Philippine Medicinal Plants Sources of Herbal Drugs
Byline: Magdalena C. Cantoria, PhD
THE Philippine Pharmacopeia Project has been described in a previous report in this column (see pp. 11, 20 of the June 26, 2005 issue). After a survey and careful review of monographs in available internationally recognized pharmacopeias, compendia, and references on herbal drugs published from 1993 to 2003, the Technical Working Group (TWG) II selected plants with sufficient scientific documentation of information for inclusion in monographs. Pharmacopeial monographs of 30 herbal drugs prepared by the Group were admitted to Part II of Philippine Pharmacopeia 1 (PP1). This was published in 2004 and given official status by Executive Order No. 302, signed by President Gloria Macapagal Arroyo on March 29, 2004.
The list of Philippine priority medicinal plants is based on the Department of Healthas (DoH) Circular No. 168-A-Series 1995 dated October 27, 1995 and a supplementary list prepared by the Bureau of Food and Drugs (BFAD). Copies of the DoH Circular and the BFAD list were given to the TWG II of the Philippine Pharmacopeia Project for study and for the preparation of monographs of plant drugs for Part II of the proposed Philippine Pharmacopeia.
The 78 plants in the DoH Circular and the 14 (out of 72) plants in the BFAD list have been rearranged alphabetically by their valid botanical names in accordance with the International Rules of Botanical Nomenclature. Since some botanical names have been revised by plant taxonomists, the former Latin binomial is cited as a synonym. Some plant families have likewise been given alternative names, and both alternative and original family names are given. The common name of each plant that is most familiar to users and practitioners of traditional medicine and the parts of the plant used as drug are also indicated.
The term "validated" can refer to certain characteristics or properties of the medicinal plant or the herbal drug. The scientific name of the plant is validated by a plant taxonomist according to the international rules of botanical nomenclature. The identity of the plant is validated by comparison with its description in the taxonomic literature or by comparison with an authentic specimen. The identity and purity of the part of the plant used as drug, whole or powdered, are validated both botanically by their macroscopic and microscopic characteristics and chemically by characteristic reactions of their constituents to appropriate reagents. Chemical identity and purity tests include general tests for the presence of the group of the main chemical constituents or specific tests for the presence of the active constituent, if known. Biological activity or potency is validated by appropriate biological or chemical assay methods. The categories "scientifically validated" and "folklorically validated" used in the DoH Circular need some clarification. The terms as used in the DoH Circular could be taken to refer particularly to uses of the specific plant part (the herbal drug) derived from the listed medicinal plant.
The World Health Organization categorizes medicinal uses of herbal drugs as (1) those uses supported by clinical data, (2) those uses described in official pharmacopeias and in traditional systems of medicine, and (3) those uses described in folk medicine not yet supported by experimental or clinical data. The first category includes medical indications that are well established in some countries and that have been validated by clinical studies documented in standard scientific literature collected from around the world. The medicinal uses in the second category are well established in some countries and are included in official pharmacopeias or national monographs. However, some well-established uses supported by older pharmacological studies should be reviewed by local experts and health workers for their applicability under local conditions. …