Processing methods and the underlying detoxification mechanisms for toxic medicinal materials used by ethnic minorities in China: A review.

ETHNOPHARMACOLOGICAL RELEVANCE: Various toxic medicinal materials have been used by different ethnic minorities in China for thousands of years because of their extraordinary pharmacological activities. However, the improper use and complex toxicity-efficacy relationship could cause poisoning and even death. Therefore, the study of toxicity-attenuating methods and mechanisms is necessary. AIM OF THE STUDY: This review aims to summarize commonly used toxic ethnomedicines and their processing methods as well as the underlying mechanisms to potentially reduce toxicity and even enhance or preserve efficacy. Prospective for possible future investigations is also discussed. MATERIALS AND METHODS: Processing methods and mechanisms are investigated mainly through literature review. RESULTS: Processing methods with heating (boiling, stir frying, and steaming, etc.) and without heating (soaking) are usually used by Chinese ethnic minorities to attenuate the toxicity of ethnomedicines. Wheat bran, vinegar, wine, and herbal decoction are commonly used processing excipients. The mechanisms of detoxification by processing can be briefly summarized into three major categories: (1) direct elimination of impurities or reduction of toxic constituents' contents of ethnomedicines by cutting, washing, soaking or frosting; (2) chemical structure transformation of toxic constituents, such as alkaloids, glycosides, toxic proteins, animal toxicants, and mineral components, during heating and/or soaking; and (3) biological synergism or antagonism effects between the chemical constituents of processing excipients and ethnomedicines in vivo, to reduce toxicity and protect target organs. CONCLUSION: Toxic ethnomedicines have long been used in China, and detoxification by processing is the prerequisite for their safe clinical application. However, understanding on the special processing methods and detoxification mechanisms of ethnomedicines in China remains insufficient. Investigations on quality control of toxic ethnomedicines, as well as evaluation of processing methods and studies of the corresponding mechanisms should be further strengthened for safe and effective clinical application.

Aconitum pendulum and Aconitum flavum: A narrative review on traditional uses, phytochemistry, bioactivities and processing methods.

ETHNOPHARMACOLOGICAL RELEVANCE: Composed of dried Aconitum pendulum and Aconitum flavum roots, Tiebangchui, is an important Tibetan medicine and has been traditionally and widely used as a remedy for cold and pain for thousands of years because of its extraordinary pharmacological activities. The toxicity and efficacy of Tiebangchui as a typical toxic traditional Tibetan medicine, are interdependent, and thus to make sure its safe use in clinics is also noteworthy. AIM OF THE STUDY: This review aims to document and summarize critical and comprehensive information about traditional uses, phytochemistry, pharmacology, toxicology and processing methods of Tiebangchui. Perspectives for possible future investigations have been discussed. MATERIALS AND METHODS: Relevant information about Tiebangchui (A. pendulum and A. flavum) was collected from internationally recognized electronic scientific databases, such as Web of Science, PubMed, Science Direct, Springer Link, ACS, and CNKI. Then, classic Tibetan medical books, such as Four Medical Tantra, and Jing Zhu Materia Medica, and official drug standards were reviewed. RESULTS: A total of 95 chemical constituents have been isolated and identified from Tiebangchui, and most of them were diterpenoid alkaloids. These phytochemicals showed a wide range of pharmacological properties, such as anti-inflammation, anti-rheumatoid arthritis, analgesic, local anesthetic, anti-cancer and anti-bacterial activities. Hence, Tiebangchui is broadly used in hundreds of preparations to treat fever, arthritis, rheumatic arthralgia, traumatic injury, furuncle and swelling. Cardiotoxicity, neurotoxicity and gastrointestinal toxicity are the main toxic effects caused by the Aconitum alkaloids of Tiebangchui. Various processing methods, including steaming, decocting and sand-frying, and traditional Tibetan medicine processing methods, such as processing with Hezi decoction, Qingke wine and Zanba, are effective in attenuating toxicity while retaining efficacy. CONCLUSIONS: The present review provides primary information of Tiebangchui, particularly for its traditional uses, botanical characteristics, phytochemicals, outstanding bioactivities and processing methods. However, studies that explored the in vivo pharmacokinetics and mechanism of Tiebangchui, as well as its quality markers, qualitative and quantitative analysis are still insufficient. Processing methods that attenuate toxicities, evaluations of efficacy, in vivo processes and biological effects, the mechanisms of processed products should be further explored.

Origin of the mysterious Yin-Shang bronzes in China indicated by lead isotopes.

