Page 5 - Pharmacognosy 02-06203

1- Primary metabolites:
• Carbohydrates (as cellulose, starch, pectin, etc..).
• Fixed oils, Proteins, etc..

2- Secondary metabolites: as alkaloids, glycosides, essential oils, poly-phenol compounds,
steroids, etc….) that may have certain specific pharmacological activity.

All these constituents act with each other by certain mechanism (s) to give the final
pharmacological actions of the herbal. This means that the therapeutic action of the herbal is due
to the combined action of these several constituents, so, the herbal drug act as a whole.
Several herbal drugs and their natural products have been used for a long time and thoroughly
evaluated for safety and efficacy, but the majority of herbs have not been fully evaluated and
need further recent studies and evaluation {this may be due to ecologic and genetic factors
(radiations, mutation, etc….)}.

In addition, the patient should receive doses with equal strength; therefore, standardized
methods should be documented to test for the purity, authenticity, chemical characteristics, and
also for measuring the potency of the herbal drug.
Modern chemical and spectral as well as chromatographic procedures using for molecular
characterization of individual pharmacologically active component, as well as recent
pharmacological and clinical studies have greatly facilitated the methodology to solve these
problems. But, this may need enormous costs and time (up to 12 years) to fully evaluate them.
All these reasons coupled with the strong consumer movement to maintain the freedom of choice
in self- medication, monopoly, and race and family habit, led to the DSHEA (Dietary Supplement
and Health Education Act). This law defined herbal products, vitamins, minerals and amino acids
as Dietary Supplements. Acupuncture, diet, homeopathy, hypnosis, massage, etc.., are defined
as Complimentary and Alternative Medicine (CAM).

3