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OBJECTIVE@#To investigate and reveal the underlying mechanism of the effect of total saponins from Dioscoreae nipponica Makino (TSDN) on the arachidonic acid pathway in monosodium urate (MSU) crystal-induced M1-polarized macrophages.@*METHODS@#M1 polarization of RAW264.7 cells were induced by 1 µ g/mL lipopolysaccharide (LPS). The methylthiazolyldiphenyl-tetrazolium bromide method was then used to screen the concentration of TSDN. MSU (500 µ g/mL) was used to induce the gouty arthritis model. Afterwards, 10 µ g/L TSDN and 8 µ mol/L celecoxib, which was used as a positive control, were added to the above LPS and MSU-induced cells for 24 h. The mRNA and protein expressions of cyclooxygenase (COX) 2, 5-lipoxygenase (5-LOX), microsomal prostaglandin E synthase derived eicosanoids (mPGES)-1, leukotriene B (LTB)4, cytochrome P450 (CYP) 4A, and prostaglandin E2 (PGE2) were tested by real-time polymerase chain reaction and Western blotting, respectively. The enzyme-linked immunosorbent assay was used to test the contents of M1 markers, including inducible nitric oxid synthase (NOS) 2, CD80, and CD86.@*RESULTS@#TSDN inhibited the proliferation of M1 macrophages and decreased both the mRNA and protein expressions of COX2, 5-LOX, CYP4A, LTB4, and PGE2 (P<0.01) while increased the mRNA and protein expression of mPGES-1 (P<0.05 or P<0.01). TSDN could also significantly decrease the contents of NOS2, CD80, and CD86 (P<0.01).@*CONCLUSION@#TSDN has an anti-inflammation effect on gouty arthritis in an in vitro model by regulating arachidonic acid signaling pathway.
Subject(s)
Uric Acid/metabolism , Arachidonic Acid/metabolism , Dioscorea , Arthritis, Gouty , Lipopolysaccharides , Saponins/pharmacology , Macrophages , Signal Transduction , RNA, Messenger/metabolismABSTRACT
OBJECTIVE@#To investigate the mechanism of Chinese herbal medicine Dioscorea nipponica for the treatment of monosodium urate crystals-induced gouty arthritis (GA) in rats.@*METHODS@#Sixty male Wistar rats were divided into 6 groups: normal, model, indomethacin and three total saponin (900, 300 and 100 mg/kg) groups. The liver, kidney and serum levels of lysosomal enzymes, antioxidant capacities, and inflammatory factors were measured. In addition, the mRNA and protein levels of the NALP3 inflammasome components in the mononuclear cells of rats' peripheral blood were analyzed using real-time polymerase chain reaction and Western blotting methods, respectively.@*RESULTS@#Total saponins groups could reduce the activities of β-galactosidase, β-N acetyl glucosamine enzyme, β-glucuronidase, acid phosphatase, and malonaldehyde as well as the contents of TNF-α, IL-1β and IL-8 (all P<0.05). They could also increase the activities of glutathione peroxidase and total superoxide dismutase (both P<0.05). Further studies showed that total saponins groups of high, middle and low doses could all increase the mRNA and protein levels of caspase-1, adapter apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) and NALP3 in the mononuclear cells of peripheral blood (all P<0.05).@*CONCLUSION@#Dioscorea nipponica may treat GA by regulating lysosomal enzymes, antioxidant capacities and the NALP3 inflammasome.
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A rapid and accurate method was established by psbA-trnH sequence to distinguish Dioscorea nipponica from other species belonging to the same genus.In this study, we collected 144 samples of D. nipponica from 17 different producing areas in China, the psbA-trnH sequenced of 23 nucleotide sequences were downloaded from GenBank, the sequences from Dioscorea genus. DNAMAN 8.0 software was used to show splicing, MEGA 6.0 software was applied for sequence analysis and comparison. The results showed that the genetic relationship between D. nipponica and D. subcalva was the closest, and the genetic relationship with D. zingiberensis was the furthest. It is indicated that the psbA-trnH sequence as a DNA barcode can effectively distinguish between D. nipponica and other plants in the genus of Dioscorea.
