Herb pair of Polygala tenuifolia Willd and Acorus tatarinowii Schott decoction attenuates seizures and alleviates anxiety in mice: Evidence for modulating inflammation, alleviating oxidative stress and mediating GABA pathway.

Currently, prolong use of standard anti-epileptics may cause tolerance and ineffective for about 30% of epileptic patients. Medicinal plants provide an attractive therapeutic effect in preventing and treating seizures in traditional and folk medicine. In this study, we investigate the antiepileptic effects of PTAT decoction on acute and chronic seizure models in mice and explore the potential mechanisms. PTAT decoction dose-dependently protected mice against MES and PTZ induced seizure. Meanwhile, it decreased the seizure severity and reduced seizure-caused anxious behavior in the PTZ-kindling mice, suggesting a significant antiepileptic activity and anxiolytic/anxiogenic potential. PTAT decoction dose-dependently increased the levels of GSH and the activity SOD and CAT, while decreased the level of MDA in the hippocampi of treated mice. Furthermore, a significant decrease in the proinflammatory cytokine levels, including TNF-α, IL-1ß, IL-6 and MCP-1 was found in treated mice compared with the mice in the vehicle + PTZ group. Moreover, PTAT decoction dose-dependently reversed the alterations induced by PTZ in GABA, GABA-T, L-GAD and glutamate levels in kindling mice, showing an effect on the modulation of the GABA neurotransmission. Thus, PTAT decoction has a promising anticonvulsant activity mediated via multiple mechanisms, which might be used as an up-and-coming phytotherapy strategy in the management of epilepsy and its complications.

Isolation, Characterization and In Silico Studies of Secondary Metabolites from the Whole Plant of Polygala inexpectata Pesmen & Erik.

Polygala species are frequently used worldwide in the treatment of various diseases, such as inflammatory and autoimmune disorders as well as metabolic and neurodegenerative diseases, due to the large number of secondary metabolites they contain. The present study was performed on Polygala inexpectata, which is a narrow endemic species for the flora of Turkey, and resulted in the isolation of nine known compounds, 6,3'-disinapoyl-sucrose (1), 6-O-sinapoyl,3'-O-trimethoxy-cinnamoyl-sucrose (tenuifoliside C) (2), 3'-O-(O-methyl-feruloyl)-sucrose (3), 3'-O-(sinapoyl)-sucrose (4), 3'-O-trimethoxy-cinnamoyl-sucrose (glomeratose) (5), 3'-O-feruloyl-sucrose (sibiricose A5) (6), sinapyl alcohol 4-O-glucoside (syringin or eleutheroside B) (7), liriodendrin (8), and 7,4'-di-O-methylquercetin-3-O-ß-rutinoside (ombuin 3-O-rutinoside or ombuoside) (9). The structures of the compounds were determined by the spectroscopic methods including 1D-NMR (1H NMR, 13C NMR, DEPT-135), 2D-NMR (COSY, NOESY, HSQC, HMBC), and HRMS. The isolated compounds were shown in an in silico setting to be accommodated well within the inhibitor-binding pockets of myeloperoxidase and inducible nitric oxide synthase and anchored mainly through hydrogen-bonding interactions and π-effects. It is therefore plausible to suggest that the previously established anti-inflammatory properties of some Polygala-derived phytochemicals may be due, in part, to the modulation of pro-inflammatory enzyme activities.

Tenuifolin ameliorates chronic restraint stress-induced cognitive impairment in C57BL/6J mice.

The general consensus is that stress affects the central nervous system and can lead to cognitive problems. The root of Polygala tenuifolia (P. tenuifolia) is a well-known traditional Chinese medicine used for improving brain function. Tenuifolin (TEN) is the major constituent of P. tenuifolia and has a promising neuroprotective property. The purpose of this study was to investigate the alleviating effect of TEN on cognitive impairment induced by chronic restraint stress (CRS) and its mechanism. Our results showed that CRS exposure resulted in impaired cognitive performance in C57BL/6J mice, as indicated by decreased responses in Y-maze, novel objects recognition, and step-through passive avoidance tests. TEN treated daily orally (10 and 20 mg/kg) for 30 days reversed these behavior changes. Meanwhile, TEN could significantly regulate interleukin (IL)-6 and IL-10 levels in the hippocampus. TEN inhibited the toll-like receptor 4/nuclear factor-kappa B-mediated inflammation, as well as adrenocorticotropic hormone and corticosterone levels in serum. Most importantly, we found that TEN also upregulated the expressions of brain-derived neurotrophic factor, tropomyosin kinase B, glucocorticoid receptor, glutamate receptor 1, and synapse-associated proteins. Collectively, these data suggest that TEN has a potential improvement effect on memory loss caused by CRS.

