Zhi-Tao Liang

Publications of Zhi-Tao Liang

• Study of the relationship between genetics and geography in determining the quality of Astragali Radix.

  Authors: Jing Liu, Hu-Biao Chen, Bao-Lin Guo, Zhong-Zhen Zhao, Zhi-Tao Liang, Tao Yi

  Biological & pharmaceutical bulletin. 01/2011; 34(9):1404-12.

  Astragali Radix (AR), prepared from the roots of Astragalus membranaceus (FISCH. ex LINK) BUNGE or its variey, A. membranaceus (FISCH. ex LINK) BUNGE var. mongholicus (BUNGE) HSIAO., is one of theAstragali Radix (AR), prepared from the roots of Astragalus membranaceus (FISCH. ex LINK) BUNGE or its variey, A. membranaceus (FISCH. ex LINK) BUNGE var. mongholicus (BUNGE) HSIAO., is one of the most used and valuable traditional Chinese medicines (TCMs). Historically, Hunyuan, Shanxi Province in China is the geo-authentic producing area of AR and crude AR from here called "geo-authentic." According to tradition, geo-authentic TCMs define both authenticity and quality. However, no scientific investigation has ever determined whether the superior quality of Hunyuan AR is due to the genetic characteristics or to the local environment. In our study, seeds of 30 AR samples representing the two varieties from different regions were cultivated in Hunyuan under the same conditions. A method, using ultra-performance liquid chromatography coupled with photodiode array detector and evaporative light scattering detectors, was developed to evaluate the quality through a simultaneous determination of four major isoflavonoids and four major saponins. The two AR varieties were successfully distinguished by principal component analysis while samples of the same species with different seeds origins could not be distinguished. A genetic study demonstrated that the internal transcribed spacer sequences of the nuclear ribosomal DNA in A. membranaceus var. mongholicus samples from different geographical regions were highly conservative. These results indicate that the content of active components in AR depends on the interaction of genotype and environment. At the varietal level, genetic properties appear to be more important for pharmaceutical quality than environmental factors, while on the intraspecific level environmental factors might be more important than genetic properties.

• Histochemical analysis of the root tuber of Polygonum multiflorum Thunb. (Fam. Polygonaceae).

  Authors: Zhi-Tao Liang, Yi-Xiao Shi, Hu-Biao Chen, Zhong-Zhen Zhao

  Microscopy research and technique. 10/2010; 74(6):488-95.

  Authentication is the first priority in quality evaluation of Chinese herbal medicines (CHMs). The most commonly used authentication methods are morphological identification and microscopicAuthentication is the first priority in quality evaluation of Chinese herbal medicines (CHMs). The most commonly used authentication methods are morphological identification and microscopic identification. Unfortunately, these two methods cannot provide the chemical information needed to assess the quality of CHMs. In this study, a combination of fluorescence microscopy and high performance liquid chromatography-mass spectrometry (HPLC-MS) was used to analyze the chemical profiles of the tissues of the raw root tubers of Polygonum multiflorum Thunb. The results showed that the cork cells, cortex, and vessels in transverse sections of the raw root tuber of P. multiflorum fluoresced differently. Further analysis by HPLC-MS revealed that anthraquinones are mainly distributed in the cortex, and 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucopyranoside could be found in all tissues of the raw root tubers of P. multiflorum with its relative content as cork > cortex > xylem of allotype vascular bundles > xylem of central vascular bundles. Moreover, the fluorescence characteristics of the tissues from the steamed root tuber of P. multiflorum were compared and showed different fluorescence from those of raw material. From these results, it can be deduced that the root tuber of P. multiflorum with a broader cortex and fewer vascular bundles visible in a transverse section should be of better quality. The different fluorescence characteristics can be used to differentiate raw root tubers of P. multiflorum from those that have been steamed.

• Identification of powdered Chinese herbal medicines by fluorescence microscopy, Part 1: Fluorescent characteristics of mechanical tissues, conducting tissues, and ergastic substances.

