Byung Ok Im

Wild Ginseng Prevents the Onset of High-Fat Diet Induced Hyperglycemia and Obesity in ICR Mice

Ginseng is a shade-loving perennial herb that is cultivated mainly in Korea, Japan, and China. The ginseng root has been used as a tonic remedy, and its antidiabetic activity has been demonstrated as early as 1920s. Although wild ginseng was anecdotally thought to be superior to cultivated ginseng as far as pharmacological properties were concerned, there have been no prior reports on the antidiabetic effect of wild ginseng. In this study, we investigated the preventative anti-diabetic and anti-obese effects of wild ginseng ethanol extract (WGEE). In the preventive experiment, WGEE co-administered with a high fat diet significantly inhibited body weight gain, fasting blood glucose, triglyceride, and free fatty acid levels in a dose dependent manner. WGEE-treated mice at doses of 250 and 500 mg/kg improved the insulin resistance index by 55% and 61% compared to the high fat diet (HFD) control, respectively. Diameters of white and brown adipocytes were also decreased by 62% and 46% in the WG500-treated group compared to those in HFD fed control mice. Taken together, WGEE has potential as a preventive agent for type 2 diabetes mellitus (and possibly obesity) and deserves clinical trial in the near future.

Changes in the Contents of Prosapogenin in the Red Ginseng (Panax ginseng) Depending on Steaming Batches

This study compared the contents of ginsenosides depending on steaming conditions of red ginsengs to provide basic information for developing functional foods using red ginsengs. The red ginseng steamed eight times at 98℃ ranked atop the amounts of prosapogenins ever detected in red ginsengs (ginsenoside Rg2, Rg3, Rg5, Rg6, Rh1, Rh4, Rk1, Rk3, F1, F4, 1.15%) among red ginsengs steamed more than twice. When steamed eight times at 98℃, 2.7 times as much prosapogenins such as ginsenosides Rg2, Rg3, Rg5, Rg6, Rh1, Rh4, Rk1, Rk3, F1, and F4 as those steamed just once at 98℃ was collected. In addition, the red ginsengs steamed eight times at 98℃ contained more amounting ginsenoside Rg3 (0.28%) than that in the red ginseng steamed several times at random. Accordingly, it is recommendable that red ginsengs steamed 8 times, which proved to be the optimal steaming condition, be used rather than those steamed 9 times (black ginsengs), in order to develop red ginseng products of high prosapogenin concentration and high functions.

The signaling mechanism of the sphingosylphosphorylcholine-induced contraction in cat esophageal smooth muscle cells.

We investigated the signaling pathway on sphingosinephosphorylcholine (SPC) -induced contraction in cat esophageal smooth muscle cells. SPC induced in a dose-dependent manner contractile effect. We have previously shown that lysophospholipid (LPL) receptor subtypes including the S1P1, S1P2, S1P3, and S1P5 receptor are present in esophageal smooth muscle. Only EDG-5 (S1P2) receptor antibody penetration into permeablilized cells inhibited the SPC-induced contraction. Pertussis toxin (PTX) and specific antibodies to Gi1, Gi2, Gi3 and Go inhibited the contraction, implying that SPC-induced contraction depends on PTX-sensitive Gi1, Gi2, Gi3, and Go protein. A phospholipase inhibitor U73122 and incubation of permeabilized cells with PLC-β3 antibody inhibited SPC-induced contraction. The PKC-mediated contraction may be isozyme specific since only PKCε antibody inhibited the contraction. Preincubation with MEK inhibitor PD98059 blocked the SPC-induced contraction, but p38 MAPK inhibitor SB202190 did not. Cotreatment with GF109203X and PD98059 did not show synergistic effects, suggesting that these two kinases are involved in the same signaling pathway in the SPC-induced contraction. The data suggest that S1P-induced contraction in feline esophageal smooth muscle cells depends on activation of the Gi1, Gi2, Gi3 and Go proteins and the PLCβ3 isozyme via the S1P2 receptor, leading to stimulation of a PKCε pathway, which subsequently activates a p44/p42 MAPK pathway.

Inhibitory effects of ginsenoside re isolated from ginseng berry on histamine and cytokine release in human mast cells and human alveolar epithelial cells.

The berry of Panax ginseng significantly inhibited the histamine releases at the concentration of 30 μg/mL (p<0.05) and 10 μg/mL (p<0.01). The ginsenoside Re from ginseng berry was found out to have a potent effect in the experiment of histamin and cytokine release.

Extremely low frequency magnetic fields modulate bicuculline-induced-convulsion in rats.

The effect of extremely low frequency (ELF, 60Hz) magnetic fields (MFs) on convulsions was investigated in rats. We determined the onset and duration of convulsions induced by bicuculline alone or by co-exposure to MFs and bicuculline. In addition, we measured the GABA concentrations in the rat brains using HPLC-ECD. MFs strengthened the convulsion induced by bicuculline (0.3, 1, and 3 μg, i.c.v.), with a shortening of the onset time, but lengthening of the duration time. Co-exposure to MFs and bicuculline decreased the GABA levels in the cortex, hippocampus and hypothalamus, whereas MFs alone reduced the level of GABA only in the hippocampus. These results suggest that the exposure to MFs may modulate bicucullineinduced convulsions due to GABA neurotransmissions in rat brains.