Site-directed mutagenesis enhances the activity of benzylidene acetone synthase of polyketide synthase from Polygonum cuspidatum / 生物工程学报

Polygonum cuspidatum polyketide synthase 1 (PcPKS1) has the catalytic activity of chalcone synthase (CHS) and benzylidene acetone synthase (BAS), which can catalyze the production of polyketides naringenin chalcone and benzylidene acetone, and then catalyze the synthesis of flavonoids or benzylidene acetone. In this study, three amino acid sites (Thr133, Ser134, Ser33) that may affect the function of PcPKS1 were identified by analyzing the sequences of PcPKS1, the BAS from Rheum palmatum and the CHS from Arabidopsis thaliana, as well as the conformation of the catalytic site of the enzyme. Molecular modification of PcPKS1 was carried out by site-directed mutagenesis, and two mutants were successfully obtained. The in vitro enzymatic reactions were carried out, and the differences in activity were detected by high performance liquid chromatography (HPLC). Finally, mutants T133LS134A and S339V with bifunctional activity were obtained. In addition to bifunctional activities of BAS and CHS, the modified PcPKS1 had much higher BAS activity than that of the wild type PcPKS1 under the conditions of pH 7.0 and pH 9.0, respectively. It provides a theoretical basis for future use of PcPKS1 in genetic engineering to regulate the biosynthesis of flavonoids and raspberry ketones.

Effect of ethanolic extract of Polygonum cuspidatum on acute gouty arthritis in mice through NLRP3/ASC/caspase-1 axis / 中国中药杂志

The aim of this paper was to study the effect and mechanism of alcohol extract from Polygonum cuspidatum(PCE) on acute gouty arthritis in C57 BL/6 mice through NLRP3/ASC/caspase-1 axis. The model mice which injected with ankle joint injection of sodium urate crystals(MSU) were orally administrated with three different concentration of PCE, with colchicine as positive control. HE staining was used for observing the morphological changes of synovial tissue; concentration of IL-1β, IL-6 and TNF-α secreted by synovial tissue of the ankle joint were detected by ELISA; mRNA and protein expression of NLRP3, ASC and caspase-1 in synovial tissue were detected by RT-PCR and Western blot respectively. The results showed that the swelling degree of ankle joint in model mice were significantly elevated; expression of IL-1β, IL-6 and TNF-α were significantly increased; mRNA and protein expression of NLRP3, ASC and caspase-1 also significant increase, compared with normal control group. The swelling degree of ankle joint significantly relief; expression of IL-1β, IL-6 and TNF-α in joint synovium significantly decrease; mRNA and protein expression of NLRP3, ASC and caspase-1 were significantly decrease in PCE treatment group compared with model group. Our research implied that alcohol extract from P. cuspidatum had positive effect on acute gouty arthritis in mice, and the regulation of NLRP3/ASC/caspase-1 axis may be its mechanism.

Effects of Polygonum cuspidatum on AMPK-FOXO3α Signaling Pathway in Rat Model of Uric Acid-Induced Renal Damage / 中国结合医学杂志

