title: Null and opposing effects of Asian ginseng (Panax ginseng C.A. Meyer) on acute glycemia: results of two acute dose escalation studies.
abstract: OBJECTIVE
  We have repeatedly reported that a batch of American ginseng with a specific ginsenoside (glycosidal saponin) profile decreases acute postprandial glycemia. We investigated whether Asian ginseng is able to replicate this glycemia-lowering efficacy in two separate acute dose escalation studies.
  
  
  METHODS
  Each study was conducted in a separate sample of 11 healthy subjects (gender: 8M:3F and 6M:5F, age: 29 +/- 2y and 27 +/- 3y, BMI: 28.5 +/- 2.1 kg/m(2) and 26.9 +/- 1.4 kg/m(2)) using a randomized, single-blind, placebo-controlled, multiple-crossover design. Treatments consisted of 0 (placebo), 1, 2, and 3 g of Asian ginseng for the first study and 0 (placebo), 3, 6, and 9 g Asian ginseng for the second study administered 40 minutes before a 75g-OGTT protocol with blood drawn at -40, 0, 15, 30, 45, 60, 90, and 120 minutes. Ginsenosides were analyzed by HPLC-UV.
  
  
  RESULTS
  Neither the main effect of pooled-treatment, nor dose, nor either factors interaction with time was significant for incremental plasma glucose and insulin. But the diagnostically and therapeutically relevant two-hour plasma glucose (2h-PG) value was significantly higher for pooled Asian ginseng treatment than placebo (5.46 +/- 0.31 versus 4.99 +/- 0.30 mmol/L, p = 0.050). Ginsenoside analyses showed that the Asian ginseng contained up to 96% lower and sevenfold higher quantities of various ginsenosides and their ratios than our previous efficacious batch of American ginseng.
  
  
  CONCLUSIONS
  Asian ginseng showed both null and opposing effects on indices of acute postprandial plasma glucose and insulin. This is in contrast to our findings with American ginseng. One explanation may be the marked ginsenoside differences. Practitioners and consumers should be aware of ginseng's variable effects.
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, #6 138-61 Queen Street East, Toronto, Ontario M5C 2T2, CANADA.
authors.forename: John L
authors.initials: JL
authors.lastname: Sievenpiper
authors.forename: John T
authors.initials: JT
authors.lastname: Arnason
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Leiter
authors.forename: Vladimir
authors.initials: V
authors.lastname: Vuksan
mesh_terms: D000208:Acute Disease; D000328:Adult; D001786:Blood Glucose / Q000187:drug effects; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D036145:Ginsenosides / Q000008:administration & dosage / Q000145:classification; D005951:Glucose Tolerance Test; D006801:Humans; D006943:Hyperglycemia / Q000188:drug therapy*; D007328:Insulin / Q000097:blood; D008297:Male; D005894:Panax; D008517:Phytotherapy; D019518:Postprandial Period; D012016:Reference Values; D012503:Saponins / Q000008:administration & dosage; D016037:Single-Blind Method; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D036145:Ginsenosides; D007328:Insulin; C079995:Panax quinquefolium saponin; D012503:Saponins