Polygalacic acid attenuates cognitive impairment by regulating inflammation through PPARγ/NF-κB signaling pathway.

AIMS: We aimed to explore the role and molecular mechanism of polygalacic acid (PA) extracted from traditional Chinese medicine Polygala tenuifolia in the treatment of Alzheimer's disease (AD). METHODS: The network pharmacology analysis was used to predict the potential targets and pathways of PA. Molecular docking was applied to analyze the combination between PA and core targets. Aß42 oligomer-induced AD mice model and microglia were used to detect the effect of PA on the release of pro-inflammatory mediators and its further mechanism. In addition, a co-culture system of microglia and neuronal cells was constructed to assess the effect of PA on activating microglia-mediated neuronal apoptosis. RESULTS: We predict that PA might regulate inflammation by targeting PPARγ-mediated pathways by using network pharmacology. In vivo study, PA could attenuate cognitive deficits and inhibit the expression levels of inflammation-related factors. In vitro study, PA can also decrease the production of activated microglia-mediated inflammatory cytokines and reduce the apoptosis of N2a neuronal cells. PPARγ inhibitor GW9662 inversed the neuroprotective effect of PA. Both in vivo and in vitro studies showed PA might attenuate the inflammation through the PPARγ/NF-κB pathway. CONCLUSIONS: PA is expected to provide a valuable candidate for new drug development for AD in the future.

Polygala tenuifolia: a source for anti-Alzheimer's disease drugs.

Context: Alzheimer's disease (AD) is a chronic neurodegenerative disease that originates from central nervous system lesions or recessions. Current estimates suggest that this disease affects over 35 million people worldwide. However, lacking effective drugs is the biggest handicap in treating AD. In traditional Chinese medicine (TCM), Polygala tenuifolia Willd. (Polygalaceae) is generally used to treat insomnia, memory dysfunction and neurasthenia.Objective: This review article explores the role of P. tenuifolia and its active components in anti-Alzheimer's disease.Methods: Literature for the last ten years was obtained through a search on PubMed, SciFinder, CNKI, Google Scholar, Web of Science, Science Direct and China Knowledge Resource Integrated with the following keywords: Polygala tenuifolia, polygalasaponin XXXII (PGS 32), tenuifolin, polygalacic acid, senegenin, tenuigenin, Alzheimer's disease.Results: Polygala tenuifolia and its active components have multiplex neuroprotective potential associated with AD, such as anti-Aß aggregation, anti-Tau protein, anti-inflammation, antioxidant, anti-neuronal apoptosis, enhancing central cholinergic system and promote neuronal proliferation.Conclusions: Polygala tenuifolia and its active components exhibit multiple neuroprotective effects. Hence, P. tenuifolia is a potential drug against Alzheimer's disease, especially in terms of prevention.

Content determination and quality analysis of five main components in Polygala tenuifolia from different habitats / 中草药

Objective: The contents of five main components in Polygala tenuifolia from different habitats were determined, which provided certain data support and theoretical basis for the quality evaluation system of P. tenuifolia. Methods: The contents of polygalaxanthone III, 3,6’-disinapoyl sucrose, polygalacic acid, senegenin and tenuifolin of roots from different wild samples were determined by HPLC. Then SPSS 20.0 and SIMCA 11.5 were used for difference analysis, correlation analysis, hierarchical cluster analysis (HCA), and principal component analysis (PCA). Results: The content of the five main components in wild P. tenuifolia samples from different habitats was significantly different. The 20 samples were placed into two clusters (I, II) by HCA and PCA. Cluster I comprised three samples with higher content of 3,6’-disinapoyl sucrose, polygalaxanthone III, senegenin and tenuifolin from Weinan, Xianyang in Shannxi Province, and Xinjiang in Shanxi Province, whereas cluster II contained the other 17 samples. Conclusion: The results showed that the main components of P. enuifolia from Weinan, Xianyang in Shannxi Province and Xinjiang in Shanxi Province were significantly higher than other origins, and which provided a reference for the quality control, selection of excellent germplasm and cultivation bases of P. tenuifolia.

Polygalacic acid inhibits MMPs expression and osteoarthritis via Wnt/ß-catenin and MAPK signal pathways suppression.