BACKGROUND@#To observe the effects of Chinese medicine (CM) Polygonum cuspidatum (PC) on adenosine 5'-monophosphate-activated protein kinase (AMPK), forkhead box O3α (FOXO3α), Toll-like receptor-4 (TLR4), NACHT, LRR and PYD domains-containing protein 3 (NLRP3), and monocyte chemoattractant protein-1 (MCP-1) expression in a rat model of uric acid-induced renal damage and to determine the molecular mechanism.@*METHODS@#A rat model of uric acid-induced renal damage was established, and rats were randomly divided into a model group, a positive drug group, and high-, medium-, and low-dose PC groups (n=12 per group). A normal group (n=6) was used as the control. Rats in the normal and model groups were administered distilled water (10 mL•kg) by intragastric infusion. Rats in the positive drug group and the high-, medium-, and low-dose PC groups were administered allopurinol (23.33 mg•kg), and 7.46, 3.73, or 1.87 g•kg•d PC by intragastric infusion, respectively for 6 to 8 weeks. After the intervention, reverse transcription polymerase chain reaction, Western blot, enzyme linked immunosorbent assay, and immunohistochemistry were used to detect AMPK, FOXO3α, TLR4, NLRP3, and MCP-1 mRNA and protein levels in renal tissue or serum.@*RESULTS@#Compared with the normal group, the mRNA transcription levels of AMPK and FOXO3α in the model group were significantly down-regulated, and protein levels of AMPKα1, pAMPKα1 and FOXO3α were significantly down-regulated at the 6th and 8th weeks (P<0.01 or P<0.05). The mRNA transcription and protein levels of TLR4, NLRP3 and MCP-1 were significantly up-regulated (P<0.01 or P<0.05). Compared with the model group, at the 6th week, the mRNA transcription levels of AMPK in the high- and medium-dose groups, and protein expression levels of AMPKα1, pAMPKα1 and FOXO3α in the high-dose PC group, AMPKα1 and pAMPKα1 in the mediumdose PC group, and pAMPKα1 in the low-dose PC group were significantly up-regulated (P<0.01 or P<0.05); the mRNA transcription and protein levels of TLR4 and NLRP3 in the 3 CM groups, and protein expression levels of MCP-1 in the medium- and low-dose PC groups were down-regulated (P<0.01 or P<0.05). At the 8th week, the mRNA transcription levels of AMPK in the high-dose PC group and FOXO3α in the medium-dose PC group, and protein levels of AMPKα1, pAMPKα1 and FOXO3α in the 3 CM groups were significantly up-regulated (P<0.01 or P<0.05); the mRNA transcription levels of TLR4 in the medium- and low-dose PC groups, NLRP3 in the high- and low-dose PC groups and MCP-1 in the medium- and low-dose PC groups, and protein expression levels of TLR4, NLRP3 and MCP-1 in the 3 CM groups were down-regulated (P<0.01 or P<0.05).@*CONCLUSION@#PC up-regulated the expression of AMPK and its downstream molecule FOXO3α and inhibited the biological activity of TLR4, NLRP3, and MCP-1, key signal molecules in the immunoinflammatory network pathway, which may be the molecular mechanism of PC to improve hyperuricemia-mediated immunoinflflammatory metabolic renal damage.

Comparative analysis of chemical constituents, antimicrobial and antioxidant activities of ethylacetate extracts of Polygonum cuspidatum and its endophytic actinomycete, Streptomyces sp. A0916 / 中国天然药物

The present study investigated the chemical composition of ethylacetate extracts from an endophytic actinomycete Streptomyces sp. A0916 and its host Polygonum cuspidatum. A comparative analysis of the antimicrobial and antioxidant properties of the extracts was also conducted. 32 compounds of P. cuspidatum and 23 compounds of Streptomyces sp. A0916 were isolated and identified by GC/MS. Antimicrobial activities of the extracts were evaluated using eight microbial strains (3 Gram-positive bacteria, 3 Gram-negative bacteria, and 2 fungi). The Streptomyces sp. A0916 extracts showed a wide range of antimicrobial activities and presented greater antimicrobial effectiveness than the P. cuspidatum extracts. The minimum inhibitory concentration (MIC) of Streptomyces sp. A0916 extracts against the ampicillin-resistant strain Enterococcus faecium SIIA843 was 32 μg·mL(-1). Furthermore, the extracts had greater antimicrobial effect against Gram-positive bacteria than Gram-negative bacteria. Finally, the antioxidant activity of the Streptomyces sp. A0916 extracts was equal to that of the P. cuspidatum extracts. In conclusion, our results suggest that the endophytic actinomycetes of the medicinal plants are an important source of bioactive substances.

