Korean red ginseng (Panax ginseng C.A. Meyer) root fractions: differential effects on postprandial glycemia in healthy individuals

Brain plasticity and ginseng

Brain plasticity refers to the brain's ability to modify its structure, accompanied by its functional changes. It is influenced by learning, experiences, and dietary factors, even in later life. Accumulated researches have indicated that ginseng may protect the brain and enhance its function in pathological conditions. There is a compelling need for a more comprehensive understanding of ginseng's role in the physiological condition because many individuals without specific diseases seek to improve their health by incorporating ginseng into their routines. This review aims to deepen our understanding of how ginseng affects brain plasticity of people undergoing normal aging process. We provided a summary of studies that reported the impact of ginseng on brain plasticity and related factors in human clinical studies. Furthermore, we explored researches focused on the molecular mechanisms underpinning the influence of ginseng on brain plasticity and factors contributing to brain plasticity. Evidences indicate that ginseng has the potential to enhance brain plasticity in the context of normal aging by mediating both central and peripheral systems, thereby expecting to improve age-related declines in brain function. Moreover, given modern western diet can damage neuroplasticity in the long term, ginseng can be a beneficial supplement for better brain health.

Ameliorative Effects of Malonyl Ginsenoside from Panax ginseng on Glucose-Lipid Metabolism and Insulin Resistance via IRS1/PI3K/Akt and AMPK Signaling Pathways in Type 2 Diabetic Mice

Our previous study has revealed that malonyl-ginsenosides from Panax ginseng (PG-MGR) play a crucial role in the treatment of T2DM. However, its potential mechanism was still unclear. In this study, we investigated the anti-diabetic mechanisms of action of PG-MGR in high fat diet-fed (HFD) and streptozotocin-induced diabetic mice and determined the main constituents of PG-MGR responsible for its anti-diabetic effects. Our results showed that 16 malonyl ginsenosides were identified in PG-MGR by HPLC-ESI-MS/MS. PG-MGR treatment significantly reduced fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels and improved insulin resistance and glucose tolerance. Simultaneously, PG-MGR treatment improved liver injury by decreasing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) expression. Furthermore, Western blot analysis demonstrated that the protein expression levels of p-PI3K/PI3K, p-AKT/AKT, p-AMPK/AMPK, p-ACC/ACC and GLUT4 in liver and skeletal muscle were significantly up-regulated after PG-MGR treatment, and the protein expression levels of p-IRS-1/IRS-1, Fas and SREBP-1c were significantly reduced. These findings revealed that PG-MGR has the potential to improve glucose and lipid metabolism and insulin resistance by activating the IRS-1/PI3K/AKT and AMPK signal pathways.

Pharmacological activities of ginsenoside Rg5 (Review)

Ginseng, a perennial plant belonging to genus Panax, has been widely used in traditional herbal medicine in East Asia and North America. Ginsenosides are the most important pharmacological component of ginseng. Variabilities in attached positions, inner and outer residues and types of sugar moieties may be associated with the specific pharmacological activities of each ginsenoside. Ginsenoside Rg5 (Rg5) is a minor ginsenoside synthesized during ginseng steaming treatment that exhibits superior pharmaceutical activity compared with major ginsenosides. With high safety and various biological functions, Rg5 may act as a potential therapeutic candidate for diverse diseases. To date, there have been no systematic studies on the activity of Rg5. Therefore, in this review, all available literature was reviewed and discussed to facilitate further research on Rg5.

A Systems Biological Approach to Understanding the Mechanisms Underlying the Therapeutic Potential of Red Ginseng Supplements against Metabolic Diseases

Red ginseng has been widely used in health-promoting supplements in Asia and is becoming increasingly popular in Western countries. However, its therapeutic mechanisms against most diseases have not been clearly elucidated. The aim of the present study was to provide the biological mechanisms of red ginseng against various metabolic diseases. We used a systems biological approach to comprehensively identify the component-target and target-pathway networks in order to explore the mechanisms underlying the therapeutic potential of red ginseng against metabolic diseases. Of the 23 components of red ginseng with target, 5 components were linked with 37 target molecules. Systematic analysis of the constructed networks revealed that these 37 targets were mainly involved in 9 signaling pathways relating to immune cell differentiation and vascular health. These results successfully explained the mechanisms underlying the efficiency of red ginseng for metabolic diseases, such as menopausal symptoms in women, blood circulation, diabetes mellitus, and hyperlipidemia.

