Immunomodulating activity of CVT-E002, a proprietary extract from North American ginseng (Panax quinquefolium)

Effects of Panax species and their bioactive components on allergic airway diseases

Panax species include Panax ginseng Meyer, Panax quinquefolium L., Panax notoginseng, Panax japonicum, Panax trifolium, and Panax pseudoginseng, which contain bioactive components (BCs) such as ginsenosides and polysaccharides. Recently, growing evidence has revealed the pharmacological effects of Panax species and their BCs on allergic airway diseases (AADs), including allergic asthma (AA) and allergic rhinitis (AR). AADs are characterized by damaged epithelium, sustained acquired immune responses with enforced Th2 responses, allergen-specific IgE production, and enhanced production of histamine and leukotrienes by activated mast cells and basophils. In this review, we summarize how Panax species and their BCs modulate acquired immune responses involving interactions between dendritic cells and T cells, reduce the pro-inflammatory responses of epithelial cells, and reduce allergenic responses from basophils and mast cells in vitro. In addition, we highlight the current understanding of the alleviative effects of Panax species and their BCs against AA and AR in vivo. Moreover, we discuss the unmet needs of research and considerations for the treatment of patients to provide basic scientific knowledge for the treatment of AADs using Panax species and their BCs.

The discovery of pivotal fungus and major determinant factor shaping soil microbial community composition associated with rot root of American ginseng

American ginseng, a valuable medicinal and food plant, is threatened by rot root, which affects its yield and quality. However, limited studies have investigated the changes in soil microbial community and physiochemical properties between healthy and rot root American ginseng. Here, high-throughput sequencing and soil physiochemical properties were used to characterize these changes. The soil physiochemical properties showed significance differences between the soil of healthy and rot root, in which the pH, available potassium, available phosphorus, soil organic carbon and soil organic matter were significantly higher in healthy root soil. Besides, fungal α-diversity was also higher in healthy root soil than that in rot root. Importantly, the dominant fungal genera differed between soils of healthy and rot root of American ginseng, and LEfSe further indicated that six fungal genera (Devriesia, Chrysosporium, Dichotomopilus, Pseudeurotium, Acaulium and Scedosporium) were significantly enriched in the soil of healthy plants, whereas six fungal genera (Gibellulopsis, Fusarium, Plectosphaerella, Tetracladium, Gibberella and Ilyonectri) were significantly enriched in the soil of rot root, suggesting that an increase in the relative abundance of these pathogenic fungi (Fusarium, Plectosphaerella, and Ilyonectri) may be associated with ginseng rot root. Notably, this study is the first to report that an increase in the relative abundances of Gibellulopsis and Gibberella in the rot root soil of American ginseng may be associated with the onset of rot root symptoms in this plant. The functional profile prediction showed that the there was a significantly Pathotrophs increase in the rot root soil compared with healthy root soil and Saprotrophs were more abundant in the healthy root soil. Finally, correlation analyses revealed that soil cation exchange capacity was an important factors affecting the composition of rot root of American ginseng soil microbial communities. This study not only used a new approach to explore the new fungal associated with rot root in American ginseng but also excavated the major soil physiochemical properties affecting the microbiome diversity, providing foundation for developing biocontrol strategies against rot root.

Polysaccharides Extracted From Panax Ginseng C.A. Mey Enhance Complement Component 4 Biosynthesis in Human Hepatocytes

Panax ginseng C.A. Mey (ginseng) is a classic medicinal plant which is well known for enhancing immune capacity. Polysaccharides are one of the main active components of ginseng. We isolated water-soluble ginseng polysaccharides (WGP) and analyzed the physicochemical properties of WGP including molecular weight, monosaccharide composition, and structural characteristics. WGP had minimal effect on the growth of hepatocytes. Interestingly, WGP significantly increased the mRNA and protein levels of complement component 4 (C4), one of the core components of the complement system. Promoter reporter gene assays revealed that WGP significantly enhanced activity of the C4 gene promoter. Deletion analyses determined that the E-box1 and Sp1 regions play key roles in WGP-induced C4 transcription. Taken together, our results suggest that WGP promotes C4 biosynthesis through upregulation of transcription. These results provide new explanation for the intrinsic mechanism by which ginseng boosts human immune capacity.

Pharmacological Efficacy of Ginseng against Respiratory Tract Infections

Respiratory tract infections are underestimated, as they are mild and generally not incapacitating. In clinical medicine, however, these infections are considered a prevalent problem. By 2030, the third most comprehensive reason for death worldwide will be chronic obstructive pulmonary disease (COPD), according to the World Health Organization. The current arsenal of anti-inflammatory drugs shows little or no benefits against COPD. For thousands of years, herbal drugs have been used to cure numerous illnesses; they exhibit promising results and enhance physical performance. Ginseng is one such herbal medicine, known to alleviate pro-inflammatory chemokines and cytokines (IL-2, IL-4, IFN-γ, TNF-α, IL-5, IL-6, IL-8) formed by macrophages and epithelial cells. Furthermore, the mechanisms of action of ginsenoside are still not fully understood. Various clinical trials of ginseng have exhibited a reduction of repeated colds and the flu. In this review, ginseng’s structural features, the pathogenicity of microbial infections, and the immunomodulatory, antiviral, and anti-bacterial effects of ginseng were discussed. The focus was on the latest animal studies and human clinical trials that corroborate ginseng’s role as a therapy for treating respiratory tract infections. The article concluded with future directions and significant challenges. This review would be a valuable addition to the knowledge base for researchers in understanding the promising role of ginseng in treating respiratory tract infections. Further analysis needs to be re-focused on clinical trials to study ginseng’s efficacy and safety in treating pathogenic infections and in determining ginseng-drug interactions.

Development of Broad-Spectrum Antiviral Agents-Inspiration from Immunomodulatory Natural Products

Developing broad-spectrum antiviral drugs remains an important issue as viral infections continue to threaten public health. Host-directed therapy is a method that focuses on potential targets in host cells or the body, instead of viral proteins. Its antiviral effects are achieved by disturbing the life cycles of pathogens or modulating immunity. In this review, we focus on the development of broad-spectrum antiviral drugs that enhance the immune response. Some natural products present antiviral effects mediated by enhancing immunity, and their structures and mechanisms are summarized here. Natural products with immunomodulatory effects are also discussed, although their antiviral effects remain unknown. Given the power of immunity and the feasibility of host-directed therapy, we argue that both of these categories of natural products provide clues that may be beneficial for the discovery of broad-spectrum antiviral drugs.

