Selection of natural health products for clinical trials: a preclinical template

2009 ◽  
Vol 87 (5) ◽  
pp. 371-378 ◽  
Author(s):  
S. Vohra ◽  
D. Adams ◽  
J.B. Hudson ◽  
J.A. Moore ◽  
S. Vimalanathan ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Pediatric Population ◽  
Echinacea Purpurea ◽  
Phytochemical Analysis ◽  
Natural Health Products ◽  
Product Identity ◽  
Health Products ◽  
Ethanol Extracts ◽  
The Impact ◽  
Selection Of

In preparation for a clinical trial on the efficacy of Echinacea products with a pediatric population, a rational method for selection of test products was developed, based on phytochemical and bioassay evaluation. Ten currently available commercial products of Echinacea angustifolia (EA) or Echinacea purpurea (EP) were selected, and 3 bottles of each of 2 different lots were purchased for each product. Investigators were blinded to product identity before phytochemical analysis. Lot-to-lot variation was small, but product variation due to species and formulation was large. Products derived from ethanol extracts had low polysaccharide content and high levels of alkamides (EA), echinacoside (EA), cynarin (EA), cichoric acid (EP), and caftaric acid (EP). These products possessed high antiviral activities that differed between EA and EP products, but limited immune activation properties. In contrast, products derived without ethanol extraction had higher polysaccharide levels, but low levels of other components. These aqueous compounds showed immunostimulant activity as measured in a mouse macrophage model and a somewhat different antiviral profile. The choice of Echinacea product for clinical trial must therefore consider the impact of immune enhancement, the specific viral infection targeted, and the potential to reduce symptoms via antiinflammatory activity. Product selection may also depend on whether the intent of the trial is prophylaxis or treatment.

Echinacea purpurea L. in children: safety, tolerability, compliance, and clinical effectiveness in upper respiratory tract infectionsThis article is one of a selection of papers published in this special issue (part 2 of 2) on the Safety and Efficacy of Natural Health Products.

2007 ◽  
Vol 85 (11) ◽  
pp. 1195-1199 ◽  
Author(s):  
Paul Richard Saunders ◽  
Fraser Smith ◽  
Read Weaver Schusky
Keyword(s):  
Respiratory Tract ◽  
Clinical Effectiveness ◽  
Echinacea Purpurea ◽  
Natural Health Products ◽  
Upper Respiratory Tract ◽  
Natural Health ◽  
Health Products ◽  
Upper Respiratory ◽  
Tract Infections ◽  
Echinacea Extract

Echinacea purpurea (L.) Moench was mistakenly taken from North America to Germany in 1939 where it was cultivated and various extractions were prepared and subsequently used to treat upper respiratory tract infections. Parents often administer Echinacea to their children, but safety data on the use of Echinacea in Canadian children is lacking. A screening history, physical examination, and daily record of symptoms from an initial visit through to a the follow-up visit 13 days later were used to increase patient safety. Each subject was administered an aerial part Echinacea extract. The dose was based on age (2.5 mL three times per day for children aged 2–5 years, and 5 mL two times per day for children aged 6–12 years) and administered for 10 days in an open-label trial. A rating scale was used to measure tolerance to the treatment. We assessed the safety and compliance of use of the Echinacea extract by measuring the amount of extract returned at the end of the study, having the parents complete and return a daily symptom diary, and recording the subjects’ use of other natural health products or medications during the trial. Clinical effectiveness of the Echinacea extract could not be accurately assessed because of the small trial size and because the extract had been administered when some of the subjects had an upper respiratory tract infection that had begun 1 or more days prior to the study; however, each subject’s symptoms improved. No allergic or adverse reaction occurred and no safety issues arose.

Senecio latifolius induces in vitro hepatocytotoxicity in a human cell lineThis article is one of a selection of papers published in this special issue (part 2 of 2) on the Safety and Efficacy of Natural Health Products.

2007 ◽  
Vol 85 (11) ◽  
pp. 1063-1075 ◽  
Author(s):  
Manuela G. Neuman ◽  
Angela Y. Jia ◽  
Vanessa Steenkamp
Keyword(s):  
Control Treatment ◽  
Natural Health Products ◽  
Dependent Manner ◽  
Aqueous Extracts ◽  
Natural Health ◽  
Transmission Electron ◽  
Health Products ◽  
Induced Apoptosis ◽  
Selection Of

