Zhongzhen Zhao

A unique issue in the standardization of Chinese materia medica: processing.

Processing of Chinese Materia Medica (CMM) is a pharmaceutical technique to fulfill the different requirements of therapy, dispensing and making preparations according to traditional Chinese medicine theory. The aims of processing are to enhance the efficacy and/or reduce the toxicity of crude drugs. Those processed products are named as decoction pieces, which are used in clinics. Therefore, there is a close relationship between processing, safety, and efficacy of Chinese medicines. Some toxicity or side effects are caused by improper processing methods and some are due to improper combination of herbal mixtures. Standardization of processing methods for Chinese herbs is as important as authentication to maintain their quality and ensure their safe use. The objective of this paper is to review the literature covering the current situation and problems of CMM processing as well as recent progress in research in this area. A summary of the most urgent work needed is proposed.

Heavy Metal and Pesticide Content in Commonly Prescribed Individual Raw Chinese Herbal Medicines

Heavy metal and pesticide contamination has previously been reported in Chinese Herbal Medicines (CHMs), in some cases at potentially toxic levels. This study was conducted to determine general patterns and toxicological significance of heavy metal and pesticide contamination in a broad sample of raw CHMs. Three-hundred-thirty-four samples representing 126 species of CHMs were collected throughout China and examined for arsenic, cadmium, chromium, lead, and mercury. Of the total, 294 samples representing 112 species were also tested for 162 pesticides. At least 1 metal was detected in all 334 samples (100%) and 115 samples (34%) had detectable levels of all metals. Forty-two different pesticides were detected in 108 samples (36.7%), with 1 to 9 pesticides per sample. Contaminant levels were compared to toxicological reference values in the context of different exposure scenarios. According to a likely scenario of CHM consumption, only 3 samples (1%) with heavy metals and 14 samples (5%) with pesticides were found with concentrations that could contribute to elevated background levels of contaminant exposure. According to the most conservative scenario of CHM consumption, 231 samples (69%) with heavy metals and 81 samples (28%) with pesticides had contaminants that could contribute to elevated levels of exposure. Wild collected plants had higher contaminant levels than cultivated samples. Cadmium, chromium, lead, and chlorpyrifos contamination showed weak correlations with geographic location. Based on our assumptions of the likely mode of consumption of raw CHMs, the vast majority (95%) of the 334 samples in this study contained levels of heavy metals or pesticides that would be of negligible concern. However, given the number of samples with detectable contaminants and the range between the more likely and more conservative scenarios of contaminant exposure, more research and monitoring of heavy metals (especially cadmium and chromium) and pesticide residues (especially chlorpyrifos) in raw CHMs are advised.

The formation of daodi medicinal materials

Daodi medicinal material is produced and assembled in specific geographic regions with designated natural conditions and ecological environment, with particular attention to cultivation technique, harvesting and processing. The quality and clinical effects surpass those of same botanical origin produced from other regions. It is thus widely recognized and has long enjoyed a good reputation. Based on literature, market and field investigation on daodi medicinal materials, the historical background and reasons behind the formation and the development of daodi medicinal material are analyzed. This review clarifies the concept and rationalizes the formation of daodi medicinal material.

Ethnobotanical study of medicinal plants used by Hakka in Guangdong, China

ETHNOPHARMACOLOGICAL RELEVANCE An ethnobotanical survey was conducted to collect information on the use of medicinal plants by the Hakka living in Guangdong. AIM OF THE STUDY This investigation was to document valuable knowledge represented by Hakka herbal medicine. MATERIALS AND METHODS Information was obtained from semi-structured interviews, personal conversations with practitioners, direct observations, and by reviewing studies of Hakka and Cantonese reported in the literature. RESULTS Our data covered 94 species belonging to 77 genera in 40 families. We found that most species used for medical purposes were for hepatitis (14 species) and skin diseases (12 species). These disorders are prevalent and are primarily treated with medicinal plants. For treatment, the plants were mainly used as teas (Luica, Bugingca and Lopêdca), medicinal baths and soups. The Hakka and non-Hakka people living in Guangdong use different medicinal plants and, in some cases, use the same medicinal plants differently. CONCLUSIONS The fast disappearance of traditional culture and natural resources due to urbanization and industrialization suggests that unrecorded information may be lost forever. Thus, there is an urgent need both to record this valuable Hakka medicinal knowledge and to encourage its transfer to the next generation.

