AUTHOR=Liang Guihong , Zhao Jinlong , Dou Yaoxing , Yang Yuan , Zhao Di , Zhou Zhanpeng , Zhang Rui , Yang Weiyi , Zeng Lingfeng 

TITLE=Mechanism and Experimental Verification of Luteolin for the Treatment of Osteoporosis Based on Network Pharmacology

JOURNAL=Frontiers in Endocrinology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2022.866641

DOI=10.3389/fendo.2022.866641

ISSN=1664-2392

ABSTRACT=<sec><title>Purpose</title><p>To explore the molecular mechanism of <italic>luteolin</italic> in the treatment of osteoporosis (OP) by network pharmacological prediction and experimentation.</p></sec><sec><title>Methods</title><p>The target proteins of <italic>luteolin</italic> were obtained with the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). OP-related proteins were extracted from the Comparative Toxicogenomics Database (CTD) and GeneCards and DisGeNET databases. We imported the common protein targets of <italic>luteolin</italic> and OP into the STRING database to obtain the relationships between the targets. The common target proteins of <italic>luteolin</italic> and OP were assessed by KEGG and GO enrichment analyses with the DAVID database. Animal experiments were conducted to verify the effect of <italic>luteolin</italic> on bone mineral density in ovariectomised (OVX) rats. Finally, the effects of <italic>luteolin</italic> on key signalling pathways were verified by cell experiments <italic>in vitro</italic>.</p></sec><sec><title>Results</title><p>Forty-four targets of <italic>luteolin</italic> involved in the treatment of OP, including key target proteins such as TP53, AKT1, HSP90AA1, JUN, RELA, CASP3, and MAPK1, were screened. KEGG enrichment analysis found that <italic>luteolin</italic> inhibits OP by regulating the PI3K-Akt, TNF, oestrogen and p53 signalling pathways. The results of animal experiments showed that bone mass in the low-dose <italic>luteolin</italic> group (<italic>Luteolin</italic>-L group, 10 mg/kg), high-dose <italic>luteolin</italic> group (<italic>Luteolin</italic>-H group, 50 mg/kg) and positive drug group was significantly higher than that in the OVX group (P&lt;0.05). Western blot (WB) analysis showed that the protein expression levels of Collagen I, Osteopontin and RUNX2 in bone marrow mesenchymal stem cells (BMSCs) cultured with 0.5, 1 and 5 μM <italic>luteolin</italic> for 48 h were significantly higher than those in the dimethyl sulfoxide (DMSO) group (P&lt;0.05). <italic>In vitro</italic> cell experiments showed that the p-PI3K/PI3K and p-Akt/Akt expression ratios in BMSCs cultured with 0.5, 1 and 5 μM <italic>luteolin</italic> for 48 h were also significantly higher than those in the DMSO group (P&lt;0.05).</p></sec><sec><title>Conclusions</title><p><italic>Luteolin</italic> has multitarget and multichannel effects in the treatment of OP. <italic>Luteolin</italic> could reduce bone loss in OVX rats, which may be due to its ability to promote the osteogenic differentiation of BMSCs by regulating the activity of the PI3K-Akt signalling pathway.</p></sec>