Kyu Jae Lee

HMG-CoA reductase inhibitors induce apoptosis of lymphoma cells by promoting ROS generation and regulating Akt, Erk and p38 signals via suppression of mevalonate pathway

Statins, the inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are widely used cholesterol-lowering drugs. Convincing evidence indicates that statins stimulate apoptotic cell death in several types of proliferating tumor cells in a cholesterol-lowering-independent manner. The objective here was to elucidate the molecular mechanism by which statins induce lymphoma cells death. Statins (atorvastatin, fluvastatin and simvastatin) treatment enhanced the DNA fragmentation and the activation of proapoptotic members such as caspase-3, PARP and Bax, but suppressed the activation of anti-apoptotic molecule Bcl-2 in lymphoma cells including A20 and EL4 cells, which was accompanied by inhibition of cell survival. Both increase in levels of reactive oxygen species (ROS) and activation of p38 MAPK and decrease in mitochondrial membrane potential and activation of Akt and Erk pathways were observed in statin-treated lymphoma cells. Statin-induced cytotoxic effects, DNA fragmentation and changes of activation of caspase-3, Akt, Erk and p38 were blocked by antioxidant (N-acetylcysteine) and metabolic products of the HMG-CoA reductase reaction, such as mevalonate, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). These results suggests that HMG-CoA reductase inhibitors induce lymphoma cells apoptosis by increasing intracellular ROS generation and p38 activation and suppressing activation of Akt and Erk pathways, through inhibition of metabolic products of the HMG-CoA reductase reaction including mevalonate, FPP and GGPP.

Anti-diabetic effect of alkaline-reduced water on OLETF rats.

Alkalin-reduced water (ARW) is known to exert several anti-cancer effects, as well as to scavenge reactive oxygen species (ROS) and reduce blood-glucose levels. This study was performed in order to determine the effects of ARW on the control of spontaneous diabetes in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. We assigned 16 male OLETF rats (4 wk) to two groups: an experimental group, which was given ARW, and a control group, which received laboratory tap water. From week 6 to 32, the body weight, lipid composition, and glucose levels in the blood of the rats were measured. The glucose levels of both groups tended to increase. However, the ARW group’s glucose levels were significantly lower than those of the control group after 12 weeks (p<0.05). The total cholesterol and triglyceride levels in the ARW group were found to be significantly lower than those of the control group during the experimental period. These results suggest that ARW spurred the growth of OLETF rats during the growth stage, and that long-term ingestion of ARW resulted in a reduction in the levels of glucose, triglycerides, and total cholesterol in the blood.

The melamine excretion effect of the electrolyzed reduced water in melamine-fed mice.

Our hypothesis is that the intake of functional water, electrolyzed reduced water (ERW) can excrete melamine in body was evoked by melamine-tainted feed (MTF). To address this issue, we investigated the effect of ERW in MTF-mice model by way of body weight gain, incidence of urinary crystals and bladder stone, biochemical and haematological examination, histopathologic finding of kidney and urinary bladder, and the evaluation of bladder stone. We found that the rate of body weight gain was significantly more increased in MTF+ERW group than MTF+PW group. Accordingly, the number of immunocytes such as leukocyte, neutrophil and monocyte as well as the mean weight of spleen was significantly increased in MTF+ERW group. The incidence of urinary crystals was significantly higher in MTF+ERW group, whereas the incidence of urinary bladder stones was lower in MTF+ERW group (52.4%) than in MTF+PW group (38.1%). Also, urinary crystals were more precipitated in MTF+ERW group than MTF+PW group, and urinary bladder stone consists of 100% melamine. Collectively, our data clearly show that ERW intake is helpful to excrete of melamine in MTF mice model and this is the first report on the melamine excretion and clinically implying the safer fluid remedy for melamine-intoxicated hosts.

The balneotherapy effect of hydrogen reduced water on UVB-mediated skin injury in hairless mice

Exposure to UVB radiation induced skin damage that results to increase risk of skin cancer. Despite the clinical importance of skin-induced damage, antioxidants imposed limited therapeutic success. Hydrogen molecule (H2) has been known as a safe antioxidant in the prevention and therapeutic approach towards several diseases. Drinking hydrogen reduced water (HRW), inhalation of hydrogen gas, and injecting H2-dissolved saline are widely accepted to incorporate H2 in the body. However, there is no document about the beneficial effect of hydrogen water bath. Here, we investigated the effect of hydrogen bathing on the UVB-induced skin damage in hairless mice. For this, mice of the bathing group are allowed to freely swim on HRW, and let the HRW penetrate for 60 mins. Scoring of skin injury, reactive oxygen species (ROS) enzyme activity quantification, cytokine analysis, and ultrastructural change of corneocytes were measured after exposure to UVB radiation of 360–540 mJ/cm2. In summary, the bathing with HRW significantly reduced the levels of skin damage, as well as increased activity of glutathione peroxidase. Further, the effect of HRW on cytokine network in the skin after UVB exposure revealed that HRW significantly decreased the level of inflammatory cytokines such as IL-1β, IL-6, TNF-α and IFN-γ. Finally, scanning electron microscopy data revealed low number of defected corneocytes and ultrastructural changes, suggesting that HRW bathing would protect UV-induced cell damage.