Cloning, Yeast Expression, and Characterization of a ß-Amyrin C-28 Oxidase (CYP716A249) Involved in Triterpenoid Biosynthesis in Polygala tenuifolia.

Polygala tenuifolia Willd. is a traditional Chinese herbal medicine that is widely used in treating nervous system disorders. Triterpene saponins in P. tenuifolia (polygala saponins) have excellent biological activity. As a precursor for the synthesis of presenegin, oleanolic acid (OA) plays an important role in the biosynthesis of polygala saponins. However, the mechanism behind the biosynthesis of polygala saponins remains to be elucidated. In this study, we found that CYP716A249 (GenBank: ASB17946) oxidized the C-28 position of ß-amyrin to produce OA. Using quantitative real-time PCR, we observed that CYP716A249 had the highest expression in the roots of 2-year-old P. tenuifolia, which provided a basis for the selection of samples for gene cloning. To identify the function of CYP716A249, the strain R-BE-20 was constructed by expressing ß-amyrin synthase in yeast. Then, CYP716A249 was co-expressed with ß-amyrin synthase to construct the strain R-BPE-20 by using the lithium acetate method. Finally, we detected ß-amyrin and OA by ultra-HPLC-Q Exactive hybrid quadrupole-Orbitrap high-resolution accurate mass spectrometry and GC-MS. The results of this study provide insights into the biosynthesis pathway of polygala saponins.

Utilization of UPLC/Q-TOF-MS-Based Metabolomics and AFLP-Based Marker-Assisted Selection to Facilitate/Assist Conventional Breeding of Polygala tenuifolia.

As one of the most important traditional Chinese medicine, the quality of Polygala tenuifolia is difficult to control and a new method must be established to facilitate/assist the breeding of P. tenuifolia. In this study, UPLC/Q-TOF-MS-based metabolomics analysis was performed to determine the chemical composition and screen metabolite biomarkers according to agronomic traits. A total of 29 compounds and 18 metabolite biomarkers were found. AFLP-based marker-assisted selection (MAS) was used to identify molecular marker bands and screen characteristic bands associated with specific agronomic traits. 184 bands and 76 characteristic AFLP bands were found. The correlation network between compounds and characteristic AFLP bands was built, so we may directly breed certain P. tenuifolia herbs with special agronomic traits (or characteristic AFLP bands), which exhibit specific pharmacological functions depending on the content of the active compounds. The proposed method of metabolomics coupled with MAS could facilitate/assist the breeding of P. tenuifolia.

Antioxidant and anti-inflammatory activities of zinc oxide nanoparticles synthesized using Polygala tenuifolia root extract.

The exploitation of various plant materials for the green synthesis of nanoparticles is considered an eco-friendly technology because it does not involve toxic chemicals. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized using the root extract of Polygala tenuifolia. Synthesized ZnO NPs were characterized by UV-Vis spectroscopy, FTIR, TGA, TEM, SEM and EDX. Anti-inflammatory activity was investigated in LPS-stimulated RAW 264.7 macrophages, whereas antioxidant activity was examined using a DPPH free radical assay. ZnO NPs demonstrated moderate antioxidant activity by scavenging 45.47% DPPH at 1mg/mL and revealed excellent anti-inflammatory activity by dose-dependently suppressing both mRNA and protein expressions of iNOS, COX-2, IL-1ß, IL-6 and TNF-α.

UPLC/Q-TOF MS-based metabolomics and qRT-PCR in enzyme gene screening with key role in triterpenoid saponin biosynthesis of Polygala tenuifolia.

