ABSTRACT
Aspergillus flavus is a notorious foodborne fungus, posing a significant risk to humans in the form of hepatocellular carcinoma or aspergillosis. Thymol, as a food preservative, could efficiently kill conidia of A. flavus. However, the underlying mechanisms by which thymol kills A. flavus are not completely understood. With specific fluorescent dyes, we detected several apoptotic hallmarks, including chromatin condensation, phosphatidylserine externalization, DNA damage, mitochondrial depolarization, and caspase 9 activation in conidia exposed to 200 µg/mL of thymol, indicating that thymol induced a caspase-dependent conidial apoptosis in A. flavus. Chemical-protein interactome (CPI) and autodock analyses showed that KCNAB, homologue to the ß-subunit of the voltage-gated potassium channel (Kv) and aldo-keto reductase, was the potential target of thymol. Following studies demonstrated that thymol could activate the aldo-keto reductase activity of KCNAB in vitro and stimulate a transient K+ efflux in conidia, as determined using a Port-a-Patch. Blocking K+ eruption by 4-aminopyridine (a universal inhibitor of Kv) could significantly alleviate thymol-mediated conidial apoptosis, indicating that activation of Kv was responsible for the apoptosis. Taken together, our results revealed a K+ efflux-mediated apoptotic pathway in A. flavus, which greatly contributed to the development of an alternative strategy to control this pathogen.
Subject(s)
Apoptosis/drug effects , Aspergillus flavus/drug effects , Potassium/metabolism , Spores, Fungal/metabolism , Thymol/pharmacology , Aspergillus flavus/cytology , Aspergillus flavus/genetics , Aspergillus flavus/metabolism , Fungal Proteins/genetics , Fungal Proteins/metabolism , Potassium Channels, Voltage-Gated/genetics , Potassium Channels, Voltage-Gated/metabolism , Spores, Fungal/cytology , Spores, Fungal/drug effects , Spores, Fungal/geneticsABSTRACT
OBJECTIVE: To investigate the effect of fluvastatin on blood levels of c-reactive protein (CRP), tumor necrosis factor alpha (TNFalpha) and cardiac troponin I (cTnI) in patients with unstable angina undergoing percutaneous coronary intervention (PCI). METHODS: Sixty patients who underwent PCI from July 2002 to April 2004 in our hospital were randomized into two groups: control group; fluvastatin group (40 mg/d). Serum levels of CRP, TNFalpha and cTnI were measured before and after two weeks treatment (in the early morning of the procedure) and at 24 hours after the procedure. RESULTS: The serum levels of CRP, TNFalpha and cTnI in fluvastatin group were distinctly lower than those in control group before (P < 0.01) and after the procedure (P < 0.01), respectively. CONCLUSION: The result suggested that PCI could lead to a detectable increase in serum levels of CRP, TNFalpha and cTnI in patients with coronary heart disease; Fluvastatin could significantly decrease the serum levels of CRP, TNFalpha and cTnI in patients with coronary heart disease; Fluvastatin could also decrease the serum levels of CRP, TNFalpha and cTnI in patients with PCI.