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Objective To isolate endophytic fungi from the fresh leaves of Dioscorea nipponica Makino,and to determine their antimicrobial activities.Methods Endophytic fungi from the fresh leaves of Dioscorea nipponica Makino were isolated by tissue isolation method,and the preliminary identification was carried out by slide plate culture,tissue culture,and plug culture.After isolating the endophytic fungi,the antimicrobial activity from the isolated endophytic fungi was detected using filter paper method with Staphylococcus aureus,Staphylococcus albus,Staphylococcus citreu,Micrococcus tetragenus,Escherichia coli,Salmonella typhi,Pseudomonas aeruginosa,Bacterium termo,Bacillus endocarditidiscapsulatus,Shigella flexneri,Bacterium paratyphosum B indicator microorganisms.Results A total of 52 strains of the endophytic fungi were isolated.According to morphological characteristics,10 endophytic fungi producing spores were identified as two orders,three families,and nine genera.The extracts of fungal mycelium had the antibiotic activity of strains of C37,C30,and C50.With the identification by morphology and molecular biology,strain C37 was determined to belong to the genus Gibberella,and C30,C50 to Alternaria.Conclusion The antibacterial activity of these endophytes in the leaves ofDioscorea nipponica Makino could be exploited for the development of new antibacterial biological agents.
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Objective To investigate the effect of the aqueous extracts from Dioscorea nipponica Makino (AEDN) against the carbon tetrachloride (CCl4)-induced mice acute liver injury by regulating TLR4/MyD88 signal pathway.Methods 60 mice were randomly divided into control group, model group, low, medium and high dose AEDN groups according to radom number table with 10 mice in each group. Mice in low, medium and high dose AEDN groups were adiminstrated with 50, 100 and 200 mg/kg AEDN, in control and model groups were adiminstrated with solvent once a day for 7 consecutive days. Two hours after the last administration, mice were intraperitoneal injected with with 0.3% CCl4 olive oil solution to induce acute liver injury model, except for the mice in control group. Twenty-four hours after injection, the expressions of TLR4, MyD88 and NF-κB in liver tissue were evaluated by Western blot, mRNA levels were evaluated by PCR, and the AST and ALT levels in serum were also detected.Results Compared with model group, the serum AST (98.00 ± 17.75 U/L, 57.49 ± 9.66 U/L, 39.60 ± 9.49 U/Lvs. 113.40 ± 9.71 U/L) and ALT levels (76.00 ± 14.73 U/L, 50.70 ± 9.35 U/L, 35.25 ± 9.93 U/Lvs. 95.42 ± 11.64 U/L) were significantly decreased in low, medium and high dose AEDN groups (P<0.01); MyD88 (0.67 ± 0.21vs. 1.74 ± 0.42), NF-κB p65 (0.51 ± 0.09vs. 1.76 ± 0.31) and TLR4 (0.97 ± 0.25vs. 2.99 ± 0.72) levels were down-regulated in high dose AEDN group (P<0.01); the mRNA levels of IL-6 (2.22 ± 0.25, 1.76 ± 0.31vs. 5.20 ± 0.60), IL-1β (1.96 ± 0.35, 1.47 ± 0.23vs. 7.37 ± 0.99)、TNF-α (2.06 ± 0.25, 1.34 ± 0.33vs. 2.98 ± 0.50) in medium and high dose AEDN groups significantly decresed (P<0.01).Conclusions The AEDN has protective effect against CCl4-induced acute liver injury in mice via adjusting TLR4/MyD88 signal pathway.
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At the urgent practical issue of resource protection and artificial cultivation area selection of Dioscorea nipponica, the dominant environmental factors affecting the distribution of D. nipponicain Jilin province were selected by field investigation and using the maximum information entropy model and geographic information technology. MaxEnt model study found that the standard deviation of seasonal variation of temperature, precipitation in October and other six environmental factors on the growth of D. nipponica are the greatest impacting factors. The range of suitability for the growth of D. nipponica was 4.612 08×10-6-0.544 31, and the regionalization study was divided into four parts: high fitness area, middle fitness area, low fitness area and unfavorable area. The high fitness area is concentrated in the central and southern areas of Jilin Province, using ArcGIS statistical environment factors in the appropriate area of the numerical situation. The results showed that the regionalization study of D. nipponica was basically the same as the actual situation. It is clear that the natural environment suitable for the growth of D. nipponica is also the basis for the protection of the resources and the selection of cultivated area.
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Dioscorea nipponica, a famous traditional Chinese medicine, belongs to the Dioscoreaceae family and has been widely distributed in the north, northeast and Qinghai regions of China. With its root and rhizome as an important herb material, it has been applied in China for several thousand years. Traditional Chinese medicine reported that this plant had been used for relieving cough and asthma, eliminating rheumatic aches, alleviating pain and improving blood circulation. Modern pharmacology studies have confirmed that saponins, the major active compounds in this herb, have shown various pharmacological actions including anti-tumor, anti-inflammatory,lipid-lowering, anti-fungal and anti-virus activities. Therefore, the studies on saponins from D. nipponica are valuable and promising. In this present research, the pharmacological actions, therapeutic effects and mechanism of saponins from D. nipponica were summarized in order to provide the theoretical basis for the further research.