Fine Yin-Shang bronzes containing lead with puzzlingly highly radiogenic isotopic compositions appeared suddenly in the alluvial plain of the Yellow River around 1400 BC. The Tongkuangyu copper deposit in central China is known to have lead isotopic compositions even more radiogenic and scattered than those of the Yin-Shang bronzes. Most of the Yin-Shang bronzes are tin-copper alloys with high lead contents. The low lead and tin concentrations, together with the less radiogenic lead isotopes of bronzes in an ancient smelting site nearby, however, exclude Tongkuangyu as the sole supplier of the Yin-Shang bronzes. Interestingly, tin ingots/prills and bronzes found in Africa also have highly radiogenic lead isotopes, but it remains mysterious as to how such African bronzes may have been transported to China. Nevertheless, these African bronzes are the only bronzes outside China so far reported that have lead isotopes similar to those of the Yin-Shang bronzes. All these radiogenic lead isotopes plot along ~2.0-2.5 Ga isochron lines, implying that deposits around Archean cratons are the most likely candidates for the sources. African cratons along the Nile and even micro-cratons in the Sahara desert may have similar lead signatures. These places were probably accessible by ancient civilizations, and thus are the most favorable suppliers of the bronzes.

[UFLC-PDA fingerprint of Tibetan medicine Pterocephalus hookeir].

This study was aimed to establish an UFLC fingerprint of Tibetan medicine Pterocephalus hookeir samples from different habitats. UFLC-PDA was adopted to analyse 21 batches of P. hookeir samples from different habitats. The chromatographic condition was as follow: Agilent proshell 120 SB-C18 column (4.6 mm x 100 mm, 2.7 microm) eluted with the mobile phases of acetonitrile and 0.2% phosphoric acid water in gradient mode. The flow rate was 1.0 mL x min(-1), and the detection wavelength was set at 238 nm. The fingerprints of 21 batches P. hookeir were carried out by similarity comparation, and 15 chromatographic peaks were extracted as the common peaks of fingerprint, of which 5 peaks were identified as chlorogenic acid, loganin, sweroside, sylvestroside III, triplostoside A. The similarity degrees of 18 batchs of samples were above 0.9, and the other 3 batchs of samples were below 0.9. This is the first established fingerprint of P. hookeir by using UFLC-PDA. This method has good precision, stability and repeatability that it could provide basis for quality control and evaluation of P. hookeir.

Isotopic evidence for continental ice sheet in mid-latitude region in the supergreenhouse Early Cretaceous.

Cretaceous represents one of the hottest greenhouse periods in the Earth's history, but some recent studies suggest that small ice caps might be present in non-polar regions during certain periods in the Early Cretaceous. Here we report extremely negative δ(18)O values of -18.12‰ to -13.19‰ for early Aptian hydrothermal zircon from an A-type granite at Baerzhe in northeastern China. Given that A-type granite is anhydrous and that magmatic zircon of the Baerzhe granite has δ(18)O value close to mantle values, the extremely negative δ(18)O values for hydrothermal zircon are attributed to addition of meteoric water with extremely low δ(18)O, mostly likely transported by glaciers. Considering the paleoaltitude of the region, continental glaciation is suggested to occur in the early Aptian, indicating much larger temperature fluctuations than previously thought during the supergreenhouse Cretaceous. This may have impact on the evolution of major organism in the Jehol Group during this period.

Phenanthrenes from Juncus effusus.

A chemical investigation of the EtOAc-soluble fraction from the ethanol extract of the medullae of Juncus effusus led to the isolation of three new 9,10-dihydrophenanthrenes, juncuenins E-G (1-3); two new phenanthrenes, dehydrojuncuenins D-E (4-5); one new feruloylated glycoside (6); and one known 9,10-dihydrophenanthrene (7). The structures of these compounds were determined by analyzing their spectroscopic data. Metabolites 1-4 and 7 were further evaluated for their in vitro cytotoxic activities against seven human cancer lines (A549, MCF-7, BEL-7402, HeLa, COLO205, BGC-823, and SK-OV-3). Among them, compound 1 exhibited weak cytotoxicity against MCF-7 and HeLa cell lines. Compound 7 showed moderate cytotoxicity against MCF-7 and HeLa cell lines, with IC50 values of 9.17 and 19.6 µM, respectively.

A new acorane sesquiterpene from Lysionotus pauciflorus.

AIM: To study the chemical constituents of the whole plant of Lysionotus pauciflorus METHODS: Chromatographic separations on silica gel, Toyopearl HW-40F gel, and MCI gel were used to isolate the compounds. The structures were elucidated on the basis of spectral data. RESULTS: Three compounds were obtained and their structures were identified as 3, 10-dihydroxyacoronene (1), bis(2-butylhexyl)phthalate (2) and 3, 5-dimethoxy-4-hydroxy-trans-stilbene (3). CONCLUSION: Compound 1 is a new acorane sesquiterpene, this is the first report of acorane sesquiterpenes from the Lysionotus genus.

New dimeric phenanthrene and flavone from Spiranthes sinensis.

From the whole plant of Spiranthes sinensis, one novel dimeric phenanthrene, 2,2'-dihydroxy-5,5',7,7'-tetramethoxy-9,9',10,10'-tetrahydro-3,3'-biphenanthrene (1) and flavone 5-hydroxy-3,7-dimethoxy-4'-(1-hydroxy-3-methylbut-3-en-2-yloxy)-flavone (2) were isolated along with three other known flavonoids, which are reported for the first time from this species. Their structures were established after an extensive analysis by 1D and 2D NMR spectroscopy (NOESY, HSQC, and HMBC) as well as HR-TOF-MS.