Exploring the pharmacological mechanism of Glycyrrhiza uralensis against KOA through integrating network pharmacology and experimental assessment.

Knee osteoarthritis (KOA), a major health and economic problem facing older adults worldwide, is a degenerative joint disease. Glycyrrhiza uralensis Fisch. (GC) plays an integral role in many classic Chinese medicine prescriptions for treating knee osteoarthritis. Still, the role of GC in treating KOA is unclear. To explore the pharmacological mechanism of GC against KOA, UPLC-Q-TOF/MS was conducted to detect the main compounds in GC. The therapeutic effect of GC on DMM-induced osteoarthritic mice was assessed by histomorphology, µCT, behavioural tests, and immunohistochemical staining. Network pharmacology and molecular docking were used to predict the potential targets of GC against KOA. The predicted results were verified by immunohistochemical staining Animal experiments showed that GC had a protective effect on DMM-induced KOA, mainly in the improvement of movement disorders, subchondral bone sclerosis and cartilage damage. A variety of flavonoids and triterpenoids were detected in GC via UPLC-Q-TOF/MS, such as Naringenin. Seven core targets (JUN, MAPK3, MAPK1, AKT1, TP53, RELA and STAT3) and three main pathways (IL-17, NF-κB and TNF signalling pathways) were discovered through network pharmacology analysis that closely related to inflammatory response. Interestingly, molecular docking results showed that the active ingredient Naringenin had a good binding effect on anti-inflammatory-related proteins. In the verification experiment, after the intervention of GC, the expression levels of pp65 and F4/80 inflammatory indicators in the knee joint of KOA model mice were significantly downregulated. GC could improve the inflammatory environment in DMM-induced osteoarthritic mice thus alleviating the physiological structure and dysfunction of the knee joint. GC might play an important role in the treatment of knee osteoarthritis.

Establishment and quality assessment of tissue cultures in Glycyrrhiza uralensis Fisch.

In this study, seedling, callus, cell, and adventitious root of Glycyrrhiza uralensis Fisch. have been established. In order to find the best one for producing G. uralensis active constituents, triterpenoid saponins and flavonoids in native root and tissue cultures were determined, and the contents in different G. uralensis materials were analyzed using cluster analysis. The contents of triterpenoid saponins and glycyrrhizic acid in tissue cultures were much lower than that in native G. uralensis. The total flavonoids content we determined in adventitious root was 6.31 mg g(-1), which was close to that of native root (9.82 mg g(-1)). Based on the cluster analysis, we found that G. uralensis cultures were not suitable for production of glycyrrhizic acid, while adventitious root had a greater capability of flavonoids production comparing to seedling, callus, and cell.

[Investigation on medicinal plant resources of Glycyrrhiza uralensis in China and chemical assessment of its underground part].

OBJECTIVE: In order to find out the current situation of wild and cultivated resources of Glycyrrhiza uralensis, at the same time, the contents of glycyrrhizic acid and liquiritin were detected by HPLC. METHOD: Field investigation was carried out, and chemical composition of collected underground part was analyzed in laboratory. RESULT: The natural distribution range of wild G. uralensis in China has no significant change. We can still find its distribution in the distribution areas recorded ten years ago, but the intensity of species group has greatly changed. Estimated according to the survey data obtained by quadrat reserves and distribution (i.e., reserves per unit area) or cultivation area, that the current wild reserves is less than 500,000 tons and the less than 150,000 tons for cultivated. The analysis results of glycyrrhizic acid and liquiritin contents in 99 wild samples of collected underground part show that the average contents of glycyrrhizic acid and liquiritin were respectively 34.8, 17.3 mg x g(-1), of which 61.6% samples can reach the standard (not less than 20, 10 mg x g(-1)) marked by "Chinese Pharmacopoeia" (2005 edition); The average glycyrrhizic acid and liquiritin contents of cultivated samples were respectively 28.5, 15.3 mg x g(-1), which were much lower than the wild samples. CONCLUSION: We should enhance efforts in protecting the wild resources, strive to improve the quality of cultivated herbs, vigorously develop high-quality G. uralensis cultivation industries and promote farmers income to resolve the resource crisis, which is the reasonable way to achieve continuable use of G. uralensis resources.

Survey of Glycyrrhizae Radix resources in Mongolia: chemical assessment of the underground part of Glycyrrhiza uralensis and comparison with Chinese Glycyrrhizea Radix.

In order to reveal the chemical characteristics of Glycyrrhiza uralensis growing in Mongolia and to clarify whether it can be the source of Glycyrrhizae Radix used in Japan, eight major bioactive constituents in the underground parts of G. uralensis collected in Mongolia were quantitatively analyzed and compared with Glycyrrhizae Radix produced in China. Most of the 15 samples from eastern, southern and western parts of Mongolia contained 26.95-58.55 mg/g of glycyrrhizin, exceeding the criterion (25 mg/g) assigned in the Japanese Pharmacopoeia. The sample collected in Tamsagiyn hooly, Dornod province, in eastern Mongolia was of the highest content 58.55 mg/g. The contents of three flavanone constituents (liquiritin apioside, liquiritin and liquiritigenin) and three chalcones (isoliquiritin apioside, isoliquiritin and isoliquiritigenin) varied significantly according to collection places; the subtotal of the three flavanones ranged from 3.00 to 26.35 mg/g, and the subtotal of the three chalcones ranged from 1.13 to 10.50 mg/g. The content of glycyrrhizin and subtotal contents of flavanones and chalcones in the underground parts of G. uralensis from Mongolia were obviously lower than wild samples, but higher than cultivated samples derived from the same species produced in China. Glycycoumarin, a species-specific constituent of G. uralensis, was detected in all Mongolian samples. Its contents in samples from eastern Mongolia, Sergelen and Tamsagiyn hooly of Dornod province were very high and were compatible with Tohoku-kanzo derived from wild Chinese G. uralensis. The present study suggested that Mongolian G. uralensis could be a source of Glycyrrhizae Radix, mostly of Japanese Pharmacopoeia grade. However, the producing area should be taken into consideration to ensure relatively high quality. In addition, planned use and promotion of cultivation must be advocated to avoid confronting Mongolian Glycyrrhiza with the same threat as its congener in China. Our study sheds some light on selecting cultivation areas and superior strains, which are important tasks to promote cultivation.