Anti-proliferative effects of ginsenosides extracted from mountain ginseng on lung cancer / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of three major ginsenosides from mountain ginseng as anticancer substance and explore the underlying mechanism involved in lung cancer.</p><p><b>METHODS</b>The inhibitory proliferation of lung cancer by major five ginsenosides (Rb1, Rb2, Rg1, Rc, and Re) was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Calculated 50% inhibition (IC50) values of five ginsenosides were determined and compared each other. Apoptosis by the treatment of single ginsenoside was performed by fluorescence-assisted cytometric spectroscopy. The alterations of apoptosis-related proteins were evaluated by Western blot analysis.</p><p><b>RESULTS</b>The abundance of ginsenosides in butanol extract of mountain ginseng (BX-MG) was revealed in the order of Rb1, Rg1, Re, Rc and Rb2. Among them, Rb1 was the most effective to lung cancer cell, followed by Rb2 and Rg1 on the basis of relative IC50 values of IMR90 versus A549 cell. The alterations of apoptotic proteins were confirmed in lung cancer A549 cells according to the administration of Rb1, Rb2 and Rg1. The expression levels of caspase-3 and caspase-8 were increased upon the treatment of three ginsenosides, however, the levels of caspase-9 and anti-apoptotic protein Bax were not changed.</p><p><b>CONCLUSION</b>Major ginsenosides such as Rb1, Rb2 and Rg1 comprising BX-MG induced apoptosis in lung cancer cells via extrinsic apoptotic pathway rather than intrinsic mitochondrial pathway.</p>

Dexamethasone Induces FcgammaRIIb Expression in RBL-2H3 Cells

Mast cells are involved in allergic responses, protection against pathogens and autoimmune diseases. Dexamethasone (Dex) and other glucocorticoids suppress FcepsilonRI-mediated release of inflammatory mediators from mast cells. The inhibition mechanisms were mainly investigated on the downstream signaling of Fc receptor activations. Here, we addressed the effects of Dex on Fc receptor expressions in rat mast cell line RBL-2H3. We measured mRNA levels of Fc receptors by real-time PCR. As expected, Dex decreased the mRNA levels of activating Fc receptor for IgE (FcepsilonR) I and increased the mRNA levels of the inhibitory Fc receptor for IgG FcgammaRIIb. Interestingly, Dex stimulated transcriptions of other activating receptors such as Fc receptors for IgG (FcgammaR) I and FcgammaRIII. To investigate the mechanisms underlying transcriptional regulation, we employed a transcription inhibitor actinomycin D and a translation inhibitor cycloheximide. The inhibition of protein synthesis without Dex treatment enhanced FcgammaRI and FcgammaRIII mRNA levels potently, while FcepsilonRI and FcgammaRIIb were minimally affected. Next, we examined expressions of the Fc receptors on cell surfaces by the flow cytometric method. Only FcgammaRIIb protein expression was significantly enhanced by Dex treatment, while FcgammaRI, FcgammaRIII and FcepsilonRI expression levels were marginally changed. Our data showed, for the first time, that Dex regulates Fc receptor expressions resulting in augmentation of the inhibitory receptor FcgammaRIIb.

Pharmacokinetics of Glutathione and Its Metabolites in Normal Subjects

To determine the loading and maintenance dosage of glutathione (GSH) for patients suffering from reactive oxygen species (ROS) injury such as acute paraquat intoxication, a kinetic study of reduced GSH was performed in synchrony with that of cysteine (Cys), cystine (Cys2), and methionine (Met). Human subject's porticipitation was voluntary. The effective dose of Cys, Cys2, and Met against ROS in fibroblast cells generated by paraquat was assessed using laser scanning confocal microscopy. Both Cys and Met suppressed ROS in a dose-dependent manner at concentrations of 1-1,000 micrometer; the concentration required to suppress ROS by 50% was 10 micrometer for Cys and 50 micrometer for Met. Using metabolite kinetics with the assumption that Cys and Met are the metabolites of GSH, expected concentrations of Cys and Met of above 20 and 50 micrometer were estimated when GSH was administered at 50 mg/kg body weights every 205.4 min for Cys and 427.4 min for Met.

Effects of N-acetyl-L-cysteine and Glutathione on Antioxidant Status of Human Serum and 3T3 Fibroblasts

The effectiveness of several sulfhydryl compounds in the treatment of paraquat intoxication has been previously tested based on their antioxidant ability. However, practical guidelines for their clinical use remain to be determined. As a preliminary pharmacokinetic study on sulfhydryl compounds, we attempted to establish the optimal concentration of N-acetyl-L-cysteine, glutathione, superoxide dismutase, and catalase. We measured the antioxidant effect of these antioxidants in normal pooled plasma and on intracellular reactive oxygen species (ROS) induced by paraquat. N-acetyl-L-cysteine begins to suppress the production of ROS in plasma at concentrations as low as 5 mM, with the suppression being maximal at 40 mM. In the same way, glutathione increased the total antioxidant status in plasma at concentrations of 5-40 mM in a dose-dependent manner. Complete suppression of ROS in plasma induced by exposure to 500 micrometer paraquat for 40 min was observed when using 40 mM N-acetyl-L-cysteine and 5 mM glutathione. These concentrations are comparable with 50 units of catalase, which reduced ROS at concentrations of 5-100 units. Further pharmacokinetic study into the systemic administration of these antioxidants is necessary, using effective concentrations of 5-40 mM for both N-acetyl-L-cysteine and glutathione, and 1-50 units of catalase.

The Analysis of Methylenetetrahydrofolate Reductase Mutation in Recurrent Spontaneous Abortion Associated with Hyperhomocysteinemia / 대한불임학회지

OBJECTIVE : To analyze the methylenetetrahydrofolate reductase (MTHFR) mutation in recurrent spontaneous abortion associated with hyperhomocysteinemia. MATERIAL AND METHOD: The blood Sample of habitual aborter with high fasting homocysteine level was tested by PCR-RFLP method. RESULTS: The patient was found to be a homozygosity for MTHFR gene mutation that was confirmed by the finding which is consistent with the mutation at the nucleotide 677 C to T, Corresponding to Ala to Val. CONCLUSIONS: Hyperhomocysteinemia due to MTHFR mutation is a cause of recurrent spontaneous abortion. Therefore, the MTHFR mutation should be examined in the workup of recurrent spontaneous abortion showing hyperhomocysteinemia.