Importance of Proper Analytical Methodology
IMPORTANCE OF PROPER ANALYTICAL METHODOLOGY AND THE 10% GUGULIPID MYTH
Muhammed Majeed, Ph.D., Lakshmi Prakash, Ph.d. and S.Natarajan, Ph.D.
Gugulipid®, a registered trademark of Sabinsa Corporation, is the standardized extract of the oleogum resin of Commiphora mukul, an Indian medicinal plant. This resin is a mixture of diterpenes, sterols, steroids, esters and higher alcohols. The active ingredients responsible for the use of the plant in the maintenance of healthy cholesterol levels, are the guggulsterones, specifically gugulsterone E and gugulsterone Z. When purchasing guggul products, it is vital that the extract be assessed for purity and appropriate standardization. Sabinsa's product Gugulipid® (supplied in powder form) is purified and standardized to contain a minimum of 2.5% guggulsterones E and Z. The Indian Pharmacopeia (IP) limits the maximum level of guggulsterones (E and Z) to 4.0 to 6.0% in a soft extract.
It is probable that powdered guggul products which claim an active ingredient level in excess of 6.0% may be crude and unpurified extracts. In clinical studies, the administration of crude (unpurified) guggul caused mild side effects such as skin rashes, diarrhea and irregular menstruation. There are no reports of these undesirable effects with a purified and appropriately standardized extract.
GUGGULSTEROLS
Estimation of Guggulsterones and Guggulsterols in Gugulipid® extract:
The methods used include UV (ultraviolet) spectrophotometry and HPLC (High Pressure Liquid Chromatography).
UV Analysis
This method involves measuring the optical density of a solution of a known concentration at a particular wave length. All components that have the UV absorption spectrum at that wave length will absorb UV light in proportion to their amount in solution. Since UV is a cumulative function, the results will be for the total amount of sterone, sterol and steroidal components present.
An examination of the chemical structures reveals that the guggulsterones, Z&E, and the guggulsterols have the following similarities:
- They are tetracyclic
- They have an alpha-beta unsaturated ketone Carbonyl at Position 3
- They have an olefinic double bond at Position 4
Therefore, if a sample of powdered guggul extract is analyzed by UV method, the results would be cumulative, including a variety of structurally similar compounds and in excess of the actual guggulsterone levels.
HPLC Analysis 2
This method offers a more accurate analysis of guggulsterols and guggulsterones content. It involves the following steps:
- Physical separation of the mixture into individual components.
- Elution of the separated components from the chromatographic column at different rates.
- Using UV detector, only the eluted components (one particular compound at a time) is quantitated. This procedure ensures that each component is quantitated separately.
HPLC CHROMATOGRAMS OF THE Z AND E GUGGULSTERONES (STANDARDS)
HPLC CHROMATOGRAM OF A GUGULIPID® SAMPLE
TYPICAL ANALYTICAL RESULTS :
Guggulsterones content in commercial Commiphora mukul extract samples.
| Sample ID | Label claim (%) | By HPLC (%) | By UV (%) |
| 1 | 2.5 | 2.5 | 4.8 |
| 2 | 2.5 | 2.6 | 5.3 |
| 3 (SE)* | 16.0 | 3.6 | 16.5 |
| 4 | 10.0 | 1.1 | 10.6 |
* SE : Soft extract
Thus, a sample analyzed as containing 10.6% active constituents (by UV method) could be erroneously labeled as containing 10% guggulsterones. It would actually contain only 1.1% guggulsterones (the value determined by HPLC), the remainder being sterol compounds.