The Synergistic Effects of Polysaccharides and Ginsenosides From American Ginseng (Panax quinquefolius L.) Ameliorating Cyclophosphamide-Induced Intestinal Immune Disorders and Gut Barrier Dysfunctions Based on Microbiome-Metabolomics Analysis

Cyclophosphamide (CTX), used in cancer chemotherapy, a high dose of which would cause immunosuppressive effect and intestinal mucosa damage. American ginseng (Panax quinquefolius L.) has a long history of functional food use for immunological disorder, colitis, cancer, and so on. This study aimed to illustrate the underlying mechanism of American ginseng’s immunomodulatory effect in CTX-induced mice. In this study, all groups of American ginseng (American ginseng polysaccharide [AGP], American ginseng ginsenoside [AGG], co-treated with American ginseng polysaccharide and ginsenoside [AGP_AGG]) have relieve the immune disorder by reversing the lymphocyte subsets ratio in spleen and peripheral blood, as well as stimulating CD4⁺T cells and IgA-secreting cells in small intestine. These three treatment groups, especially AGP_AGG co-treated group recovered the intestine morphology that up-regulated villus height (VH)/crypt depth (CD) ratio, areas of mucins expression, quantity of goblet cells, and expression of tight junction proteins (ZO-1, occludin). Importantly, the microbiome-metabolomics analysis was applied in this study to illustrate the possible immuno-modulating mechanism. The synergistic effect of polysaccharides and ginsenosides (AGP_AGG group) restored the gut microbiota composition and increased various beneficial mucosa-associated bacterial taxa Clostridiales, Bifidobacterium, and Lachnospiraceae, while decreased harmful bacteria Escherichia-Shigella and Peptococcaceae. Also, AGP_AGG group altered various fecal metabolites such as uric acid, xanthurenic acid, acylcarnitine, 9,10-DHOME, 13-HDoHE, LysoPE15:0, LysoPC 16:0, LysoPI 18:0, and so on, that associated with immunometabolism or protective effect of gut barrier. These results suggest AG, particularly co-treated of polysaccharide and ginsenoside may be used as immunostimulants targeting microbiome-metabolomics axis to prevent CTX-induced side effects in cancer patients.

Micronutrients and bioactive substances: Their potential roles in combating COVID-19

OBJECTIVES

The coronavirus disease 2019 (COVID-19) pandemic is seriously threatening public health and setting off huge economic crises across the world. In the absence of specific drugs for COVID-19, there is an urgent need to look for alternative approaches. Therefore, the aim of this paper was to review the roles of micronutrients and bioactive substances as potential alternative approaches in combating COVID-19.

METHODS

This review was based on the literature identified using electronic searches in different databases.

RESULTS

Vitamins (A, B, C, D, and E), minerals (selenium and zinc), and bioactive substances from curcumin, echinacea, propolis, garlic, soybean, green tea, and other polyphenols were identified as having potential roles in interfering with spike glycoproteins, angiotensin converting enzyme 2, and transmembrane protease serine 2 at the entry site, and inhibiting activities of papain-like protease, 3 chymotrypsin-like protease, and RNA-dependent RNA polymerase in the replication cycle of severe acute respiratory syndrome coronavirus 2. Having immunomodulating, antiinflammatory, antioxidant, and antiviral properties, such micronutrients and bioactive substances are consequently promising alterative nutritional approaches to combat COVID-19.

CONCLUSIONS

The roles of micronutrients and bioactive substances in the fight against COVID-19 are exciting areas of research. This review may suggest directions for further study.

Panax quinquefolius (North American Ginseng) Polysaccharides as Immunomodulators: Current Research Status and Future Directions

Panax quinquefolius (North American ginseng, NAG) is a popular medicinal plant used widely in traditional medicine. NAG products are currently available in various forms such as roots, extracts, nutraceuticals, dietary supplements, energy drinks, etc. NAG polysaccharides are recognized as one of the major bioactive ingredients. However, most NAG reviews are focused on ginsenosides with little information on polysaccharides. NAG polysaccharides have demonstrated a therapeutic activity in numerous studies, in which many of the bioactivities involve regulation of the immune response. The purpose of this review is to summarize the structural features and the immunomodulatory properties of crude, partially purified, and pure polysaccharides isolated from NAG. Receptors of the innate immune system that potentially bind to NAG polysaccharides and the respective signal transduction pathways initiated by these compounds are discussed. Major challenges, recent innovations, and future directions in NAG polysaccharide research are also summarized.

Ginseng integrative supplementation for seasonal acute upper respiratory infections: A systematic review and meta-analysis

BACKGROUND

The aim of the review was to assess whether ginseng can be a useful supplementation for seasonal acute upper respiratory infections (SAURIs).

METHODS

All clinical studies investigating ginseng efficacy for the treatment or prevention of SAURIs were included in the review. Medline, EMBASE, Web of Science, Scopus, Cochrane Library, Google Scholar were systematically screened for relevant articles up to May 26th, 2020. The risk of bias was assessed with the Cochrane tool (RoB 2).

RESULTS

Nine articles (describing ten trials about P. ginseng or P. quinquefolius) were included in the review. Evidence globally indicated some useful activity of intervention when administered in adjunct to influenza vaccination. The results of our quantitative synthesis suggested a significant effect on SAURIs incidence (RR = 0.69 [95 % C.I. 0.52 to 0.90], p < 0.05), as well as a significant reduction of their duration if only studies with healthy individuals were included in the analysis (MD=-3.11 [95 % C.I.-5.81 to -0.40], p < 0.05). However, the risk of bias was high-to-unclear for most included trials, and publication bias couldn't be excluded.

DISCUSSION

Limitations of existing evidence don't allow to draw conclusions on the topic. Nevertheless, it is not excluded that ginseng supplementation in adjunct to influenza vaccination and standard care might be useful for SAURIs prevention and management in healthy adult subjects, but further high-quality trials are needed to support this hypothesis.

OTHER

This research was not funded. The protocol was registered in PROSPERO under the following code: CRD42020156235.