Involvement of the FoxO3a pathway in the ischemia/reperfusion injury of cardiac microvascular endothelial cells

FoxO3a, a member of the forkhead transcription factors, has been demonstrated to be involved in myocardial ischemia/reperfusion (I/R) injury. Cardiac microvascular endothelial cells (CMECs) are some of the predominant cells damaged immediately after myocardial I/R injury. Despite the importance of injured CMECs in an ischemic heart, little is known about the involvement of FoxO3a in regulating CMECs injury. Thus, we used rat CMECs following simulated I/R to examine FoxO3a activation and signaling in relation to survival, the cell cycle and apoptosis in CMECs. We found that Akt negatively regulates activation of the FoxO3a pathway by phosphorylating FoxO3a in CMECs as demonstrated with an Akt inhibitor and activator. Upon I/R injury, the FoxO3a pathway was significantly activated in CMECs, which was accompanied by Akt deactivation. In parallel, the I/R of CMECs induced G1-phase arrest through p27(Kip1) up-regulation and significant activation of caspase-3. Accordingly, inhibition of the FoxO3a pathway by IGF-1, an Akt activator, could significantly block the I/R-enhanced activation of p27(Kip1) and caspase-3 in CMECs. Collectively, our results indicate that the FoxO3a pathway is involved in the I/R injury of CMECs at least in part through the regulation of cell cycle arrest and apoptosis, suggesting that the FoxO3a pathway may be a novel therapeutic target that protects against microvascular endothelial damage in ischemic hearts.

Immunotoxicity of silicon dioxide nanoparticles with different sizes and electrostatic charge.

Silicon dioxide (SiO2) nanoparticles (NPs) have been widely used in the biomedical field, such as in drug delivery and gene therapy. However, little is known about the biological effects and potential hazards of SiO2. Herein, the colloidal SiO2 NPs with two different sizes (20 nm and 100 nm) and different charges (L-arginine modified: SiO2EN20[R], SiO2EN100[R]; and negative: SiO2EN20[−], SiO2EN100[−] were orally administered (750 mg/kg/day) in female C57BL/6 mice for 14 days. Assessments of immunotoxicity include hematology profiling, reactive oxygen species generation and their antioxidant effect, stimulation assays for B- and T-lymphocytes, the activity of natural killer (NK) cells, and cytokine profiling. In vitro toxicity was also investigated in the RAW 264.7 cell line. When the cellularity of mouse spleen was evaluated, there was an overall decrease in the proliferation of B- and T-cells for all the groups fed with SiO2 NPs. Specifically, the SiO2EN20(−) NPs showed the most pronounced reduction. In addition, the nitric oxide production and NK cell activity in SiO2 NP-fed mice were significantly suppressed. Moreover, there was a decrease in the serum concentration of inflammatory cytokines such as interleukin (IL)-1β, IL-12 (p70), IL-6, tumor necrosis factor-α, and interferon-γ. To elucidate the cytotoxicity mechanism of SiO2 in vivo, an in vitro study using the RAW 264.7 cell line was performed. Both the size and charge of SiO2 using murine macrophage RAW 264.7 cells decreased cell viability dose-dependently. Collectively, our data indicate that different sized and charged SiO2 NPs would cause differential immunotoxicity. Interestingly, the small-sized and negatively charged SiO2 NPs showed the most potent in vivo immunotoxicity by way of suppressing the proliferation of lymphocytes, depressing the killing activity of NK cells, and decreasing proinflammatory cytokine production, thus leading to immunosuppression.

Differential immune profiles following experimental Echinostoma hortense infection in BALB/c and C3H/HeN mice

Despite the increasing incidence in food-borne Echinostoma hortense infection, the underlying immune mechanism along with the clinical manifestations and the expulsion of the worms from the mucosal surfaces are not well understood. To clarify the differences in the immune mechanisms induced by E. hortense in the host, we examined the interleukin (IL)-4, IL-5, IL-12, and interferon-γ profiles and the kinetics in two genetically different mouse strains, BALB/c and C3H/HeN mice, in vivo as well as in vitro. Both the crude extract and the excretory–secretory protein prepared from E. hortense increased the mRNA and protein expressions of IL-4 and IL-5 in the splenocytes isolated from both strains of infected mice. The E. hortense recovery rate of the C3H/HeN mice was much higher than that of the BALB/c mice. When analyzing the sera from the infected BALB/c and C3H/HeN mice, the IL-5 and immunoglobulin (Ig)G1 levels in the infected BALB/c mice were significantly higher than those from the C3H/HeN mice (p < 0.05). Taken together, these results show that the BLAB/c mice with E. hortense infection are more resistant than are the C3H/HeN mice due to the significantly higher induction of protective Th2 immunity.

