Chunsheng Liu

The antiviral and antimicrobial activities of licorice, a widely-used Chinese herb

Licorice is a common herb which has been used in traditional Chinese medicine for centuries. More than 20 triterpenoids and nearly 300 flavonoids have been isolated from licorice. Recent studies have shown that these metabolites possess many pharmacological activities, such as antiviral, antimicrobial, anti-inflammatory, antitumor and other activities. This paper provides a summary of the antiviral and antimicrobial activities of licorice. The active components and the possible mechanisms for these activities are summarized in detail. This review will be helpful for the further studies of licorice for its potential therapeutic effects as an antiviral or an antimicrobial agent.

HuGE systematic review and meta-analysis demonstrate association of CASP-3 and CASP-7 genetic polymorphisms with cancer risk.

Genetic variations in the caspase genes CASP-3 and CASP-7 are known to be involved in apoptosis, cytokine maturation, cell growth and differentiation. Polymorphisms of CASP-3 and CASP-7 genes have been increasingly recognized as important regulators in the development of cancer. However, whether there is a specific association is still controversial. Therefore, we made a Human Genome Epidemiology review and meta-analysis to explore the association between polymorphisms of CASP-3 and CASP-7 genes and cancer risk. Based on the inclusion criteria, we examined 9 case-control studies, with a total of 3142 cancer cases and 3670 healthy controls. Meta-analysis results showed that the homozygote (CC) of rs2705897 in the CASP-3 gene is positively associated with cancer susceptibility [odds ratio (OR) = 4.36, 95% confidence interval (CI) = 1.26-15.11, P = 0.02], while the C allele and C carrier (TC+CC) of rs1049216 are negatively associated with cancer risk (OR = 0.81, 95%CI = 0.69-0.95, P = 0.01; OR = 0.78, 95%CI = 0.63-0.97, P = 0.02, respectively). The G allele and G carrier of rs4647603 (A/G) in CASP-3 had positive associations with cancer susceptibility (OR = 1.69, 95%CI = 1.37-2.09, P < 0.001; OR = 1.93, 95%CI = 1.26-2.93, P = 0.002, respectively). The T allele of rs12415607, the G allele and homozygote (GG) of rs2227310, and homozygote (CC) of rs3124740 also had positive associations with cancer risk (OR = 1.18, 95%CI = 1.02-1.37, P = 0.03; OR = 1.17, 95%CI = 1.01-1.34, P = 0.03; OR = 1.34, 95%CI = 1.04-1.74, P = 0.03; OR = 1.30, 95%CI = 1.04-1.63, P = 0.02, respectively). In addition, homozygote (AA) of rs11196418 showed a significant negative association with cancer risk (OR = 0.36, 95%CI = 0.14-0.93, P = 0.03). These meta-analysis results demonstrated that CASP-3 and CASP-7 genetic polymorphisms are involved in the pathogenesis of cancer.

Enhancing ergosterol production in Pichia pastoris GS115 by overexpressing squalene synthase gene from Glycyrrhiza uralensis.

Abstract The present study was designed to determine the effects of copy number variations (CNVs) of squalene synthase 1(SQS1) gene on the mevalonate (MVA) pathway. SQS1 gene from G. uralensis (GuSQS1) was cloned and over-expressed in Pichia pastoris GS115. Six recombinant P. pastoris strains containing different copy number of GuSQS1 were constructed. HPLC was used to assay the level of ergosterol in all transgenic P. pastoris strains containing GuSQS1. HPLC analysis showed that the contents of ergosterol in all of the transgenic P. pastoris containing GuSQS1 were higher than that in the negative control. And with the increase of copy number of GuSQS1, the content of ergosterol showed an increasing-decreasing-increasing pattern. The contents of ergosterol in 10-copy-GuSQS1 P. pastoris and 47-copy-GuSQS1 P. pastoris were significantly higher than that in the rest recombinant P. pastoris strains. In conclusion, the CNVs of GuSQS1 influence the content of secondary metabolites in the MVA pathway. The present study provides a basis for over-expressing GuSQS1 and increasing the content of glycyrrhizin in G. uralensis cultivars.