Proteomics analyses revealed the reduction of carbon- and nitrogen-metabolism and ginsenoside biosynthesis in the red-skin disorder of Panax ginseng

Red-skin disorder (RSD), a non-infectious disorder in Panax ginseng, impairs the quality and yield of ginseng and impedes continuous cropping. Since the mechanism of this disorder is unknown, there are no effective prevention measures for RSD. The proteomic changes in RSD ginseng were analysed in this study by two-dimensional electrophoresis (2-DE) and isobaric tags for relative and absolute quantification (iTRAQ). The differential expression of 137 proteins (60 from 2-DE and 77 from iTRAQ) was identified in RSD ginseng as compared with healthy ginseng. Most changes are related to carbon- and nitrogen- metabolism, redox homeostasis, and stress resistance. We also found that the concentration of metal elements, such as iron (Fe), aluminium (Al), and manganese (Mn), was significantly increased in RSD ginseng. These increased metals would be chelated with phenols to form red spots on the ginseng epidermis. Moreover, RSD disturbed the carbon and nitrogen metabolism and affected the biosynthesis of nutrients (sugar, proteins, amino acids) and active components (ginsenosides), which reduced the survival rate and medicinal value of ginseng. These differences between RSD and healthy ginseng will contribute to the understanding of RSD mechanism.

Effects of ginseng on C-reactive protein level: A systematic review and meta-analysis of clinical trials

OBJECTIVE

The aim of this meta-analysis was to assess effects of ginseng supplementation on CRP/hs-CRP levels in clinical trial studies.

DESIGN

A systematic literature search was carried out for clinical trials published in ISI web of Science, Scopus, PubMed and Cochrane Library databases from the beginning to 16th February 2018. Of 83 articles found in the first step of the systematic search, seven studies with nine arms included in this meta-analysis.

RESULTS

Results of pooled random-effect size analysis of nine trials showed non-significant decreasing effects of ginseng supplementation on CRP level (WMD: -0.1 mg/l, 95% CI, -0.26, 0.1; P = 0.27) with significant heterogeneity shown within the studies. The subgroup analysis showed that ginseng supplementation could significantly reduce CRP level by 0.51 (95% CI: -0.68, -0.34; P < 0001, test for heterogeneity: P = 0.44, I² = 0.0%) in patients with a baseline serum CRP level of greater than 3 mg/dl. Trial duration and dose of ginseng supplementation included no significant effects on CRP level in this meta-analysis.

CONCLUSION

Results of the current meta-analysis study have shown that ginseng supplementation can decrease significantly serum CRP/hsCRP levels in patients with elevated serum level of this inflammatory marker.

Ginsenoside Rg5 induces apoptosis in human esophageal cancer cells through the phosphoinositide‑3 kinase/protein kinase B signaling pathway

The role of ginsenoside in the prevention of cancer has been well established. Ginsenoside Rg5 is one of the main components isolated from red ginseng, which has been demonstrated to have anti-tumor effects by inhibiting cell proliferation and causing DNA damage. However, the role of ginsenoside Rg5 and its molecular mechanisms remain unclear in human esophageal cancer. In the present study, Rg5 was investigated as a novel drug for the chemotherapy of esophageal cancer in in vitro experiments. Esophageal cancer Eca109 cells were exposed to various concentrations of ginsenoside Rg5 (0–32 µΜ) for 24 h. Subsequent cell proliferation assays demonstrated that treatment with ginsenoside Rg5 resulted in the dose-dependent inhibition of proliferation, while a significant increase in apoptotic rate and increased activities of caspase-3, −8 and −9 were observed. In addition, the mitochondrial membrane potential was decreased and the cytoplasmic free calcium level increased following treatment with ginsenoside Rg5. Furthermore, the expression of B-cell lymphoma 2 and phosphorylated-protein kinase B (p-Akt) decreased. The specific phosphoinositide-3 kinase (PI3K) inhibitor LY294002 promoted this effect, while insulin-like growth factor-1, a specific PI3K activator, inhibited this action. Taken together, the results suggested that ginsenoside Rg5 may have a tumor-suppressive effect on esophageal cancer by promoting apoptosis and may be associated with the downregulation of the PI3K/Akt signaling pathway.

