Ethnobotanical Leaflets 12:603-06. 2008.
A Note on Variation of Active Principles in Indian Medicinal Plants and TIM Formulations
Dr. Amritpal Singh
Herbal Consultant, Ind- Swift Ltd,
����� The active principles or constituents (phytochemicals) in medicinal plants are chemical compounds known as secondary plant products. Some secondary products discourage herbivores; others inhibit bacterial or fungal pathogens. Active principles in medicinal plants may affect health, but are not-essential nutrients as our diet does not require them to sustain life in the same way as vitamins and minerals.
����� Ayurvedic scholars established fundamental rules for medicinal plant identification, collection and storage of drugs. According to Ayurveda, habitat an ecological factors have influence on pharmacological activity of plant based drugs. According to Ayurveda, habitat is known as desha. Plants growing in jangala desha, anoop desha, and are known as xerophytes, hydrophytes and mesophytes, respectively
���� Season has impact on availability of active principles in medicinal plants. According to principles of Western Herbal Medicine, Therapeutic efficacy varies during different times or seasons of the year. The constituent and active principles vary quantitavely at different seasons of the year and the majority of plant materials are usually best collected during the dry season, when the herbs are at peak maturity and concentration. Charaka and Sushruta stress timely collection of medicinal parts of plants. It is self-explanatory that ancient physicians were aware about relation between period of collection and distribution of active principles. Virya signifies energy or potency of a drug or medicinal plant. Charaka defines virya as driving force behind the therapeutic activity of the drug. According to some experts, virya is comparable to active constituent of a drug.
���� Standardization of medicinal plants used in Ayurveda, is global perspective. Numerous papers addressing the all important issue of standardization have been published; still no definite conclusion has been withdrawn. Work has been done on chemical standardization of medicinal plants used in Ayurveda. Standardized herbal extracts are available in the market, indicating the percentage of active principle on the label of the pack. Contrary to it, papers addressing the issue of standardization, challenges the percentage of active principles in several commercial preparations.
���� Standardization does have impact on quality of finished product. Mere chemical standardization of herbs is not sufficient for therapeutically active formulation. Biological standardization is crucial for establishing clinical efficacy of plant based products. As an instance foxglove, Digitalis purpurea (Tilpushpi in Ayurveda) provided the medical fraternity with most efficacious cardiac tonic, digoxin. As per instructions in the British Pharmacopoeia, the digoxin is standardized biologically, rather than chemically. Further, standardizing an herbal drug to one chemical marker as been challenged as synergy among various chemical constitutes, contribute towards medicinal activity.��
���� Recent times have witnessed increased
sale of herbal products in the international market. According to World
Health Organization, present demand for medicinal plants annually, is about
US$14 billion. Traditional Chinese Medicine (
���� Medicinal plant-related trade in
1. Adhatoda vasica (0.5% Vasicine)
2. Andrographis paniculata (10% Andrographolide)
3. Azadirachita indica 2% (Azadiractin)
4. Bacopa monneri 20% (Bacoside)
5. Boswellia seratta (40% and 70% Boswellic Acid).
6. Centella asiatica (3% Asiaticoside)
7. Commiphora mukul (5% Guggulsterones)
8. Curcuma longa (95% Curcumin)
9. Embelia ribes (8% Embellin)
10. Glycyrrihiza glabra (20% Glycyrrhizin)
11. Gymnema sylvestre (25% Gymnemic Acid).
12. Momordica charantia (3% bitters).
13. Phyllanthus niruri (2% bitters)
14. Picrorrhiza kurroa (10% bitters)
15. Tribulus terrestris (20% and 40% Saponin)
17. Trigonella foenum graceum (10% Saponin)
18. Withania somnifera (1.5% withanolides / 1% Alkaloid).
����� Majority of the companies promoting
herbal products have fixed standards (percentage of active principle). Since
the efficacy of herbal product is based on percentage of active principle, it
becomes mandatory that claimed percentage of active principle, should be present
in the finished product. Consumer laboratory in
������ Good Agricultural Practices (
Ashwagandha (reference to withaferin-A)
����� An interesting study reported variability of withaferin-A in commercial preparations of Ashwagandha (Withania somnifera). Commercial samples consisting of 250 mg Ashwagandha (as indicated on the label) were investigated for their phytochemical contents. The samples were quantified by High Performance Liquid Chromatography. The amount of withaferin-A estimated in commercial samples is given in table 14. There was significant variation in relative amount of withaferin A. The study reflected a 117-fold higher concentration of withaferin A in the highest holding product compared to one with the least. Further, according to the recommended intake of the product as mentioned on the label, dose of withaferin A ranged from 0.02 mg to 1.4 mg (Sangwan et al., 2004).
Brahami (reference to bacoside-A)
���� Brahami is used as
brain tonic in Ayurveda. The activity is due to
presence of Bacosides. As already discussed, the
maximum level of bacosides in Indian products
corresponds to 20 percent. Bacoside-A content
of herb was reported to be high from September through March and in June.
Suitable harvest times for high yields of bacoside-A
were June and September through November. An accession from Guwahati in
����� Central Institute of Medicinal and
Aromatic Plants (CIMAP),
experiment was conducted in
Vasaka alkaloids (reference to vasicine)
���� Adhatoda zeylanica Medic (Acanthaceae) is bronchodilator drug of Ayurevda. It is rich in quinazoline alkaloids. The plant shows wide seasonal variation in vasicine content in its leaves. It exhibited higher levels of vasicine twice in a year i.e. 3.0% in March and 1.4% in September. Interestingly, it coincided with the flowering of the plant. In March, it was full bloom condition and in September, it was partial flowering. During the vegetative stage, the plant contained very low concentration of vasicine. (Bagachi et al., 2003).
����� The yield of the vasicine
from different samples in
����� Geographical distribution (bacoside-A and vasicine) and method of manufacturing or processing (withaferin-A) seems to be factors are responsible for variation of active principles of medicinal plants. Shelf-life has obvious impact on availability of active principle. Although, standardization of herbal products is not easy task, manufactures must ensure proper testing of raw material for better product development. Bodies like AYUSH should issue standards for presence of active principles in finished Ayurvedic products.