Influence of the Environmental Factors on the Accumulation of the Bioactive Ingredients in Chinese Rhubarb Products

To provide a basis for controlling the quality of rhubarb under artificial cultivation, the present work was designed to evaluate the contents of 14 active pharmaceutical ingredients (API) of rhubarb in major rhubarb production areas in China and analyze the correlations between the contents of API and such factors as species, geographic distribution and soil. The levels of fourteen API in rhubarb were measured using HPLC. The geographic distributions were collected using GPS and the nutrients in the soil were measured using the methods in the literature. The results showed that the levels of major API vary significantly among plants of different locations according to variance analysis. The species factor has few obvious effect on the overall properties of the rhubarb by the cluster analysis because of the two source species occurring in all divided three groups. However, Rheum tanguticum Maxim.ex Balf. is less effective at synthesizing and accumulating 9 API out of 14 than Rheum palmatum L. The correlation analysis and regression analysis also indicated that a lower latitude should be considered in the accumulation of API and a lower longitude should be considered to produce more compound anthraquinones. Lower levels of total P, rapidly available P and available molybdenum (Mo) and higher available K and available Zn in the soil were significantly correlated to accumulation of API in rhubarb. These results provide a basis for the clinical application and controlling the levels of the major API of rhubarb during artificial cultivation.

Cloning and Characterization of Two cDNA Sequences Coding Squalene Synthase Involved in Glycyrrhizic Acid Biosynthesis in Glycyrrhiza uralensis

Glycyrrhiza uralensis are widely used in Chinese medicine for the functions of relieving cough, clearing heat and detoxicating. They are also used as food additives and industry materials. There are various components with different pharmacological activities in G. uralensis, among them glycyrrhizic acid is believed as an indicator component to characterize the quality of this herb. In the present study, two cDNA sequences coding squalene synthase (SQS1 and SQS2) involved in glycyrrhizic acid biosynthesis in G. uralensis were cloned and expressed in Escherichia coli as fusion proteins, which showed the similar activity as SQS isolated from other species to catalyze farnesyl diphosphate (FPP) into squalene (SQ). Because SQS is a key enzyme in glycyrrhizic acid metabolic pathway in G. uralensis, this work is significant for further studies concerned with exploring the molecular mechanism of biosynthesis of glycyrrhizic acid and improving the quality of G. uralensis.

Enhancing production of ergosterol in Pichia pastoris GS115 by over-expression of 3-hydroxy-3-methylglutaryl CoA reductase from Glycyrrhiza uralensis

The rate-limiting enzyme in the mevalonic acid (MVA) pathway which can lead to triterpenoid saponin glycyrrhizic acid (GA) is 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR). In order to reveal the effect of copy number variation in the HMGR gene on the MVA pathway, the HMGR gene from Glycyrrhiza uralensis Fisch. (GuHMGR) was cloned and over-expressed in Pichia pastoris GS115. Six recombinant P. pastoris strains containing different copy numbers of the GuHMGR gene were obtained and the content of ergosterol was analyzed by HPLC. The results showed that all the recombinant P. pastoris strains contained more ergosterol than the negative control and the strains with 8 and 44 copies contained significantly more ergosterol than the other strains. However, as the copy number increased, the content of ergosterol showed an increasing–decreasing–increasing pattern. This study provides a rationale for increasing the content of GA through over-expressing the GuHMGR gene in cultivars of G. uralensis.