The effects of sulfur fumigation processing on Panacis Quinquefolii Radix in chemical profile, immunoregulation and liver and kidney injury

ETHNOPHARMACOLOGICAL RELEVANCE

The influence of sulfur fumigation processing on chemical profile, pharmacological activity and safety of Chinese herbs has attracted great attention. Panacis Quinquefolii Radix (PQR) was more widely used as edible and medicinal than Ginseng because of its tonifying effect and characteristic of not getting inflamed. The disadvantage of sulfur fumigated (SF) Ginseng has been reported, but the systematic study of SF-PQR is deficient and urgently needed.

AIM OF THE STUDY

To systematically describe the influence of sulfur fumigation on chemical profile, characteristic products, immunoregulation and liver and kidney injury of PQR.

MATERIALS AND METHODS

ICP-MS and HPLC-DAD were used to detect 11 inorganic elements and 3 ginsenosides, respectively. Principal component analysis (PCA) was used to distinguish SF-PQR from non-sulfur fumigated (NSF)-PQR by combining the content changes of inorganic elements and ginsenosides. UPLC/Orbitrap-MS was applied to screen the characteristic products (m/z) after sulfur fumigation. For the effectiveness and safety, male KM mice were used to compare the immunomodulatory effects of NSF-PQR or SF-PQR under both healty and cyclophosphamide induced immunosuppressive conditions by net growth rate of body weight, thymus and spleen indices, serum IL-6, SOD, BUN, AST levels, and HE staining of liver and kidney.

RESULTS

Sulfur fumigation processing significantly reduced the contents of ginsenosides Rb₁, Re and Rg₁ with the elevation of inorganic elements in 20 batches PQR. Based on the scatter distribution of PCA, SF-PQR and NSF-PQR can be distinguished. According to the Rt, Precursor ion (m/z) and Product ion (m/z) produced by UPLC/Orbit trap-MS, R₁-SO₃ (m/z, 1059.53), Re-SO₃ (m/z, 1025.55), Rg₁-SO₃ (m/z, 878.47), Ro-SO₃ (m/z, 1035.32), Rb₁-SO₃ (m/z, 1179.58), and Rk₃-SO₃ (m/z, 745.40) could be confirmed as important markers for identifying SF-PQR. The effect of SF-PQR on reversing immunosuppression induced by cyclophosphamide was significantly reduced (P < 0.05) evidenced by the inhibition of net growth rate of body weight, immune organ index, IL-6 level and SOD activity. For healthy mice, SF-PQR not only failed to maintain the normal indexes, but also reduced the indexes to lower levels. After 2 weeks of continuous gastric administration, the abnormal liver and kidney functions in healthy mice were damaged and manifested by the increasing of BUN and AST levels, which was consistent with hepatic lesion area and renal tubular injury observed by HE staining.

CONCLUSION

Sulfur fumigation processing not only reduced the immunomodulatory effect of PQR, but also brought the hidden danger in liver and kidney injury. The sulfonated products provided in this paper can be applied for the identification of SF-PQR accurately.

Ginseng alleviates microbial infections of the respiratory tract: a review

The detrimental impact of air pollution as a result of frequent exposure to fine particles posed a global public health risk mainly to the pulmonary disorders in pediatric and geriatric population. Here, we reviewed the current literature regarding the role of ginseng and/or its components as antimicrobials, especially against pathogens that cause respiratory infections in animal and in vitro models. Some of the possible mechanisms for ginseng-mediated viral inhibition suggested are improvements in systemic and mucosa-specific antibody responses, serum hemagglutinin inhibition, lymphocyte proliferation, cell survival rate, and viral clearance in the lungs. In addition, ginseng reduces the expression levels of proinflammatory cytokines (IFN-γ, TNF-α, IL-2, IL-4, IL-5, IL-6, IL-8) and chemokines produced by airway epithelial cells and macrophages, thus preventing weight loss. In case of bacterial infections, ginseng acts by alleviating inflammatory cytokine production, increasing survival rates, and activating phagocytes and natural killer cells. In addition, ginseng inhibits biofilm formation and induces the dispersion and dissolution of mature biofilms. Most clinical trials revealed that ginseng, at various dosages, is a safe and effective method of seasonal prophylaxis, relieving the symptoms and reducing the risk and duration of colds and flu. Taken together, these findings support the efficacy of ginseng as a therapeutic and prophylactic agent for respiratory infections.

Sources, Extraction and Biomedical Properties of Polysaccharides

In the recent era, bioactive compounds from plants have received great attention because of their vital health-related activities, such as antimicrobial activity, antioxidant activity, anticoagulant activity, anti-diabetic activity, UV protection, antiviral activity, hypoglycemia, etc. Previous studies have already shown that polysaccharides found in plants are not likely to be toxic. Based on these inspirational comments, most research focused on the isolation, identification, and bioactivities of polysaccharides. A large number of biologically active polysaccharides have been isolated with varying structural and biological activities. In this review, a comprehensive summary is provided of the recent developments in the physical and chemical properties as well as biological activities of polysaccharides from a number of important natural sources, such as wheat bran, orange peel, barely, fungi, algae, lichen, etc. This review also focused on biomedical applications of polysaccharides. The contents presented in this review will be useful as a reference for future research as well as for the extraction and application of these bioactive polysaccharides as a therapeutic agent.

Structural characteristics of a red ginseng acidic polysaccharide rhamnogalacturonan I with immunostimulating activity from red ginseng

Background

Many researchers reported that the various immune activities of red ginseng are due to acid polysaccharides. But, the exact structural characteristics of the acidic polysaccharide in red ginseng have not been fully elucidated. Therefore, we isolated the acidic polysaccharide from red ginseng and characterized the structural property of the active moiety of this polysaccharide, which contributes to the immunostimulatory activity of red ginseng.

Methods

A polysaccharide (RGP-AP-I) was purified from red ginseng via size-exclusion chromatography using Sephadex G-100. Immunostimulatary activity of RGP-AP-I was investigated via anti-complementory and macrophage stimulatory activity. The structure of RGP-AP-I was characterized by HPLC, sugar composition, β-glucosyl Yariv reagent and methylation analysis.

