Chi-Leung Chan

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.

Anti-inflammatory and analgesic effects of the ethanol extract of Rosa multiflora Thunb. hips

This study aimed to assess the anti-inflammatory and analgesic effects of Fructus Rosae Multiflorae (FRM, hips of Rosa multiflora Thunb.). FRM was extracted with 75% ethanol and the dried extract (FRME) was administered intragastrically (i.g.) at 100, 200 and 400mg/kg. The anti-inflammatory effect was evaluated in four experimental animal models and analgesic effect in two animal models. Pretreatment with a single dose of FRME produced significant dose-dependent anti-inflammatory effects on carrageenin-induced rat hind paw edema, xylene-induced mouse ear edema and acetic acid-induced mouse vascular permeation. In a 7-day study, daily administration of FRME suppressed cotton pellet-induced rat granuloma formation. Pretreatment with a single dose of FRME also produced dose-dependent anti-nociceptive effects in thermally- and chemically induced mouse pain models. In addition, a single dose of FRME at 2.4g/kg body weight (equivalent to 87.6g of dried hips per kg body weight) produced no observable acute toxicity in mice within seven days. These results demonstrate that FRME possesses anti-inflammatory and analgesic effects and has no obvious acute toxicity, which advanced our understanding of the folk use of FRM in treating various inflammatory disorders.

Comparative study on the aristolochic acid I content of Herba Asari for safe use

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 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.

Liquid Chromatography‐Atmospheric Pressure Chemical Ionization Mass Spectrometry as a Tool for the Characterization of Anthraquinone Derivatives from Chinese Herbal Medicine

We have examined the anthraquinone derivatives of a Chinese herb medicine ‘Rhubarb’ by using HPLC/MS/MS, equipped with an atmospheric pressure chemical ionization source.

Xanthones from Polygala caudata

Abstract A new xanthone- O -glycoside, polycaudoside A, together with 2′-benzoylmangiferin, 1-methoxy-7-hydroxyxanthone, 1,2,8-trihydroxyxanthone, euxanthone, gentisein, wubangziside A, wubangziside B, 1,3-dihydroxy-2-methoxyxanthone, lancerin and neolancerin, stigmasterol, stigmastrol-3- O - d -glucoside, p -hydroxybenzoic acid, dihydroquercetin and quercetin were isolated from the roots of Polygala caudata . Their structures were established on the basis of chemical studies and spectral evidence, including 2D NMR analyses.

Comparisons of the chemical profiles, cytotoxicities and anti-inflammatory effects of raw and rice wine-processed Herba Siegesbeckiae

ETHNOPHARMACOLOGICAL RELEVANCE Although slightly toxic, the Chinese medicinal herb Herba Siegesbeckiae (HS) has long been used as a remedy for traditional Chinese medicine symptoms that resemble inflammatory joint disorders, because it can eliminate the wind-dampness and soothe painful joints. Proper processing can reduce the toxicity and/or enhance the efficacy of raw herbs. In this study, we aim to examine if processing with rice wine reduces the cytotoxicities and/or enhances the anti-inflammatory effects of HS, and to explore the chemical basis behind the potential changes of medicinal properties caused by the processing. MATERIALS AND METHODS We used cell models to examine the cytotoxicities and anti-inflammatory effects of HS and rice wine-processed HS (WHS). The chemical profiles of HS and WHS were compared using the ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) analysis. RESULTS We found that WHS was less toxic than HS in cultured cells as shown in the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Both HS and WHS had anti-inflammatory effects as demonstrated by their abilities to reduce nitric oxide (NO) production as well as protein and mRNA expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Interestingly, the anti-inflammatory effects of WHS were more potent than that of HS at the concentration of 100 μg/mL. By comparing the chemical profiles, we found that 19 peaks were lower, while 2 other peaks were higher in WHS than in HS. Four compounds including neo-darutoside, darutoside, stigmasterol and 16-O-acetyldarutoside corresponding to 4 individual changed peaks were tentatively identified by matching with empirical molecular formulae and mass fragments. CONCLUSION Our study showed that processing with rice wine significantly reduced the cytotoxicities and enhanced the anti-inflammatory effects of HS as demonstrated in cell models. We also developed a UPLC/Q-TOF-MS method to clearly differentiate HS from WHS by their different chemical profiles. Further study is warranted to establish the relationship between the alteration of chemical profiles and the changes of medicinal properties caused by processing with rice wine.