Study on the inhibitory effectand the mechanismof alkaloids from Sophoraalopecuroides on Candida albi-cans in vitro

LI Xin; HUO Jingchen; GAO Chaoyang; ZHANG Juan

doi:10.3969/j.issn.1673-3827.2025.04.004

Abstract：Objective To investigate thefungicidal activity and mechanism of Sophoraalopecuroides alkaloids(including al-operine,matrine,sophoridine,andsophocarpine)against Candida albicans in vitro.Methods The sensitivity of C.albicans to S.alopecuroides alkaloids was determined using the agar diffusion assay.The combined drug sensitivity effects were eval-uated through the checkerboard microdilution method,and the time-kill curves were constructed.Fungal metabolic activity was measured by XTT assay,while biofilm biomass was quantified via crystal violet staining.The content of extracellular secreted proteins was determined using the Bradford method.Apoptosis rates were analyzed by flow cytometry using annexin V-FITC/PI double staining.Mitochondrial membrane potential was monitored using JC-1 staining,while reactive oxygen species(ROS)levels were tracked with DCFH-DA,both via fluorescence-based detection.Results The minimum fungicidal concentrations(MFCs)were 7.50 mg/mL(aloperine),8.00 mg/mL(matrine),12.50 mg/mL(sophoridine),and 4.25 mg/mL(sophocarpine).Compared with the blank control,treatment with S.alopecuroidesalkaloids significantly reduced fungal viability and biofilm formation,remarkably increased the extracellular protein secretion content and apoptosis rate of C.albicans,and had no statistically significant effect on the decrease of mitochondrial membrane potential and accumulation of reactive oxygen species except for the optimal combination F(matrine 1 mg/mL+sophoridine 0.78 mg/mL+aloperine 3.75 mg/mL)of the three S.alopecuroidesalkaloids showed a trend of action.Conclusion S.alopecuroides alkaloids inhibit C.albicans through a dual mechanism:direct fungicidal activity and induction of apoptosis.The mechanism likely involves ROS burst and mitochondrial dysfunction.