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Ginseng is a well-known medicinal plant used in traditional Oriental medicine. In recent decades, ginseng root has gained popularity as a dietary supplement in the United States. Ginseng has also been commonly used in Oriental medicine to treat diabetes-like conditions. The present review discusses the research on the anti-diabetic effects of ginseng and the possible mechanisms of its anti-diabetic actions.

Cardiovascular disease continues to be the leading cause of death in the US. Recent studies found that reactive oxygen species (ROS) have been incriminated in the pathogenesis of both acute and chronic heart diseas. Many botanicals possess antioxidant properties, and these herbal antioxidants may protect against cardiovascular diseases by contributing to the total antioxidant defense system of the human body. In this article, we reviewed the antioxidant components and properties of four putative antioxidant botanicals (i.e., grape seeds, green tea, Scutellaria baicalensis, and American ginseng), and their potential role in treating cardiovascular illness. The antioxidant activities of the herbal active constituents, and the relationship between their chemical structures and biological functions were also discussed. Further investigations are needed on the mechanisms of action of these botanicals as they affect salient cellular and molecular pathways involved in major diseases. Data obtained from future studies will have the potential for translation into practical benefits for human health.

Hyperglycemia in diabetic conditions may cause oxidative stress in pancreatic ß-cells, leading to their dysfunction and insulin resistance within peripheral tissues. Previous studies suggest that American ginseng berry extract may have hypoglycemic effects, as well as offer antioxidant protection. We examined effects of American ginseng berry extract and ginsenoside Re in a pancreatic ß-cell line, MIN-6, to determine if these two properties are related. Cells were exposed to oxidative stress via hydrogen peroxide incubation and oxidative stress was measured by oxidation of 2′,7′-dichlorofluorescin diacetate. These cells showed a concentration-related response to hydrogen peroxide at 100–500 μM. In acute conditions where cells were treated with the extract for 10 min, we observed reduced oxidant injury suggesting direct scavenging effects. Chronic incubation of cells with the extract for 48 hours also demonstrated attenuation of oxidative stress. At high concentrations, Re showed a mild antioxidant effect in MIN-6 cells. Our insulin release observations also showed that the extract may help to increase insulin secretions from the cells. Our data suggest that the observed ability of ginseng to reduce blood glucose levels may be linked to its antioxidant effects on pancreatic ß-cells.

American ginseng is a commonly used herbal medicine in the United States. When ginseng is taken orally, its active components, ginsenosides, are reportedly biotransformed by intestinal microbiota. Previous pharmacokinetic evaluations of ginseng in humans have focused on its parent constituents. However, the metabolites, especially those transformed by intestinal microbiota, have not been carefully studied. We used an ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOF-MS) method to determine 15 ginsenosides and/or metabolites and their bioavailability in humans. Six healthy human subjects received a single oral dose of 10 g of American ginseng root powder, after which samples of their blood were collected at 0, 2, 4, 7, 9 and 12 h for measurement of ginsenoside/metabolite levels in plasma. Ginsenosides Rb1, Rd, Rg2 and compound K (C-K) were detected in human plasma samples at different time points. The Rb1 concentration peak was 19.90 ± 5.43 ng/ml at 4 h. C-K was detected from 7 h to 12 h with 7.32 ± 1.35 ng/ml at 12 h. Since the last time point was at 12 h, C-K peak level was not observed. The areas under the concentration curves (AUC) from 0 to 12 h were 155.0 ± 19.5 ng⋅h/ml for Rb1 and 26.4 ± 6.4 ng⋅h/ml for C-K, respectively. The gradual decrease of Rb1 levels and the delayed increase in levels of C-K observed in human subjects supported previous reports that enteric microbiota played a key role in transforming Rb1 to C-K.

Ginseng has beneficial effects in cancer, diabetes and aging. There are two main varieties of ginseng: Panax ginseng (Korean ginseng) and Panax quinquefolius (American ginseng). There are anecdotal reports that American ginseng helps reduce body temperature, whereas Korean ginseng improves blood circulation and increases body temperature; however, their respective effects on body temperature and metabolic parameters have not been studied. We investigated body temperature and metabolic parameters in mice using a metabolic cage. After administering ginseng extracts acutely (single dose of 1000 mg/kg) or chronically (200 mg/kg/day for four weeks), core body temperature, food intake, oxygen consumption and activity were measured, as well as serum levels of pyrogen-related factors and mRNA expression of metabolic genes. Acute treatment with American ginseng reduced body temperature compared with PBS-treated mice during the night; however, there was no significant effect of ginseng treatment on body temperature after four weeks of treatment. VO₂, VCO₂, food intake, activity and energy expenditure were unchanged after both acute and chronic ginseng treatment compared with PBS treatment. In acutely treated mice, serum thyroxin levels were reduced by red and American ginseng, and the serum prostaglandin E2 level was reduced by American ginseng. In chronically treated mice, red and white ginseng reduced thyroxin levels. We conclude that Korean ginseng does not stimulate metabolism in mice, whereas a high dose of American ginseng may reduce night-time body temperature and pyrogen-related factors.