Results

Peritoneal macrophages stimulated using RGP-AP-I significantly augmented the production of various cytokines such as interleukin (IL)-6, IL-12, and tumor necrosis factor (TNF)-α. The primary structure of RGP-AP-I was elucidated by assessing its sugar composition and methylation analysis. RGP-AP-I is a 96 kDa acidic polysaccharide, and comprises nine different monosaccharides, which mainly include sugars such as rhamnose (Rha, 9.5%), galacturonic acid (GalA, 18.4%), galactose (Gal, 30.4%), and arabinose (Ara, 35.0%). RGP-AP-I exhibited an considerable reaction with the β-glucosyl Yariv reagent, revealing the presence of arabino-β-3,6-galactan. Methylation analysis indicated that RGP-AP-I comprises 21 different glycosyl linkages, such as 3-, 4-, 6- and 3,6-linked Galp; 5-linked Araf; 2,4-linked Rhap; and 4-linked GalAp, which are characteristics of rhamnogalacturonan I (RG-I).

Conclusion

we assumed that the immunostimulatory activity of RGP-AP-I may be due to the RG-I structure, which comprises a main chain with a repeating linkage unit, [→2)-Rhap-(1→4)-GalAp-(1→] and three groups of side chains such as (1→5)-linked arabinan, (1→4)-linked galactan, and arabino-β-3,6-galactan, which branch at the C(O)4 positions of Rha residues in the main chain of RGP-AP-I.

American Ginseng (Panax quinquefolium L.) as a Source of Bioactive Phytochemicals with Pro-Health Properties

Panax quinquefolium L. (American Ginseng, AG) is an herb characteristic for regions of North America and Asia. Due to its beneficial properties it has been extensively investigated for decades. Nowadays, it is one of the most commonly applied medical herbs worldwide. Active compounds of AG are ginsenosides, saponins of the glycosides group that are abundant in roots, leaves, stem, and fruits of the plant. Ginsenosides are suggested to be primarily responsible for health-beneficial effects of AG. AG acts on the nervous system; it was reported to improve the cognitive function in a mouse model of Alzheimer's disease, display anxiolytic activity, and neuroprotective effects against neuronal damage resulting from ischemic stroke in animals, demonstrate anxiolytic activity, and induce neuroprotective effects against neuronal damage in ischemic stroke in animals. Administration of AG leads to inhibition of hypertrophy in heart failure by regulation of reactive oxygen species (ROS) in mice as well as depletion of cardiac contractile function in rats. It also has an anti-diabetic and anti-obesity potential as it increases insulin sensitivity and inhibits formation of adipose tissue. AG displays anti-cancer effect by induction of apoptosis of cancer cells and reducing local inflammation. It exerts antimicrobial effects against several pathogenic strains of bacteria. Therefore, AG presents a high potential to induce beneficial health effects in humans and should be further explored to formulate precise nutritional recommendations, as well as to assess its value in prevention and therapy of some disorders, including cancer.

The Effect of Pectinase-Assisted Extraction on the Physicochemical and Biological Properties of Polysaccharides from Aster scaber

The edible and medicinal perennial herb Aster scaber is known to have anticancer, antioxidant, and immunomodulatory properties. However, the biological effects of its polysaccharides are not well understood. Here, we aimed to extract novel polysaccharides with enhanced biological properties from Aster scaber using enzyme-assisted methods. Amylase, cellulase, and pectinase were used to extract enzyme-assisted polysaccharide (ASEP)-A, ASEP-C, and ASEP-P, respectively. The yields, physicochemical properties, and immunostimulatory activities of the polysaccharides were investigated and compared with those of hot water extracted polysaccharide (ASWP). The highest yield (3.8%) was achieved for ASEP-P extracted using pectinase digestion. Fourier-transform infrared spectroscopy (FT-IR) and chemical composition analysis revealed that ASWP and three ASEPs were typical acidic heteropolysaccharides, mainly comprising rhamnose, arabinose, galactose, glucose, and galacturonic acid. Immunostimulatory activity assays on RAW264.7 macrophages showed ASEP-P to have the greatest immunostimulatory potential in terms of nitric oxide (NO) and cytokine productions and phagocytic activity. ASEP-P administration improved immune-enhancing effects in normal mice by improving the spleen index and splenic lymphocyte proliferation, and in immunosuppressed mice by modulating lymphocyte proliferation, natural killer (NK) cell activity, and leukocyte counts. The ASEP-P derived from pectinase hydrolysate of Aster scaber demonstrated efficacious immunostimulatory properties and has potential applications as an immune stimulator.

Effect of Korean Red Ginseng extracts on drug-drug interactions

Background

Ginseng has been the subject of many experimental and clinical studies to uncover the diverse biological activities of its constituent compounds. It is a traditional medicine that has been used for its immunostimulatory, antithrombotic, antioxidative, anti-inflammatory, and anticancer effects. Ginseng may interact with concomitant medications and alter metabolism and/or drug transport, which may alter the known efficacy and safety of a drug; thus, the role of ginseng may be controversial when taken with other medications.

Methods

We extensively assessed the effects of Korean Red Ginseng (KRG) in rats on the expression of enzymes responsible for drug metabolism [cytochrome p450 (CYP)] and transporters [multiple drug resistance (MDR) and organic anion transporter (OAT)] in vitro and on the pharmacokinetics of two probe drugs, midazolam and fexofenadine, after a 2-wk repeated administration of KRG at different doses.

Results

The results showed that 30 mg/kg KRG significantly increased the expression level of CYP3A11 protein in the liver and 100 mg/kg KRG increased both the mRNA and protein expression of OAT1 in the kidney. Additionally, KRG significantly increased the mRNA and protein expression of OAT1, OAT3, and MDR1 in the liver. Although there were no significant changes in the metabolism of midazolam to its major metabolite, 1′-hydroxymidazolam, KRG significantly decreased the systemic exposure of fexofenadine in a dose-dependent manner.

Conclusion

Because KRG is used as a health supplement, there is a risk of KRG overdose; thus, a clinical trial of high doses would be useful. The use of KRG in combination with P-glycoprotein substrate drugs should also be carefully monitored.