Anti-Helicobacter pylori Compounds from Polygonum cuspidatum

Anti-Helicobacter pylori activity guided fractionation led to the isolation of five anthraquinones, two stilbenes and one naphthoquinone from the EtOAc fraction of Polygonum cuspidatum, using silica gel column chromatography, Sephadex-LH20, MPLC and recrystallization. The chemical structures were identified to be physcion (1), emodin (2), anthraglycoside B (3), trans-resveratrol (4), anthraglycoside A (5), polydatin (6), 2-methoxy-6-acetyl-7-methyljuglone (7) and citreorosein (8) by UV, ¹H-NMR, ¹³C-NMR and mass spectrometry. Anti-Helicobacter pylori activity including MIC values of each compound was evaluated. All of the isolates exhibited anti-H. pylori activity of which MIC values were lower than that of a positive control, quercetin. Compounds 2 and 7 showed potent growth inhibitory activity. Especially, a naphthoquinone, compound 7 displayed most potent antibacterial activity with MIC₅₀ value of 0.30 µM and MIC₉₀ value of 0.39 µM. Although anti-H. pylori activity of this plant was previously reported, this is the first report on that of compounds isolated from this species. From these findings, P. cuspidatum roots or its isolates may be useful for H. pylori infection and further study is needed to elucidate mechanism of action.

Preparation and crystallization of Polygonum cuspidatum benzalacetone synthase / 生物工程学报

The chalcone synthase (CHS) superfamily of the type III polyketide synthases (PKSs) generates backbones of a variety of plant secondary metabolites. Benzalacetone synthase (BAS) catalyzes a condensation reaction of decarboxylation between the substrates of 4-coumaric coenzyme A and malonyl coenzyme A to generate benzylidene acetone, whose derivatives are series of compounds with various biological activities. A BAS gene Pcpks2 and a bifunctional CHS/BAS PcPKSI were isolated from medicinal plant P. cuspidatum. Crystallographic and structure-based mutagenesis studies indicate that the functional diversity of the CHS-superfamily enzymes is principally derived from small modifications of the active site architecture. In order to obtain an understanding of the biosynthesis of polyketides in P. cuspidatum, which has been poorly described, as well as of its activation mechanism, PcPKS2 was overexpressed in Escherichia coli as a C-terminally poly-His-tagged fusion protein, purified to homogeneity and crystallized, which is helpful for the clarification of the catalytic mechanism of the enzyme and lays the foundation for its genetic engineering manipulation.

Comparison of stilbene synthase from different plant sources for resveratrol biosynthesis / 生物工程学报

Resveratrol is a natural phytoalexin with special pharmacological and health functions. Stilbene synthase (STS) is a key and rate-limiting enzyme in the biosynthesis of resveratrol that is present only in a limited number of plants. The content of resveratrol from Polygonum cuspidatum is more than 1000 times higher than grapes and peanuts. We speculate that the catalytic ability of different STS may be one of the reasons causing differences in the content of resveratrol. To verify the above speculation, Vitis vinifera stilbene synthase gene (VvSTS) was amplified according to overlap PCR protocol with genomic DNA as template. VvSTS and PcSTS (PcPKS5) were analyzed through heterologous expression in Escherichia coli. The expression products were purified with Ni-NTA sepharose affinity chromatography and desalted through PD-10 column. The molecular weight of the two fusion proteins was about 43 kDa. Enzyme reaction and product analysis showed that the two products were resveratrol. The enzyme kinetic analysis showed that the catalyze efficiency (Kcat/Km) of PcPKS5 was 2.4 times of the VvSTS. Our findings confirms that STS from certain plants has much higher catalytic capability.