A Metabolomic Approach for the Discrimination of Red Ginseng Root Parts and Targeted Validation

Ginsenosides are used as existing markers of red ginseng (RG) quality, and ginsenoside ratios are also indicative of the different components of red ginseng. For the analysis and classification of ginsenoside content, red ginseng was separated into three parts, namely, main roots, lateral roots, and fine roots, and each extract was subjected to ultra-performance liquid chromatography quadruple time-of-flight mass spectrometry (UPLC-QToF-MS) with multivariate statistical analysis. Principal component analysis (PCA) showed a clear discrimination between the extracts of main roots and fine roots and suggested discrimination markers (four for the main roots and five for the fine roots). The fine root markers were identified as ginsenoside. We identified two markers for the main roots of red ginseng in this study. Moreover, the contents of 22 ginsenosides were analyzed in all three components of red ginseng. Fine roots have the highest protopanaxadiol (PPD)/protopanaxatriol (PPT) ratio. The PPD group of ginsenosides, which is quantitatively dominant in fine roots, clearly distinguishes the main roots from the other parts.

Rg3 Improves Mitochondrial Function and the Expression of Key Genes Involved in Mitochondrial Biogenesis in C2C12 Myotubes

BACKGROUND

Panax ginseng has glucose-lowering effects, some of which are associated with the improvement in insulin resistance in skeletal muscle. Because mitochondria play a pivotal role in the insulin resistance of skeletal muscle, we investigated the effects of the ginsenoside Rg3, one of the active components of P. ginseng, on mitochondrial function and biogenesis in C2C12 myotubes.

METHODS

C2C12 myotubes were treated with Rg3 for 24 hours. Insulin signaling pathway proteins were examined by Western blot. Cellular adenosine triphosphate (ATP) levels and the oxygen consumption rate were measured. The protein or mRNA levels of mitochondrial complexes were evaluated by Western blot and quantitative reverse transcription polymerase chain reaction analysis.

RESULTS

Rg3 treatment to C2C12 cells activated the insulin signaling pathway proteins, insulin receptor substrate-1 and Akt. Rg3 increased ATP production and the oxygen consumption rate, suggesting improved mitochondrial function. Rg3 increased the expression of peroxisome proliferator-activated receptor γ coactivator 1α, nuclear respiratory factor 1, and mitochondrial transcription factor, which are transcription factors related to mitochondrial biogenesis. Subsequent increased expression of mitochondrial complex IV and V was also observed.

CONCLUSION

Our results suggest that Rg3 improves mitochondrial function and the expression of key genes involved in mitochondrial biogenesis, leading to an improvement in insulin resistance in skeletal muscle. Rg3 may have the potential to be developed as an anti-hyperglycemic agent.

The Efficacy of Ginseng-Related Therapies in Type 2 Diabetes Mellitus: An Updated Systematic Review and Meta-analysis