  Authors: Ya-Qiong Wang, Zhi-Tao Liang, Qin Li, Hua Yang, Hu-Biao Chen, Zhong-Zhen Zhao, Ping Li

  Microscopy research and technique. 07/2010;

  The light microscope has been successfully used in identification of Chinese herbal medicines (CHMs) for more than a century. However, positive identification is not always possible. Given theThe light microscope has been successfully used in identification of Chinese herbal medicines (CHMs) for more than a century. However, positive identification is not always possible. Given the popularity of fluorescence microscopy in bioanalysis, researchers dedicated to finding new ways to identify CHMs more effectively are now turning to fluorescence microscopy for authentication purposes. Some studies on distinguishing confused species from the same genus and on exploring distributions of chemicals in tissues of CHMs by fluorescence microscopy have been reported; however, no systematic investigations on fluorescent characteristics of powdered CHMs have been reported. Here, 46 samples of 16 CHMs were investigated. Specifically, the mechanical tissues including stone cells and fibers, the conducting tissues including three types of vessels, and ergastic substances including crystals of calcium oxalate and secretions, in various powdered CHMs were investigated by both light microscope and fluorescence microscope. The results showed many microscopic features emit fluorescence that makes them easily observed, even against complex backgrounds. Under the fluorescence microscope, different microscopic features from the same powdered CHM or some same features from different powdered CHMs emitted the different fluorescence, making this information very helpful for the authentication of CHMs in powder form. Moreover, secretions with unique chemical profiles from different powdered CHMs showed different fluorescent characteristics. Hence, fluorescence microscopy could be a useful additional method for the authentication of powdered CHMs if the fluorescent characteristics of specific CHMs are known. Microsc. Res. Tech. 2010. (c) 2010 Wiley-Liss, Inc.

• Oleanolic acid isolated from Oldenlandia diffusa exhibits a unique growth inhibitory effect against ras-transformed fibroblasts.

  Authors: Pui Kei Wu, William Tai, Zhi-Tao Liang, Zhong-Zhen Zhao, Wen Luan Wendy Hsiao

  Life sciences. 06/2009;

  AIMS: Oldenlandia diffusa (Willd.) Roxb. (O. diffusa) is a commonly used traditional Chinese medicine for treating cancer. Its pharmacological activities and anti-cancer effects have been the focusAIMS: Oldenlandia diffusa (Willd.) Roxb. (O. diffusa) is a commonly used traditional Chinese medicine for treating cancer. Its pharmacological activities and anti-cancer effects have been the focus of intense research in recent years. In the present study, we aim to investigate whether the five major compounds from O. diffusa possess a unique inhibitory activity against ras-transformed cells in a well-established cell model. MAIN METHODS: The anti-cancer effects of O. diffusa were assessed in a co-culture system containing normal and transformed Rat 6 (R6) fibroblasts. In addition, a transwell assay was used to examine the interaction between the drugs and the co-cultivated cells. KEY FINDINGS: Our data showed that among the samples tested, oleanolic acid (OA), but not the structural isomer ursolic acid (UA), inhibits the growth of ras oncogene-transformed R6 cells at a dosage that is not toxic to the co-cultivated normal fibroblasts. A significant inhibitory effect was also observed in the transwell experiments, indicating that the mode of action for OA-mediated growth inhibition of transformed cells does not require direct cell-to-cell contact between normal and ras-transformed cells. Data obtained from experiments conducted with the conditioned medium that was collected from normal R6 cells treated with OA also suggest that OA might cause normal cells to secrete inhibitory factor(s) against the transformed cells. The enhanced ability of OA to cause cytotoxicity in transformed cells in the presence of normal fibroblasts is also observed with the human hepatocellular carcinoma cell line, SMMC-7721. SIGNIFICANCE: The present study demonstrates that OA may possess both cancer chemotherapeutic and chemopreventive activities. Thus, it may have great potential for clinical application as a novel anti-cancer drug.

• Comparative study on the aristolochic acid I content of Herba Asarifor safe use.

  Authors: Zhong-Zhen Zhao, Zhi-Tao Liang, Zhi-Hong Jiang, Kelvin Sze-Yin Leung, Chi-Leung Chan, Hon-Yee Chan, Jaime Sin, Tim-On Man, Kwok-Wai Law

  Phytomedicine : international journal of phytotherapy and phytopharmacology. 10/2008; 15(9):741-8.

  Herba Asari (Xixin, Manchurian Wildginger, Asarum spp.) is a traditional Chinese medicinal herb commonly used as a crude drug and an ingredient in patent medicines. The herb contains aristolochicHerba Asari (Xixin, Manchurian Wildginger, Asarum spp.) is a traditional Chinese medicinal herb commonly used as a crude drug and an ingredient in patent medicines. The herb contains aristolochic acid I (AA-I), which has recently caused several incidents of poisoning in Hong Kong. Therefore, the safe use of Asarum is questionable. The present study was undertaken to assess the levels of AA-I using liquid chromatography-mass spectrometry (LC/MS) indifferent medicinal parts of Herba Asari and some proprietary Chinese medicines (PCM) containing it as an ingredient. The AA-I content in the aerial and root portions were compared, in the form of water and methanolic extracts. The results showed that all the aerial portions of Herba Asari generally contain higher levels of AA-I than the roots (in water extract: 0.0870.06 microg/g of root and 0.3270.021 microg/g of aerial), and the methanolic extracts typically contained more AA-I than the water extracts. Moreover, all the three PCM studies showed negligible amounts of AA-I(containing 0.0370.006 microg/g). Therefore, the root portion of Herba Asari was recommended for prescription as a decoction instead of grinding it into powder for oral administration.

