The first complete chloroplast genome of Vicatia thibetica de Boiss.: genome features, comparative analysis, and phylogenetic relationships.

Vicatia thibetica de Boiss.: a herb in the family Apiaceae, has been used for over a hundred years as an essential medicinal and edible plant in the Bai ethnic group of Dali City. However, due to the lack of study on plastid genomes of V. thibetica, studies of comparison and phylogeny with other related species remain scarce. In the current study, we assembled, annotated, and characterized the entire chloroplast (cp) genome of V. thibetica through high-throughput sequencing for the first time, compared with published whole chloroplast genomes from the same family. A phylogenetic analysis of the chloroplast genome has also been performed. The whole chloroplast genome of V. thibetica was 145,796 in size and consisted of a large single-copy region (LSC; 92,186 bp), a small single-copy region (SSC; 17,452 bp), and a pair of inverted repeat regions (IRs; 18,079 bp) forming a circular quadripartite structure. Annotation resulted in 128 genes, including 84 protein-coding genes (PCGs), 35 transfer RNA genes (tRNAs), eight ribosomal genes (rRNAs), and one pseudogene. Repeat sequence analysis displayed V. thibetica plastid genome contains 75 simple repeats, 37 long repeats, and 29 tandem repeats. Compared with the cp genome of other Apiaceae species, a common feature was that the IR regions of the genome were more conservative compared to the LSC and SSC regions. Highly variable hotspots included rps16, ndhC-trnV-UAC, clpP, ycf1, and ndhB in the genomes, which supply valuable molecular markers for phylogeny, identification, and classification in the Apiaceae family. The results of phylogenetic analysis strongly supported the genus Vicatia as an independent genus in the family Apiaceae, in which the closest affinities to the related species of Angelica, Peucedanum, and Ligusticum were observed. In conclusion, the first chloroplast genome of Vicatia reported in this study may  improve our understanding of phylogenetic relationship of different genera of Apiaceae. In addition, the current data will be valuable as chloroplast genomic resource for species identification and population genetics. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01154-y.

[Anti-inflammatory target prediction of Gentianae Radix et Rhizoma based on network pharmacology and construction of a bioassay method for its quality control].

Based on the heat-clearing and detoxifying effects of Gentianae Radix et Rhizoma, the network pharmacology is mainly used to predict the potential targets of Gentianae Radix et Rhizoma for anti-inflammatory activity and to perform the experimental verification. A method for detecting the biological potency of Gentianae Radix et Rhizoma based on verifiable targets has been established to provide a reference for improving the quality evaluation and control standards of Gentianae Radix et Rhizoma. High performance liquid chromatography can be used to construct chemical fingerprints of different batches of Gentianae Radix et Rhizoma. Constructing a component-target-disease network of Gentianae Radix et Rhizoma for its anti-inflammatory activity was applied to screen potential anti-inflammatory components and related targets of Gentianae Radix et Rhizoma, and to verify the target of Gentianae Radix et Rhizoma by using biological evaluation methods. Detecting the biological potency of different batches of Gentianae Radix et Rhizoma extracts was used to inhibit COX-2 enzyme activity based the verifiable target cyclooxygenase-2(COX-2). The results showed that different batches of Gentianae Radix et Rhizoma accorded with the pharmacopoeia testing regulations, and the chemical fingerprints have a high similarity(similarity>0.93), suggesting that there is no significant difference in the characteristics of the chemical components. Based on network pharmacology predictions, 18 candidate targets were found to have potential direct interactions with the ingredients in Gentianae Radix et Rhizoma. Among them, the most important target is COX-2. Based on the experimental verification of recombinant human COX-2 protease activity inhibition, Gentianae Radix et Rhizoma can inhibit the COX-2 enzyme activity in a dose-dependent manner. It can function with a low concentration(0.75 mg·mL~(-1)), which preliminarily confirmed the accuracy of network pharmacology prediction. The biological potency detection method of Gentianae Radix et Rhizoma based on COX-2 inhibitory activity was optimized and established. The qualitative response parallel line method was used to calculate the biological potency of anti-inflammatory activity, which ranged from 23.04 to 46.60 U·mg~(-1). For network pharmacology prediction, it can screen and clarify the possible targets of traditional Chinese medicine rapidly, which can guide the establishment of a biological evaluation method for the quality of medicinal materials with related activities. Compared with chemical fingerprints, the biological potency testing can better detect quality fluctuations of traditional Chinese medicine.