Few randomized clinical trials have evaluated the efficacy of ginseng in patients with type 2 diabetes mellitus (T2DM). The current meta-analysis evaluated the ginseng-induced improvement in glucose control and insulin sensitivity in patients with type-2 diabetes or impaired glucose tolerance.Randomized clinical trials comparing ginseng supplementation versus control, in patients with T2DM or impaired glucose tolerance, were hand-searched from Medline, Cochrane, and Google Scholar databases by 2 independent reviewers using the terms "type 2 diabetes/diabetes/diabetic, impaired glucose tolerance, and ginseng/ginsenoside(s)." The primary outcome analyzed was the change in HbA1c, whereas the secondary outcomes included fasting glucose, postprandial glucose, fasting insulin, postprandial insulin, insulin resistance Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), triglycerides, total cholesterol, low density lipoprotein (LDL), and high density lipoprotein (HDL).Of the 141 studies identified, 8 studies were chosen for the current meta-analysis. The average number of patients, age, and sex distribution among the groups were comparable. Results reveal no significant difference in HbA1c levels between the ginseng supplementation and the control groups (pooled standardized difference in means = -0.148, 95% CI: -0.637 to 0.228, P = 0.355). Ginseng supplementation improved fasting glucose, postprandial insulin, and HOMA-IR levels, though no difference in postprandial glucose or fasting insulin was observed among the groups. Similarly, triglycerides, total cholesterol, and LDL levels showed significant difference between the treatment groups, while no difference in HDL was seen. In addition, ginseng-related therapy was ineffective in decreasing the fasting glucose levels in patients treated with oral hypoglycemic agents or insulin.The present results establish the benefit of ginseng supplementation in improving glucose control and insulin sensitivity in patients with T2DM or impaired glucose intolerance.

Panax ginseng aqueous extract prevents pneumococcal sepsis in vivo by potentiating cell survival and diminishing inflammation

BACKGROUND

More than 50% of sepsis cases are caused by Streptococcus pneumoniae, and hospital mortality related to sepsis comprises 52% of all hospital deaths. Therefore, sepsis is a medical emergency, and any treatment against the agent that produces it, is welcome.

PURPOSE

The role of Panax ginseng C.A. Meyer (Araliaceae) aqueous extract in bacterial infection in vivo is not well understood. Here, the protective effect of Korean red ginseng (KRG) extract against pneumococcal infection and sepsis was elucidated.

STUDY DESIGN

In this study, mice were administrated KRG (25, 50, 100 mg/kg) for 15 days, and then infected with a lethal S. pneumoniae strain. Survival rate, body weight, and colonization were determined.

METHODS

The RAW 264.7 macrophage cells were infected with S. pneumoniae and cell viability was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Inflammation was examined using an enzyme-linked immunosorbent assay (ELISA) and hematoxylin and eosin (HE) staining while gene expression was determined using western blotting.

RESULTS

KRG-pre-treated mice (100 mg/kg of KRG) had significantly higher survival rates and body weights than those of the non-treated controls; KRG-pre-treated mice had lower bacterial number and morbidity than those of the non-treated controls. 100 mg/kg of KRG administration decreased cytokine levels including tumor necrosis factor (TNF)-α (897 and 623 pg/ml, control and KRG groups, respectively, P < 0.05) and interleukin (IL)-1β (175 and 127 pg/ml, control and KRG groups, respectively, P = 0.051), nitric oxide level (149 and 81 nM, control and KRG groups, respectively, P < 0.05), and neutrophil infiltration 48 h post-infection, in vivo. In pneumococcal infection, KRG pre-treatment downregulated toll-like receptor (TLR) 4 and TNF-ɑ expressions in RAW 264.7 macrophage cells and increased cell survival by activating phosphoinositide 3-kinase (PI3K)/AKT signaling.

CONCLUSION

Taken together, 100 mg/kg of KRG appeared to protect host cells from lethal pneumococcal sepsis by inhibiting inflammation as well as by enhancing bacterial clearance thereby reinforcing cell survival against pneumococcal infection.

Ethanol extraction preparation of American ginseng (Panax quinquefolius L) and Korean red ginseng (Panax ginseng C.A. Meyer): differential effects on postprandial insulinemia in healthy individuals

ETHNOPHARMACOLOGICAL RELEVANCE

Ginsenosides are the proposed bioactive constituent of ginseng, especially for the attenuation of postprandial glycemia (PPG). The efficacious proportion of total and specific ginsenosides, remains unknown. Alcohol extraction of whole ginseng root can be used to selectively manipulate the ginsenoside profile with increasing alcohol concentrations producing high yields of total ginsenosides and varying their individual proportions.

