Si-Kwan Kim

Effect of fermented Panax ginseng extract (GINST) on oxidative stress and antioxidant activities in major organs of aged rats.

The intracellular levels of oxidant and antioxidant balances are gradually distorted during the aging process. An age associated elevation of oxidative stress occurring throughout the lifetime is hypothesized to be the major cause of aging. The present study was undertaken to evaluate the putative antioxidant activity of the fermented Panax ginseng extract (GINST) on lipid peroxidation and antioxidant status of major organs of aged rats compared to young rats. Increased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea and creatinine were observed in the serum of aged rats. Increased levels of malondialdehyde (MDA) and significantly lowered activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) were observed in the liver, kidneys, heart and lungs of aged rats, when compared with those in young rats. Quantitative analysis of the non-enzymatic antioxidants such as reduced glutathione (GSH), ascorbic acid and α-tocopherol levels showed significantly lower values in the liver, kidneys, heart and lungs of aged rats. On the other hand, administration of the fermented Panax ginseng extract (GINST) to aged rats resulted in increased activities of SOD, CAT, GPx, GR and GST as well as elevation in GSH, ascorbic acid and α-tocopherol levels. Besides, the level of MDA, AST, ALT, urea and creatinine were reduced on administration of GINST to aged rats. These results suggested that treatment of GINST can improve the antioxidant status during aging, thereby minimizing the oxidative stress and occurrence of age-related disorders associated with free radicals.

Panax ginseng reduces oxidative stress and restores antioxidant capacity in aged rats

Nutritional antioxidants interact with cells in an active mode, including retrieving and sparing one another, to diminish oxidative stress. However, the intracellular balance of prooxidants and antioxidants becomes unbalanced, favoring prooxidants during the aging process. One hypothesis is that an aging-associated increase in oxidative stress is the primary cause of aging. Hence, the research hypothesis for this study is that Korean red ginseng reduces oxidative stress in vivo. Therefore, we investigated the efficacy of Korean red ginseng water extract (GWE) in reducing aging-associated oxidative stress by measuring lipid peroxidation and antioxidant levels in older rats compared with young rats. We observed a significant increase in the markers for oxidative damage (eg, lipid peroxidation) and markers for vital organ damage (eg, aspartate aminotransferase, alanine aminotransferase, urea, and creatinine levels) in aged rats. The oxidative damage was accompanied by a significant decrease in enzymatic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase, and nonenzymatic antioxidants such as reduced glutathione, vitamin E, and vitamin C. Aged rats fed a diet supplemented with Korean red ginseng water extract had significantly less oxidative damage, possibly by enhancing the enzymatic and nonenzymatic antioxidants status. Our data suggest that consumption of Korean red ginseng reduces lipid peroxidation and restores antioxidant capacity by suppressing oxidative stress in rats.

Panax ginseng improves survival and sperm quality in guinea pigs exposed to 2,3,7,8-tetrachlorodibenzo- p-dioxin

To further assess the effect of Panax ginseng on survival and sperm quality of guinea pigs exposed to 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD).

Cordycepin (3′-deoxyadenosine) attenuates age-related oxidative stress and ameliorates antioxidant capacity in rats

Free radical-induced oxidative damage is considered to be the most important consequence of the aging process. The activities and capacities of antioxidant systems of cells decline with increased age, leading to the gradual loss of pro-oxidant/antioxidant balance and resulting in increased oxidative stress. Our investigation was focused on the effects of cordycepin (3-deoxyadenosine) on lipid peroxidation and antioxidation in aged rats. Age-associated decline in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), reduced glutathione (GSH), vitamin C and vitamin E, and elevated levels of malondialdehyde (MDA) were observed in the liver, kidneys, heart and lungs of aged rats, when compared to young rats. Furthermore, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea, and creatinine were found to be significantly elevated in aged rats compared to young rats. Aged rats receiving cordycepin treatment show increased activity of SOD, CAT, GPx, GR and GST, and elevated levels of GSH, and vitamins C and E such that the values of most of these parameters did not differ significantly from those found in young rats. In addition, the levels of MDA, AST, ALT, urea and creatinine became reduced upon administration of cordycepin to aged rats. These results suggest that cordycepin is effective for restoring antioxidant status and decreasing lipid peroxidation in aged rats.