Panax ginseng and Panax quinquefolius: From pharmacology to toxicology

The use of Panax ginseng and Panax quinquefolius in traditional Chinese medicine dates back to about 5000 years ago thanks to its several beneficial and healing properties. Over the past few years, extensive preclinical and clinical evidence in the scientific literature worldwide has supported the beneficial effects of P. ginseng and P. quinquefolius in significant central nervous system, metabolic, infectious and neoplastic diseases. There has been growing research on ginseng because of its favorable pharmacokinetics, including the intestinal biotransformation which is responsible for the processing of ginsenosides - contained in the roots or extracts of ginseng - into metabolites with high pharmacological activity and how such principles act on numerous cell targets. The aim of this review is to provide a simple and extensive overview of the pharmacokinetics and pharmacodynamics of P. ginseng and P. quinquefolius, focusing on the clinical evidence which has shown particular effectiveness in specific diseases, such as dementia, diabetes mellitus, respiratory infections, and cancer. Furthermore, the review will also provide data on toxicological factors to support the favorable safety profile of these medicinal plants.

Animal lectins: potential receptors for ginseng polysaccharides

Panax ginseng Meyer, belonging to the genus Panax of the family Araliaceae, is known for its human immune system-related effects, such as immune-boosting effects. Ginseng polysaccharides (GPs) are the responsible ingredient of ginseng in immunomodulation, and are classified as acidic and neutral GPs. Although GPs participate in various immune reactions including the stimulation of immune cells and production of cytokines, the precise function of GPs together with its potential receptor(s) and their signal transduction pathways have remained largely unknown. Animal lectins are carbohydrate-binding proteins that are highly specific for sugar moieties. Among many different biological functions in vivo, animal lectins especially play important roles in the immune system by recognizing carbohydrates that are found exclusively on pathogens or that are inaccessible on host cells. This review summarizes the immunological activities of GPs and the diverse roles of animal lectins in the immune system, suggesting the possibility of animal lectins as the potential receptor candidates of GPs and giving insights into the development of GPs as therapeutic biomaterials for many immunological diseases.

Cheonggukjang polysaccharides enhance immune activities and prevent cyclophosphamide-induced immunosuppression

Cheonggukjang is a traditional Korean fermentation product prepared from soybean that is reported to have various biological functions. We previously reported that the polysaccharides from Cheonggukjang (PSCJ) have immunostimulatory activities in RAW 264.7 macrophages and primary cultured splenocytes. In this study, the immunostimulatory activities of the PSCJ were investigated further using various experimental models such as in vitro, ex vivo, and in vivo. The PSCJ was able to stimulate the complement system (ITCH50: 30.6%). In primary cultured mouse peritoneal macrophages, the PSCJ was found to significantly increase nitric oxide and immunostimulatory cytokines (IL-6 and IL-12) production in a concentration-dependent manner (1-100 μg/mL). In the normal mice model, the oral administration of the PSCJ increased the weight of spleen (p < 0.05 at 100 and 200 mg/kg) and improved the phagocytic rates of peritoneal macrophages (p < 0.05 at 200 mg/kg) and lymphocytes proliferation (p < 0.05 at 100 and 200 mg/kg). Similarly, the PSCJ markedly restored the decreased lymphocytes proliferation (p < 0.01 at 200 mg/kg), natural killer cell activity (p < 0.01 at 200mg/kg), and white blood cell count (p<0.01 at 100 and 200 mg/kg) in the cyclophosphamide-induced immunosuppressed mice model. These results suggest that the PSCJ could be utilized as an effective immunostimulatory agent.

Chemical Diversity of Panax ginseng, Panax quinquifolium, and Panax notoginseng

The major commercial ginsengs are Panax ginseng Meyer (Korean ginseng), P. quinquifolium L. (American ginseng), and P. notoginseng (Burk.) FH Chen (Notoginseng). P. ginseng is the most commonly used as an adaptogenic agent and has been shown to enhance physical performance, promote vitality, increase resistance to stress and aging, and have immunomodulatory activity. These ginsengs contain saponins, which can be classified as dammarane-type, ocotillol-type and oleanane-type oligoglycosides, and polysaccharides as main constituents. Dammarane ginsenosides are transformed into compounds such as the ginsenosides Rg3, Rg5, and Rk1 by steaming and heating and are metabolized into metabolites such as compound K, ginsenoside Rh1, protoand panaxatriol by intestinal microflora. These metabolites are nonpolar, pharmacologically active and easily absorbed from the gastrointestinal tract. However, the activities metabolizing these constituents into bioactive compounds differ significantly among individuals because all individuals possess characteristic indigenous strains of intestinal bacteria. To overcome this difference, ginsengs fermented with enzymes or microbes have been developed.

Preventive effect of Korean red ginseng for acute respiratory illness: a randomized and double-blind clinical trial

Korean Red Ginseng (KRG) is a functional food and has been well known for keeping good health due to its anti-fatigue and immunomodulating activities. However, there is no data on Korean red ginseng for its preventive activity against acute respiratory illness (ARI). The study was conducted in a randomized, double-blinded, placebo-controlled trial in healthy volunteers (Clinical Trial Number: NCT01478009). Our primary efficacy end point was the number of ARI reported and secondary efficacy end point was severity of symptoms, number of symptoms, and duration of ARI. A total of 100 volunteers were enrolled in the study. Fewer subjects in the KRG group reported contracting at least 1 ARI than in the placebo group (12 [24.5%] vs 22 [44.9%], P = 0.034), the difference was statistically significant between the two groups. The symptom duration of the subjects who experienced the ARI, was similar between the two groups (KRG vs placebo; 5.2 ± 2.3 vs 6.3 ± 5.0, P = 0.475). The symptom scores were low tendency in KRG group (KRG vs placebo; 9.5 ± 4.5 vs 17.6 ± 23.1, P = 0.241). The study suggests that KRG may be effective in protecting subjects from contracting ARI, and may have the tendency to decrease the duration and scores of ARI symptoms.

Neoplasm prevention and immuno-enhancement mediated by daily consumption of a proprietary extract from North American ginseng by elderly mice of a cancer-prone strain

Cells belonging to the innate immune system, known as natural killer (NK) cells, act as the first line of defense against developing neoplasms. We have previously shown in a leukemia-induced tumor model (mouse) that a proprietary extract (CVT-E002), of North American ginseng, administered in the diet, significantly increased the absolute numbers of NK cells, significantly decreased leukemia cells and significantly increased the life span of CVT-E002-fed leukemic mice. In the present study, we assessed the efficacy of this extract to inhibit the spontaneous development of tumors in elderly mice of the cancer-prone C3H strain. Dietary CVT-E002 was fed for approximately a year beginning when mice were almost 2 years of age. Control mice, consuming the same chow without CVT-E002, all developed assorted, palpable tumors between 22 and 33 months, while all mice consuming CVT-E002 remained alive and tumor-free until they were purposely euthanized as healthy animals. The absolute numbers of NK cells at euthanasia, in CVT-E002-consuming mice, were significantly elevated in both the spleen and bone marrow. Given these profoundly positive results and the fact that CVT-E002 already exists in the marketplace under the label Cold-fX®, the potential for cancer prevention in humans becomes apparent.

