The use of traditional herbal medicines and phytotherapeutics in developing countries

Transcription

1 The use of traditional herbal medicines and phytotherapeutics in developing countries Are we underestimating their toxicological challenges? NEERGHEEN-BHUJUN Vidushi Department of Health Sciences, Faculty of Science and ANDI Centre of Excellence for Biomedical and Biomaterials Research, University of Mauritius, Reduit, Republic of Mauritius IAP for Health Conference Promoting Health, September 2016, Beijing, China

2 - Island in the Indian Ocean - About 2,000 km 2 - Population 1.3 million - Multi-ethnic population Mauritius

3 Non-Communicable Diseases

4 Non-Communicable Diseases (continued)

5 Communicable diseases and their prevalence EMERGING AND OTHER ENDEMIC-PRONE COMMUNICABLE DISEASES

6 Burden of diseases

7 Traditional medicine Ancient medicine Traditional herbal medicine

8 Prevalence of herbal medicine use China 18.9 % USA 11.8 % India 20 % Thailand 15.5 % Vietnam 17.1 % Africa 8.7 % Sri Lanka 16.6 % Malaysia 7.7 % Medicinal plants Plants species

9 Worldwide evolution of the nutraceutical industry Global sales of Chinese Herbal Medicine reached US $83 billion in Global market for all herbal supplements and remedies could reach US $ 115 billion by 2020.

10 2015 Nobel Prize in Physiology or Medicine awards William C. Campbell Satoshi Ōmura Youyou Tu

11 2015 Nobel Prize in Physiology or Medicine awards

12 Youyou Tu "for her discoveries concerning a novel therapy against Malaria"

13 Toxicological concerns I a Intrinsic to herbal drugs themselves due to toxic constituents of the herbal ingredients and overdosage Leafy, flowery vines called Aristolochia are used in an herbal supplement that may cause cancer. Herbal compounds containing Aristolochia are classified as a Group 1 carcinogen by the International Agency for Research on Cancer. Vicious vine, Aristocholia Carsten Niehaus /Creative Commons End-stage renal disease cases was reported from Belgium associated with a weight loss treatment, which contained Aristolochia fangchi. Science, August 2013

14 Toxicological concerns I b Herb Induced Liver Injuries Aloe barbadensis Traditional uses: Laxative, gastric problems, aging, general well being Elevated ALT and AST, jaundice, acute hepatitis Suggested active compounds: Anthraquinones Larrea divaricata Traditional uses: Cancer (melanoma), bronchitis, colds, rheumatic pain, stomach pain, and chicken pox. Hepatitis, liver toxicity, liver failure. 13 cases of hepatitis reported to FDA between Suggested active compounds: Nordihydroguaiaretic acid (NDGA) Centella asiatica Traditional use: Weight loss 4 cases of hepatitis with 2 positive rechallenges Suggested active compounds:pentacyclic triterpenic saponosides Food Chemical Toxicology 2016 (in press) DOI: /j.fct

15 Toxicological concerns I c Potential adverse drug reactions Medicinal plants Pygeum africanum (Prunus africana) Madagascar rosy periwinkle (Catharanthus roseus) Hoodia cactus (Hoodia gordonii) Characteristics Traditional uses Potential adverse effects Prostate cancer, prostatitis, benign prostatic hyperplasia, other urinary tract infections, and Aphrodisiac Cancer chemotherapy Appetite suppressant and anorectic action Gastrointestinal upsets Medullary aplasia, leucopoenia, incoordination of movements, convulsions, fatigue, mucositis, constipation, and neutropenia of short duration Potentiation of diabetes mellitus (hyperglycemia), sometimes hypoglycemia and confusions Origin Cameroon, South Africa, and Madagascar Madagascar South Africa and Namibia Source: Integr Med Res 3 (2014)

16 Toxicological concerns II Herb-drug interactions Garlic drug interactions Induce hepatic CYP3A4 metabolism of saquinivir resulting in decreased plasma drug levels. Ginkgo biloba drug interactions Case reports of G. biloba possible interactions resulting in bleeding have been reported with aspirin, ibuprofen, and warfarin, possibly due to the antiplatelet effects of the ginkgolide B component St. John's wort drug interactions Case reports suggest St. John's wort induces CYP3A4 and intestinal p- glycoprotein. Drugs which are likely to interact include the immunosuppressants cyclosporine and tacrolimus, the HIV protease inhibitor indinavir, the HIV reverse transcriptase inhibitor nevirapine, the antineoplastic drugs irinotecan

17 Toxicological concerns III Extrinsic factors due to manufacturing practice, including contamination, substitution, incorrect preparation and dosage, intentional addition of unnatural toxic substances, intentional or unintentional mislabeling, and the presence of natural toxic contaminants.

18 Problems associated with herbal medicine Quality Safety Efficacy Consistency

19 Quality & Safety control 3 important pharmacopeial definitions Identity Is the herb the one it should be? Purity Are there contaminants, e.g., in the form of other herbs which should not be there? Content or assay Is the content of active constituents within the defined limits?

20 Identity: Herbal Genomics Model herb systems and their applications

21 Purity & Content: Safety concerns Williamson et al, Science 2014: Part 2: S47-S49

22 Standardisation Holistic quality control model Guo et al, Science 2014: Part 2: S29-S31

23 Quality control for traditional herbal medicine Guo et al, Science 2014: Part 2: S29- S31

24 Lifting the veil from traditional herbal medicine and phytotherapeutics Photograph: Antoine Pedro via Flickr EVIDENCE - BASED EFFICACY

25 Integrated toxicological approaches

26 Integration of traditional herbal medicine into modern healthcare Evidence- Based Standards Way forward for traditional herbal medicine & phytotherapeutics in developing countries Evidence- Based Clinical Research Omics

27 ACKNOWLEDGEMENT

28 Published by AAAS Priyanka Pulla Science 2014;346:410