Efficacy of COLD-fX in the prevention of respiratory symptoms in community-dwelling adults: a randomized, double-blinded, placebo controlled trial.

BACKGROUND: COLD-fX (CVT-E002), a proprietary extract of the roots of North American ginseng (Panax quinquefolium), rich in poly-furanosyl-pyranosyl-saccharides, has been found efficacious in the prevention of respiratory infections in institutionalized seniors and healthy adults. OBJECTIVE: We examined the efficacy of COLD-fX in the prevention of acute respiratory illness (ARI) in community dwelling seniors. DESIGN: This was a randomized, double-blind, placebo controlled trial. INTERVENTION: The participants were asked to take 2 capsules/day of either COLD-fX or placebo (200 mg/ capsule) for a period of 4 months. SUBJECTS: A total of 43 community-dwelling adults aged 65 years or older were recruited. Following one month of intervention, subjects were immunized with influenza vaccine. OUTCOME MEASURES: Subjects recorded the incidence and duration of respiratory symptoms during the study. They also recorded the incidence of adverse events during the study. RESULTS: The frequency and duration of ARI during the first two months of the study was found to be similar in the two groups. However, during the last 2 months (November and December) significantly fewer subjects in the COLD-fX group 32% reported ARI compared to the placebo group 62%. The duration of symptoms during the last 2 months was significantly shorter in the COLD-fX group than the placebo group (5.6 days in the COLD-fX group vs 12.6 days in the placebo group). There was no influenza illness circulating in the community during the period of the study. CONCLUSIONS: Ingestion of COLD-fX by immunocompetent seniors during an early "cold and flu" season reduced the relative risk and duration of respiratory symptoms by 48% and 55%, respectively. Daily COLD-fX administration can thus be a safe, natural therapeutic means for the prevention of ARI in healthy seniors.

Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: a randomized controlled trial.

BACKGROUND: Upper respiratory tract infections are a major source of morbidity throughout the world. Extracts of the root of North American ginseng (Panax quinquefolium) have been found to have the potential to modulate both natural and acquired immune responses. We sought to examine the efficacy of an extract of North American ginseng root in preventing colds. METHODS: We conducted a randomized, double-blind, placebo-controlled study at the onset of the influenza season. A total of 323 subjects 18-65 years of age with a history of at least 2 colds in the previous year were recruited from the general population in Edmonton, Alberta. The participants were instructed to take 2 capsules per day of either the North American ginseng extract or a placebo for a period of 4 months. The primary outcome measure was the number of Jackson-verified colds. Secondary variables measured included symptom severity, total number of days of symptoms and duration of all colds. Cold symptoms were scored by subjects using a 4-point scale. RESULTS: Subjects who did not start treatment were excluded from the analysis (23 in the ginseng group and 21 in the placebo group), leaving 130 in the ginseng group and 149 in the placebo group. The mean number of colds per person was lower in the ginseng group than in the placebo group (0.68 [standard deviation (SD) 0.82] v. 0.93 [SD 0.91], difference 0.25%, 95% confidence interval [CI] 0.04-0.45). The proportion of subjects with 2 or more Jackson-verified colds during the 4-month period (10.0% v. 22.8%, 12.8% difference, 95% CI 4.3-21.3) was significantly lower in the ginseng group than in the placebo group, as were the total symptom score (77.5 [SD 84.6] v. 112.3 [SD 102.5], difference 1.5%, 95% CI 1.2-2.0) and the total number of days cold symptoms were reported (10.8 [SD 9.7] v. 16.5 [SD 13.8] days, difference 1.6%, 95% CI 1.3-2.0) for all colds. INTERPRETATION: Ingestion of a poly-furanosyl-pyranosyl-saccharide-rich extract of the roots of North American ginseng in a moderate dose over 4 months reduced the mean number of colds per person, the proportion of subjects who experienced 2 or more colds, the severity of symptoms and the number of days cold symptoms were reported.

A proprietary extract from the echinacea plant (Echinacea purpurea) enhances systemic immune response during a common cold.

In a previous paper, it was reported that Echinilin (Factors R & D Technologies, Burnaby, British Columbia, Canada) a formulation prepared from freshly harvested Echinacea purpurea plants and standardized on the basis of three known active components (alkamides, cichoric acid and polysaccharides) is effective for the treatment of a naturally acquired common cold. However, the mechanism by which this effect is achieved remains unknown. In the present study, Echinilin or placebo were administered to volunteers at the onset of their cold for a period of 7 days, with eight doses (5 mL/dose) on day 1 and three doses on subsequent days. Fasting blood samples were obtained before and during their colds. The decrease in total daily symptomatic score was more evident in the echinacea group than in the placebo group. These effects of echinacea were associated with a significant and sustained increase in the number of circulating total white blood cells, monocytes, neutrophils and NK cells. In the later part of the cold, the echinacea treatment suppressed the cold-related increase in superoxide production by the neutrophils. These results suggest that Echinilin, by enhancing the non-specific immune response and eliciting free radical scavenging properties, may have led to a faster resolution of the cold symptoms.