High molecular weight polysaccharides are key immunomodulators in North American ginseng extracts: characterization of the ginseng genetic signature in primary human immune cells

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng (GS) has played a pivotal role in traditional Chinese medicine for thousands of years. Its use has become increasingly popular in North America, in part due to the many claims of its immune-enhancing properties. The immunopharmacology of the North American variety of GS and its extracts is needed to substantiate these claims.

MATERIALS AND METHODS

Human peripheral blood mononuclear cells were exposed to different North American GS extracts and microarray analysis was performed. The profile of cytokine response to GS extracts was established by ELISA, and Ingenuity Pathway Analysis was used to identify potential signaling pathways responsible for the transcriptional profile induced by GS. Fractionation of the aqueous and polysaccharide extracts was done to determine the molecular weight of the active immune modulatory ingredient(s).

RESULTS

We found that GS induced a transcriptional profile of immunomodulation characterized by a net T(h)1 immune response, with up-regulation of multiple pro-inflammatory cytokines (e.g., IFN-γ, IL-23A and IL-6) and down-regulation of TGF-β, IL-13 and the LPS co-receptor CD14. Ingenuity Pathway Analysis (IPA) revealed that the MAPK (ERK-1/2), PI3K, p38 and NF-κB cascades were key signaling pathways through which GS may trigger its immunomodulatory action. Furthermore, induction of such an immunomodulatory signature was recapitulated with the high molecular weight polysaccharides found in aqueous and polysaccharide GS extracts.

CONCLUSIONS

Based on our results, we conclude that high molecular weight polysaccharides in North American GS aqueous and polysaccharide extracts likely trigger the MAPK (ERK-1/2), PI3K, p38 and NF-κB signaling pathways in PBMC resulting in the induction of a T(h)1 transcriptional profile. Our results may assist in optimizing GS-mediated immunomodulation and focus the search for compounds in GS extracts with specific immunomodulatory activities.

Structural characterization and immunological activities of the water-soluble oligosaccharides isolated from the Panax ginseng roots

Water-soluble ginseng oligosaccharides (designated as WGOS) with a degree of polymerization ranging from 2 to 10 were obtained from warm-water extract of Panax ginseng roots, and fractionated into five purified fractions (i.e., WGOS-0, WGOS-1, WGOS-2, WGOS-3, and WGOS-4) by gel-filtration chromatography. In order to ascertain the monosaccharide residues in the WGOS, a technique that combines acid hydrolysis and high-performance liquid chromatography was employed. It was found that only glucose residues were present in the WGOS. Fourier transform infrared spectroscopy and electrospray ionization tandem mass spectrometry provided the sequence, linkage, and configuration information. It is noteworthy that α-Glcp-(1 → 6)-α-Glcp, α-Glcp-(1 → 6)-α-Glcp-(1 → 4)-α-Glcp, α-Glcp-(1 → 6)-α-Glcp-(1 → 6)-α-Glcp-(1 → 4)-α-Glcp, and other six malto-oligosaccharides (i.e., maltopentaose, maltohexaose, maltoheptaose, maltooctaose, maltononaose, and maltodecaose) were detected in ginseng. Preliminary immunological tests in vitro indicated that WGOS were potent B and T-cell stimulators and WGOS-1 has the highest immunostimulating effect on lymphocyte proliferation among those purified fractions. It is hoped that the WGOS will be developed into functional food or medicine.

A placebo-controlled trial of Korean red ginseng extract for preventing influenza-like illness in healthy adults

Abstracts

Trial Registration

NCT01478009.

A randomized, controlled trial of Panax quinquefolius extract (CVT-E002) to reduce respiratory infection in patients with chronic lymphocytic leukemia

BACKGROUND

Chronic lymphocytic leukemia (CLL) patients are at high risk for acute respiratory illness (ARI).

OBJECTIVE

We evaluated the safety and efficacy of a proprietary extract of Panax quinquefolius, CVT-E002, in reducing ARI.

METHODS

This was a double-blind, placebo-controlled, randomized trial of 293 subjects with early-stage, untreated CLL conducted January-March 2009.

RESULTS

ARI was common, occurring on about 10% of days during the study period. There were no significant differences of the 2 a priori primary end points: ARI days (8.5 ± 17.2 for CVT-E002 vs 6.8 ± 13.3 for placebo) and severe ARI days (2.9 ± 9.5 for CVT-E002 vs 2.6 ± 9.8 for placebo). However, 51% of CVT-E002 vs 56% of placebo recipients experienced at least 1 ARI (difference, -5%; 95% confidence interval [CI], -16% to 7%); more intense ARI occurred in 32% of CVT-E002 vs 39% of placebo recipients (difference, -7%; 95% CI, -18% to 4%), and symptom-specific evaluation showed reduced moderate to severe sore throat (P = .004) and a lower rate of grade ≥3 toxicities (P = .02) in CVT-E002 recipients. Greater seroconversion (4-fold increases in antibody titer) vs 9 common viral pathogens was documented in CVT-E002 recipients (16% vs 7%, P = .04).

LIMITATIONS

Serologic evaluation of antibody titers was not tied to a specific illness, but covered the entire study period.

CONCLUSION

CVT-E002 was well tolerated. It did not reduce the number of ARI days or antibiotic use; however, there was a trend toward reduced rates of moderate to severe ARI and significantly less sore throat, suggesting that the increased rate of seroconversion most likely reflects CVT-E002-enhanced antibody responses.

Compound CVT-E002 attenuates allergen-induced airway inflammation and airway hyperresponsiveness, in vivo

Immune modulation has been a sought after means of therapy for atopic diseases. CVT-E002 is an extract derived from North American Ginseng shown to promote T-helper-1-like responses. We determined what effect CVT-E002 could have in a mouse model of atopic asthma. We report that oral CVT-E002 inhibited the development of allergic airway inflammation and airway hyperresponsiveness. This correlated with an increased presence of interferon-γ in the lung, and also increased regulatory T cells and IL-10. The ability of CVT-E002 to induce regulatory T-cell development was also seen in human in vitro co-cultures.