Seeing the Unseen of the Combination of Two Natural Resins, Frankincense and Myrrh: Changes in Chemical Constituents and Pharmacological Activities.

For the treatment of diseases, especially chronic diseases, traditional natural drugs have more effective therapeutic advantages because of their multi-target and multi-channel characteristics. Among many traditional natural medicines, resins frankincense and myrrh have been proven to be effective in the treatment of inflammation and cancer. In the West, frankincense and myrrh have been used as incense in religious and cultural ceremonies since ancient times; in traditional Chinese and Ayurvedic medicine, they are used mainly for the treatment of chronic diseases. The main chemical constituents of frankincense and myrrh are terpenoids and essential oils. Their common pharmacological effects are anti-inflammatory and anticancer. More interestingly, in traditional Chinese medicine, frankincense and myrrh have been combined as drug pairs in the same prescription for thousands of years, and their combination has a better therapeutic effect on diseases than a single drug. After the combination of frankincense and myrrh forms a blend, a series of changes take place in their chemical composition, such as the increase or decrease of the main active ingredients, the disappearance of native chemical components, and the emergence of new chemical components. At the same time, the pharmacological effects of the combination seem magically powerful, such as synergistic anti-inflammation, synergistic anticancer, synergistic analgesic, synergistic antibacterial, synergistic blood-activation, and so on. In this review, we summarize the latest research on the main chemical constituents and pharmacological activities of these two natural resins, along with chemical and pharmacological studies on the combination of the two.

Effect of breviscapine on CYP3A metabolic activity in healthy volunteers.

OBJECTIVE: The purpose of this study was to investigate the influence of breviscapine on the pharmacokinetics of concomitantly administered midazolam (MID) and its associations with and effects on genetic polymorphism of the gene encoding cytochrome P450 3A5 (CYP3A5) in healthy volunteers. METHODS: The study group comprised 17 healthy volunteers who had been genotyped for CYP3A5*3 prior to start of the study. These volunteers were given daily doses of 120 mg (40 mg, three times a day) of breviscapine or a placebo for 14 days, followed by 7.5 mg midazolam (MID) on day 15. The plasma concentrations of MID and the metabolite 1-hydroxy-midazolam (1-OH-MID) were determined by ultra-performance liquid chromatography-mass spectrometry for up to 12 h after drug administration. RESULTS: The pharmacokinetics of MID and 1-OH-MID were significantly different between the breviscapine and placebo groups, with a point estimate for MID AUC(0-12) of 1.56 (90% confidence interval 1.26, 1.87). The pharmacokinetics of MID and 1-OH-MID were not different among the CYP3A5 genotype groups, regardless of whether MID was coadministered with breviscapine or with placebo. CONCLUSIONS: These findings suggest that breviscapine inhibited the metabolism of CYP3A in the volunteers, with no interaction difference among the different CYP3A5 genotypes.

[Activating blood biological potency assay and chemical fingerprint chromatogram applied to quality evaluation of rhubarb].

The biological potency assay and chemical fingerprint chromatogram were applied to quality evaluation of rhubarb. Using the biological potency as indicators, we evaluated the differences in quality of multiple batches of rhubarbs and related products. Using the platelet aggregation analyzer, we determined platelet aggregation rate in the different rhubarbs preparations, and calculated the biological potency based on the simplified probit principle. UPLC was adopted to establish the fingerprint spectra for rhubarbs. The spectral efficiency correlation analysis between chromatograms and biological potencies were conducted using the double variables of SPSS 22.0 software. We used three chemical composition to verify the potency. The biological potency results suggest that Rheum palmatum has a more potent activity than Rheum tanguticum, and wine-treated rhubarb had a higher potentcy than charred. We identified 10 elements in the Fingerprint Spectrum. The relevant elements including rhein-8-O-ß-D-glucoside, emodin-8-O-ß-D-glucoside and rhein have the strongest activity in the inhibition of platelet aggregation. In conclusion, this study provides a analytical method for rhubarb biological potency based on determination of the maximum antagonism rate model. The rhein may be the effective substance. It may serve as a reference in the quality control of wine processed rhubarb products.

[Quality evaluation of rhubarb dispensing granules based on multi-component simultaneous quantitative analysis and bioassay].

