In the present study, anti-chronic nonbacterial prostatitis (CNP) pharmacological experiments using water and ethanol extraction of the aerial parts of Glycyrrhiza uralensis were performed to select the best active parts by comparing their efficacy in a CNP model established by injecting carrageenin into the ventral lobe of rat prostate. The anti-CNP activities and expression of serum inflammatory factors in rats were also analyzed. A Protein-Protein Interaction network was constructed, and core targets were screened using topology and analyzed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. Water and ethanol extraction exhibited good inhibitory effect on the pathological changes of the prostate tissue, the expression of inflammatory factors and fibrosis factors in CNP rats, whereas no differences were observed compared with the positive control drug. Water extraction was more effective and significantly reduced PGE2 expression (P<0.05). Network pharmacology assays showed 15 active components in the aerial part of Glycyrrhiza uralensis , and 9 key CNP therapeutic targets of the aerial parts of Glycyrrhiza uralensis were identified. The effect of water exraction on chronic prostatitis rats was significant. The aerial part of Glycyrrhiza uralensis downregulated the levels of inflammatory factors and inhibited proinflammatory gene transcription, reduced oxidative stress response, inhibited cell survival pathways, regulated sex hormone levels, prevented immunostimulation and attenuated inflammation. This study provides a theoretical reference for the development of anti-CNP agents, and offers a novel methodology for identifying and clarifying the mechanisms underlying the efficacy of the anti-CNP components in the aerial part of Glycyrrhiza uralensis .

Our previous study found that the aerial parts of Chinese liquorice (Glycyrrhiza uralensis Fisch.) had pharmacological effects against chronic non-bacterial prostatitis in rats, however the pharmacologically active compounds remain unclear. Here, a method based on UPLC-Q-Exactive Orbitrap-MS was established to qualitatively analyse the flavonoid glycosides rich fraction extracted from the aerial part of G. uralensis Fisch., after pretreatment with n-butanol and enrichment using AB-8 macroporous resin. Using both positive and negative ion modes, 52 compounds were identified or tentatively characterised by comparison with standards and the literature: 40 flavonoids, 8 organic acids, 2 chromones, 1 coumarin, and 1 phenylethanoid glycoside.This study provides not only an approach to enrich flavonoid glycosides but also a methodology for quickly determining the relevant bioactive components in the aerial parts of G. uralensis Fisch.

(1) Background: The aerial part of G. uralensis had pharmacological effects against chronic non-bacterial prostatitis (CNP), and flavonoids are the main efficacy components. The purpose of this study was to obtain the pharmacokinetics, prostate distribution and metabolic characteristics of some flavonoids in rats. (2) Methods: The prototype flavones and the metabolites of four representative flavonoids, namely puerarin, luteolin, kaempferol and pinocembrin in plasma, prostate, urine and feces of rats were analyzed by UPLC-Q-Exactive Orbitrap-MS. In addition, the pharmacokinetic parameters in plasma and distribution of prostate of four components were analyzed by HPLC-MS/MS. (3) Results: In total, 22, 17, 22 and 11 prototype flavones were detected in the prostate, plasma, urine and feces, respectively. The metabolites of puerarin in the prostate are hydrolysis and glucose-conjugated products, the metabolites of kaempferol and luteolin in the prostate are methylation and glucuronidation, and the metabolites of pinocembrin in the prostate are naringenin, oxidation, sulfation, methylation and glucuronidation products. The t1/2 of puerarin, luteolin, kaempferol and pinocembrin was 6.43 ± 0.20, 31.08 ± 1.17, 18.98 ± 1.46 and 13.18 ± 0.72 h, respectively. The concentrations of the four flavonoids in prostate were ranked as kaempferol > pinocembrin > luteolin > puerarin. (4) Conclusions: Methylation and glucuronidation metabolites were the main metabolites detected in the prostate. A sensitive and validated HPLC–MS/MS method for simultaneous determination of puerarin, luteolin, kaempferol and pinocembrin in rat plasma and prostate was described, and it was successfully applied to the pharmacokinetic and prostate distribution studies.