Clinical study on treatment of carotid atherosclerosis with extraction of polygoni cuspidati rhizoma et radix and crataegi fructus: a randomized controlled trial / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of detoxifying and blood circulation activating Chinese herb extraction of polygonum cuspidatum and hawthorn on carotid intima-media thickness (IMT), plaque integral and plaque stability related serum indexes of patients with carotid atherosclerosis.</p><p><b>METHOD</b>Sixty and four cases of carotid artery atherosclerosis patients were assigned randomly to 2 groups: detoxifying and blood circulation activating treatment group (treatment group, 32 cases) and control group (32 cases). Patients in treatment group were treated with capsules of extraction of polygonum cuspidatum and hawthorn, 1 pill po, bid (dosage of administration: polygonum cuspidatum extraction 5.33 mg x kg(-1) x d(-1), hawthorn extraction 5.0 mg x kg(-1) x d(-1)); patients in control group were treated with lovastatin 20 mg po, qd (dosage of administration: 0.33 mg x kg(-1) x d(-1)). The course of treatment was six months. To observe changes of IMT, plaque integral, and detect the level of plaque stability related serum indexes such as Hs-CRP, MMP-1 and TIMP-1.</p><p><b>RESULT</b>After 6 months of treatment, in control group one patient quit the clinical trial because of liver dysfunction and one patient was rejected because of having not followed the therapeutic regimen. 32 cases in treatment group and 30 cases in control group were analyzed. The results showed that IMT and plaque integral of treatment group decreased significantly after the treatment (P < 0.05, P < 0.01), and there was no significant difference compared with control grope. Serum Hs-CRP, MMP-1 and MMP-1/TIMP-1 decreased after the treatment (P < 0.05, P < 0.01), and the treatment group was superior to control group in decreasing serum Hs-CRP (P < 0.05).</p><p><b>CONCLUSION</b>Detoxifying and blood circulation activating Chinese herb extraction of polygonum cuspidatum and hawthorn has good effect of anti-atherosclerosis and promoting plaque stability. Its mechanism might be related with anti-inflammation and inhibiting degradation of extracellular matrix, and deserves further studies.</p>

The Spectrum-Effect integrated fingerprint of Polygonum cuspidatum based on HPLC-diode array detection-flow injection-chemiluminescence / 中国天然药物

AIM@#To establish the Spectrum-Effect integrated fingerprint of Polygonum cuspidatum to evaluate the quality of P. cuspidatum.@*METHODS@#An on-line HPLC-DAD-flow injection chemiluminescence (FICL) method was developed to investigate the quality of P. cuspidatum from different habitats based on the established Spectrum-Effect integrated fingerprint.@*RESULTS@#Nineteen batches of samples of P. cuspidatum were evaluated for the similarity of their chromatographic and free radical scavenging fingerprints, and the results compared. Main antioxidants were estimated by regression analysis between peak areas of thirteen compounds and their activities. Some active compounds were identified by HPLC-ESI-MS.@*CONSULSIONS@#The results indicated that main antioxidants in P. cuspidatum could be rapidly screened by the established Spectrum-Effect integrated fingerprint based on on-line HPLC-DAD-FICL, and would be more efficient and objective method to evaluate the quality of P. cuspidatum.

Validation of HPLC method for the determination of polydatin in giant knotweed rhizome / 药学学报

An HPLC method has been developed to determine polydatin in giant knotweed rhizome. In order to systematically validate the method, specificity, precision, linearity of reference solution and test solution, repeatability, reproducibility, accuracy, stability and robustness were measured. In the robustness test, a one-variable-at-a-time procedure was applied to evaluate the influence of slight variations in method factors, including the flow rate, the column temperature, the extraction time, and etc., on the assay result of polydatin. No significant differences were found when the process parameters changed during the experimental domain. And system suitability test limits were defined based on the robustness test. Results showed that the developed method was accurate, reproducible and robust.

Pharmacological of Polygoni cuspidati rhizoma / 中国中药杂志

Through searching some domestic or abroad literatures of rhizoma polygoni cuspidati in recent years, the paper summarized its pharmacological effects, including antibacterial, antiviral, anti-inflammatory, analgesic, cardiovascular system protection, liver protection, anti tumor, improving immunity pharmacology and so on. These studies indicated Polygoni Cuspidati Rhizoma was a kind of drugs with exploiting and using value. [Key words]

Active neuraminidase constituents of Polygonum cuspidatum against influenza A(H1N1) influenza virus / 中国中药杂志