This study attempts to evaluate the quality of Chinese formula granules by combined use of multi-component simultaneous quantitative analysis and bioassay. The rhubarb dispensing granules were used as the model drug for demonstrative study. The ultra-high performance liquid chromatography (UPLC) method was adopted for simultaneously quantitative determination of the 10 anthraquinone derivatives (such as aloe emodin-8-O-ß-D-glucoside) in rhubarb dispensing granules; purgative biopotency of different batches of rhubarb dispensing granules was determined based on compound diphenoxylate tablets-induced mouse constipation model; blood activating biopotency of different batches of rhubarb dispensing granules was determined based on in vitro rat antiplatelet aggregation model; SPSS 22.0 statistical software was used for correlation analysis between 10 anthraquinone derivatives and purgative biopotency, blood activating biopotency. The results of multi-components simultaneous quantitative analysisshowed that there was a great difference in chemical characterizationand certain differences inpurgative biopotency and blood activating biopotency among 10 batches of rhubarb dispensing granules. The correlation analysis showed that the intensity of purgative biopotency was significantly correlated with the content of conjugated anthraquinone glycosides (P<0.01), and the intensity of blood activating biopotency was significantly correlated with the content of free anthraquinone (P<0.01). In summary, the combined use of multi-component simultaneous quantitative analysis and bioassay can achieve objective quantification and more comprehensive reflection on overall quality difference among different batches of rhubarb dispensing granules.

[Quality characteristic comparison of Schisandrae Chinensis Fructus from different place].

The contents of schisandrol A, schisandrol B, schisantherin A, schisandrin A , schisandrin B, schisandrin C in Schisandrae Chinensis Fructus (SCF) were determined simultaneously by HPLC. Collect 100-seed weight, color, pulp content, longitude and latitude of SCF of different batches were collected. SIMCA-P and SPSS were applied to make PLS-DA analysis of 24 batches of SCF and correlation analysis of relevant parameters. According to the 13 parameters, SCF from three different places of origin could be distinguished effectively. It was found that the content of chemical component of SCF increased with latitude and longitude first, and then decrease. The results provide some theoretical basis for study of SCF genuineness and traditional method of identifying just from experience.

Sequencing and characterization of the chloroplast genome of Aconitum forrestii Stapf provide insights into phylogenetics in Aconitum.

Aconitum forrestii Stapf is an essential traditional Chinese medicine, and is beneficial in dispelling wind, removing dampness, warming, and relieving pain. However, its phylogenetic position of Aconitum is not accepted yet. In order to clarify the evolutionary relationship of A. forrestii, complete sequencing of chloroplast genome was carried out using Illumina sequencing technology. In total, the chloroplast genome was about 155,869 base pair (bp) in length and carried a typical tetrad structure that included a large single-copy, a small-single copy and two inverted repeat regions. A total of 132 genes were annotated, that included 85 protein -coding genes, 37 transfer RNA genes, eight ribosomal RNA genes, and two pseudogenes. The phylogenetic tree analysis indicated that Aconitum forrestii is closely related to Aconitum episcopale and Aconitum delavayi.

Metabolomic Signatures of Autoimmune Hepatitis in the Development of Cirrhosis.

Objectives: Autoimmune hepatitis (AIH) can progress into severe outcomes, i.e., decompensated cirrhosis, from remarkable and persistent inflammation in the liver. Considering the energy-expending nature of inflammation, we tried to define the metabolomics signatures of AIH to uncover the underlying mechanisms of cirrhosis development and its metabolic biomarkers. Methods: Untargeted metabolomics analysis was performed on sera samples from 79 AIH patients at the stages (phenotypes) of non-cirrhosis (n = 27), compensated cirrhosis (n = 22), and decompensated cirrhosis (n = 30). Pattern recognition was used to find unique metabolite fingerprints of cirrhosis with or without decompensation. Results: Out of the 294 annotated metabolites identified, 2 metabolic fingerprints were found associated with the development of cirrhosis (independent of the decompensated state, 42 metabolites) and the evolution of decompensated cirrhosis (out of 47 metabolites), respectively. The cirrhosis-associated fingerprints (eigenmetabolite) showed better capability to differentiate cirrhosis from non-cirrhosis patients than the aminotransferase-to-platelet ratio index. From the metabolic fingerprints, we found two pairs of metabolites (Mesobilirubinogen/6-Hydroxynicotinic acid and LysoPA(8:0/0:0)/7alpha-Hydroxycholesterol) calculated as ratio of intensities, which revealed robust abilities to identify cirrhosis or predict decompensated patients, respectively. These phenotype-related fingerprint metabolites featured fundamental energy supply disturbance along with the development of AIH cirrhosis and progression to decompensation, which was characterized as increased lipolysis, enhanced proteolysis, and increased glycolysis. Conclusions: Remodeling of metabolism to meet the liver inflammation-related energy supply is one of the key signatures of AIH in the development of cirrhosis and decompensation. Therefore, drug regulation metabolism has great potential in the treatment of AIH.

