment of invasive fungal infections.
authors.affiliation: Shanghai Tenth People's Hospital, and Department of Pharmacology, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, PR China.
authors.forename: Li Ping
authors.initials: LP
authors.lastname: Li
authors.affiliation: Shanghai Tenth People's Hospital, and Department of Pharmacology, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: New Drug Research and Development Center, School of Pharmacy, Second Military Medical University, Shanghai, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.affiliation: Shanghai Tenth People's Hospital, and Department of Pharmacology, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, PR China.
authors.forename: Fang
authors.initials: F
authors.lastname: Zhu
authors.affiliation: New Drug Research and Development Center, School of Pharmacy, Second Military Medical University, Shanghai, China.
authors.forename: Da Zhi
authors.initials: DZ
authors.lastname: Zhang
authors.affiliation: Shanghai Tenth People's Hospital, and Department of Pharmacology, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Shen
authors.affiliation: New Drug Research and Development Center, School of Pharmacy, Second Military Medical University, Shanghai, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Xu
authors.affiliation: New Drug Research and Development Center, School of Pharmacy, Second Military Medical University, Shanghai, China.
authors.forename: Yun Peng
authors.initials: YP
authors.lastname: Qi
authors.affiliation: Shanghai Tenth People's Hospital, and Department of Pharmacology, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, PR China.
authors.forename: Shi Qun
authors.initials: SQ
authors.lastname: Zhang
authors.affiliation: Shanghai Tenth People's Hospital, and Department of Pharmacology, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, PR China.
authors.forename: Si Min
authors.initials: SM
authors.lastname: Chen
authors.affiliation: New Drug Research and Development Center, School of Pharmacy, Second Military Medical University, Shanghai, China.
authors.forename: Li Juan
authors.initials: LJ
authors.lastname: He
authors.affiliation: New Drug Research and Development Center, School of Pharmacy, Second Military Medical University, Shanghai, China.
authors.forename: Xin Ju
authors.initials: XJ
authors.lastname: Cao
authors.affiliation: Shanghai Tenth People's Hospital, and Department of Pharmacology, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.affiliation: Shanghai Tenth People's Hospital, and Department of Pharmacology, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, PR China.
authors.forename: Jun Dong
authors.initials: JD
authors.lastname: Zhang
authors.affiliation: New Drug Research and Development Center, School of Pharmacy, Second Military Medical University, Shanghai, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Yan
authors.affiliation: Shanghai Tenth People's Hospital, and Department of Pharmacology, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, PR China.
authors.forename: Mao Mao
authors.initials: MM
authors.lastname: An
authors.affiliation: Shanghai Tenth People's Hospital, and Department of Pharmacology, Tongji University School of Medicine, 1239 Siping Road, Shanghai, 200092, PR China; New Drug Research and Development Center, School of Pharmacy, Second Military Medical University, Shanghai, China.
authors.forename: Yuan Ying
authors.initials: YY
authors.lastname: Jiang
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D001599:Berberine / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects; D003455:Cryptococcus neoformans / Q000187:drug effects; D025141:Drug Resistance, Fungal; D004357:Drug Synergism; D015725:Fluconazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests
chemical_list: D000935:Antifungal Agents; D001599:Berberine; D015725:Fluconazole