Dietary supplementation with an extract of North American ginseng in adult and juvenile mice increases natural killer cells

Cells belonging to the innate immune system are referred to as natural killer (NK) cells. We recently demonstrated that normal, pre-weaned infant mice, injected with a proprietary extract of ginseng (CVT-E002) had augmented NK cell numbers vs. sham-injected mice. In the present study, we extended these observations into juvenile and adult mice. Thus, young adult (age: 8-9 wk) C3H mice were given daily dietary CVT-E002 for 4 wk followed by untreated chow for the following 2 months, then euthanized (age: 20-21 wk). Other C3H mice (juvenile: 4-wk-old) were given CVT-E002 under the same protocol and sampled at 18 wk of age. In spite of withdrawing the extract 2 months earlier, the absolute numbers of NK cells in the young adults, remained significantly (p < 0.01), and slightly, elevated in the spleen and bone marrow (BM), respectively. The relative numbers (%) of NK cells in the blood also remained elevated (p < 0.05). In juvenile mice fed CVT-E002, the absolute numbers (spleen, BM) and % (blood) of NK cells were all elevated (p<0.01 - p<0.05). The mechanisms responsible for these super-normal numbers of NK cells long after withdrawal of CVT-E002, is as yet unknown.

Efficacy and Safety of CVT-E002, a Proprietary Extract of Panax quinquefolius in the Prevention of Respiratory Infections in Influenza-Vaccinated Community-Dwelling Adults: A Multicenter, Randomized, Double-Blind, and Placebo-Controlled Trial

CVT-E002 (a proprietary extract) was found to be effective in the prevention of upper respiratory infections (URIs) in healthy adults, and institutionalized and community-dwelling seniors. A multicenter, randomized, double-blind, placebo-controlled trial was carried out to determine effects of CVT-E002 in the prevention of URIs in influenza-vaccinated community-dwelling adults. 783 community-dwelling adults were randomized to receive placebo, 400 mg or 800 mg treatment/d (1 : 1 : 1) for 6 months. Primary analysis on the incidence of laboratory-confirmed-clinical URIs (LCCUs), including influenza A and B, was performed on those receiving at least one dose. Secondary analysis was performed on study completers and included incidence, severity, and duration of URIs meeting a Jackson-based criteria and safety of CVT-E002. The incidence of LCCUs in the ITT group was 5.5%, 5.2%, and 4.6% in the placebo, 400 mg and 800 mg groups, respectively (P = 0.89). Jackson-confirmed URIs were significantly lower in the treated groups (P < 0.04). CVT-E002 supplementation reduced the severity and duration of Jackson-confirmed URIs. The results indicate that CVT-E002 can be safely used by similar groups and may prevent symptoms of URIs; larger sample size is warranted.

Human dendritic cells promote an antiviral immune response when stimulated by CVT-E002

Objectives

There is interest in developing new compounds to enhance the immune response to airway virus infections. CVT-E002 is a patented ginseng extract shown to decrease symptoms of virus infection in clinical trials. We hypothesized that the mechanism for this antiviral effect could be through modulation of dendritic cells leading to enhanced T-cell activation.

Methods

Human monocyte-derived dendritic cells (moDC) exposed to CVT-E002 (or not) were co-cultured with autologous T cells, with or without virus (respiratory syncytial virus or parainfluenza virus). Effects of CVT-E002 on cell function were determined through flow cytometry, 5-bromo-2′-deoxyuridine (BrdU) incorporation and ELISA.

Key findings

moDC cultured with CVT-E002 or virus induced greater activation of T cells, as measured by CD25 expression and BrdU incorporation, compared with untreated moDC. Responding T cells were CD4+CD45RO+. Co-cultures of CVT-E002 treated moDC with T cells responded with increased release of Th1-type cytokines (interferon-gamma, tumour necrosis factor and interleukin-12). CVT-E002-treated moDC showed increased expression of CD83, CD80 and CD86. Lipopolysaccharide levels were not detected in CVT-E002 and antagonists for Toll-like receptor-4 did not inhibit CVT-E002-induced moDC maturation.

Conclusions

CVT-E002 induced moDC maturation, which caused increased memory T-cell activation and Th1-type cytokine response.

Efficacy and safety of a multiherbal formula with vitamin C and zinc (Immumax) in the management of the common cold

OBJECTIVE

To study the potential efficacy and tolerability of a natural multiherbal formula (Immumax) containing Echinacea extract 120 mg, garlic powder 100 mg, Nigella sativa oil 200 mg, and Panax ginseng extract 50 mg plus vitamin C 50 mg and elemental zinc 7.5 mg in the treatment of patients suffering from the common cold.

DESIGN AND SETTING

The study was conducted in a prospective, double-blind, randomized, controlled study design in an outpatient setting.

PATIENTS AND METHODS

Sixty-two eligible patients with symptoms of the common cold were randomized to either Immumax or placebo treatment groups for the duration of their symptoms or a maximum of 14 days. Resolution rates were estimated using Kaplan-Meier analysis, and resolution profiles were compared between groups using the log-rank test. The mean percentage change in total symptom severity scores at days 4 and 8 from baseline were compared between the two groups by one-way analysis of variance (ANOVA).

RESULTS

The median (interquartile range) time to resolution of all symptoms was 8 (5-9) days in the placebo group and 4 (3-6) days in the Immumax group. The results of the log-rank test indicate that symptoms resolved significantly faster in the Immumax group than in the placebo group (P < 0.001). The mean percentage reduction in total symptom severity scores from baseline at days 4 and 8 was significantly greater in the Immumax group than in the placebo group by one-way ANOVA (P < 0.01).

CONCLUSION

We can conclude from our study that Immumax is helpful in reducing the duration and severity of common cold symptoms.

Safety and tolerability of North American ginseng extract in the treatment of pediatric upper respiratory tract infection: a phase II randomized, controlled trial of 2 dosing schedules

BACKGROUND

Upper respiratory tract infections are the most common childhood illness. Panax quinquefolius (American ginseng root extract) standardized to contain 80% poly-furanosyl-pyranosyl-saccharides is purported to be effective in adult upper respiratory tract infection but has not been evaluated yet in a pediatric population.