The complete chloroplast genome sequence of the medicinal plant Lepidium meyenii Walp. (Cruciferae).

Lepidium meyenii Walp. is a frequently used medicinal plant (namely, 'maca') in Yunnan Province of China. In this study, we sequenced the complete chloroplast (cp) genome sequence of L. meyenii to investigate its phylogenetic relationship in the family Cruciferae. The chloroplast genome of L. meyenii was 154,839 bp in length with 36.39% overall GC content, including a large single copy (LSC) region of 83,943 bp, a small single copy (SSC) region of 17,978 bp and a pair of inverted repeats (IRs) of 52,918 bp. The cp genome contained 103 genes, including 78 protein-coding genes, 21 tRNA genes, and four rRNA genes. The phylogenetic analysis indicated L. meyenii was closely related to the genus Capsella.

Identification of a Pharmacological Biomarker for the Bioassay-Based Quality Control of a Thirteen-Component TCM Formula (Lianhua Qingwen) Used in Treating Influenza A Virus (H1N1) Infection.

As chemical analysis for quality control (QC) of traditional Chinese medicine (TCM) formula is difficult to guarantee the effectiveness, a bioassay method that combines QC with evaluation of therapeutic effects has been developed to assess the TCM quality. Here, we chose a thirteen-component TCM formula, Lianhua Qingwen capsule (LHQW), as a representative sample, to explore the pivotal biomarkers for a bioassay and to investigate close association between QC and pharmacological actions. Initially, our results showed that chemical fingerprinting could not effectively distinguish batches of LHQW. Pharmacological experiments indicated that LHQW could treat influenza A virus (H1N1) infection in the H1N1 mouse model, as claimed in clinical trials, by improving pathologic alterations and bodyweight loss, and decreasing virus replication, lung lesions and inflammation. Furthermore, by using serum metabolomics analysis, we identified two important metabolites, prostaglandin F2α and arachidonic acid, and their metabolic pathway, arachidonic acid metabolism, as vital indicators of LHQW in treatment of influenza. Subsequently, macrophages transcriptomics highlighted the prominent role of cyclooxygenase-2 (COX-2) as the major rate-limiting enzyme in the arachidonic acid metabolism pathway. Finally, COX-2 was validated by in vivo gene expression and in vitro enzymatic activity with 43 batches of LHQW as a viable pharmacological biomarker for the establishment of bioassay-based QC. Our study provides systematic methodology in the pharmacological biomarker exploration for establishing the bioassay-based QC of LHQW or other TCM formulas relating to their pharmacological activities and mechanism.

Cardiac function evaluation for a novel one-step detoxification product of Aconiti Lateralis Radix Praeparata.

BACKGROUND: Aconiti Lateralis Radix Praeparata has been used as the first cardiac drug over a 1000 years in Asian countries. Although most detoxification products are confirmed to be safe, the effect is not potent as desired. In previous study, we designed a one-step detoxification product by fresh cutting and continuously dried, which preserved more water-soluble alkaloids while eliminating toxicity. It is thus necessary to find more in vivo evidence to support its industrial development. METHODS: Initially, network pharmacology was applied to analyze the related pathways of candidate components acting on heart failure diseases. Then, two heart failure models that were induced by propafenone hydrochloride and nimodipine (v/v, 1:1) and were given doxorubicin were carried out to test the cardiac activity. Moreover, the effect on mitochondrial energy metabolism was further assessed. RESULTS: Network pharmacology results indicated that Aconiti Lateralis Radix Praeparata treated heart failure through cAMP signaling pathway, calcium signaling pathway, adrenergic signaling in cardiomyocytes and so on. These pathways were highly correlated with myocardial contractility and mitochondrial energy metabolism. Trials on heart failure rats demonstrated that the novel processed-product could produce a stronger positive inotropic action and increase more Na +-K +-ATPase and Ca 2+-Mg 2+-ATPase than Heishunpian. Pathological results also revealed the novel one could better restore the morphology of cardiomyocytes and reduce vacuolar lesions. It also could inspire more energy with a lower concentration. CONCLUSIONS: This study provides scientific evidence for the clinical application of new products. It is of great benefit to innovate the industrial detoxification process of Aconitum.