Osteoarthritis (OA) is a chronic degenerative joint disease that has been shown to be closely related to the over expression of matrix metalloproteinases (MMPs). Polygalacic acid is a triterpene isolated from the root of Polygala tenuifolia Willd. In the present study, the anti-inflammatory effect of polygalacic acid in OA was investigated as well as its in vitro and in vivo mechanism. In vitro, rat chondrocytes were induced with interleukin-1beta (IL-1ß) and treated with different concentrations of polygalacic acid; real-time PCR and Western blotting were performed to evaluate the expressions of MMP-3, MMP-9, MMP-13, and COX-2. In addition, the MAPK and Wnt/ß-catenin signaling pathways were analyzed via Western blotting and immunofluorescence staining. In vivo, a rat OA model was treated with polygalacic acid. Gross morphological and histological assessments were performed to evaluate the resulting cartilage damage. Polygalacic acid significantly reduced the expression of MMPs and COX-2, which could be induced by IL-1ß in rat chondrocytes. Furthermore, polygalacic acid treatment prevented the degeneration of cartilage in the rat OA model. To investigate the underlying mechanism, we found that polygalacic acid suppressed both the IL-1ß-induced activation of Wnt/ß-catenin and the mitogen-activated protein kinase (MAPK) signal pathway in chondrocytes. These results suggest that polygalacic acid may have a therapeutic effect in OA treatment.

Effects of different drying methods on active constituents of root bark and root of Polygala tenuifolia / 中草药

Objective To investigate the effects of different drying methods on composition and content of five active constituents in root bark and root of Polgala tenuifoliaroot. Methods The contents of polygalaxanthone III, 3,6’-disinapoyl sucrose, polygalacic acid, senegenin, and tenuifolin in root bark and root from different drying samples were determined by HPLC. Then the data analysis was performed by ANOVA and TOPSIS methods. Results There is a difference in the order of drying methods for bark and root of P. tenuifoliaroot. For P. tenuifoliaroot root bark, the order of different drying methods was microwave drying > 60 ℃ hot-air drying > 50 ℃ hot-air drying > 70 ℃ hot-air drying > freeze-drying > 40 ℃ hot-air drying > shade drying > sun drying; For P. tenuifolia root, the different drying methods were sorted by microwave drying > 60 ℃ hot-air drying > shade drying > sun drying > 50 ℃ hot-air drying > 40 ℃ hot-air drying > 70 ℃ hot-air drying > freeze-drying. Conclusion Combined with the production practice, this study suggests that microwave drying and hot-air drying at 60 ℃ are suitable drying methods for P. tenuifoliaroot bark and root, providing a basis for the determination of drying methods for the origin processing of P. tenuifolia.

Quality research and analysis of Polygala tenuifolia with different commodity grade / 中草药

Objective To establish the main component analysis method of commodity grade Polygala tenuifolia, and to explore the correlation between the grade character of P. tenuifolia and the main chemistry. Methods P. tenuifolia of four markets were determined by high performance liquid chromatography (HPLC) to analyze the different level of medicine and explore the correlation between commodity grade and composition for P. tenuifolia. Results The main components determination of P. tenuifolia in different market grades were not completely consistent with the grade of commodity. Conclusion There are certain limitations of the commodity grading standards for P. tenuifolia in the medicinal materials market. It is necessary to establish a new grade quality standard for accurately evaluating the quality of P. tenuifolia. This study also provides some reference for the comprehensive quantitative evaluation of P. tenuifolia.

Neuroprotective effects of polygalacic acid on scopolamine-induced memory deficits in mice.

BACKGROUND: Polygala tenuifolia Willd is a Traditional Chinese Medicine used for the treatment of learning and memory deficits. Triterpenoid saponins, the main bioactive compounds of Polygala tenuifolia Willd, are easily hydrolyzed to polygalacic acid (PA). PURPOSE: The present study was undertaken to investigate the neuroprotective effects of PA on scopolamine-induced cognitive dysfunction and to elucidate its underlying mechanisms of action. METHODS: PA (3, 6, and 12 mg/kg) was administered orally to mice for fourteen days, and scopolamine (1 mg/kg) was injected intraperitoneally for fourteen days to induce memory impairment. Memory-related behaviors were evaluated using the Morris water maze. Cholinergic and neuroinflammatory activities were measured in brain tissue. Superoxide dismutase activities, malondialdehyde and reduced glutathione contents were also measured in the brains. RESULTS: Treatment with scopolamine significantly increased the escape latency time, decreased the number of crossings, and shortened the time spent in the target quadrant, while PA reversed these scopolamine-induced effects. PA significantly improved cholinergic system reactivity, as indicated by decreased acetylcholinesterase (AChE) activity, increased choline acetyltransferase (ChAT) activity, and elevated levels of acetylcholine (ACh) in the hippocampus and frontal cortex. PA also significantly ameliorated neuroinflammation and oxidative stress in mice. CONCLUSION: These results suggest that PA might exert a significant neuroprotective effect on cognitive impairment, driven in part by the modulation of cholinergic activity and neuroinflammation.