No therapeutic effect.

This statement is often seen in the packaging of medicinal plant formulations. This is the challenge of herbal medicine.

While the preference of people for natural remedies and wellness has seen the popularity of herbal medicines growing, the scientific evidence of their efficacy and quality has been lacking.

Researchers are standing up to that challenge with a three-year project aimed to prepare a quantitative phytochemical profile for six Philippine medicinal plants: ampalaya, banaba, malunggay, sambong, and tsaang gubat.

The profiles are expected to lead to phytochemical standards for these medicinal plants that can be used by the Department of Health’s Food and Drug Administration as well as the herbal medicine industry to ensure product safety and efficacy.

In particular, the information obtained from the project will assist farmers in producing quality – and thus higher value – raw plant materials. For example, it will guide farmers in the proper drying methods and help manufacturers meet herbal drug product standards here and the export market.

Most importantly, safe and effective herbal medicines will finally have the scientific basis to their therapeutic claims.

Most traditional herbal medicines have not been scientifically studied, here and elsewhere worldwide. In the Philippines, less than two percent of the 860 herbal medicines listed in Eduardo Quisumbing’s “Medicinal Plants of the Philippines” book have been subjected to detailed investigation.

There is great potential in the development of medicinal plants but we have to invest resources in research and development to realize this potential.

In the 1980s, the Department of Health (DOH) prepared a list of top 10 herbal medicines. Only a handful of herbal medicines have been approved by the DOH FOOD and Drug Administration (FDA) as herbal medicine products.

This is because one of the barriers to the growth of the Philippine herbal medicine industry is the absence of standardized product specifications.

A medicinal plant contains hundreds of chemical constituents called phytochemicals (phyto means plant). Phytochemicals range from relatively small simple compounds to the complex. Citral, the active substance in lemon grass, has a structure with 10 carbon atoms. Momordicin – suspected to be one of the anti-diabetes compounds in ampalaya leaves – has a more complex compound with 30 carbon atoms.

The chemical analysis of medicinal plants requires specialized equipment to determine the precise placement of every atom – carbon, hydrogen, oxygen, nitrogen, and others – in the chemical structure. The job is made more difficult because of the countless ways in which nature assembles its phytochemicals.

An essential requirement for the commercial production of herbal medicines is Good Manufacturing Practice or GMP which requires manufactures of herbal medicines to standardize the product according to an accepted phyto chemical profile.

The phytochemical profile refers to the identification of the characteristic compounds of the plant and their quantitative measurements. This helps ensure the identity and quality of the product. Standardization and chemical profiling are important to establish consistent farm production, formulation, manufacturing, product quality, and safety. The chemical profile is also one of the criteria for the determination of shelf life.

However, there are a number of parameters that can lead to variations in the composition of herbal medicines. One difference is the agricultural conditions, including the use of difference plant varieties, soil quality, fertilization, harvesting practices, and drying.

The preparation and packaging of commercial herbal medicine can also introduce differences. Thus, the profiling and standardization of herbal medicine products can ensure their safety and efficacy.

This information is required for the export of herbal medicine products. For example, the US Food and Drug Administration and the European Community require chemical profiles of herbal medicine products.

In response, many Southeast Asian countries such as Thailand and Malaysia have developed herbal medicine product standards. With the establishment of the single market of the Association of Southeast Asian Nations, the Philippines needs to develop its own herbal medicine standards.

Research in the development of the profiles and standards of herbal medicines requires precise chemical tools such as the gas chromatography-mass spectrometry, high performance liquid chromatography and high performance thin layer chromatography, nuclear magnetic resonance spectroscopy, and liquid chromatography-mass spectrometry.

The three-year project will provide medical researchers with these tools and finally put herbal medicines in the country’s drug formulary.

Herbal medicine refers to the use plants to treat or cure diseases and ailments. Throughout history, human societies have practiced herbal medicine in order to cure sickness and maintain health.

Starting around the 1930s, interest in herbal medicines waned as people turned to the use of pure pharmaceuticals. Many of the traditional cures were replaced by pure drug products: aspirin was the first widely produced pure pharmaceutical.

Today, there is a revival of interest in herbal medicine as people realize that it still has great potential to provide society the drugs that it needs for old diseases, like malaria, as well as modern afflictions, like AIDS and even Alzheimer’s disease.

About 40% of modern pharmaceuticals, in fact, trace their origin to medicinal plants, whether as synthetic models or purified extracts.

With the application of modern scientific techniques, there are now two directions of research in herbal medicines: the discovery of new pure drug candidates from medicinal plants and the validation and understanding why herbal medicines work.


Written by:
Dr. Fabian M. Dayrit
Ateneo de Manila University

Published by:
Department of Science and Technology-Science and Technology Information Institute (DOST-STII)