OBJECTIVES

Our primary objective was to document the safety and tolerability of 2 weight-based dosing schedules (standard dose versus low dose versus placebo) in children. We also used the Canadian Acute Respiratory Infection Flu Scale, a quantitative scoring sheet for measuring the severity and duration of upper respiratory symptoms, to establish the SD of the treatment effect to allow sample-size calculations for future clinical trials.

METHODS

We conducted a randomized, double-blind dose-finding 3-arm trial (2 dosing schedules of American ginseng extract with 1 placebo control) during the winter months (November 2005 to March 2006) in children 3 to 12 years of age.

RESULTS

Seventy-five subjects were prerecruited from the general population in Edmonton. Of these, 46 subjects developed an upper respiratory tract infection and were randomly assigned (15 standard dose, 16 low dose, and 15 placebo), with 1 subject withdrawing from the low-dose arm before beginning the intervention. No serious adverse events were reported. The frequency, severity, and degree of association between the intervention and reported adverse events were not significantly different among each of the 3 treatment arms.

CONCLUSIONS

Standard doses of ginseng were well tolerated and merit additional evaluation with regard to treatment of pediatric upper respiratory tract infection.

Effect of CVT-E002 (COLD-fX) versus a ginsenoside extract on systemic and gut-associated immune function

CVT-E002 (sold commercially as COLD-fX) is a patented, polysaccharide-rich extract of North American ginseng (Panax quinquefolium) with purported beneficial effects on influenza and the common cold, although its mechanism of action is largely unknown. This study was conducted to determine the effects of feeding CVT-E002 versus a ginsenoside-containing extract on systemic and gut-associated immune function. For 7 days, male weanling Sprague-Dawley rats (n=10/group) were fed one of four diets: control, low CVT-E002 (450 mg/kg), high CVT-E002 (900 mg/kg), or ginsenoside (450 mg/kg). Lymphocytes were isolated from spleen, mesenteric lymph nodes and Peyer's patches, and immune cell proportions and cytokine production were measured. IgA-positive cells in the jejunum were also assayed. CVT-E002 consumption (particularly at the higher dose) decreased spleen IL-2 and IFN-gamma production following ConA and/or LPS stimulation for 24 or 48 h (P<0.05). Also, CVT-E002-fed rats had a lower proportion of total CD3+ cells and activated T cells (P<0.05). After 48 h of ConA stimulation, spleen IL-1beta production was higher (P<0.05) for animals fed the high dose CVT-E002, whereas TNF-alpha production did not differ significantly from the control group. Feeding the ginsenoside diet resulted in lower (P<0.05) spleen IL-2 production, but the IFN-gamma, TNF-alpha and IL-1beta response to ConA was not different from control animals at 48 h. A higher proportion of jejunal IgA-positive cells was found in rats fed the ginsenoside diet (P<0.05). In conclusion, feeding CVT-E002 modifies systemic immune responses and appears to affect gut-associated immunity in a manner distinct from that of ginsenoside-containing extracts of North American ginseng.

Improvement of the efficacy of influenza vaccination (H5N1) in chicken by using extract of Cochinchina momordica seed (ECMS)

Seeds of a Chinese traditional medicine plant, Cochinchina momordica were used in the present study for the improvement of influenza vaccine (H5N1) in chicken. Crude extraction from Cochinchina momordica seed (ECMS) was obtained by ethanol extraction method. In experiment No. 1, two weeks old chickens were immunized with influenza vaccine (H5N1) alone or combined with ECMS (5, 10, 20, 40 and 80 microg/dose). Serum IgG antibody levels (by ELISA) as well as effects on daily weight gain were measured on 0, 7, 14 and 28th day after immunization. Results revealed that all ECMS groups numerically increased the antibody levels while 10 and 20 microg/dose groups significantly (P<0.05) enhanced total IgG antibody on day 28, when compared with control. Average daily weight gain was also significantly higher in 20 microg/dose ECMS group. Adjuvant effect was also confirmed in experiment No. 2 when chickens were immunized with 20 microg/dose ECMS and antibody titer was measured through hemagglutination inhibition (HI). It is concluded that ECMS has potential to improve the immune responses and deserve further study as an adjuvant.

Adjuvant effects of saponins on animal immune responses

Vaccines require optimal adjuvants including immunopotentiator and delivery systems to offer long term protection from infectious diseases in animals and man. Initially it was believed that adjuvants are responsible for promoting strong and sustainable antibody responses. Now it has been shown that adjuvants influence the isotype and avidity of antibody and also affect the properties of cell-mediated immunity. Mostly oil emulsions, lipopolysaccharides, polymers, saponins, liposomes, cytokines, ISCOMs (immunostimulating complexes), Freund's complete adjuvant, Freund's incomplete adjuvant, alums, bacterial toxins etc., are common adjuvants under investigation. Saponin based adjuvants have the ability to stimulate the cell mediated immune system as well as to enhance antibody production and have the advantage that only a low dose is needed for adjuvant activity. In the present study the importance of adjuvants, their role and the effect of saponin in immune system is reviewed.

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.

Natural health products, modulation of immune function and prevention of chronic diseases

The immune system is increasingly found to be involved in the development of several chronic illnesses, for which allopathic medicine has provided limited tools for treatment and especially prevention. In that context, it appears worthwhile to target the immune system in order to modulate the risk of certain chronic illnesses. Meanwhile, natural health products (NHPs) are generating renewed interest, particularly in the prevention and treatment of several chronic diseases. Over 20 scientists from fields related to immune function and NHPs were thus convened to establish the state of knowledge on these subjects and to explore future research directions. This review summarizes the result of discussions held during the symposium. It thus seeks to be thought provoking rather than to comprehensively cover such broad areas of research. Notably, a brief overview of the immune system is presented, including potentially useful targets and strategies to keep it in an equilibrated state, in order to prevent certain disorders. The pertinence and limitations of targeting the immune system to prevent chronic diseases is also discussed. The paper then discusses the usefulness and limitations of current experimental tools available to study the immune modulating effects of NHPs. Finally, a concise review of some of the most studied NHPs showing promising immunomodulatory activity is given, and avenues for future research are described.