These WHO monographs are not pharmacopoeial monographs. Their purpose is to provide scientific information on the safety, efficacy and quality control/quality assurance of widely used medicinal plants, in order to facilitate their appropriate use in WHO’s Member States; to provide models to assist WHO’s Member States in developing their own monographs or formularies for these and other herbal medicines; and to facilitate information exchange among WHO’s Member States.
The format used for volume 2 essentially follows that of volume 1. However, to keep relevant sections together, Geographical distribution now precedes Description; and Dosage forms appears before Posology.
The Definition describes the identity of the plant material of interest and the Latin binomial name of the source plant, the binomial name being the most important criterion in quality assurance of the crude drug. Latin pharmacopoeial synonyms and vernacular names, listed in the sections Synonyms and Selected vernacular names, respectively, are those names used in commerce or by local consumers. The monographs place outdated botanical nomenclature in the synonyms category, based on the International rules of nomenclature.
The vernacular names listed are a selection of names from individual countries worldwide, in particular from areas where the medicinal plant is in common use. The lists are not complete, but reflect the names found at the time of preparation in official monographs, reference books and the Natural Products Alert (NAPRALERT) database (a database of literature from around the world on ethnomedical, biological and chemical information on medicinal plants, fungi and marine organisms, located at the WHO Collaborating Centre for Traditional Medicine at the University of Illinois at Chicago, USA).
A detailed botanical description (in Description) is intended for quality assurance at the stages of production and collection of the source plant, whereas the detailed description of the specific plant part used (the crude drug) - in Plant material of interest - is for quality assurance at the manufacturing and commercial stages. Geographical distribution is not normally found in official compendia, but it is included here to provide additional quality assurance information.
General identity tests, Purity tests and Chemical assays are all normal compendial components included under those headings in these monographs. Where purity tests do not specify accepted limits, those limits should be set in accordance with requirements of the respective national health authorities.
Each medicinal plant and crude drug contains active or major chemical constituents with a characteristic profile that can be used for chemical quality control and quality assurance. These constituents are described in the section Major chemical constituents.
Descriptions included in the section on Medicinal uses should not be taken as implying WHO’s official endorsement or approval. They merely represent the systematic collection of scientific information available at the time of preparation, for information exchange. Medicinal uses are categorized as uses supported by clinical data; uses described in pharmacopoeias and in traditional systems of medicine; and uses described in folk medicine, not yet supported by experimental or clinical data.
The first category includes medicinal indications that are well established in some countries and have been validated by clinical studies documented in the scientific literature. The clinical trials may have been controlled, randomized, double-blind studies, trials without controls, cohort studies, or well-documented observations of therapeutic applications.
The second category includes medicinal uses that are well established in many countries and are included in official pharmacopoeias or national monographs. Well-established uses having a plausible pharmacological basis and supported by older studies that clearly need to be repeated are also included. The references cited provide additional information useful in evaluating specific herbal preparations. The uses described should be reviewed by local experts and health workers for their applicability in the local situation.
The third category refers to indications described in unofficial pharmacopoeias and other literature, and to traditional uses. The appropriateness of these uses could not be assessed, owing to a lack of scientific data to support the claims. The possible uses of these remedies must be carefully considered in the light of therapeutic alternatives.
The Experimental pharmacology section includes only the results of investigations that prove or disprove the cited medicinal uses. Abbreviated details of the best-performed studies have been included in this section. Other published experimental data that are not associated with the medicinal uses have not been included to avoid confusion.
The details included in the section on References have been checked against the original sources wherever possible. However, in some cases, details are missing as the original sources were not available. For non-English language references, the title is given in the original language, except in cases where an English summary is available.