Asmachilca – an Andean Herbal Medicine with Harmful but Hidden Side-Effects * Steven M
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Asmachilca – an Andean herbal medicine with harmful but hidden side-effects * Steven M. Colegate1,2, Michael Boppré3, Julio Monzón3, Joseph M. Betz4 1 USDA, Poisonous Plant Research Laboratory, Logan, UT, USA; 2 Department of Animal, Dairy & Veterinary Sciences, Utah State University, Logan, UT, USA; 3 Chair of Forestzoology and Entomology, Albert-Ludwigs-Universität, Freiburg, Germany; 4 Office of Dietary Supplements, NIH, Bethesda, MD 20892, USA Background monoesters with two ‚head-to- • Asmachilca is a Peruvian medicinal tail‘-linked viridifloric and/or herb preparation ostensibly derived trachelanthic acids (Figs 3, 4). from Aristeguietia gayana (Wedd.) • The concentrations of dehydro- R.M. King & H. Rob. (Asteraceae: PAs in asmachilca plant material Eupatorieae). Decoctions of the plant (Table 2) were assessed as lycop- have a reported bronchodilation samine-equivalents of methanol effect that is purported to be useful extracts using HPLC-esi(+)MS. in the treatment of respiratory aller- • Mean pyrrolizidine alkaloid gies, the common cold and bronchial Graphical abstract content of a hot water infusi- asthma. on of a commercial asmachilca herbal tea • During field work in Peru, asmachilca was bag was 2.2 ± 0.5 mg (Table 2). observed to attract pyrrolizidine alkaloid-phar- macophagous moths (cf. Boppré 2011). 1,2-Dehydropyrrolizidine alkaloids (dehydro- Table 2 PA content of asmachilca-related investigated samples. PAs) are hepatotoxic, pneumotoxic and are genotoxic carcinogens. They can be rationally Conclusions implicated in the etiology of chronically-deve- • The pharmacophagous moths proved to be a loping disease in humans (Edgar et al. 2015). reliable bioindicator of the presence of toxic • This study was undertaken to determine if 1,2-dehydropyrrolizidine alkaloids. commercial asmachilca samples, including • Asmachilca preparations lack standardization, fully processed herbal teas, contain potentially Fig. 1 Leaf surfaces (a upper, b lower), perianths and achenes and recipes for utilization of the plant vary. (c) of: A Sample II; B Sample III; and C Sample V. Scale toxic dehydroPAs that may impact adversely on bars: a, b 1 mm, c 2 mm. • Exposures to high doses of dehydroPAs are the health of consumers. known to cause diagnostic hepatic sinusoidal obstruction syndrome (hepatic veno-occlusi- Methods ve disease) while diseases such as cirrhosis, • Commercial samples of asmachilca plant ma- pulmonary arterial hypertension and various terial (Table 1) were examined morphologically cancers associated with chronic low level and extracted for qualitative, quantitative and exposures are generally not apparent without structural analysis using HPLC-esi(+)MS and epidemiological studies (Edgar et al. 2015). MS/MS, high resolution MS, and 1D and 2D • The unequivocal determination of potentially NMR experiments. Fig. 2 Representative HPLC-esi(+)MS ion chromatogram of toxic dehydroPAs in dried and fresh plant ma- an extract of asmachilca material. Also shown are examples • As a preliminary indicator of possible human of MS/MS profiles used for dehydroPA identification. See terial sold as asmachilca, and in Asmachilca Fig. 3 for structure numbers. 24 exposure, hot water infusions of commercial HO 17 OH herbal teas indicates a potential health risk to R 18 16 2425 5 17 OH23 asmachilca herbal tea bags were also analyzed HO 15 consumers. HO R5 20 18 O16 2O3 25 O 19 15 for the presence of dehydroPAs. 21 13 • Tisanes made using asmachilca expose con- HO 13 20 O O O HO 12 22 19 13 21 11 sumers to amounts of dehydroPA in excess of O 13 R3 R 9 HOO 12O 22 R 2 H R4 1 R R 11 existing regulations and/or recommendations in 9 O 3 H O 9 O R2 1 R R1 H 4 7 8 R 1 7 H 9 various countries (e.g., 0.1 μg/day (Germany); 1 2 8 2 7 N8 1 7 2 N8 0.007 μg/kg BW/day (UK); 0.1 μg/kg BW/day N 2 R1 = R4 = R5 = H; R2 = R3 = OH: lycopsamine (1) N R1 = R3 = R5 = H; R2 = R4 = OH: intermedine (2) (Netherlands); and 1 μg/kg BW/day (Australia/ R2 = R4 = R5 = H; R1 = R3 = OH: echinatine (3) R2 = R3 = R5 = H; R1 = R4 = OH: rinderine (4) As above with R3 or R4 = OCOCH : 13-O-acetyl lycopsamine/intermedine/rinderine/ New Zealand) (EMA 2014). 3 echinatine (5) R1 = R2 = R3 = R5 = H; R4 = OH: supinine (6) Table 1 Asmachilca-related samples investigated in this R = OH: asmachilcadine (7) study. Names of suppliers are withheld intentionally. R = H: asmachilcadinine (8) Fig. 3 Structures of dehydropyrrolizidine alkaloids identified Future research needs in extracts of asmachilca plant material and in asmachilca-de- • Plant species used to prepare asmachilca need rived tisanes. Results to be unambiguously identified and complete • Morphological evidence showed that the phytochemical characterization needs to iden- purchased asmachilca samples II and III, and tify beneficial bioactives (if any). sample V (Table 1) were sourced from at least • Asmachilca use patterns and epidemiological two different plant species (Fig. 1). studies needed to determine risks and benefits. • HPLC-esi(+)MS and MS/MS revealed a qualitative similarity of the asmachilca samples comprising two distinct suites of dehydroPAs References Boppré M (2011) The ecological context of pyrrolizidine alkaloids in food, including the major presence of the dehydroPA feed and forage: an overview. Food Addit Contam A 28:260–281 monoesters rinderine (4) and supinine (6) and Fig. 4 1D 1H and 13C, and 2D COSY, HSQC and HMBC * Colegate SM, Boppré M, Monzón J, Betz JM (2015) Pro-toxic pyrrolizi- NMR structure elucidation. For example: 2D COSY spec- dine alkaloids in the traditional Andean herbal medicine „asmachilca“. J their N-oxides (Figs 2, 3). Ethnopharmacol 172:197–194 trum of asmachilcadine (7) showing two distinct CH3CH --O entities. Edgar JA, Molyneux RJ, Colegate SM (2015) Pyrrolizidine alkaloids: po- • Sample V did not contain supinine or its tential role in the etiology of cancers, pulmonary hypertension, congenital N-oxide. This is consistent with morphological anomalies, and liver disease. Chem Res Toxicol 28:4–20 • Two major, previously undescribed alkaloids, EMA (European Medicines Agency) (2014) Public statement on the use of herbal distinctiveness and confirms that it is a different asmachilcadine (7) and asmachilcadinine (8), medicinal products containing toxic, unsaturated pyrrolizidine alkaloids (PAs). http://www.ema.europa.eu/docs/en_GB/document_library/Public_state- plant species. were isolated and identified as dehydroPA ment/2014/12/WC500179559.pdf.