Osmanthus fragrans has been used as folk medicine for thousands of years. The extracts of Osmanthus fragrans flowers were reported to have various bioactivities including free radical scavenging, anti-inflammation, neuroprotection and antitumor effects. However, there is still lack of knowledge about its essential oil. In this work, we analyzed the chemical composition of the essential oil from Osmanthus fragrans var. thunbergii by GC-MS. A complex network approach was applied to investigate the interrelationships between the ingredients, target proteins, and related pathways for the essential oil. Statistical characteristics of the networks were further studied to explore the main active ingredients and potential bioactivities of O. fragrans var. thunbergii essential oil. A total of 44 ingredients were selected from the chemical composition of O. fragrans var. thunbergii essential oil, and that 191 potential target proteins together with 70 pathways were collected for these compounds. An ingredient-target-pathway network was constructed based on these data and showed scale-free property as well as power-law degree distribution. Eugenol and geraniol were screened as main active ingredients with much higher degree values. Potential neuroprotective and anti-tumor effect of the essential oil were also found. A core subnetwork was extracted from the ingredient-target-pathway network, and indicated that eugenol and geraniol contributed most to the neuroprotection of this essential oil. Furthermore, a pathway-based protein association network was built and exhibited small-world property. MAPK1 and MAPK3 were considered as key proteins with highest scores of centrality indices, which might play an important role in the anti-tumor effect of the essential oil. This work predicted the main active ingredients and bioactivities of O. fragrans var. thunbergii essential oil, which would benefit the development and utilization of Osmanthus fragrans flowers. The application of complex network theory was proved to be effective in bioactivities studies of essential oil. Moreover, it provides a novel strategy for exploring the molecular mechanisms of traditional medicines.

Background: Flavonoids from plant medicines are supposed to be viable alternatives for the treatment of type 2 diabetes (T2D) as less toxicity and side effects.Radix scutellariae(RS) is a widely used traditional medicine in Asia. It has shown great potential in the research of T2D. However, the pharmacological actions remain obscured due to the complex chemical nature of plant medicines.Methods: In the present study, a systematic method combining ultrafiltration UPLC-TripleTOF-MS/MS and network pharmacology was developed to screenα-glucosidase inhibitors from flavonoids ofRS, and explore the underlying mechanism for the treatment of T2D.Results: Then-butanol part of ethanol extract fromRSshowed a strongα-glucosidase inhibition activity (90.55%, IC₅₀0.551 mg/mL) against positive control acarbose (90.59%, IC₅₀1.079 mg/mL). A total of 32 kinds of flavonoids were identified from the extract, and their ESI-MS/MS behaviors were elucidated. Thirteen compounds were screened asα-glucosidase inhibitors, including viscidulin III, 2′,3,5,6′,7-pentahydroxyflavanone, and so on. A compound-target-pathway (CTP) network was constructed by integrating theseα-glucosidase inhibitors, target proteins, and related pathways. This network exhibited an uneven distribution and approximate scale-free property. Chrysin (k = 87), 5,8,2′-trihydroxy-7-methoxyflavone (k = 21) and wogonin (k = 20) were selected as the main active constituents with much higher degree values. A protein-protein interaction (PPI) weighted network was built for target proteins of theseα-glucosidase inhibitors and drug targets of T2D. PPARG (C_d = 0.165,C_b = 0.232,C_c = 0.401), ACACB (C_d = 0.155,C_b = 0.184,C_c = 0.318), NFKB1 (C_d = 0.233,C_b = 0.161,C_c = 0.431), and PGH2 (C_d = 0.194,C_b = 0.157,C_c = 0.427) exhibited as key targets with the highest scores of centrality indices. Furthermore, a core subnetwork was extracted from the CTP and PPI weighted network. Type II diabetes mellitus (hsa04930) and PPAR signaling pathway (hsa03320) were confirmed as the critical pathways.Conclusions: These results improved current understanding of natural flavonoids on the treatment of T2D. The combination of ultrafiltration UPLC-TripleTOF-MS/MS and network pharmacology provides a novel strategy for the research of plant medicines and complex diseases.

Background: Thioredoxin reductase (TrxR) plays vital role in regulating cellular redox balance as well as redox-mediated signal transduction. Accumulating evidence supports that overactivation of TrxR is closely related to tumorigenesis and that targeting TrxR ablation reverses the growth of numerous malignant tumors, making TrxR a promising target for cancer chemotherapy. Thus, the discovery and development of molecules as promising anticancer agents that target TrxR is of great significance. Oridonin was shown to inhibit TrxR activity, but the detailed cellular mechanism is largely unknown. Objective: The study investigated the mechanism of action and underlying inhibitory properties of oridonin on TrxR in HeLa cells. Methods: A covalent docking was performed to reveal the possible interaction between oridonin and TrxR by Schrödinger Software Suite. TrxR activity was determined by 5,5’-dithiobis-2- nitrobenzoic acid reduction assay and endpoint insulin reduction assay. Sulforhodamine B and colony formation assay were employed to assess the viability and growth of cells. Reactive oxygen species level was measured by probe 2’, 7’-dichlorfluorescein diacetate, and dihydroethidium. Hoechst 33342 staining, caspase 3 activation, and fluorescein-5-isothiocyanate-conjugated Annexin V and propidium iodide double staining were used to evaluate apoptosis. Results: Here, we reported the oridonin as a potent inhibitor of TrxR. Inhibition of TrxR results in a decrease of thiols content and total glutathione, elevates reactive oxygen species levels, and finally promotes oxidative stress-mediated apoptosis of cancer cells. Conclusion: Targeting TrxR by oridonin discloses a novel molecular mechanism underlying the biological action of oridonin and sheds light on developing oridonin as a potential tumor therapeutic agent.

Natural products have been widely used in the treatment of type 2 diabetes (T2D). However, their mechanisms are often obscured due to multi‐components and multi‐targets. The authors constructed a pathway‐based protein–protein association (PPA) network for target proteins of 13 α‐glucosidase inhibitors (AGIs) identified from Scutellaria baicalensis Georgi ( SBG ), designed to explore the underlying mechanisms. This network contained 118 nodes and 1167 connections. An uneven degree distribution and small‐world property were observed, characterised by high clustering coefficient and short average path length. The PPA network had an inherent hierarchy as C(k)∼k ^−0.71 . It also exhibited potential weak disassortative mixing pattern, coupled with a decreased function Knn ( k ) and negative value of assortativity coefficient. These properties indicated that a few nodes were crucial to the network. PGH2, GNAS, MAPK1, MAPK3, PRKCA, and MAOA were then identified as key targets with the highest degree values and centrality indices. Additionally, a core subnetwork showed that chrysin, 5,8,2′‐trihydroxy‐7‐methoxyflavone, and wogonin were the main active constituents of these AGIs, and that the serotonergic synapse pathway was the critical pathway for SBG against T2D. The application of a pathway‐based protein–protein association network provides a novel strategy to explore the mechanisms of natural products on complex diseases.