Genetic diversity and population structure of Rheum tanguticum ( Dahuang ) in China

BackgroundWild Rheum tanguticum (Dahuang in Chinese) has becoming endangered in China. This study aims to examine the genetic structure and genetic diversity of R. tanguticum within species, and the genetic differentiation within and among populations in China.MethodsThe variability and structure of 19 populations of R. tanguticum were investigated by their chloroplast DNA mat K sequences. The genetic diversity index was calculated by Dnasp, PERMUT, and Arlequin 3.0 software, and a neighbor-joining (NJ)-tree was constructed by MEGA 5.0 software.ResultsFifteen haplotypes were obtained based on the mat K sequence analysis. The mean genetic diversity within species was 0.894, and the genetic variability among populations (67.6%) was relatively higher than that within populations (13.88%) according to the AMOVA and PERMUT analyses. The NJ-tree and a pairwise difference analysis indicated geographical isolation of R. tanguticum. The gene flow among populations was 0.05, indicating a genetic drift among some populations, which was also confirmed by the NJ-tree and haplotype distributions. Furthermore, a mismatch distribution analysis revealed the molecular evolution of R. tanguticum.ConclusionGenetic diversity among and within populations of R. tanguticum in China was demonstrated.

Effect of Abscisic Acid on Accumulation of Five Active Components in Root of Glycyrrhiza uralensis

Licorice is one of the most generally used herbal medicines in the world; however, wild licorice resources have decreased drastically. Cultivated Glycyrrhiza uralensis Fischer are the main source of licorice at present, but the content of main active components in cultivated G. uralensis are lower than in wild G. uralensis. Therefore, the production of high-quality cultivated G. uralensis is an urgent issue for the research and production fields. In this study, the content of five active components and seven endogenous phytohormones in cultivated G. uralensis (two-year-old) were determined by high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA), respectively. Furthermore, different concentrations (25–200 mg/L) of exogenous abscisic acid (ABA) were sprayed on the leaves of G. uralensis in the fast growing period. Results showed that ABA, zeatin riboside (ZR), and dihydrozeatin riboside (DHZR) had strong correlation with active components. In addition, the content of five active components increased remarkably after ABA treatment. Our results indicate that ABA is significantly related to the accumulation of active components in G. uralensis, and the application of exogenous ABA at the proper concentration is able to promote the accumulation of main components in G. uralensis.

Identification of three Daphne species by DNA barcoding and HPLC fingerprint analysis

In order to well identify the 93 wild Cortex Daphnes samples from different species and habitats in western China and develop a standard operating procedure (SOP) for the authentication and quality of them in the future, a comprehensive and efficient identification system based on DNA barcoding and HPLC fingerprint technologies has been developed. The result showed that only 17 samples (18%) were Daphne giraldii Nitsche (DG), which is recorded in Chinese Pharmacopeia, while the others (82%) might have safety hazards. Additionally, the result of HPLC fingerprint analysis indicated that samples in the same species origins and wild distributions could be clustered together, which was consistent with DNA barcoding analysis. The study can provide a significant system for the authentication and quality of commercial Cortex Daphnes herbs. Undoubtedly, this study undoubtedly confirmed that the chemical compositions of Cortex Daphnes herbs were affected by both species origins and ecological environments, which is required more in-depth research.

Identification of Clematidis radix et Rhizoma and its adulterants by core haplotype based on the ITS sequences

To develop a method to identify Clematidis radix et Rhizoma using sequence similarity and sequence-specific genetic polymorphisms based on the ITS sequences. DNA was extracted from leaves of Clematis mandshurica Rupr and C. hexapetala using a DNA extraction kit. ITS sequences were amplified by PCR, and analyzed in Contig Express, DNAman, and MEGA 5.0. The core haplotype was determined, and similarities between the core and other haplotypes were calculated. In total, 138 ITS sequences of C. mandshurica were obtained with a length of 611 bp. The similarity threshold between C. mandshurica and counterfeit species was 99%. Using specific mutation sites, we could identify C. chinensis, C. hexapetala, and C. mandshurica rapidly and accurately. A new DNA-based method has been established to rapidly and accurately identify Clematidis radix et Rhizoma.