Herbal Medicine quality and safety issues a primer for health professionals

Transcription

1 Herbal Medicine quality and safety issues a primer for health professionals Dr Hans Wohlmuth PhD BSc Southern Cross University Lismore NSW

2 Expectations of all medicines EFFECTIVE SAFE QUALITY

3 Medicine Environment Stability Age Formulation Plant part Extraction Chemotype Post-harvest Species Plant Harvest

4 The industry chain Grower / Collector Primary processor / Regional middlemen / Cooperative Middlemen Exporter Consumer country importer / Secondary processor Secondary processor / National retailer Consumer / Patient Retailer / Practitioner Patient / Consumer After Booker A et al, J Ethnopharmacology 2012;140:624-33

5 The challenge of herbal quality control Chemical complexity Natural variability CONSISTENT MEDICINE

6 Analytical Chemistry 101 Advanced Analytical Chemistry vs

7 Aspects of quality of medicines Authenticity they are what they purport to be Consistency they have a consistent composition Purity they contain ONLY what they re supposed to contain

8 Authenticity

9 Herbal authentication Authentication Taxonomy Macroscopic morphology Microscopic morphology Chemistry TLC HPLC LC-MS GC-MS Reaction tests DNA analysis

10 Thyme from Morocco

11 5 1 Comparative chemistry ma U DAD1 A, Sig=210,8 Ref=off (040112X\CP D) 80 0 Fluid extract DAD1 A, Sig=210,8 Ref=off (040127\CPQ4012.D) mau Authentic reference HPTLC HPLC

12 There is something about Marigold Authentic reference Extract

13 Don t rely on common names! Calendula officinalis Tagetes erecta

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15 Skullcap (Scutellaria lateriflora) Native to N America cultivated US, Chile, Mexico, Costa Rica, Australia Leaf rich in flavonoid glycosides baicalin (~5%), dihydrobaicalin, lateriflorin King s Dispensatory 1898: larger part of the drug sold is derived from two other species AHP Monograph 2009: substituted with S. galericulata, S. alpina, S. incana, S. baicalensis, Teucrium spp.

16 HPTLC on silica gel 60 F 254 plates Mobile phase: tetrahydrofuran:toluene: formic acid:water (16:8:2:1 v/v) Visualisation: Natural Products Reagent followed by polyethylene glycol 4000 Photographed under UV 366 nm S. lateriflora (6 samples) S. lateriflora (left) Scutellaria sp. (4 samples) Left to right: Scutellaria sp. S. baicalensis root S. galericulata Scutellaria Bluebird S. baicalensis aerial

17 Scutellarin Baicalin Baicalein Chrysin Concentration mg/ml S. lateriflora S2 S. lateriflora S37 S. galericulata S35 Scutellaria 'Bluebird' S32 S. baicalensis root S23 S. baicalensis leaf S33 Scutellaria sp. S5 S. altissima S34 S. barbata S43

18 Looking for Teucrium spp T. chamaedrys S. lateriflora mau mau No Teucrium found in Scutellaria samples Minutes T. chamaedrys contained teucrioside no verbascoside no flavonoids typical of Scutellaria

19 Saffron the world s most precious botanical commodity Styles and stigmas from Crocus sativus Retails for $10-30 per gram flowers needed for 1 g Spice Anti-cancer, anti-depressant activity O R 1 O OR 2 O

20 70% EtOH extracts from (l-r): Iran, Tasmania, Kashmir

21 Fake saffron mau 80 DAD1 B, Sig=254,8 Ref=off (O:\DA137D~1\0911DATA\091118A\CPA91777.D) min DAD1 B, Sig=254,8 Ref=off (O:\DA137D~1\0911DATA\091118A\REF615.D) mau 1200 Safranal CHO HOOC Crocetin COOH Authentic saffron min

22 Variability

23 Natural variability 8 wild SJW population in Montana and N California Sirvent et al. Economic Botany 2002

24 Passiflora incarnata Some material grown in Australia have atypical C-glycosyl flavone profiles Wohlmuth et al. Biol Pharm Bull 2010 Six Australian samples (1-6) and two typical samples. (C=chlorogenic acid, H=hyperoside, R=rutin.)