Identification of five hepatotoxic pyrrolizidine alkaloids in a commonly used traditional Chinese medicinal herb, Herba Senecionis scandentis (Qianliguang)

Senecio scandens Buch.-Ham is a plant source for a commonly used traditional Chinese medicinal (TCM) herb Qianliguang. A TCM herbal proprietary product containing Qianliguang as the major herb for the treatment of sinusitis has been used in China for several decades, and has also been exported to other regions and countries worldwide. In the present study, the aqueous extract of S. scandens collected in the Shanxi Province of China was determined, for the first time, to contain hepatotoxic and tumorigenic pyrrolizidine alkaloids (PAs) by using high-performance liquid chromatography/mass spectrometric (HPLC/MS) analysis in various scanning modes. A total of nine toxic and two non-toxic PAs were detected in the aqueous extract of S. scandens, of which six PAs, namely neoplatyphylline, senecionine, senecionine N-oxide, seneciphylline, seneciphylline N-oxide and senkirkine, were unequivocally characterized, while other PAs were tentatively assigned as jacobine, jacozine N-oxide (or erucifoline N-oxide), 7-tigloylplatynecine, usaramine and an isomer of yamataimine. The estimated total content of toxic PAs in S. scandens was 10.82 microg/g herb, which was significantly higher than that (> or =1 microg/g herb) recommended by Belgium and Germany not to be used clinically. Among the PAs definitively identified, senecionine, seneciphylline, and senkirkine are known tumorigens capable of inducing liver tumors in experimental animals, while seneciphylline N-oxide and senecionine N-oxide are probably tumorigenic due to their potential conversion into seneciphylline and senecionine via metabolic reduction in the body. Thus, the current finding of the presence of toxic/tumorigenic PAs in S. scandens challenges the safety of using this TCM herb and its proprietary products.

Chemistry, bioactivity and quality control of Dendrobium, a commonly used tonic herb in traditional Chinese medicine

The fresh or dried stems of many Dendrobium species are well known as one of the most expensive tonics in traditional Chinese medicine. Documented as a “superior grade” herbal medicine in the ancient text “Shen Nong’s Herbal Classic”, Dendrobium has been used for thousands of years and is now a popular health food worldwide. The main chemical components of Dendrobium are alkaloids, aromatic compounds, sesquiterpenoids and polysaccharides, with multiple biological activities, including immunomodulatory, neuroprotective and anti-tumor effects, etc. Various qualitative and quantitative methods have been developed for the quality evaluation of Dendrobium. In this review, the research progress since the 1930s relating to the chemistry, bioactivity and quality control of Dendrobium is summarized, existing problems and prospects are also discussed.

Tissue-specific metabolite profiling of alkaloids in Sinomenii Caulis using laser microdissection and liquid chromatography–quadrupole/time of flight-mass spectrometry

Secondary metabolites accumulated in different tissues and cells of herbs are usually bioactive components of herbal medicines. Thus, tissue- and cell-specific phytochemical profiling should be useful for indicating relationship between herbal tissues and chemicals, and evaluating the quality of a medicinal herb. Here, a method that combining laser microdissection and ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (LMD with UPLC-Q/TOF-MS) was established to achieve simultaneous localization and determination of bioactive components in herbal medicines. Sinomenii Caulis, sourced from the stems of Sinomenium acutum (Thunb.) Rehd. et Wils., was set as an illustrative case, and its phytochemicals were profiled by the present method through analyses of different microdissected tissues and cells, involving epidermis, cortex, stone cells, pericycle, vascular bundles and pith. Results revealed that different tissues and cells contained varied alkaloids, among which six alkaloids, i.e. 6-Me-ether-12-O-β-D-glucopyranoside-laudanosoline (peak 4), sinomenine (peak 6), N-norsinoacutine (peak 7), magnoflorine (peak 11), laurifoline (peak 16) and menisperine (peak 17) were detected in all microdissected parts, and sinomenine and magnoflorine were the two most abundant components. By further quantitative determination, alkaloids were generally demonstrated to distribute in the outer part of the cortex, phloem and xylem. According to the relationship between alkaloids and tissues revealed in our study, Sinomenii Caulis of larger diameter has proportionately more bioactive components, and is therefore of higher quality for medicinal use. The method of LMD with UPLC-Q/TOF-MS developed in this study was initially applied to the research of medicinal herbs, and proved to be high sensitive, low cost, convenient and practical.