<p><b>OBJECTIVE</b>To isolate and identify active neuraminidase constituents of Polygonum cuspidatum against influenza A (H1N1) influenza virus.</p><p><b>METHOD</b>On the basis of the bioassay-guided fractionation,such chromatographic methods as silica gel, sephadex LH-20 and HPLC were adopted to isolate active constituents of extracts from Polygonum cuspidatum, and their molecular structures were identifiied on the basis of their spectral data such as NMR and MS and physico-chemical properties.</p><p><b>RESULT</b>Seven compounds were isolated from the ethyl acetate extract of P. cuspidatum and identified as 2-methoxystypandrone (1), emodin (2), resveratrol (3), polydatin (4), emodin-8-O-beta-D-glucopyranoside (5), (E)-3, 5, 12-trihydroxystilbene-3-O-beta-D-glucopyranoside-2'-(3", 4", 5"-trihydroxybenzoate) (6) and catechin-3-O-gallate (7), respectively. Among them, the NA test showed that compounds 3, 6 and 7 had inhibitory effect against NAs activity, with IC50 values of 129.8, 44.8 and 21.3 micromol x L(-1), respectively. Moreover, the further CPE test showed compounds 6 and 7 had significant inhibitory effect against H1N influenza virus (EC50 = 5.9, 0.9 micromol x L(-1), respectively), with very low cytotoxicity to the host cells, their therapeutic selective index(SI) in MDCK cells ranged from 56 to 269.</p><p><b>CONCLUSION</b>The neuraminidase inhibitors against H1N1 anti-influenza virus isolated from extracts of P. cuspidatum on the basis of the bioassay-guided fractionation are significant in specifying their therapeutic material basis and drug R&D against influenza.</p>

Simultaneous determination of contents of five major bioactive components contained in Polygoni Cuspidati Rhizoma et Radix by microwave extraction-ultra performance liquid chromatography / 中国中药杂志

<p><b>OBJECTIVE</b>To establish a microwave extraction and UPLC method for simultaneous determination of polydatin, resveratrol, anthraglycoside B, emodin and physicion contained in Polygoni Cuspidati Rhizoma et Radix, in order to provide scientific basis for improving quality standards of Polygoni Cuspidati Rhizoma et Radix.</p><p><b>METHOD</b>The test solutions were prepared in a MDS-8 closed microwave system at 160 degrees C with methanol as the solvent. The UPLC analysis was performed in a Waters Acquity UPLC system. A BEH C18 column (2. 1 mm x 100 mm, 1.7 microm) was adopted for gradient elution with acetonitrile and water as the mobile phase. The temperature of column was 30 degrees C, and the detection wavelength was 226 nm.</p><p><b>RESULT</b>The five active components can be completely extracted in 10 minutes and separated completely in 12 minutes according to UPLC analysis, with a good linearity (r > or = 0. 999 6) within the linear ranges. The average recovery rate was 97.00%-103.7% with RSD < or = 2. 2%. Despite a large difference in content among tested components from Polygoni Cuspidati Rhizoma et Radix, the total content of the five major constituents was relatiely stable (3.683 3%-7.1031%).</p><p><b>CONCLUSION</b>The microwave extraction-ultra performance liquid chromatography method in simultaneous determination for contents of five major bioactive components contained in polygoni cuspidati rhizoma et radix is so rapid and highly reproducible that it can be used for quality control and assessment of Polygoni Cuspidati Rhizoma et Radix.</p>

Optimization of ultrahigh pressure extraction for polydatin and resveratrol from Polygonum cuspidatum by using uniform design / 中国中药杂志