The objectives of this study were twofold: (i) to determine the mechanism(s) of Senecio -induced toxicity in human hepatoblastoma cells (HepG2) in vitro and whether such toxicity could be prevented using N-acetyl-cysteine (NAC), and (ii) to evaluate whether caspases are involved in Senecio-induced apoptosis. Cells were treated with aqueous extracts of Senecio (10 mg·mL–1) with and without NAC. Cytotoxicity was determined by using the MTT assay. Total glutathione (GSH) was measured by using the Tietze assay. Cells were also treated with aqueous extracts of Senecio in the presence or absence of 50 μmol/L caspase-3 inhibitor (IDN) for 24 h. Apoptosis was determined by transmission electron microscopy, and DNA fragmentation was determined by ELISA and terminal dUTP nick-end labelling (TUNEL). Senecio produced cytotoxicity and depleted GSH in a concentration- and time-dependent manner. A significant depletion in GSH was observed after 15 min (p < 0.001 vs. control), whereas significant cytotoxicity was only observed after 3 h (p < 0.001 vs. control). Treatment with NAC prevented Senecio-induced GSH depletion and resulted in a significant decrease in Senecio-induced cytotoxicity (p < 0.001 vs. NAC-untreated cells). Treatment with Senecio for 24 h resulted in 22% ± 2.5% (p < 0.001) apoptosis (vs. control). Pretreatment with 50 μmol caspase inhibitor reduced Senecio-induced apoptosis significantly (vs. non-exposed to IDN) (12% ± 1.5%; p < 0.05). Our results suggest the mechanism of Senecio-induced cytotoxicity in HepG2 cells in vitro involves depletion of cellular GSH. Cytotoxicity is reduced by supplementation with NAC, which thus prevents GSH depletion. Caspase activation is involved in Senecio-induced apoptosis.

scholarly journals The Impact of Implementation of the Canadian Regulatory Requirements on the Quality of Natural Health Products: The Glucosamine Case

2014 ◽  
Vol 17 (1) ◽  
pp. 20
Author(s):  
Ali Aghazadeh-Habashi ◽  
John Duke ◽  
Fakhreddin Jamali
Keyword(s):  
Active Ingredient ◽  
Natural Health Products ◽  
Regulatory Requirements ◽  
Canadian Market ◽  
Health Products ◽  
Label Claim ◽  
Standard Quality ◽  
Health Canada ◽  
The Impact

ABSTRACT – Purpose. We investigated whether the recent implementation of the regulatory requirements for the entry to the Canadian market of natural products has resulted in improved quality of the available glucosamine products. Methods. Eleven available products, of which 8 had been tested in 2002 (7 had contained substantially lower than the label claim of the active ingredient), and a European pharmaceutical grade tablet were assayed for their glucosamine content. The potassium and sodium contents of the products were also tested. Results. Nine of the 11 Canadian products and the European tablet had more than 91% of the label claim of the active ingredient, hence, met the criterion. Two products contained 71 and 78% label claim. The electrolyte contents were very variable but constituted only a small fraction of the daily requirements. Conclusion. Most tested glucosamine products passed the Health Canada requirements. This improvement is likely due to the publicity regarding the low quality of the products in the past and also a result, at least in part, of the introduction of the new regulatory requirements.  The sub-standard quality of a few tested products is still of concern.This  article  is  open  to  POST-PUBLICATION  REVIEW.  Registered  readers  (see  “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

Effects of Natural Health Products on Blood Pressure

2005 ◽  
Vol 39 (4) ◽  
pp. 712-720 ◽  
Author(s):  
Cynthia L Richard ◽  
Tannis M Jurgens
Keyword(s):  
Blood Pressure ◽  
Scientific Literature ◽  
Human Study ◽  
Mechanisms Of Action ◽  
Therapeutic Use ◽  
Cochrane Library ◽  
Natural Health Products ◽  
Natural Health ◽  
Health Products ◽  
The Impact

OBJECTIVE: To review the scientific literature to identify reports of the effects of natural health products (NHPs) on blood pressure. DATA SOURCES: Electronic databases (MEDLINE [1965–May 2004] via PubMed, the Cochrane Library [1995–May 2004], International Pharmaceutical Abstracts [1970–May 2004], Iowa Drug Information Services [1965–May 2004]) were searched using the key words medicine, herbal plants, medicinal plant preparations, phytotherapy, angiosperms/therapeutic use, gymnosperms/therapeutic use, ethnopharmacology, pharmacognosy, blood pressure, hypertension, hypotension, and diuretic. Searches were not limited by date, language, or publication type. Review articles and texts, as well as reference lists of relevant articles, were used to identify additional reports. STUDY SELECTION AND DATA EXTRACTION: Articles (English-language after 1980) were assigned to the following categories: human study, case report, animal study, in vitro study, or theoretical prediction based on chemical constituents. Discussions of mechanisms of action were noted. DATA SYNTHESIS: A comprehensive search of the scientific literature identified NHPs capable of affecting blood pressure. Case reports and clearly defined mechanisms of action provided strong evidence for the ability of ephedra and licorice to increase blood pressure. Coenzyme Q10 was reported to decrease systolic and diastolic blood pressure, although the mechanism is unclear. The clinical significance of the blood pressure effects of other NHPs is unclear due to lack of conclusive in vivo data, as well as substantial variability in the chemical content of preparations of NHPs. CONCLUSIONS: Among published information, there is little definitive evidence with regard to the impact of NHPs on blood pressure. Additionally, effects may vary in a given patient with the formulation and standardization of a particular product. Until research better characterizes the effect of NHPs on blood pressure, patients should be encouraged to talk with their healthcare provider before starting or stopping any herbal product.

The Impact of Natural Health Products on Radiation Response in Breast Cancer

2008 ◽  
Vol 72 (1) ◽  
pp. S699
Author(s):  
Y. Hasan ◽  
S. Galoforo ◽  
J. Boerner ◽  
G.D. Wilson ◽  
A.A. Martinez ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Radiation Response ◽  
Natural Health Products ◽  
Natural Health ◽  
Health Products ◽  
The Impact
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