Macroscopic identification of Chinese medicinal materials: traditional experiences and modern understanding.

Authentication is fundamental for the standardization of Chinese Materia Medica. Macroscopic identification, an important method of authentication, has a long history rooted in practice and experience over generations. In ancient times, macroscopic features were used not only to identify the genuineness, but also to evaluate the quality of Chinese medicinal materials (CMMs). In many ancient documents, picturesque terms were used to describe the quality of certain specific CMMs. These traditional macroscopic descriptions used for identification are filled with characteristics, quality descriptions, and specifications of CMM that need to be confirmed by modern scientific analysis. In this paper, the essential and fundamental components of macroscopic identification are introduced. As the quality and macroscopic characteristics of CMM are traditionally thought to be closely related, modern scientific approaches to confirm the validity of these associations are discussed. This review clarifies the role of macroscopic features in the quality assessment of CMM.

Inhibitions of mast cell-derived histamine release by different Flos Magnoliae species in rat peritoneal mast cells.

Flos Magnoliae (FM) is a commonly used Chinese medicinal herb for symptomatic relief of allergic rhinitis, sinusitis and headache. A number of FM species have been used as substitutes or adulterants for clinical application, although the differences in their pharmacological actions have not been reported. The present study investigated the effects of six identified FM species M. biondii, M. denudata, M. kobus, M. liliflora, M. sargentiana and M. sprengeri, as well as the marker compounds magnolin and fargesin on compound 48/80-induced histamine release in rat peritoneal mast cells (RPMC) in vitro. Ethanolic extracts of all FM species produced a concentration-dependent inhibition of compound 48/80-induced histamine release in RPMC. The rank order of the IC(50)s was M. biondii<M. kobus<M. liliflora<M. denudata<M. sprengeri<M. sargentiana. The marker compound magnolin, but not fargesin, only slightly inhibited the histamine release. The contents of magnolin and fargesin, determined by using RP-HPLC, varied significantly among these FM species. Magnolin was found in M. biondii, M. kobus and M. liliflora, but not in M. denudate, M. sprengeri and M. sargentiana, while fargesin was only found in M. biondii and M. kobus. These findings provide the first evidence of differences in pharmacological actions of different FM species on mast cell-derived histamine release in vitro. In addition, the marker compounds magnolin and fargesin may not play a major role in the observed pharmacological actions of FM species.

The retention behavior of ginsenosides in HPLC and its application to quality assessment of radix ginseng

This study systematically investigated the retention behavior of seven neutral ginsenosides Rg1, Re, Rf, Rb1, Rb2, Rc, Rd, and an acidic ginsenoside R0, the major pharmacologically active components of Radix Ginseng with RP-HPLC. The effects of solvent, pH value, ionic strength of the mobile phase, and column temperature were investigated using an octadecylsiloxane-bonded silica gel column. Based on the ginsenosides’ retention characteristics, the concentration of acetonitrile and the gradient of the mobile phase needed to maintain the baseline separation of the major neutral ginsenosides in Radix Ginseng were theoretically predicted. Furthermore, the ionic strength of mobile-phase necessary to achieve good resolution of the neutral ginsenosides and acidic ginsenosides was carefully investigated. According to the results of the quantitative analysis of ginsenosides in eight batches of ginseng samples from different sources, the developed HPLC technique may be a valuable tool for the quality assessment of Radix Ginseng.