Unit 5 Standardization and plant medicine quality

In herbal medicine, standardization refers to providing processed plant material that meets a specified concentration of a specific marker constituent. Active constituent concentrations may be misleading measures of potency if cofactors are not present. A further problem is that the important constituent is often unknown. For instance St John’s wort is often standardized to the antiviral constituent hypericin which is now known to be the ‘active ingredient’ for antidepressant use. Other companies standardize to hyperforin or both, although there may be some 24 known possible constituents. Only a minority of chemicals used as standardization markers are known to be active constituents. Standardization has not been standardized yet: different companies use different markers, or different levels of the same markers, or different methods of testing for marker compounds. Herbalist and manufacturer David Winston points out that whenever different compounds are chosen as ‘active ingredients’ for different herbs, there is a chance that suppliers will get a substandard batch (low on the chemical markers) and mix it with a batch higher in the desired marker to compensate for the difference.

The quality of crude drugs or plant medicines depends upon a variety of factors, including the variability in the specie (or species) of plant being used; the plant’s growing conditions (i.e. soil, sun, climate); and the timing of harvest, post-harvest processing, and storage conditions. The quality of some plant drugs can be judged by organoleptic factors (i.e. sensory properties such as the taste, color, odor or feel of the drug), or by administering a small dose of the drug and observing the effects.

These conditions have been noted in historical herbals such as Culpepper’s Complete Herbal or The Shen Nong or Divine Farmer’s Materia Medica.This was standard pharmacognosy curriculum for many years. Storage after collection is a factor worthy of study; researchers in Nara, Japan have stored samples of ginseng root (Panax ginseng), licorice root (Glycyrrhiza glabra) and rhubarb root (Rheum emodi) that have been shown to retain their active properties for over 1,200 years.

In modern times the foregoing aspects are no less important, but have been neglected with the advent of laboratory testing, although it is true that only certain constituents are identified and measured. Processes like HPLC (High performance liquid chromatography), GC (gas chromatography), UV/VIS (Ultraviolet/Visible spectrophotometry) or AA (Atomic Absorption spectroscopy) are used to identify species, measure bacteriological contamination, assess potency and eventually creating Certificates of Analysis for the material.

Quality should be overseen by either authorities ensuring Good Manufacturing Practices or regulatory agencies by the US FDA (Food and Drug Administration). In the United States one frequently sees comments that herbal medicine is unregulated, but this is not correct since the FDA and GMP regulations are in place. In Germany, the Commission E has produced a book of German legal-medical regulations which includes quality standards.

Active Vocabulary

ginseng	женьшень
constituent	складова частина
misleading	помилковий, хибний
licorice	солодка (локриця)
rhubarb	ревінь
crude drugs	лікарська сировина
cofactor	спільно діючий фактор, кофактор
potency	сила, ефективність, дієвість
St John’s wort	звіробій
antiviral	противірусний
batch	порція, певна кількість
organoleptic	органолептичний (той, що сприймається органами відчуття, а саме особливості смаку, кольору, аромату)
to retain	зберігати, акумулювати
foregoing	попередній, вищезазначений
contamination	забруднення
to assess	визначити
pharmacognosy	фармакогнозія (розділ фармації, що вивчає лікарську сировину рослинного та тваринного походження)

Tasks

Task 1. Answer the questions to the text.

1. What does the term ‘standardization’ means in herbal medicine?

2. What does the quality of crude drugs or plant medicines depend upon?

3. What do you know about laboratory testing of crude drugs?

Task 2. Read the dialogue and act it out.

Daughter:	Dad! I am doing my home task and I don’t know the meaning of some words. You are a doctor. Could you help me, please?
Father:	But you are a doctor too.
Daughter:	Future doctor, Dad. I haven’t finished my study yet.
Father:	To be frank I am not sure that I know everything but I’ll try to explain to you in case I’ve run across it in my practice.
Daughter:	What is gas chromatography?
Father:	Gas chromatography is a technique for analyzing a mixture of volatile substances in which the mixture is carried by an inert gas through a column packed with a selective adsorbent and a detector records on a moving strip the conductivity of the gas leaving the tube. Peaks on the resulting graph indicate the presence of a particular component. It is also called gas-liquid chromatography.
Daughter:	What is spectroscopy?
Father:	Spectroscopy is the science and practice of using spectrometers and spectroscopes and of analyzing spectra, the methods employed depending on the radiation being examined. The techniques are widely used in chemical analysis and in studies of the properties of atoms, molecules, ions.
Daughter:	What is spectrophotometer?
Father:	Spectrophotometer is an instrument for producing or recording a spectrum and measuring the photometric intensity of each wavelength present, especially such an instrument used for infrared, visible, and ultraviolet radiation. What else?
Daughter:	That’s all. Dad, you are a real encyclopedia! Kiss you!

Task 3. Make up a dialogue using the following words and word combinations:

Standardization, misleading, gas chromatography, crude drugs, constituent, antiviral, herbal medicine, laboratory testing, in Ukraine, abroad, people’s health, dangerous illnesses, to assess, worth doing.

Task 4. Agree or disagree.

1. The quality of crude drugs or plant medicines depends upon a variety of factors.

2. The quality of some plant drugs can’t be judged by organoleptic factors.

3. Only a minority of chemicals used as standardization markers are known to be active constituents.

4. Active constituent concentrations may be leading measures of potency if cofactors are present.

5. Herbal medicine is unregulated.

Task 5. Points for discussion:

a) “Standardization of plants in Ukraine”

b) “ Quality of plants medicine in Ukraine”

c) “What do you know about pharmacognosy?”