Screening for the anti-inflammation quality markers of Xiaojin Pills based on HPLC-MS/MS method, COX-2 inhibition test and protein interaction network.

Nowadays, breast disorders seriously affect women's health in an increasing number. In China, Xiaojin Pills are commonly used in the treatment of breast diseases. Doctors have concluded that the combined use of Xiaojin Pills with conventional therapy can significantly improve the efficacy with fewer side effects. However, the prescription of Xiaojin Pills is complicated and their quality control methods cannot completely ensure the quality of Xiaojin Pills. On the basis of its mechanism, our study combined chemical evaluation and biological evaluation to identify the anti-inflammatory markers of Xiaojin Pills. In this manuscript, 13 compounds in Xiaojin Pills were quantified. At the same time, the cyclooxygenase-2 inhibition rates of different Xiaojin Pills were measured and the possible markers were screened by spectrum-effect relationship. Further, anti-inflammatory activities of markers were verified and protein interaction network was analyzed, identifying the components of Protocatechuate, Beta-Boswellic acid and Levistilide A as the anti-inflammatory quality markers of Xiaojin Pills. We hope our studies can provide a scientific theoretical basis for accurately quality control of Xiaojin Pills and reasonable suggestions for pharmaceutical companies and new ideas for the quality control of other medicines.

Toxic Constituents Index: A Toxicity-Calibrated Quantitative Evaluation Approach for the Precise Toxicity Prediction of the Hypertoxic Phytomedicine-Aconite.

Complex chemical composition is an important reason for restricting herbal quality evaluation. Despite the multi-components determination method significantly promoted the progress of herbal quality evaluation, however, which mainly concerned the total amount of multiple components and ignored the activity variation between each one, and did not accurately reflect the biological activity of botanical medicines. In this manuscript, we proposed a toxicity calibrated contents determination method for hyper toxic aconite, called toxic constituents index (TCI). Initially, we determined the minimum lethal dose value of mesaconitine (MA), aconitine (AC), and hypaconitine (HA), and established the equation TCI = 100 × (0.3387 ×X MA + 0.4778 ×X AC + 0.1835 ×X HA). Then, 10 batches of aconite were selected and their evaluation results of toxic potency (TP), diester diterpenoid alkaloids (DDAs), and TCI were compared. Linear regression analysis result suggested that the relevance between TCI and TP was the highest and the correlation coefficient R was 0.954. Prediction error values study also indicated that the evaluation results of TCI was highly consistent with that of TP. Moreover, TCI and DDAs were both applied to evaluate 14 batches of aconite samples oriented different origins; from the different evaluation results, we found when the proportion of HA was reached 25% in DDAs, the pharmacopeia method could generate false positive results. All these results testified the accuracy and universality of TCI method. We believe that this study method is rather accurate, simple, and easy operation and it will be of great utility in studies of other foods and herbs.

Poria Attenuates Idiosyncratic Liver Injury Induced by Polygoni Multiflori Radix Praeparata.

The hepatotoxicity induced by Polygoni Multiflori Radix Praeparata (PM) has aroused great concern throughout the world. Hence, it is worthwhile to perform studies on the detoxification with the combined use of medicinal herbs based on the compatibility theory of traditional Chinese medicine. In this work, the rat model of PM/LPS-induced idiosyncratic liver injury was used. The effects of Poria, Licorice, and Panax notoginseng on rats of PM/LPS-induced liver injury were investigated respectively, hoping to find the most effective herbal medicine to reduce the hepatotoxicity. According to results of biochemical and histological tests, PM could induce the idiosyncratic hepatotoxicity of rats which presented modest inflammation triggered by non-injurious dose of lipopolysaccharide (LPS). We also found that the combined use of Poria and PM in the ratio of 1:2 could significantly ameliorate the PM/LPS-induced liver injury and systemic inflammation. Furthermore, UPLC/QTOF-MS-based metabolomics was performed to identify possible biomarkers and underlying biological pathways. Ten metabolites were expressed differentially among LPS, PM/LPS, and detoxification-treated groups in terms of PCA and OPLS-DA analysis, which could be potential biomarkers. MetaboAnalyst and pathway enrichment analysis revealed that alterations of these metabolites were primarily involved in three pathways: arginine and proline metabolism, primary bile acid biosynthesis and sphingolipid metabolism. This research provides systematic experimental evidences for the hepatoprotective effect of Poria against PM/LPS-induced liver injury for the first time. And these findings may help better understand the underlying mechanisms of pathophysiologic changes in PM/LPS-induced liver injury.