Dietary rhubarb (Rheum rhaponticum) stalk fibre does not lower plasma cholesterol levels in diabetic rats.

Rhubarb (Rheum rhapontiam) stalk fibre was previously shown to be hypolipidaemic under clinical and experimental conditions. The present study was undertaken to investigate whether rhubarb stalk fibre has a hypolipidaemic effect under diabetic conditions. Two models of diabetic rats were used: streptozotocin-induced diabetic rats, and diabetes-prone BB (BBdp) rats. The plasma cholesterol and triacylglycerol concentrations were elevated after the onset of diabetes in BBdp rats, but not in sterptozotocin-induced diabetic rats. The rhubarb-fibre diet had no effect on the plasma cholesterol or triacylglycerol concentrations of diabetic rats. The hypolipidaemic effect of rhubarb stalk fibre has been suggested to be due to the bile-acid-binding capacity of rhubarb fibre, which in turn up regulates cholesterol 7alpha-hydroxylase (cyp7a) activity. cyp7a is the first and the rate-limiting enzyme in the breakdown of cholesterol to bile acids. We measured the cyp7a activity and mRNA levels in control and diabetic rats fed rhubarb- and cellulose-fibre diets. The cyp7a activity and mRNA abundance were increased in both diabetic rat models, indicating that bile acid synthesis is enhanced in diabetes. Feeding a diet enriched with rhubarb fibre caused a slight but significant increase (P<0.05) in cyp7a enzyme activity in BBdp rats, but no change in cyp7a mRNA abundance was detected. These results suggest that although a rhubarb-fibre-enriched diet increased cyp7a activity in BBdp rats, there was no apparent therapeutic benefit in terms of lowering plasma cholesterol concentrations.

Echinacea stimulates macrophage function in the lung and spleen of normal rats.

Echinacea plant extract has been used for immunostimulation for many years but the evidence supporting its therapeutic potential is still controversial. Using male Sprague-Dawley rats (425-475 g), an in vivo study was conducted to examine the immunomodulatory effects of preparations of Echinacea containing its components cichoric acid, polysaccharides and alkylamides in different concentrations. The rats were gavaged orally with these preparations, two times/day for 4 days. Phagocytic activity of alveolar macrophage was increased with increasing concentrations of the Echinacea components. A trend of increase in TNF-alpha and nitric oxide release by the alveolar macrophages following an in vitro stimulation with LPS was also evident. An enhanced release of cytokines (such as TNF-alpha and IFN-gamma) in response to Echinacea components, was also apparent in rat's spleen macrophage, but at higher concentrations. These results suggest that the Echinacea preparations containing optimal concentrations of cichoric acid, polysaccharides and alkylamides are potentially effective in stimulating an in vivo, non-specific immune response in normal rats.

Alkylamides of Echinacea purpurea stimulate alveolar macrophage function in normal rats.

Echinacea plant extract is widely used for the prevention and the treatment of upper respiratory tract infections. However, the active components in the herb, their optimal dosages and their in vivo effects are still undefined. Using male Sprague-Dawley rats (425-475 g), an in vivo study was conducted to examine the immunomodulatory effects of various dose levels of three components, isolated and purified from Echinacea purpurea. The components were cichoric acid, polysaccharides and alkylamides. The rats were gavaged orally two times/day for 4 days with three different concentrations of each of the Echinacea components. Among the components, alkylamides at the dose level of 12 microg/kg body weight/day significantly increased the phagocytic activity as well as phagocytic index of the alveolar macrophages. The alveolar macrophages obtained from this group of rats also produced significantly more TNF-alpha and nitric oxide after an in vitro stimulation with LPS than any other active component or the control. None of the components at any concentration had any effect on the release of TNF-alpha, IFN-gamma and IL-2 by the splenocytes. These results suggest that the alkylamides are one of the active constituents of E. purpurea plant. At a dose level of approximately 12 microg/kg body weight/day they effectively stimulate alveolar macrophage function in healthy rats. The immunomodulatory effects of alkylamides appear to be more pronounced in lungs than in spleen.