Elucidating the mechanism of Ligustri Lucidi Fructus in treating liver and kidney Yin deficiency based on network pharmacology

• LC-MS technique, network pharmacology and animal experiments were used to study the mechanism of LLF to protect liver and kidney Yin deficiency. • 112 compounds in LLF were identified by LC-MS technique, which provided a basis for subsequent active ingredient screening and mechanism research. • The chemical composition, pharmacological action and mechanism of LLF, a traditional Chinese medicine, were systematically studied, which provided a theoretical basis for its application in modern medicine. Traditional Chinese Medicine (TCM) syndrome, also known as ZHENG, represents a fundamental concept in TCM. It summarizes the pathological changes of a disease at specific stages of its development. Liver and kidney Yin deficiency syndrome (LKYDS), one of a pathologic and diagnostic pattern caused by the imbalance of Yin and Yang. Ligustri Lucidi Fructus (LLF) is the dried mature fruit of Ligustrum lucidum Ait. It has the effects of nourishing the liver and kidneys. To screen the active ingredients of LLF for treating liver and kidney yin deficiency based on network pharmacology and to explore their potential targets and mechanisms. We obtained disease-related targets through GeneCards and DisGeNET databases, and utilized Venny 2.1.0 to obtain targets at the intersection of components and diseases. Protein-protein interaction (PPI) analysis and GO function and KEGG pathway enrichment analysis were performed on the potential targets with the help of STRING and DAVID databases, respectively. To clarify the biological process and pathway information, which were further visualized by using the microbiology platform. 120 male SD rats were randomly divided into a blank group, a model group, a raw product group, a processed product group, and a positive group for in vivo experiments. A liver and kidney yin deficiency model induced by levothyroxine sodium was established and continuously administered for 14 days. After the last administration, measure the thymus index, as well as the levels of ALT, AST, ALP, TP, ALB, CREA, UREA, and UA. LLF contains to 63 active components, 511 component targets, 1467 liver-related disease targets, 164 potential targets, 3571 kidney-related disease targets, 292 potential targets. GO functional enrichment involves negative regulation of protein phosphorylation, response to xenobiotic stimuli, apoptotic process, etc. KEGG signaling pathway involves lipids and atherosclerosis, PI3K-Akt signaling pathway and so on. Compared with the blank group, the model group rats showed weight loss, significant thymus atrophy, and a significant decrease in thymus index. The levels of ALT, AST, ALP, CREA, UREA, UA, TP and cGMP were significantly increased, while the levels of cAMP, ALB and cAMP/cGMP were significantly decreased. Compared with the model group, both the positive group and each treatment group showed an increase in thymus index, which significantly reduced the levels of ALT, AST, ALP, CREA, UREA, UA, TP and cGMP in the serum of rats, and significantly increased the levels of cAMP, ALB and cAMP/cGMP. Moreover, there were certain differences between the processed and raw products of LLF. Compared with the raw group, processed LLF showed better effects in ALT, ALB, UREA, TP, cAMP, cAMP/cGMP and other aspects. The main active ingredients in LLF may participate in inflammation-related signaling pathways and biological functions by acting on the core targets such as AKT1, GAPDH, APP, etc. to inhibit inflammation and reduce liver and kidney injury, thus exerting the effect of protecting the yin deficiency of liver and kidney.