25 Passiflora incarnata chemotypes Much (but not all) material grown in Australia is of swertisin chemotype Isovitexin-2-Oβ-glucopyranose Vitexin Isovitexin Swertisin HPLC trace of six samples of swertisin chemotype Typical material is of shaftoside/isovitexin chemotype Schaftoside/isoschaftoside Isovitexin-2-Oβ-glucopyranose Vitexin Isovitexin Wohlmuth et al. Biol Pharm Bull 2010 HPLC trace of four samples with the typical flavonoid profile.

26 Extraction solvent matters! Percentage extracted Rosmarinic acid from Melissa - extraction efficiency of different solvents Drug Percentage ethanol

27 Non-alcoholic liquid extract m A U *D AD 1, : Sorbate: E200 Sorbic acid E201 Sodium sorbate E202 Potassium sorbate % EtOH

28 Alkylamides in Echinacea preparations mau 70 DAD1 A, Sig=210,8 Ref=off (O:\DATA20~4\0804DATA\080430\CPA80507.D) DAD1 A, Sig=210,8 Ref=off (O:\DATA20~4\0804DATA\080430\CPA80508.D) 60 60% EtOH 0% EtOH min

29 Purity

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32 Ginkgo biloba adulteration USP, EP/BP 22-27% flavonoids, expressed as flavonol glycosides, but quantified after hydrolysis specified aglycone ratios: kaempferol : quercetin isorhamnetin : quercetin 0.1 Does not allow for detection of adulteration with aglycones! Assay aglycones before and after hydrolysis: A (glycosides) = A (post) A (pre)

33 Ginkgo biloba adulteration Ginkgo leaf (5) contained no free aglycones 8 ginkgo products tested

34 Ginkgo biloba adulteration Current USP method overestimated flavonoid glycoside content by 29-41%. Genistein

35 Ginkgo biloba adulterant? Styphnolobium japonicum genistein quercetin and kaempferol glycosides previously reported as a suspected adulterant of ginkgo extracts He K, Roller M (2011) In Formulating, Packaging and Marketing of Natural Cosmetic Products, ed. N Dayan & L Kromidas, Wiley, pp Qi Y et al. (2007) J Chromatogr A 1140:

36 Heavy metal contamination Heavy metals may be intentionally added to Indian and Chinese remedies Some plants accumulate heavy metals from the soil (e.g. Hypericum, Salix cadmium) (Wenzig & Bauer, in Houghton & Mukherjee, Evaluation of Herbal Medicinal Products 2009) 3.5% of 317 batches of dried herbs delivered to German TCM hospital had heavy metal content exceeding legal limits (Melchart, Alt Ther Health Med 2001)

37 Pharmaceuticals in traditional Chinese medicines In Taiwan, 24% of 2600 TCM preparations contained at least one drug compound (Huang, J Clin Pharmacol 1997) In the US, 10% of 500+ Chinese patent medicines contained undeclared drugs and/or toxic levels of heavy metals (Au, Bull Env Contam Toxicol 2000)

38 Herbal Viagra products

39 Herbal Viagra indeed!

40 Tea tree oil Oil of Melaleuca, terpinen-4-ol type ISO 4730, Australian Standard 2782: α-pinene 1-6% sabinene tr-3.5% α-terpinene 5-13% limonene % p-cymene 0.5-8% 1,8-cineole tr-15% γ-terpinene 10-28% terpinolene 1.5-5% terpinen-4-ol 30-48% α-terpineol 1.5-8% + 4 others

41 Tea tree oil adulteration issues Terpinen-4-ol content >40% attracts premium Adulteration with t-4-ol from other sources: pine bark marjoram synthetic T-4-ol chiral ratio (+/-) should be ~2.1 Synthetic oil lacks sesquiterpenes short-chain hydrocarbons

42 Tea tree oil safety concerns Methyl eugenol < % (mean 0.02%) 10 6 times lower than carcinogenic dose in rats Contact allergy Sensitising potential linked to oxidation products increased p-cymene peroxides, endoperoxides and epoxides protect from oxygen, light, heat Southwell et al. Flavour & Fragrance 2011

43 Conclusions Quality assurance of natural products presents unique challenges Rigorous quality assurance must be maintained to ensure the quality, safety and effectiveness of herbal medicines

44 Acknowledgments Ashley Dowell, SCU Peter Mouatt, SCU Roy Upton, American Herbal Pharmacopoeia Dr Reg Lehmann, Integria Healthcare Rose Cornelissen, Integria Healthcare

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