<p><b>OBJECTIVE</b>To optimize the ultrahigh pressure extraction (UPE) process of polydatin and resveratrol from Polygonum cuspidatum by using uniform design.</p><p><b>METHOD</b>On the basis of single factor screening, the uniform design was adopted for getting the optimal technique parameters. The optimum result of UPE was compared with conventional extractions.</p><p><b>RESULT</b>The optimal conditions of UPE for polydatin and resveratrol were that the solvent was 55% ethanol, the ratio of solvent to material( mL: g) was 30, the extraction pressure was 170 MPa, and the extraction time was 120 second. With this extracting process, the extraction yield of polydatin and resveratrol were 14.29 and 2.53 mg x g(-1), respectively. The extraction yield of polydatin was 46.1% higher than the heat reflux extraction, 6.4% higher than the ultrasonic extraction and 28.5% higher than the microwave extraction, while the yield of resveratrol was 67.5% higher than the heat reflux extraction, 29.7% higher than the ultrasonic extraction and 24.6% higher than the microwave extraction, respectively.</p><p><b>CONCLUSION</b>As a novel extraction technology for Chinese herbal medicine, the UPE procedure has higher extraction yield, lower extracting temperature, shorter extacting time and less power consumption. The UPE has provided a brand-new method for extraction of polydatin and resveratrol from P. cuspidatum.</p>

Selective removal of tannins from Polygonum cuspidatum extracts using collagen fiber adsorbent / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the selective removal of tannins from Polygonum cuspidatum extracts by using collagen fiber adsorbent, and to evaluate the adsorption and desorption performances of collagen fiber adsorbent to tannins.</p><p><b>METHOD</b>The adsorbent was prepared from bovine skin collagen fiber through crosslinking reaction of glutaraldehyde, and then used for the selective removal of tannins from P. cuspidatum extracts. Gelatin-turbidity method, gelatin-ultraviolet spectrometry method and HPLC were used for detection of tannins in the solutions. Ethanol-water solutions with varying concentration were used to test their desorption ability of tannins in order to choose proper desorption solution. On the basis of batch experimental results, the column adsorption and desorption tests were carried out, by using gelatin-turbidity method for detection of tannins.</p><p><b>RESULT</b>The collagen fiber adsorbent exhibited excellent adsorption selectivity to tannins. It was found that tannins of P. cuspidatum were completely removed, while nearly no adsorption of active components (resveratrol as representative) was found. Moreover, the collagen fiber adsorbent could be regenerated by using 30% ethanol-water solution and then reused.</p><p><b>CONCLUSION</b>The collagen fiber adsorbent can be considered as a promising material for selective removal of tannins from P. cuspidatum extracts.</p>

Antioxidant activity of extract from Polygonum cuspidatum

Numerous diseases are induced by free radicals via lipid peroxidation, protein peroxidation and DNA damage. It has been known that a variety of plant extracts have antioxidant activities to scavenge free radicals. Whether Polygonum cuspidatum Sieb. et Zuce has antioxidant activity is unknown. In this study, dried roots of Polygonum cuspidatum were extracted by ethanol and the extract was lyophilized. Free radical scavenging assays, superoxide radical scavenging assays, lipid peroxidation assays and hydroxyl radical-induced DNA strand scission assays were employed to study antioxidant activities. The results indicate that the IC50 value oí Polygonum cuspidatum extract is 110 µg/ml in free radical scavenging assays, 3.2 µg/ml in superoxide radical scavenging assays, and 8 µg/ml in lipid peroxidation assays, respectively. Furthermore, Polygonum cuspidatum extract has DNA protective effect in hydroxyl radical-induced DNA strand scission assays. The total phenolics and flavonoid content of extract is 641.1 ± 42.6 mg/g and 62.3 ± 6.0 mg/g. The results indicate that Polygonum cuspidatum extract clearly has antioxidant effects.