AIM OF THE STUDY

We aimed to compare the acute efficacy of different ethanol-extraction preparations of American ginseng (AG) and Korean red ginseng (KRG), with their whole-root origins, on PPG and insulin parameters in healthy adults.

MATERIALS AND METHODS

Following an overnight fast, 13 healthy individuals (Gender: 5M:8F, with mean ± SD, age: 28.9 ± 9.2 years, BMI: 26.3 ± 2.7 kg/m(2) and fasting plasma glucose: 4.21 ± 0.04 mmol/L) randomly received 3g of each of the following 10 different ginseng treatments on separate visits: whole root KRG and AG; 30%, 50% or 70% ethanol extracts of KRG and AG and 2 cornstarch placebos. Treatments were consumed 40 min prior to a 50 g oral glucose challenge test with capillary blood samples collected at baseline, 15, 30, 45, 60, 90 and 120 min. Insulin samples were collected at 0, 30, 60 and 120 min.

RESULTS

There was no difference in attenuation of PPG among the tested ginseng preparations. Measures of Insulin Sensitivity Index (ISI) showed increased insulin sensitivity (IS) with KRG-30% and AG-50% extracts compared to placebo (p<0.05).

CONCLUSIONS

The insulin sensitizing effects of KRG-30% and AG-50% extracts suggest that other root parts, including other ginsenosides not typically measured, may influence PPG and insulin parameters. There is potential for AG and KRG extracts to modulate IS, an independent predictor of type 2 diabetes.

A review on the medicinal potential of Panax ginseng saponins in diabetes mellitus

This review article summarizes the anti-diabetic effects and mechanisms ofPanax ginsengsaponins and its active specific ginsenosides.

Korean red ginseng improves glucose control in subjects with impaired fasting glucose, impaired glucose tolerance, or newly diagnosed type 2 diabetes mellitus

This study was designed to evaluate the effect of Korean red ginseng (KRG) supplementation on glucose control in subjects with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or newly diagnosed type 2 diabetes mellitus (T2DM). The study was a 12-week randomized, double-blinded, placebo-controlled (5 g of KRG [n=21] or placebo [n=20] in tablet form) trial. Glucose-related biomarkers, including serum and whole blood levels of glucose, insulin, and C-peptide, were measured by 2-h oral glucose tolerance tests (OGTTs) at baseline and after the 12-week intervention. After the intervention, the test group showed a significant decrease in serum levels of glucose at 30 min (-22.24±10.77 mg/dL) and whole blood levels of glucose at 30 min (-17.52±5.22 mg/dL). In addition, the test group tended to have lower whole blood levels of glucose at 0 min and glucose area under curve (AUC). However, the placebo group did not show any changes in blood glucose-related indices. The changes (difference from baseline) in serum glucose levels at 30 min, whole blood glucose levels at 60 min, and glucose AUC during OGTTs in the test group exhibited a tendency toward a decrease from those in the placebo group. There were significant decreases or trends toward a decrease in both serum insulin and C-peptide concentrations at most time intervals in the test group. In conclusion, KRG supplementation (5 g/day) may be beneficial for controlling serum and whole blood glucose levels compared with placebo among patients with IFG, IGT, or T2DM.

Effects of korean red ginseng on hearing and blood glucose levels in steroid therapy for sudden sensorineural hearing loss

OBJECTIVES

Korean red ginseng (KRG) has hypoglycemic, antioxidant, antithrombotic, and other beneficial effects in human. The present study evaluate the therapeutic effects of KRG on hearing recovery and glucocorticoid-induced hyperglycemia in patients with idiopathic sudden sensorineural hearing loss (SSNHL) undergoing systemic steroid therapy.

METHODS

The patients were divided into 2 groups: the steroid, and the combination of steroid and red ginseng. Pure tone averages (PTA) were assessed at the first visit and 2-month follow-up. All patients underwent fasting blood glucose analyses just before and on the fifth day of treatment. Both groups were treated with a 10-day course of oral methylprednisolone at tapering doses starting from a daily dose of 48 mg. To the combination group, KRG extract was administered by mouth at a daily dose of 3 g for 20 days in addition to methylprednisolone. Hearing gain was calculated comparing the initial PTA and PTA at 2 months' follow-up. Treatment responses were classified according to Siegel's criteria.