Korean red ginseng attenuates hypercholesterolemia‐enhanced platelet aggregation through suppression of diacylglycerol liberation in high‐cholesterol‐diet‐fed rabbits

Intake of Korean red ginseng (KRG, ginseng Radix rubra), rich in glycosylated saponins (ginsenosides), has been known to inhibit platelet aggregation in the normocholesterolemic condition. However, it is unclear whether KRG can attenuate hypercholesterolemia‐enhanced platelet aggregation. This study examined whether the daily consumption of a KRG‐water extract (WE) could prevent the hypercholesterolemia‐enhanced platelet aggregation and progression of hypercholesterolemic atherosclerosis. KRG‐WE administration (200 mg/kg/day) for 8 weeks potently inhibited the platelet aggregation induced by low doses of agonists (0.5 µg/mL collagen and 0.025 unit/mL thrombin), whereas it weakly reduced the blood‐cholesterol levels and formation of atheromatous lesions. In further investigation, KRG‐WE significantly suppressed collagen‐induced 1,2‐diacylglycerol liberation, but had no significant effect on arachidonic acid liberation. Taken together, it can be suggested that the antiplatelet effect of KRG‐WE may, at least partly, be due to the inhibition of 1,2‐diacylglycerol generation rather than regulation of blood lipid levels. In conclusion, daily consumption of KRG‐WE could be a useful alternative measure for the prevention of thrombus and atheroma formation in hypercholesterolemia. Copyright

Effect of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin on testicular spermatogenesis‐related panels and serum sex hormone levels in rats

To determine the detrimental role of tetrachlorodibenzo‐p‐dioxin (TCDD) in testicular histology, spermatogenesis‐related panels and proteome, and serum sex hormone levels.

Effect of long-term administration of cordycepin from Cordyceps militaris on testicular function in middle-aged rats.

This study was carried out to examine the potential beneficial effect of cordycepin on the decline of testicular function induced with age. A total of 30 male Sprague-Dawley rats (twenty-four 12-month-olds and six 2-month-olds) were divided into five groups. The young control (YC) and middle-aged control (MC) groups received vehicle only. Cordycepin-treated groups were administered daily doses of oral cordycepin at 5, 10, and 20 mg/kg body weight for 4 months. As a result, the MC group exhibited epididymal weight loss, decreased sperm motility, and reduced spermatogenesis compared to the young control group. Interestingly, the epididymal weights of middle-aged rats were dose-dependently increased by treatment with cordycepin. Cordycepin also improved calcium levels and decreased urea and nitrogen, uric acid, and creatinine in the blood of middle-aged rats. In addition, cordycepin significantly increased sperm motility and the progressiveness of sperm movement. All cordycepin-treated groups showed well-arranged spermatogonia, densely packed cellular material, and increased numbers of mature spermatozoa in the seminiferous lumen compared to the middle-aged control group. These results indicate that long-term administration of cordycepin can counteract the decline of testicular function in middle-aged rats.

Anti-inflammatory activity of the active components from the roots of Cosmos bipinnatus in lipopolysaccharide-stimulated RAW 264.7 macrophages.

We isolated a sesquiterpene lactone from the methanol extract of the roots of Cosmos bipinnatus, namely, MDI (a mixture of dihydrocallitrisin and isohelenin). The anti-inflammatory activity of MDI was evaluated using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. MDI significantly inhibited the expression of inducible nitric oxide synthase and cyclooxygenase-2. Consistent with these results, the production of NO and prostaglandin E2 (PGE2) was suggested to be suppressed by MDI in a concentration-dependent manner (IC50 value was 0.94 and 2.88u2009µgu2009mL−1 for NO and PGE2, respectively). In addition, MDI significantly inhibited the expressions of pro-inflammatory cytokines such as IL-1β, IL-6, IFN-γ and TNF-α. Furthermore, MDI attenuated DNA-binding activity of NF-κB by inhibiting the phosphorylation of IκB. These results indicate that MDI isolated from the roots of C. bipinnatus shows anti-inflammatory activity in LPS-stimulated murine macrophages by modulating the NF-κB pathway.