Metabolomic Study on Idiosyncratic Liver Injury Induced by Different Extracts of Polygonum multiflorum in Rats Integrated with Pattern Recognition and Enriched Pathways Analysis.

Currently, numerous liver injury cases related to a famous Chinese herb- Polygonum Multiflorum (Heshouwu in Chinese) have attracted great attention in many countries. Our previous work showed that Heshouwu-induced hepatotoxicity belonged to idiosyncratic drug-induced liver injury (IDILI). Unfortunately, the components and mechanisms attributed to IDILI of Heshouwu are difficult to determine and thus remain unknown. Attempts to explore puzzles, we prepared the chloroform (CH)-, ethyl acetate (EA)-, and residue (RE) extracts of Heshouwu to investigate IDILI constituents and underlying mechanisms, using biochemistry, histopathology, and metabolomics examinations. The results showed that co-treatment with non-toxic dose of lipopolysaccharide (LPS) and EA extract could result in evident liver injury, indicated by the significant elevation of plasma alanine aminotransferase and aspartate aminotransferase activities, as well as obvious liver histologic damage; whereas other two separated fractions, CH and RE extracts, failed to induce observable liver injury. Furthermore, 21 potential metabolomic biomarkers that differentially expressed in LPS/EA group compared with other groups without liver injury were identified by untargeted metabolomics, mainly involved two pathways: tricarboxylic acid cycle and sphingolipid metabolism. This work illustrated EA extract had close association with the idiosyncratic hepatotoxicity of Heshouwu and provided a metabolomic insight into IDILI of different extracts from Heshouwu.

Quality Assessment of Panax notoginseng from Different Regions through the Analysis of Marker Chemicals, Biological Potency and Ecological Factors.

Panax notoginseng (Burk.) F.H. Chen, called Sanqi in China, is a perennial herb that has been used as a medicinal herb in traditional Chinese medicine for more than 400 years. Because notoginseng is included in many proprietary Chinese medicines, the quality of notoginseng directly affects its efficacy and safety. However, considering the complex and special growth environment requirements of notoginseng, it is insufficient to evaluate its quality based solely on the analysis of marker chemicals. Thus, in this study, we tried to evaluate the quality of notoginseng with integrated indicators: (1) the concentration of five marker chemicals, notoginsenoside R1, ginsenoside Rg1, ginsenoside Re, ginsenoside Rb1 and ginsenoside Rd; (2) the anticoagulant activity (ACA); and (3) twenty-one ecological factors (e.g., longitude, latitude, elevation and soil data). Using these 27 parameters, notoginseng from different regions could be distinguished effectively, indicating a remarkable divergence of quality. A correlation analysis showed that variations of the ecological factors were closely associated with the saponins content and biopotency. For instance, the total nitrogen (TN), alkali hydrolysis nitrogen (AHN) and rapidly available potassium (RAPT) were significantly correlated with ACA, and RAPT was significantly correlated with the content of ginsenoside Rd and notoginsenoside R1. The results demonstrated that the high-quality notoginseng was produced from the emerging regions such as Kunming, Qujing and Honghe, which had higher ACA and saponin content than the notoginseng produced in traditional regions such as Wenshan and Baise.

[Long QT syndrome gene diagnosis by haplotype analysis].

OBJECTIVE: Three long QT syndrome(LQTS) pedigrees were brought together for genetic diagnosis by using short tandem repeat(STR) markers. METHODS: Genomic DNA was extracted from blood samples. STR markers (D7S1824, D7S2439, D7S483, D3S1298, D3S1767, D3S3521) in or spanning the HERG and SCN5A gene were amplified; the haplotype analysis for LQTS was performed. RESULTS: Clinical diagnosis showed that 15 are LQTS patients (3 died) and 11 are probable patients. Linkage analysis showed that LQTS patients are linked with the SCN5A gene in family 1, HERG is linked with the disease in family 2 and 3. Fourteen gene carriers were identified, 2 patients and 7 probable patients were excluded. CONCLUSION: Linkage analysis using STR markers can serve as useful tool for presymptomatic diagnosis.