• Characterization of shapes for use in classification of starch grains images.

  Authors: Chong-Sze Tong, Siu-Kai Choy, Sung-Nok Chiu, Zhong-Zhen Zhao, Zhi-Tao Liang

  Microscopy research and technique. 06/2008;

  As tradition Chinese herbal medicine becomes increasingly popular, there is an urgent need for efficient and accurate methods for the authentication of the Chinese Materia Medica (CMM) used in theAs tradition Chinese herbal medicine becomes increasingly popular, there is an urgent need for efficient and accurate methods for the authentication of the Chinese Materia Medica (CMM) used in the herbal medicine. In this work, we present a denoising filter and introduce the use of chord length distribution (CLD) for the classification of starch grains in microscopic images of Chinese Materia Medica. Our simple denoising filter is adaptive to the background and is shown to be effective to remove noise, which appears in CMM microscopic starch grains images. The CLD is extracted by considering the frequency of the chord length in the binarized starch grains image, and we shall show that the CLD is an efficient and effective characterization of the starch grains. Experimental results on 240 starch grains images of 24 classes show that our method outperforms benchmark result using the current state-of-the-art method based on circular size distribution extracted by morphological operators at much higher computational cost. cost. Microsc. Res. Tech., 2008. (c) 2008 Wiley-Liss, Inc.

• Authentication of the 31 species of toxic and potent Chinese Materia medica (T/PCMM) by microscopic technique, part 1: three kinds of toxic and potent animal CMM.

  Authors: Li Xia, Li-Ping Bai, Ling Yi, Bin-Bin Liu, Chu Chu, Zhi-Tao Liang, Ping Li, Zhi-Hong Jiang, Zhong-Zhen Zhao

  Microscopy research and technique. 12/2007; 70(11):960-8.

  Microscopic authentication is an effective method for quality control of Chinese Materia Medica (CMM) because of its speed, convenience and low cost. However, the application of modern microscopicMicroscopic authentication is an effective method for quality control of Chinese Materia Medica (CMM) because of its speed, convenience and low cost. However, the application of modern microscopic technique in quality evaluation of Toxic and Potent Chinese Materia Medica (T/PCMM) of animal origin is seldom reported. This gap in published knowledge is increasingly serious because confusion in T/PCMM has led to serious medical problems in China and other countries in recent years. To ensure the safe and effective use of T/PCMM, an accurate and convenient method, based on macroscopic and microscopic techniques, was developed for the authentication of animal T/PCMM. The color microscopic photos of the crude drug were acquired with the light microscope, and from these their morphological and microscopic characters were described. The present method was successfully applied in the analysis of 31 T/PCMM including 17 samples originating from plants, 3 from animals, 9 from minerals, and the remaining 2 from secreta. The macro- and microscopic characters of three animal T/PCMM, namely Mylabris (Mylabris phalerata or Mylabris cichorii), Huechys (Huechys sanguinea), and Lytta (Lytta caraganae) were conclusively determined and are here presented. The results demonstrated that it was feasible to use the present microscopic characters for the authentication of the above three animal T/PCMM.

• Identification of starch grains in microscopic images based on granulometric operations.

  Authors: Chong-Sze Tong, Siu-Kai Choy, Zhong-Zhen Zhao, Zhi-Tao Liang, Hubiao Chen

  Microscopy research and technique. 09/2007; 70(8):724-32.

  This study demonstrates the feasibility of feature extraction and similarity measurement for the identification of starch grains, which are often found in microscopic images of Chinese Materia MedicaThis study demonstrates the feasibility of feature extraction and similarity measurement for the identification of starch grains, which are often found in microscopic images of Chinese Materia Medica (CMM) and as such is an important feature for use in the authentication of CMM with abundance of starch grains and otherwise without other special microscopic characteristics. Our proposed image signature, namely, the size distribution, indicates that it is effective to characterize starch grains in microscopic images of those CMM. Experimental results in a small scale study show that the recognition rate for the proposed signature using different measures of discrepancy is around 90%, which is considered very good while the benchmark wavelet-based energy signature has only about 60% recognition. Moreover, the extraction of the size distribution only requires moderate level of computational complexity. In this study, our proposed image signature provides greater accuracy and flexibility in capturing starch grains information for the authentication of CMM, compared with other existing preliminary identification approach in which manual image segmentation is necessary.

