This guide is an introduction to finding information pertaining to medicinal plants. Herbal science research can encompass ecology, botany, ethnography, and chemistry - this guide will help point you towards research in theses areas. Herbal science research requires multiple searches in multiple resources, so it's a good idea to consult with a librarian in addition to exploring the resources and techniques in this guide.
Be sure to check out our "How To" Guides to help you get started with search skills, writing and citation tips.
Research - Known Issues and On-going Debates
This introduction to some of the issues and on-going debates is intended to prompt further inquiry and critical evaluation of what you find – and don’t find – in the research. It is not a comprehensive overview of the field or the state of the research in the field. Librarians are available to help you explore the research, and help you answer questions about the context of that research.
Herbal medicine (phytotherapy) today evolved from traditional practices across the world, including indigenous peoples’ knowledge and use of plants. This traditional knowledge is often passed down orally and was often uncredited by the first western practitioners. There is therefore a lost history of the origins of some western herbalism practices.1
While traditional medicine has used plants for centuries and has empirical evidence of its efficacy; it has only been studied using evidence-based research approaches relatively recently.
Indigenous people may use the whole plant/herb (or more than one) rather than only one part or constituent, so there is sometimes a disconnect between the traditional use and the approach that science-based research has used. 2,3
Studies may yield inconsistent results if plants from different batches are used.
Active constituents in many herbs aren’t known, and there may be many.4,5
Quality control and weak methodologies have been noted in several herbal medicine studies.6
Rasoanaivo P, Wright CW, Willcox ML, Gilbert B. Whole plant extracts versus single compounds for the treatment of malaria: synergy and positive interactions. Malar J. 2011;10 Suppl 1(Suppl 1):S4. Published 2011 Mar 15. -S1-S4doi:10.1186/1475-2875-10
Niemeyer K, Bell IR, Koithan M. Traditional Knowledge of Western Herbal Medicine and Complex Systems Science. J Herb Med. 2013;3(3):112-119. doi:10.1016/j.hermed.2013.03.001
Wachtel-Galor S, Benzie IFF. Chapter 1: Herbal Medicine: An Introduction to Its History, Usage, Regulation, Current Trends, and Research Needs. In: Benzie IFF, Wachtel-Galor S, eds. Herbal Medicine: Biomolecular and Clinical Aspects. 2nd ed. Boca Raton (FL): CRC Press/Taylor & Francis; 2011. https://pubmed.ncbi.nlm.nih.gov/22593937/
Parveen A, Parveen B, Parveen R, Ahmad S. Challenges and guidelines for clinical trial of herbal drugs. J Pharm Bioallied Sci. 2015;7(4):329-333. doi:10.4103/0975-7406.168035
Karbwang J, Crawley FP, Na-Bangchang K, Maramba-Lazarte C. Herbal medicine development: Methodologies, challenges, and issues. Evid Based Complement Alternat Med. 2019; e4935786. doi:10.1155/2019/4935786
Fact Finding: define terms & gather background information
Determine the common and scientific names for your herb. Books, herbal monographs and encyclopedias in the BU Library Reference Section or on reserve, and the botanical databases, including Natural Medicines, will be helpful for identifying names.
Identify any bioactive chemical constituents (not broad constituent categories, such as flavonoids or turpines), but rather plant-specific ones, such as silymarin for milk thistle or curcumin for turmeric. Note: bioactive/therapeutic constituents that are unique to a species or genus haven't been identified for all herbs.
Gather additional general information about your herb such as therapeutic use, safety, effectiveness etc.before you search the databases.This will help you figure out your search terms and give you context.