Hepatoprotection of different water extracts from Acer tegmentosum M. on CCl 4-induced acute hepatotoxicity in mice: Comparative efficacies between the extracts of boughs, twigs, and leaves

While Acer tegmentosum M. (AT) has been widely used as a popular folk remedy to prevent or treat liver diseases in Korea, the scientific evidences for the usage of AT against liver disease are poorly documented. To address this issue, we compared hepatoprotection of hot water extract (WEAT) from three parts of AT, boughs (E1), twigs (E2), and leaves (E3), on CCl4-induced acute hepatic injury in mice by way of morphometric and biochemical examination: liver function test, antioxidant enzymes activity of liver, histopathological and ultrastructural examination of liver, and antioxidant capacity (DPPH assay) of WEAT. We found that only oral intake group of WEAT-boughs showed significant differences in aspartate transaminase (AST), alanine transaminase (ALT) levels and glutathione peroxidase (GPx) activities as compared to CCl4 control group, whereas the glutathione levels were significantly low in all WEAT-pretreated groups. Consistently, histopathological and ultrastructural findings displayed hepatoprotection in the order of WEAT-boughs >WEAT-twigs>WEAT-leaves. Collectively, these results indicate that of three WEAT, WEAT-bough extract has the highest hepatoprotection against CCl4-induced acute hepatic injury in mice via the possible regulation of antioxidant enzyme activities in liver.

Hydrogen Water Drinking Exerts Antifatigue Effects in Chronic Forced Swimming Mice via Antioxidative and Anti-Inflammatory Activities

Purpose This study was performed to evaluate antifatigue effect of hydrogen water (HW) drinking in chronic forced exercise mice model. Materials and Methods Twelve-week-old C57BL6 female mice were divided into nonstressed normal control (NC) group and stressed group: (purified water/PW-treated group and HW-treated group). Stressed groups were supplied with PW and HW, respectively, ad libitum and forced to swim for the stress induction every day for 4 consecutive weeks. Gross antifatigue effects of HW were assessed by swimming endurance capacity (once weekly for 4 wk), metabolic activities, and immune-redox activities. Metabolic activities such as blood glucose, lactate, glycogen, blood urea nitrogen (BUN), and lactate dehydrogenase (LDH) as well as immune-redox activities such as reactive oxygen species (ROS), nitric oxide (NO), glutathione peroxidase (GPx), catalase, and the related cytokines were evaluated to elucidate underlying mechanism. Blood glucose and lactate were measured at 0 wk (before swimming) and 4 wk (after swimming). Results HW group showed a higher swimming endurance capacity (p < 0.001) than NC and PW groups. Positive metabolic effects in HW group were revealed by the significant reduction of blood glucose, lactate, and BUN in serum after 4 wk (p < 0.01, resp.), as well as the significant increase of liver glycogen (p < 0.001) and serum LDH (p < 0.05) than PW group. In parallel, redox balance was represented by lower NO in serum (p < 0.01) and increased level of GPx in both serum and liver (p < 0.05) than PW group. In line, the decreased levels of serum TNF-α (p < 0.01), IL-6, IL-17, and liver IL-1β (p < 0.05) in HW group revealed positive cytokine profile compared to PW and NC group. Conclusion This study shows antifatigue effects of HW drinking in chronic forced swimming mice via metabolic coordination and immune-redox balance. In that context, drinking HW could be applied to the alternative and safety fluid remedy for chronic fatigue control.

Antioxidant and Anti-Inflammatory Effects of Shungite against Ultraviolet B Irradiation-Induced Skin Damage in Hairless Mice

As fullerene-based compound applications have been rapidly increasing in the health industry, the need of biomedical research is urgently in demand. While shungite is regarded as a natural source of fullerene, it remains poorly documented. Here, we explored the in vivo effects of shungite against ultraviolet B- (UVB-) induced skin damage by investigating the physiological skin parameters, immune-redox profiling, and oxidative stress molecular signaling. Toward this, mice were UVB-irradiated with 0.75 mW/cm2 for two consecutive days. Consecutively, shungite was topically applied on the dorsal side of the mice for 7 days. First, we found significant improvements in the skin parameters of the shungite-treated groups revealed by the reduction in roughness, pigmentation, and wrinkle measurement. Second, the immunokine profiling in mouse serum and skin lysates showed a reduction in the proinflammatory response in the shungite-treated groups. Accordingly, the redox profile of shungite-treated groups showed counterbalance of ROS/RNS and superoxide levels in serum and skin lysates. Last, we have confirmed the involvement of Nrf2- and MAPK-mediated oxidative stress pathways in the antioxidant mechanism of shungite. Collectively, the results clearly show that shungite has an antioxidant and anti-inflammatory action against UVB-induced skin damage in hairless mice.