• Application of microscopic techniques in authentication of herbal tea--Ku-Ding-Cha.

  Authors: Chun-Fung Tam, Yong Peng, Zhi-Tao Liang, Zhen-Dan He, Zhong-Zhen Zhao

  Microscopy research and technique. 12/2006; 69(11):927-32.

  Ku-Ding-Cha, a kind of herbal tea, has been widely used in China for a long time to support cardiovascular health. Confusion arises because in different parts of China different plants are used toKu-Ding-Cha, a kind of herbal tea, has been widely used in China for a long time to support cardiovascular health. Confusion arises because in different parts of China different plants are used to produce the commercial teas. It is important to determine the identity of the used species in order to authenticate genuine Ku-Ding-Cha. However, once the plants have been processed, it is difficult to identify them through macroscopic identification; other means are necessary. A comparative study was made on 24 samples of Ku-Ding-Cha, including five standard identified and authenticated plants and 19 commercial samples, by microscopic techniques. The results showed that the shapes of leaf blades, xylem cells, stone cells, and calcium oxalate crystals could be used for the identification of the plants from which the commercial products were made. The method was proven to be quick, handy, simple, and convenient.

• Determination of iridoid glucosides for quality assessment of Herba Oldenlandiae by high-performance liquid chromatography.

  Authors: Zhi-Tao Liang, Zhi-Hong Jiang, Kelvin Sze-Yin Leung, Zhong-Zhen Zhao

  Chemical & pharmaceutical bulletin. 09/2006; 54(8):1131-7.

  Herba Oldenlandiae, the dried herb of Oldenlandia diffusa (WILLD.) ROXB. (Family Rubiaceae), is officially listed in the Chinese Pharmacopoeia. In the herbal market, two substitutes originated fromHerba Oldenlandiae, the dried herb of Oldenlandia diffusa (WILLD.) ROXB. (Family Rubiaceae), is officially listed in the Chinese Pharmacopoeia. In the herbal market, two substitutes originated from O. corymbosa (L.) LAM and O. tenelliflora BL. are commonly used. In light of this, the target in setting up a method for quality assessment of Herba Oldenlandiae is urgently needed. In this article, a simple and reliable high-performance liquid chromatographic (HPLC) method was developed for quantifying asperuloside (1), E-6-O-p-coumaroyl scandoside methyl ester (2) and E-6-O-p-coumaroyl scandoside methyl ester-10-methyl ether (3) in Herba Oldenlandiae derived from O. diffusa. Among them, compound 3 is a new compound isolated from O. diffusa. All these unique compounds were used as markers for the first time in the quality assessment of Herba Oldenlandiae. The results showed that the contents of compounds 1-3 were significantly varied among different samples whilst those of compounds 2 and 3 were found to be lower in contents in the two substitutes of O. diffusa. The analytical method is suitable for quality control of Herba Oldenlandiae and useful in differentiation from its confusable species. The method has been fully validated with satisfactory linearity, accuracy, precision and stability.

• Distinguishing the medicinal herb Oldenlandia diffusa from similar species of the same genus using fluorescence microscopy.

  Authors: Zhi-Tao Liang, Zhi-Hong Jiang, Kelvin Sze-Yin Leung, Yong Peng, Zhong-Zhen Zhao

  Microscopy research and technique. 05/2006; 69(4):277-82.

  The light microscope is routinely used for microscopic identification of Chinese Materia Medica (CMM). However, the fluorescence microscope has not been used for this purpose until now. The CMM,The light microscope is routinely used for microscopic identification of Chinese Materia Medica (CMM). However, the fluorescence microscope has not been used for this purpose until now. The CMM, Baihuasheshecao, mostly used as a component of herb tea, is a well known folk-medicine in China. According to the Chinese Pharmacopoeia, its source is the species Oldenlandia diffusa (Willd.) Roxb. Two other species of the same genus, namely O. corymbosa (L.) Lam and O. tenelliflora Bl., had been found in use as Baihuasheshecao. To find a quick and easy method to distinguish O. diffusa from these similar species of the same genus, the fluorescence microscope was used to investigate the fluorescence emission characteristics of the three tissues, which were compared with light microscopy images of the same material. The results showed that some tissues of the three herbs emit autofluorescence. Specially, the wall of endoderm cells of O. diffusa and O. tenelliflora emit autofluorescence, while similar tissue of O. corymbosa does not. Hence, fluorescence microscopy can be helpful in the identification of CMM.