RESULTS

Pretreatment conditions were similar between the steroid (n=37) and combination groups (n=36). At 2 months after the treatment, PTA improved significantly in both groups, but there was no significant difference in the mean hearing gain & recovery rate. The non-diabetic subjects in the steroid group (n=27) exhibited a 24% increase in the mean blood glucose level during the systemic steroid therapy, while those in the combination group (n=34) showed no changes.

CONCLUSION

Although the KRG did not provide greater therapeutic effects on hearing recovery, we suggest that red ginseng can be a useful adjuvant to the current steroid therapy to normalize glucocorticoid-induced hyperglycemia in non-diabetic patients during the treatment of SSNHL.

Quality and risk of bias in Panax ginseng randomized controlled trials: a review

Panax ginseng is one of the most frequently used herbs in the world. Numerous trials have evaluated its clinical benefits. However, the quality of these studies has not been comprehensively and systematically assessed. We reviewed randomized controlled trials (RCTs) of Panax ginseng to evaluate their quality and risk of bias. We searched four English databases, without publication date restriction. Two reviewers extracted details about the studies' methodological quality, guided by the Consolidated Standards of Reporting Trials (CONSORT) checklist and its extension for herbal interventions. Risk of bias was determined using the Cochrane Risk of Bias tool. Of 475 potentially relevant studies, 58 met our inclusion criteria. In these 58 studies, 48.3% of the suggested CONSORT checklist items and 35.9% of the extended herbal items were reported. The quality of RCTs published after the CONSORT checklist improved. Until 1995 (before CONSORT) (n = 4), 32.8% of the items were reported in studies. From 1996-2006 (CONSORT published and revised) (n = 30), 46.1% were reported, and from 2007 (n = 24), 53.5% were reported (p = 0.005). After the CONSORT extension for herbal interventions was published in 2006, RCT quality also improved, although not significantly. Until 2005 (n = 34), 35.2% of the extended herbal items were reported in studies; and from 2006 onwards (n = 24), 37.3% were reported (p = 0.64). Most studies classified risk of bias as "unclear". Overall, the quality of Panax ginseng RCT methodology has improved since the CONSORT checklist was introduced. However, more can be done to improve the methodological quality of, and reporting in, RCTs.

Ginsenoside Rg3 induces apoptosis in the U87MG human glioblastoma cell line through the MEK signaling pathway and reactive oxygen species

Ginsenoside is known to have potential cancer-preventive activities. The major active components in red ginseng consist of a variety of ginsenosides including Rg3, Rg5 and Rk1, each of which has different pharmacological activities. Among these, Rg3 has been reported to exert anticancer activities through inhibition of angiogenesis and cell proliferation. However, the effects of Rg3 and its molecular mechanism on glioblastoma multiforme (GBM) remain unclear. Therefore, it is essential to develop a greater understanding of this novel compound. In the present study, we investigated the effects of Rg3 on a human glioblastoma cell line and its molecular signaling mechanism. The mechanisms of apoptosis by ginsenoside Rg3 were related with the MEK signaling pathway and reactive oxygen species. Our data suggest that ginsenoside Rg3 is a novel agent for the chemotherapy of GBM.

Antidiabetic effects of malonyl ginsenosides from Panax ginseng on type 2 diabetic rats induced by high-fat diet and streptozotocin

ETHNOPHARMACOLOGY RELEVANCE

Ginseng (Panax ginseng C. A. Meyer) has been recorded to treat 'Xiao-ke' (emaciation and thirst) symptom in many ancient Chinese medical literatures (such as 'Shen Nong Ben Cao Jing') for thousands of years. 'Xiao-ke' symptom, in general, indicates diabetes mellitus.

AIM OF THE STUDY

Malonyl ginsenosides (MGR) are natural ginsenosides which exist in both fresh and air-dried ginseng. The objective of this study is to determine the antidiabetic function of MGR on type 2 diabetes.