BACKGROUND: The dried root of Polygala tenuifolia, named Radix Polygalae, is a well-known traditional Chinese medicine. Triterpenoid saponins are some of the most important components of Radix Polygalae extracts and are widely studied because of their valuable pharmacological properties. However, the relationship between gene expression and triterpenoid saponin biosynthesis in P. tenuifolia is unclear. METHODOLOGY/FINDINGS: In this study, ultra-performance liquid chromatography (UPLC) coupled with quadrupole time-of-flight mass spectrometry (Q-TOF MS)-based metabolomic analysis was performed to identify and quantify the different chemical constituents of the roots, stems, leaves, and seeds of P. tenuifolia. A total of 22 marker compounds (VIP>1) were explored, and significant differences in all 7 triterpenoid saponins among the different tissues were found. We also observed an efficient reference gene GAPDH for different tissues in this plant and determined the expression level of some genes in the triterpenoid saponin biosynthetic pathway. Results showed that MVA pathway has more important functions in the triterpenoid saponin biosynthesis of P. tenuifolia. The expression levels of squalene synthase (SQS), squalene monooxygenase (SQE), and beta-amyrin synthase (ß-AS) were highly correlated with the peak area intensity of triterpenoid saponins compared with data from UPLC/Q-TOF MS-based metabolomic analysis. CONCLUSIONS/SIGNIFICANCE: This finding suggested that a combination of UPLC/Q-TOF MS-based metabolomics and gene expression analysis can effectively elucidate the mechanism of triterpenoid saponin biosynthesis and can provide useful information on gene discovery. These findings can serve as a reference for using the overexpression of genes encoding for SQS, SQE, and/or ß-AS to increase the triterpenoid saponin production of P. tenuifolia.

Occupational asthma and rhinitis induced by a herbal medicine, Wonji (Polygala tenuifolia).

Occupational asthma is induced by many agents, including herbal materials, that are exposed in working places. Although there are a few case reports for occupational allergy induced by herbal materials, there is none for that induced by Wonji (Polygala tenuifolia). This study was conducted to evaluate clinical characteristics and immunologic mechanism of Wonji-induced asthma in a exposed-worker. A patient who complained of asthma and rhinitis symptoms, and who had worked in a herbal manufacturing factory for 8 yr, underwent a skin prick test with crude extract of Wonji under the impression of occupational asthma induced by the agent. The patient had a strong positive response to the extract on the skin prick test. Allergen bronchial challenge to the extract demonstrated a typical dual response. Serum specific IgE level to the extract was higher in the patient than in healthy controls, and ELISA inhibition test revealed complete inhibition of IgE binding with the extract, but no inhibition with Der p 2 or mugwort extracts. Six IgE binding components to the extract (10, 25, 28, 36, 50, and 90 kDa) were detected using SDS-PAGE and immunoblot analysis. These findings suggest that Polygala tenuifolia, a herbal material, can induce IgE-mediated bronchoconstriction in exposed workers.

Occupational Asthma and Rhinitis Induced by a Herbal Medicine, Wonji (Polygala tenuifolia)

Occupational asthma is induced by many agents, including herbal materials, that are exposed in working places. Although there are a few case reports for occupational allergy induced by herbal materials, there is none for that induced by Wonji (Polygala tenuifolia). This study was conducted to evaluate clinical characteristics and immunologic mechanism of Wonji-induced asthma in a exposed-worker. A patient who complained of asthma and rhinitis symptoms, and who had worked in a herbal manufacturing factory for 8 yr, underwent a skin prick test with crude extract of Wonji under the impression of occupational asthma induced by the agent. The patient had a strong positive response to the extract on the skin prick test. Allergen bronchial challenge to the extract demonstrated a typical dual response. Serum specific IgE level to the extract was higher in the patient than in healthy controls, and ELISA inhibition test revealed complete inhibition of IgE binding with the extract, but no inhibition with Der p 2 or mugwort extracts. Six IgE binding components to the extract (10, 25, 28, 36, 50, and 90 kDa) were detected using SDS-PAGE and immunoblot analysis. These findings suggest that Polygala tenuifolia, a herbal material, can induce IgE-mediated bronchoconstriction in exposed workers.