• Quantification of sinomenine in caulis sinomenii collected from different growing regions and wholesale herbal markets by a modified HPLC method.

  Authors: Zhong-Zhen Zhao, Zhi-Tao Liang, Hua Zhou, Zhi-Hong Jiang, Zhong Qiu Liu, Yuen Fan Wong, Hong-Xi Xu, Liang Liu

  Biological & pharmaceutical bulletin. 01/2005; 28(1):105-9.

  Caulis Sinomenii is the dried plant stems of Sinomenium acutum and Sinomenium acutum var. cinereum and has been used in Chinese medicine for treating rheumatic diseases for over a thousand years.Caulis Sinomenii is the dried plant stems of Sinomenium acutum and Sinomenium acutum var. cinereum and has been used in Chinese medicine for treating rheumatic diseases for over a thousand years. Previous studies have demonstrated that sinomenine is a major active constituent in both plants and can be utilized as an indicator of quality of the medicinal herb Caulis Sinomenii. Currently, S. acutum and S. acutum var. cinereum are growing over a wide geographical range in China, with equally wide variations in growing conditions. The objectives of this research were to determine whether there were difference between the species and varieties, and whether the different growing conditions could result in different quality by determining the content of sinomenine in different samples. A modified HPLC method using a diode array detector (DAD) has been developed for efficiently quantifying sinomenine in the plants. Using this method, fourteen samples of S. acutum var. cinereum and eleven samples of S. acutum from growing regions as well as eighteen herbal samples of Caulis Sinomenii from wholesale herbal markets were evaluated. The results showed that there was no marked difference in the content of sinomenine between the species and varieties collected from growing regions; however, a very large variation was found among the samples collected from different regions. Moreover, the content of sinomenine in the plants of large size (stem diameter>3 cm) was much higher than those of small size (stem diameter<1 cm). This implies that the growing region has greater impact on the quality of Caulis Sinomenii in terms of the content of sinomenine than the species and varieties. The results also showed that the content of sinomenine in commercial Caulis Sinomenii was markedly lower than that in the plants collected directly from growing regions. This suggests that to obtain the herb with higher content of sinomenine and thus ensure greater efficacy, both in clinical applications and in pharmacological investigations, the plant of Caulis Sinomenii with controlled stem size collected directly from growing regions is preferable.

• Oleanolic acid isolated from Oldenlandia diffusa exhibits a unique growth inhibitory effect against ras-transformed fibroblasts

  Authors: Pui Kei Wu, William Chi Shing Tai, Zhi-Tao Liang, Zhong-Zhen Zhao, Wen Luan Wendy Hsiao

  Life Sciences.

  AimsOldenlandia diffusa (Willd.) Roxb. (O. diffusa) is a commonly used traditional Chinese medicine for treating cancer. Its pharmacological activities and anti-cancer effects have been the focus ofAimsOldenlandia diffusa (Willd.) Roxb. (O. diffusa) is a commonly used traditional Chinese medicine for treating cancer. Its pharmacological activities and anti-cancer effects have been the focus of intense research in recent years. In the present study, we aim to investigate whether the five major compounds from O. diffusa possess a unique inhibitory activity against ras-transformed cells in a well-established cell model.Main methodsThe anti-cancer effects of O. diffusa were assessed in a co-culture system containing normal and transformed Rat 6 (R6) fibroblasts. In addition, a transwell assay was used to examine the interaction between the drugs and the co-cultivated cells.Key findingsOur data showed that among the samples tested, oleanolic acid (OA), but not the structural isomer ursolic acid (UA), inhibits the growth of ras oncogene-transformed R6 cells at a dosage that is not toxic to the co-cultivated normal fibroblasts. A significant inhibitory effect was also observed in the transwell experiments, indicating that the mode of action for OA-mediated growth inhibition of transformed cells does not require direct cell-to-cell contact between normal and ras-transformed cells. Data obtained from experiments conducted with the conditioned medium that was collected from normal R6 cells treated with OA also suggest that OA might cause normal cells to secrete inhibitory factor(s) against the transformed cells. The enhanced ability of OA to cause cytotoxicity in transformed cells in the presence of normal fibroblasts is also observed with the human hepatocellular carcinoma cell line, SMMC-7721.SignificanceThe present study demonstrates that OA may possess both cancer chemotherapeutic and chemopreventive activities. Thus, it may have great potential for clinical application as a novel anti-cancer drug.