Application of macroporous resin in purification for effective part from Polygonum cuspidatum / 中国中药杂志

<p><b>OBJECTIVE</b>To study the technological parameters of the purification process for effective part from Polygonum cuspidatum.</p><p><b>METHOD</b>Using adsorption capacities and desorption rates of polydatin, resveratrol,emodin,physcion and total anthraquinone as the primary screening indexes, six resins were surveyed,and the optimized conditions of adsorption and desorption of the effective ingredients were studied.</p><p><b>RESULT</b>Resin D101 gave good separation performance and was selected to purify the effective part in Polygonum cuspidatum. The optimum parameters were established as the following: 1 BV (bed volume) sample extract was passed through the column with a flow rate of 2.4 BV x h(-1), 30 min later,the column was washed with 2 BV water, 2 BV 20% ethanol, 5 BV 50% ethanol, 2 BV 70% ethanol and 5 BV 95% ethanol, respectively. The combined 50% and 95% ethanolic elutes were concentrated to yield the purified effctive part.</p><p><b>CONCLUSION</b>The purity of the total effective ingredients in the product was up to 36. 87%. Macroporous resin D101 could be well used in separating and purifying the effective part from Polygonum cuspidatum.</p>

Study on drug release in vitro and rat intestinal absorption of resveratrol nanoliposomes / 中国中药杂志

<p><b>OBJECTIVE</b>To study the release feature of Res-nanoliposomes in vitro and clarify the difference in absorption of Res-nanoliposomes from varied intestinal segments and the absorptive mechanism in vivo.</p><p><b>METHOD</b>Dialytic method was used to determine resveratrol release rate of Res-nanoliposomes in vitro. An in situ rat perfusion method was used to investigate the intestinal absorption of Res-nanoliposomes.</p><p><b>RESULT</b>Resveratrol release from nanoliposomes in vitro fitted the log-normal distribution equation and had a property of sustained release. Compared with other intestinal segments, significantly high percentage of Res-nanoliposomes was absorbed in ileum (P < 0.001). The absorption rate constants (ka) of Res-nanoliposomes in intestine were not significantly different.</p><p><b>CONCLUSION</b>Res-nanoliposomes could sustain to release drug in vitro. The absorption was a first-order process with the passive diffusion mechanism. The Res-nanoliposomes could promote the absorption of Res in rat small intestine.</p>

Effect of different light intensity on Polygonum cuspidatum callus / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of light intensity (LI) on the callus induction and resveratrol content of Polygonum cuspidatum.</p><p><b>METHOD</b>Taking leaves and stem segment of P. cuspidatum as explants, the callus was inducted and cultured under different LI. The growth status of callus was observed and analyzed. The content of resveratrol was determined by HPLC.</p><p><b>RESULT</b>The formation and growth of the stem segment callus were optimal under low light treatment (1340-1560 lx). The resveratrol content was 18.350 microg x g(-1) in fresh stem segment and 140.074 microg x g(-1) in dry stem segment, which was two times higher than that of wild P. cuspidatum.</p><p><b>CONCLUSION</b>Introduction and status of P. cuspidatum callus were obvious diverse under different LI, the resveratrol content of P. cuspidatum was enhanced under appropriate LI.</p>

Increasing the content of active constituents in Polygonum cuspidatum hairy root by gene transformation technology / 药学学报

To increase the content of active constituent--RE and PD of Polygonum cuspidatum hairy root, through Ri-mediated gene transformation technology, modified high salt low pH method was used to distill genome DNA of grapevine (Vitis raparia). Primer was designed according to sequence of Genebank (AF128861). Through PCR amplification obtain RS gene sequence was obtained. Binary vector pCAMBIA1300-35S-RS was constructed. Frost thawing method was used to transform Agrobacterium rhizogenes ATCC11325. Scratched aseptic seedling leaf of Polygonum cuspidatum was contaminated subsequently. DNA conformity and mRNA expression of RS gene were investigated by PCR and RT-PCR respectively. RE and PD in transgenic hairy root were determined by HPLC. For the first time successfully inducement acquires transformed RS gene hairy root of Polygonum cuspidatum. Content of active constituents--RE and PD were 17 - 187 microg x g(-1) DW and 836 - 1 970 microg x g(-1) DW, respectively, the non-transgenic hairy root was 0 - 130 microg x g(-1) DW and 190 - 320 microg x g(-1) DW. In the different root selected, the content of PD was much higher than that in non-transformed hairy roots of Polygonum cuspidatum, the highest content is 5 times, but the content of RE has not increased apparently.