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Objective To study absorption characteristic of dioscin from Dioscorea nipponica Makino extract in rat intestine.Methods Single-pass intestinal perfusion (SPIP) model was used for rat in situ and HPLC was used to determine the concentrations of dioscin.The effects of different intestinal segments,drug concentration and P-glycoprotein (P-gp) inhibitor on intestinal absorption were investigated.Results Dioscin could be absorbed in the whole intestine,the absorption rate constant (Ka) and the apparent coefficient (Papp) of dioscin decreased following the sequence of ileum > duodenum =jejunum > colon.Absorption parameters of dioscin had no significant difference at different concentrations (40,80,120 mg·L-1).There were significant differences in Ka and Papp values between P-gp inhibitor group and no P-gp inhibitor group(P<0.05).Conclusion The saturate phenomena was not observed under the test range of drug concentration,and the absorption mechanism may be passive diffusion transport.Dioscin in Dioscorea nipponica Makino extract may be the substrate of P-gp.
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The purpose of this study was to investigate the therapeutic effects of DA-9801, an optimized extract of Dioscorea species, on diabetic peripheral neuropathy in a type 2 diabetic animal model. In this study, db/db mice were treated with DA-9801 (30 and 100 mg/kg, daily, p.o.) for 12 weeks. DA-9801 reduced the blood glucose levels and increased the withdrawal latencies in hot plate tests. Moreover, it prevented nerve damage based on increased nerve conduction velocity and ultrastructural changes. Decrease of nerve growth factor (NGF) may have a detrimental effect on diabetic neuropathy. We previously reported NGF regulatory properties of the Dioscorea genus. In this study, DA-9801 induced NGF production in rat primary astrocytes. In addition, it increased NGF levels in the sciatic nerve and the plasma of type 2 diabetic animals. DA-9801 also increased neurite outgrowth and mRNA expression of Tieg1/Klf10, an NGF target gene, in PC12 cells. These results demonstrated the attenuation of diabetic peripheral neuropathy by oral treatment with DA-9801 via NGF regulation. DA-9801 is currently being evaluated in a phase II clinical study.
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Animals , Mice , Rats , Astrocytes , Blood Glucose , Diabetes Mellitus, Type 2 , Diabetic Neuropathies , Dioscorea , Models, Animal , Nerve Growth Factor , Neural Conduction , Neurites , PC12 Cells , Peripheral Nervous System Diseases , Plasma , RNA, Messenger , Sciatic NerveABSTRACT
Objective: To study the effects of different temperature conditions (10, 15, 20, 25, and 30 °C) and different concentration of gibberellin (GA3) and naphthalene acetic acid (NAA) on the germination responses of Dioscorea nipponica seeds. Methods: The seed germination rate and germination vigor were recorded and analyzed statistically, through setting conditions including cold stratification and soaking treatment with different concentration of GA3/NAA in culture dishes. Results: After sand stratification at 4 °C, the germination percentage and germination vigor of D. nipponica seeds were the highest of 80.00% and 53.33% at 25 °C, respectively. After soaking in 100 mg/L GA3 for 24 h without stratification, the germination percentage and vigor of D. nipponica seeds were 66.65% and 48.35%, respectively; After soaking in 1 mg/L NAA for 12 h, the germination percentage and germination vigor were 58.35% and 3.35%, respectively. The germination process treated with low temperature sand stratification was the fastest. The seeds began to germinate at the day 6, and germinated completely within 12 d. Conclusion: The seeds should germinate at 25 °C after sand stratification at 4 °C for 60 d, or the seeds without stratification would germinate after being treated with 100 mg/L GA3.
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Objective To study the medicinal plants of Dioscorea nipponica, the physicochemical pro-perties of starch in D. nipponica were investigated by means of various analytical methods. Methods D. nipponica starch was characterized by scanning electron microscope (SEM), X-ray diffraction, granule size analysis, DSC, and Brabender Viscograph system. Results Compared with tapioca and potato starch, the morphology of D. nipponica starch showed smaller particles, oval shaped, and dissimilar granules in size. The crystal type of D. nipponica starch was C-type pattern. The amylose content in D. nipponica starch was 26.3%. The starch separated from D. nipponica showed the highest transition temperature and intermediate enthalpy of gelatinization between potato and tapioca. According to the viscosity measurement with Brabender viscograph, D. nipponica starch exhibited lower peak viscosity, higher setback and lower breakdown viscosity. Conclusion D. nipponica starch is obtained from D. nipponica. Significant differences from D. nipponica and other tuber starches in physicochemical properties are obtained due to their geographical origin.