Abstract
Harpagophytum procumbens and H. zeyheri (Pedaliaceae) are widely distributed in southern Africa. They are highly valued traditional medicines used in the treatment of inflammation and pain-related ailments such as rheumatoid arthritis, ulcers and boils [1]. The biological activity of the species has been ascribed to the presence of iridoid glycosides such as harpagoside, harpagide and procumbide. However, only harpagoside is currently used as a 'biomarker' to determine the quality of raw material and commercial products. Harpagophytum procumbens is regarded as more commercially valuable as it contains higher levels of the biologically active constituent, harpagoside, however H. zeyheri is being used as an adulterant to meet high market demands [2]. To explore the extent of variation, three hundred samples were collected throughout the geographical distribution of the two species and the harpagoside content quantified using LC-MS. The results confirm that both species contain harpagoside and that it is present in higher amounts in H. procumbens with a range of 0.17 – 4.37%, whereas in H. zeyheri, the range was 0.00 – 3.07%. According to the standard set by the European Pharmacopoeia, the harpagoside content is required to be at least 1.2%. All of the H. procumbens samples tested contained harpagoside, although only 61 met the 1.2% specification. Only 38 H. zeyheri samples contained harpagoside and only 26 met the specifications indicating that it is not a suitable substitute. This study confirmed that the two taxa are highly variable and intricate species as reflected by the significant variation in harpagoside content. This study provides valuable information regarding the difficulties of quality control and can also be used as a basis for the selection of raw material for propagation. Acknowledgements: The National Research Foundation of South Africa is thanked for its financial contribution to the study. References: [1] Van Wyk B-E, Gericke NP (2000) Peoples Plants. A guide to Useful Plants of Southern Africa. Briza Publications, Pretoria, South Africa. [2] Stewart KM, Cole D, (2005)J Ethnopharmacol, 100: 225 – 236.
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Claims 10
Claim · model-written summary
Harpagoside content in H. procumbens samples ranged from 0.17 to 4.37%.
- Taxon
- H. procumbens
Harpagophytum procumbense0 - Outcome
- harpagosidee0
- Value
- 0.17 – 4.37%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“both species contain harpagoside and that it is present in higher amounts in H. procumbens with a range of 0.17 – 4.37%”
Claim · model-written summary
Harpagoside content in H. zeyheri samples ranged from 0.00 to 3.07%.
- Taxon
- H. zeyheri
_(47254222741).jpg?width=60)
Harpagophytum zeyherie1 - Outcome
- harpagosidee0
- Value
- 0.00 – 3.07%e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_(47254222741).jpg?width=500)
Verbatim
e0“both species contain harpagoside”
e1“whereas in H. zeyheri, the range was 0.00 – 3.07%”
Claim · model-written summary
Harpagoside is present in higher amounts in H. procumbens than in H. zeyheri.
- Taxon
- H. procumbensHarpagophytum procumbense0
- Outcome
- harpagosidee0
- Direction
- highere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“both species contain harpagoside and that it is present in higher amounts in H. procumbens”
Claim · model-written summary
All tested H. procumbens samples contained harpagoside.
- Taxon
- H. procumbensHarpagophytum procumbense0
- Outcome
- contained harpagosidee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All of the H. procumbens samples tested contained harpagoside”
Claim · model-written summary
Only 61 of the H. procumbens samples met the 1.2% harpagoside specification.
- Taxon
- H. procumbensHarpagophytum procumbense1
- Outcome
- met the 1.2% specificatione0
- Value
- 61e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“only 61 met the 1.2% specification”
e1“All of the H. procumbens samples tested contained harpagoside”
Claim · model-written summary
Only 38 H. zeyheri samples contained harpagoside.
- Taxon
- H. zeyheriHarpagophytum zeyherie0
- Outcome
- samples contained harpagosidee0
- Value
- 38e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Only 38 H. zeyheri samples contained harpagoside”
Claim · model-written summary
Only 26 H. zeyheri samples met the harpagoside specification.
- Taxon
- H. zeyheriHarpagophytum zeyherie0
- Outcome
- met the specificationse0
- Value
- 26e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Only 38 H. zeyheri samples contained harpagoside and only 26 met the specifications”
Claim · model-written summary
The authors conclude that H. zeyheri is not a suitable substitute for H. procumbens.
- Taxon
- H. zeyheriHarpagophytum zeyherie0
- Outcome
- not a suitable substitutee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Only 38 H. zeyheri samples contained harpagoside and only 26 met the specifications indicating that it is not a suitable substitute”
Claim · model-written summary
The two Harpagophytum taxa are highly variable, with significant variation in harpagoside content.
- Taxon
- Harpagophytum procumbens and H. zeyheriHarpagophytum procumbensHarpagophytum zeyherit0
- Outcome
- variation in harpagoside contente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the two taxa are highly variable and intricate species as reflected by the significant variation in harpagoside content”
t0“Harpagophytum procumbens and H. zeyheri”
Claim · model-written summary
The authors state that the results can be used as a basis for selecting raw material for propagation.
- Taxon
- Harpagophytum procumbens and H. zeyheriHarpagophytum procumbensHarpagophytum zeyherit0
- Outcome
- selection of raw material for propagatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“can also be used as a basis for the selection of raw material for propagation”
t0“Harpagophytum procumbens and H. zeyheri”