Abstract:

Objective To investigate the efficacy of Balanophora involucrata Hook.f. in treatment of hyperuricemia （HUA） based on network pharmacology， molecular docking， and hyperuricemia models in vivo and in vitro，and to clarify the main targets of its active components and related signaling pathway mechanism. Methods The potential targets of Balanophora involucrata Hook.f. in treatment of HUA were identified by Databases such as the Traditional Chinese Medicine Database in Taiwan， the Chinese Herbal Medicine Identification Database，Professional Chemical Database， TargetNet Database， SwissTargetPrediction Database， GeneCards， Therapeutic Target Database （TTD），DrugBank Database， DisGeNET Database， Online Mendelian Inheritance in Man （OMIM） Database， and Venny Database. STRING Database and Cytoscape software were used to construct the active component-predictive target network and protein-protein interaction （PPI） network for Balanophora involucrata Hook.f.；topological analysis was used to select the main active components and core targets；Gene Ontology （GO） functional and Kyoto Encyclopedia of Genes and Genomes （KEGG） signaling pathway enrichment analysis were performed by R software； AutoDock Vina software was used for molecular docking validation. The NRK-52E cells were divided into blank control group， blank administration group， model group， and different concentrations （2.0， 10.0， and 50.0 μmol·L^-1） of erythrodiol （EDT） groups. High-performance liquid chromatography culture （HPLC） was used to detect the uric acid （UA） levels in the cell culture supernatants in various groups. The male ICR mice were divided into blank control group， blank administration group， model group， and EDT group； the mice in the last two groups were used to prepare the HUA models； kits were used to detect the levels of UA， creatinine （Cr）， and blood urea nitrogen （BUN） in serum of the mice in various groups；the bilateral kidney tissue of the mice was harvested and weighed； the kidney indexes of the mice in various groups were calculated；TUNEL staining was used to observe the apoptosis in kidney tissue of the mice in various groups；Western blotting method was used to detect the expression levels of protein kinase B （AKT），phosphorylated AKT （p-AKT），phosphoinositide 3-kinase （PI3K），phosphorylated PI3K（p-PI3K）， B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， and matrix metalloproteinase-9 （MMP-9） proteins in kidney tissue of the mice in various groups. Results Six active components of Balanophora involucrata Hook.f.were identified， involving 116 intersecting targets and 14 core targets.The enrichment analysis yielded 1 828 GO terms and 145 signaling pathways. The molecular docking results showed that EDT had good binding activity with MMP-9. The high uric acid cell experiment results showed that compared with blank control group， the UA level in the cells in model group was significantly increased （P<0.01）； compared with model group， the UA levels in the cells in 2.0， 10.0， and 50.0 μmol·L^-1 EDT groups were significantly decreased （P<0.01）. Compared with blank control group， the levels of UA， Cr， and BUN in serum of the mice in model group were increased（P<0.01）， and the kidney indexes were significantly increased （P<0.01）； compared with model group， the levels of UA， Cr， and BUN in serum of the mice in EDT group were decreased （P<0.05 or P<0.01），and the kidney index was significantly decreased （P<0.05 or P<0.01）. Compared with blank control group， the number of apoptotic cells in kidney tissue of the mice in model group was increased； compared with model group， the number of the apoptotic cells in kidney tissue of the mice in EDT group was significantly decreased. Compared with blank control group， the ratios of p-AKT/AKT and p-PI3K/PI3K and expression level of Bcl-2 protein in kidney tissue of the mice in model group were significantly decreased （P<0.05 or P<0.01）， while the expression levels of Bax and MMP-9 proteins were significantly increased （P<0.01）； compared with model group， the ratios of p-AKT/AKT and p-PI3K/PI3K and expression level of Bcl-2 protein in kidney tissue of the mice in EDT group were significantly increased （P<0.05 or P<0.01）， and the expression levels of Bax and MMP-9 proteins were significantly decreased （P<0.01）. Conclusion The active component of Balanophora involucrata Hook.f.，EDT，has a UA-decreasing effect and may inhibit the apoptosis and alleviate the kidney injury by activating the PI3K/AKT signaling pathway.

Key words: Network pharmacology, Balanophora involucrata Hook.f., Eriodictyol, Hyperuricemia, Kidney injury