MATERIALS AND METHODS

High fat diet-fed and streptozotocin-induced diabetic rats were treated with 50 and 100mg/kg/d of MGR or vehicle for 3 weeks. The effects of MGR on fasting blood glucose (FBG), intraperitoneal glucose tolerance test (IPGTT), serum insulin (SI), insulin tolerance test (ITT), body weight, total cholesterol (TC), and triglyceride (TG) levels in type 2 diabetic rats were measured.

RESULTS

After 3 weeks of treatment, MGR administration showed significantly lower FBG levels compared to the diabetic control group. In glucose tolerance test, IPGTT data showed that both MGR 50 and 100mg/kg groups significantly increased the glucose disposal after glucose load. The ITT also showed improvement of insulin sensitivity during 120 min of insulin treatment. In addition, MGR reduced TG and TC contents while showed no effect on body weight in diabetic rats.

CONCLUSION

The findings from this study suggest that MGR can alleviate hyperglycemia, hyperlipemia and insulin resistance of type 2 diabetes.

Panax ginseng in randomised controlled trials: a systematic review

Panax ginseng C.A. Meyer is a common herb with many purported health benefits. However, there is no conclusive evidence supporting its use in the treatment of any particular disease. We conducted a systematic review to evaluate randomised controlled trials. Four English databases were searched with no publication date restriction. Included studies evaluated P. ginseng in patients with any type of disease or in healthy individuals. We assessed the quality of studies using the Cochrane risk of bias tool. Of the 475 potentially relevant studies, 65 met the inclusion criteria. These studies examined P. ginseng's effects on psychomotor performance (17 studies), physical performance (ten), circulatory system (eight), glucose metabolism (six), the respiratory system (five), erectile dysfunction (four), immunomodulation (four), quality of life/mood (four), antioxidant function (two), cancer (two), menopausal symptoms (two) and dry mouth (one). The risk of bias was unclear in most studies. Authors evaluated adverse events in 40 studies, with 135 minor events and no serious adverse events reported. P. ginseng shows promising results for improving glucose metabolism and moderating the immune response. This may have implications for several diseases including type 2 diabetes and chronic respiratory conditions. Further studies are needed to explore P. ginseng's potential as an effective treatment for these and other health conditions.

Regulation of signaling molecules associated with insulin action, insulin secretion and pancreatic β-cell mass in the hypoglycemic effects of Korean red ginseng in Goto-Kakizaki rats

ETHNOPHARMACOLOGICAL RELEVANCE

Korean red ginseng (KRG) has long history as herbal remedy for antidiabetic effect.

AIM OF THE STUDY

To study molecular mechanisms by which KRG ameliorates diabetes mellitus, we investigated whether the supplementation with the aqueous extract of KRG as a dietary admixture (1%, w/w) regulates the expressions of signaling molecules that are associated with insulin action, insulin secretion and pancreatic β-cell mass in spontaneously diabetic Goto-Kakizaki (GK) rats.

METHODS

An aqueous extract of KRG was supplemented for the estimated dosage to be 0.2 g/kg rat/day beginning at 5 weeks of age for 12 weeks in male GK rats. Plasma glucose levels were measured every 4 weeks. The expressions of signaling molecules that are associated with insulin action, insulin secretion and β-cell mass in tissues were determined by Western blotting.

RESULTS

The 12-week supplementation with KRG significantly (P<0.05) decreased blood glucose compared to control. It up-regulated the expression of glucose transporter (GLUT) 4 in adipose tissue, and down-regulated the expression of protein tyrosine phosphatases (PTP)-1B in adipose tissue and skeletal muscle. It also up-regulated the expression of insulin and down-regulated the expression of uncoupling protein (UCP) 2, Bax and poly (ADP-ribose) polymerase (PARP) in pancreas.

CONCLUSIONS

These results suggest that GLUT4, PTP-1B, insulin, UCP2, Bax and PARP may be the primary targets of KRG that result in increase in insulin action and in insulin secretion, and decrease in β-cell mass, and that cause the normalization in glucose homeostasis.