Standardization and plant medicine quality 


Мы поможем в написании ваших работ!



ЗНАЕТЕ ЛИ ВЫ?

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 chromatographyis 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 isspectroscopy?
Father: Spectroscopyis 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 isspectrophotometer?
Father: Spectrophotometeris 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?”

 

Unit 6

Potential side effects

A number of herbs are thought to be likely to cause adverse effects. Furthermore, "adulteration, inappropriate formulation, or lack of understanding of plant and drug interactions have led to adverse reactions that are sometimes life threatening or lethal." Proper double-blind clinical trials are needed to determine the safety and efficacy of each plant before they can be recommended for medical use. Although many consumers believe that herbal medicines are safe because they are "natural", herbal medicine may interact with synthetic drugs causing toxicity to the patient, may have contamination that is a safety consideration, and herbal medicines, without proven efficacy, may be used to replace medicines that have a proven efficacy. The political issues around the safety of crude drugs vary from considering natural remedies "safe" regardless of potential dangers to considering them a dangerous unknown. Ephedra has been known to have numerous side effects, including severe skin reactions, irritability, nervousness, dizziness, trembling, headache, insomnia, profuse perspiration, dehydration, itchy scalp and skin, vomiting, hyperthermia, irregular heartbeat, seizures, heart attack, stroke, or death. Poisonous plants which have limited medicinal effects are often not sold in material doses in the United States or are available only to trained practitioners, these include:

  • Aconite
  • Arnica
  • Belladonna
  • Bryonia
  • Datura
  • Gelsemium
  • Henbane
  • Male Fern
  • Phytolacca
  • Podophyllum and
  • Veratrum

Furthermore, herbs such as Lobelia, Ephedra and Eonymus that cause nausea, sweating, and vomiting, have been traditionally prized for this action. Plants such as Comfrey and Petasites have specific toxicity due to hepatotoxic pyrrolizidine alkaloid content. There are other plant drugs which require caution or can interact with other medications, including St. John's wort and grapefruit.

Conventional treatments are subjected to testing for undesired side-effects, whereas alternative treatments generally are not subjected to such testing at all. Any treatment — whether conventional or alternative — that has a biological or psychological effect on a patient may also have potentially dangerous biological or psychological side-effects. Attempts to refute this fact with regard to alternative treatments sometimes use the appeal to nature fallacy, i.e. "that which is natural cannot be harmful".

An exception to the normal thinking regarding side-effects is Homeopathy. Since 1938 the U.S. Food and Drug Administration (FDA) has regulated homeopathic products in "several significantly different ways from other drugs." Homeopathic preparations, termed "remedies," are extremely dilute, often far beyond the point where a single molecule of the original active (and possibly toxic) ingredient is likely to remain. They are thus considered safe on that count, but "their products are exempt from good manufacturing practice requirements related to expiration dating and from finished product testing for identity and strength," and their alcohol concentration may be much higher than allowed in conventional drugs.

 

Active Vocabulary

 

side effects побічні дії
adulteration фальсифікація
interaction взаємодія
double-blind подвійний сліпий (експеримент, в якому випробувач і випробуваний не знають реальну ціль експерименту, так як це може повпливати на експеримент)
ephedra ефедра, хвойник
dizziness запаморочення
aconite аконіт
arnica арніка
belladonna беладонна
bryonia переступень
datura дурман
henbane блекота
comfrey живокіст
male fern чоловіча папороть
podophyllum подофіл
veratrum чемериця
seizure апоплексичний удар

 

Tasks

Task 1. Answer the questions to the text.

 

1. Can herbs cause adverse effects?

2. Proper double-blind clinical trials are needed to determine the safety and efficacy of each plant before they can be recommended for medical use, aren’t they?

3. Are poisonous plants which have limited medicinal effects sold in material doses in the United States?

4. What poisonous plants do you know?

5. Why are homeopathic products considered to be safe?

Task 2. Translate into English:

 

1. Вживання деяких трав у невідповідних дозах шкідливе для здоров’я людини. 2.. Гомеопатичні препарати використовують як допоміжний засіб при лікуванні складних захворювань. 3.Обов’язкова консультація лікаря перед вживанням настоїв із лікарських трав. 4. Вагітні жінки повинні бути обачливими при вживанні лікарських трав. 5. Слід негайно припинити вживання трав при негативній реакції організму.

 

Task 3. Make up sentences using the following words.

 

1. Plant, proper, clinical, are, safety, needed, to, trials, determine, the, and, efficacy, of, each, double-blind.

2. Interact, to, herbal, causing, synthetic, medicine, may, with, drugs, toxicity, the, patient.

3. Has, ephedra, been, known, to, side, numerous, effects, have.

4. Material, poisonous, the, in, United States, are, plants, often, not, sold, doses, in.

5. Plants, toxicity, some, have.

Task 4. Read the dialogue and act it out.

 

Student: Is it safe to use herbs for treatment?
Lecturer: Only in certain doses and after doctor’s consultation.
Student: Why is it dangerous?
Lecturer: Because some herbs can cause adverse effects. Misunderstanding of plant and drug interactions can lead to unforeseeable consequences that are sometimes life threatening or lethal."
Student: What can you say about the use of some plants by teenagers?
Lecturer: The age of adolescents is specific in its own. It is the age of physiological and psychological jump in the development. Teenagers don’t realize what they do. Both they and their future children are in danger.
Student: How it is possible to prevent this social phenomenon?
Lecturer: Only by joint efforts of parents, police and state control over herbs sale.
Student: What about healthy lifestyle campaigns?
Lecturer: Sometimes they are effective, but to my mind the best healthy lifestyle campaign is classmates’ healthy lifestyle, isn’t it?

 

Task 5. Points for discussion:

a)“Side effects of local plants”

b) “Is it necessary doctor’s consultation before taking herbal teas or

homeopathic remedy?”

c) “Teenagers’ abuse of poisonous plants (such as datura, henbane)”

Unit 7



Поделиться:


Последнее изменение этой страницы: 2016-07-11; просмотров: 237; Нарушение авторского права страницы; Мы поможем в написании вашей работы!

infopedia.su Все материалы представленные на сайте исключительно с целью ознакомления читателями и не преследуют коммерческих целей или нарушение авторских прав. Обратная связь - 3.137.171.121 (0.02 с.)