In recent years, biologically active natural products have gradually become important agents in the field of drug research and development because of their wide availability and variety. However, the target sites of many natural products are yet to be identified, which is a setback in the pharmaceutical industry and has seriously hindered the translation of research findings of these natural products as viable candidates for new drug exploitation. This review systematically describes the commonly used strategies for target identification via the application of probe and non-probe approaches. The merits and demerits of each method were summarized using recent examples, with the goal of comparing currently available methods and selecting the optimum techniques for identifying the targets of bioactive natural products.

A chemical investigation on 70% EtOH extract from the bark of Phellodendron chinense Schneid (Rutaceae) led to six new methyl apiofuranosides (1–6), and ten known compounds (7–16). All these compounds were characterized by the basic analysis of the spectroscopic data including extensive 1D-, 2D-NMR (HSQC, HMBC), and high-resolution mass spectrometry, and the absolute configurations were determined by both empirical approaches and NOESY. Inhibitory effects of compounds 1–9 and 11–16 on nitric oxide production were investigated in lipopolysaccharide (LPS)-mediated RAW 264.7 cells, as a result, most of these isolates inhibited nitric oxide (NO) release, and among them 9, 11, and 12 displayed the strongest inhibition on NO release at the concentration of 12.5 μM.

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by glycolipid dysregulation and hepatic steatosis. Centella asiatica (CA) and its triterpenoid constituents exert metabolic benefits. In addition, previous metabolomics study found that asiatic acid regulated pyrimidine metabolism in obese mice, while the key target and pathway were undefined. This study investigated the regulatory effects of CA and its active constituents on T2DM-related glycolipid disorders, focusing on the pyrimidine metabolism pathway. T2DM mice were established using a high-fat diet combined with streptozotocin (STZ) and treated with Centella asiatica ethanolic extract or asiatic acid (AA), with glibenclamide as a positive control. Then, glycolipid metabolism, hepatic function, pyrimidine metabolites, and related mechanisms were assessed using biochemical assays, LC–MS/MS, cellular experiments, molecular analyses, and molecular docking. CAE and AA significantly reduced FBG (decreased by 51.01% and 53.01%), improved glucose intolerance, corrected dyslipidemia, alleviated hepatic steatosis, and attenuated insulin resistance in T2DM mice. They elevated hepatic uridine, cytidine, and UDP-glucose (UDPG) levels, promoted glycogen synthesis, inhibited uridine phosphorylase 1 (UPP1) activity, upregulated UDPG synthesis genes (PGM1, UGP2), and downregulated lipogenic genes (ACACA, Fasn, SREBP1/2). Molecular docking indicated specific binding of AA and asiaticoside to UPP1. This work distinguishes from our prior research by identifying UPP1 as a functional target and elucidating the detailed molecular mechanism. CA improves T2DM-associated glycolipid disorders and hepatic injury by modulating the pyrimidine metabolism-UDPG-glycogen synthesis pathway and targeting UPP1, highlighting its therapeutic potential for metabolic diseases.