[Rapid discovery of tyrosinase inhibitors from Sophora flavescens:significance for comprehensive utilization of its non-medicinal resources].

Sophorae Flavescentis Radix,derived from the root of Sophora flavescens in the Leguminosae family,has been widely used in the medicine,agriculture,animal husbandry,and daily chemical industry. A pharmacophore model-based method for rapid discovery of tyrosinase inhibitors( TIs) from S. flavescens was established by molecular docking under Lipinski rules,and verified by enzyme assays. Briefly,the chemical constituent database of S. flavescens( CDSF) was established based on the previous papers. Theoptimal pharmacophore model( OPM) was constructed by DS 2019 on the basis of known active TIs. Eighty-three hits predominated by flavonoids having higher fitting scores with OPM than the positive control were screened out,and subjected to molecular docking based on the three-dimensional structure of tyrosinase crystal protein. The potential TIs such as kurarinone and nor-kurarinone were rapidly discovered from the compounds with higher docking scores than the positive control under the Lipinski rules. The results were verified by the in vitro enzyme assays. The inhibition activities of tyrosinase from non-medicinal parts of S. flavescens were also tested to explore the relationship between the inhibition activity and chemical compositions. This study is expected to provide data support for the comprehensive application and development of S. flavescens and also a new method for the rapid discovery of active substances or functional constituents in the complex systems.

[Effect of Xuebijing Injection on TLR4-NF-κB-TNF-α pathway of rats' myocardial anoxia/reoxygenation].

OBJECTIVE: To explore the role of Xuebijing Injection (XBJI) in inhibiting inflammatory factors associated with anoxia/reoxygenation myocardial inflammatory response of rats. METHODS: Totally 36 healthy male Sprague-Dawley rats, 280 ± 30 g were randomly divided into six groups, i.e., the normal control group (N group), the balanced perfusion group (BP group),the model group (M group),the low dose XBJI group (XBJI(L) group), the middle dose XBJI group (XBJI(M) group),and the high dose XBJI group (XBJI(H) group), 6 in each group. The myocardial anoxia/reoxygenation rat model was established by Langendorff isolated heart perfusion. The concentration of TNF-α in the myocardial tissue was detected by ELISA. The expression of nuclear factor kappa B p65 (NF-κB p65) protein and Toll like receptor 4 (TLR4) protein were detected using Western blot. The expression of NF-κB p65 mRNA and TLR4 mRNA was detected by RT-PCR. Ultrastructural changes of anoxia-reoxygenation rats' heart muscle were observed under transmission electron microscope. RESULTS: Compared with the M group,the TNF-α concentration, expression levels of NF-κB p65 protein and mRNA, TLR4 protein and mRNA decreased to various degrees in the XBJI(L) group, the XBJI(M) group, and the XBJI(H) group. The TNF-α expression level decreased most significantly in the XBJI(L), group (P < 0.01), while other indices decreased most obviously in the XBJI(M) group (P < 0.01, P < 0.05). Expression levels of NF-κB p65 and TLR4 protein were obviously lower in the XBJI(M) group than in the XBJI(L) group (P < 0.05). There was no statistical difference in other indices among the three XBJI groups (P > 0.05). Myocardial fibers were loose and broken with disappearance of transverse striation, and mitochondrial cristae was dissolved and severely damaged in the M group. The aforesaid condition was improved after treated by XBJI, with the most obvious effect obtained in the XBJI(M) group. CONCLUSIONS: Different doses of XBJI could attenuate inflammatory reactions after myocardial anoxia/reoxygenation rats' heart muscle through inhibiting TLR4-NF-κB-TNF-α signal transduction pathway. The best effect could be obtained by 4 mL/100 mL XBJI.