Study on the inhibitory mechanism of fig leaf extract against postharvest Fusarium in melon.

The objective of this study was to explore the fungistatic mechanism of fig leaf extract against Fusarium and to provide a theoretical basis for the development of new plant-derived fungicides. Methods: The fungistaticity of fig leaf extract were analyzed by the ring of inhibition method. Fusarium equiseti was selected as the target for analyzing its fungistatic mechanism in terms of mycelial morphology, ultrastructure, cell membrane permeability, membrane plasma peroxidation, reactive oxygen species (ROS) content and changes in the activity of protective enzymes. The effect of this extract was verified in melon, and its components were determined by metabolite analysis using ultraperformance liquid chromatography‒mass spectrometry (UPLC‒MS). Results: Fig leaf extract had an obvious inhibitory effect on Fusarium, and the difference was significant (P < 0.05) or highly significant (P < 0.01). Scanning and transmission electron microscopy revealed that F. equiseti hyphae exhibited obvious folding, twisting and puckering phenomena, resulting in an increase in the cytoplasmic leakage of spores, interstitial plasma, and the concentration of the nucleus, which seriously damaged the integrity of the fungal cell membrane. This phenomenon was confirmed by propidium iodide (PI) and fluorescein diacetate (FAD) staining, cell membrane permeability and malondialdehyde (MDA) content. Fig leaf extract also induced the mycelium to produce excessive H2O2,which led to lipid peroxidation of the cell membrane, promoted the accumulation of MDA, accelerated protein hydrolysis, induced an increase in antioxidant enzyme activity, and disrupted the balance of ROS metabolism; these findings showed that fungal growth was inhibited, which was verified in melons. A total of 1,540 secondary metabolites were detected by broad-targeted metabolomics, among which the fungistatic active substances flavonoids (15.45%), phenolic acids (15%), and alkaloids (10.71%) accounted for a high percentage and the highest relative content of these substances 1,3,7,8-tetrahydroxy-2- prenylxanthone, 8-hydroxyquinoline and Azelaic acid were analysed for their antimicrobial, anti-inflammatory, antioxidant, preventive effects against plant diseases and acquisition of resistance by plants. This confirms the reason for the fungicidal properties of fig leaf extracts. Conclusion: Fig leaf extract has the potential to be developed into a plant-derived fungicide as a new means of postharvest pathogen prevention and control in melon.

Will the zero-margin drug policy reduce the economic burden of stroke patients in China?

BACKGROUND: China is facing a more severe stroke challenge. In 2017, China fully implemented the zero-margin drug policy (ZMDP), cancelling 15% of drug markups in public hospitals. Based on the "System of Health Accounts 2011" (SHA 2011), this paper explores the changes in the economic burden of stroke in China after implementing ZMDP to provide an accurate reference for policymakers. METHODS: Stroke patients from 2016 to 2018 were selected by multistage stratification probability-proportional random sampling in Shanxi Province. A total of 223 187 samples were included. Regression discontinuity design (RDD) was used to measure the change of drug proportion and cost. Sensitivity analysis and subgroup analysis were implied to determine the stability of the results. RESULTS: The current curative expenditure on stroke from 2016 to 2018 was 4374.69, 3727.22, and 3752.52 million Chinese Yuan (CNY). About 90% of the cost occurred during hospitalization, and 60% in general hospitals. After the implementation of ZMDP, the drug proportion from 46.54% (interquartile range (IQR) = 37.10%, 55.14%) in 2016 to 36.40% (IQR = 25.82%, 48.58%) in 2018, and average hospitalization cost per stay was from 7950.02 (IQR = 4938.76, 12 639.90) CNY in 2016 to 7362.08 (IQR = 4892.82, 11 501.40) CNY in 2018. RDD showed the drug proportion decreased by 2.76% (95% confidence interval (CI) = 1.17%, 4.35%, P = 0.001), and the expense decreased by 4698.34 (95% CI = 3047.59, 6349.09, P < 0.001) CNY. CONCLUSIONS: The economic burden of stroke patients in China was severe. ZMDP played a noticeable effect in reducing drug proportion and hospitalization costs. The Chinese government should continue to implement relevant policies to control stroke costs according to regional and population characteristics.