Chang-Won Cho

Hypolipidemic and Antioxidant Effects of Dandelion (Taraxacum officinale) Root and Leaf on Cholesterol-Fed Rabbits

Dandelion (Taraxacum officinale), an oriental herbal medicine, has been shown to favorably affect choleretic, antirheumatic and diuretin properties. Recent reports have indicated that excessive oxidative stress contributes to the development of atherosclerosis-linked metabolic syndrome. The objective of this current study was to investigate the possible hypolipidemic and antioxidative effects of dandelion root and leaf in rabbits fed with a high-cholesterol diet. A group of twenty eight male rabbits was divided into four subgroups; a normal diet group, a high-cholesterol diet group, a high-cholesterol diet with 1% (w/w) dandelion leaf group, and a high-cholesterol diet with 1% (w/w) dandelion root group. After the treatment period, the plasma antioxidant enzymes and lipid profiles were determined. Our results show that treatment with dandelion root and leaf positively changed plasma antioxidant enzyme activities and lipid profiles in cholesterol-fed rabbits, and thus may have potential hypolipidemic and antioxidant effects. Dandelion root and leaf could protect against oxidative stress linked atherosclerosis and decrease the atherogenic index.

Isoliquiritigenin, a chalcone compound, is a positive allosteric modulator of GABAA receptors and shows hypnotic effects.

Isoliquiritigenin (ILTG) is a chalcone compound and has valuable pharmacological properties such as antioxidant, anti-inflammatory, anticancer, and antiallergic activities. Recently, the anxiolytic effect of ILTG has been reported; however, its action mechanism and hypnotic activity have not yet been demonstrated. Therefore, we investigated the hypnotic effect and action mechanism of ILTG. ILTG significantly potentiated the pentobarbital-induced sleep in mice at doses of 25 and 50mg/kg. The hypnotic activity of ILTG was fully inhibited by flumazenil (FLU), a specific gamma-aminobutyric acid type A (GABA(A))-benzodiazepine (BZD) receptor antagonist. The binding affinity of ILTG was 0.453 μM and was found to be higher than that of the reference compound, diazepam (DZP, 0.012 μM). ILTG (10(-5)M) potentiated GABA-evoked currents to 151% of the control level on isolated dorsal raphe neurons. ILTG has 65 times higher affinity for GABA(A)-BZD receptors than DZP, and the dissociation constant for ILTG was 4.0 × 10(-10)M. The effect of ILTG on GABA currents was blocked by 10(-7)M FLU and ZK-93426. These results suggest that ILTG produces hypnotic effects by positive allosteric modulation of GABA(A)-BZD receptors.

Immunostimulatory activity of polysaccharides from Cheonggukjang

Cheonggukjang is a Korean whole soybean paste fermented by Bacillus subtilis and regarded as a healthy food. The objective of this study was to investigate the immunostimulatory activity of polysaccharides from Cheonggukjang (PSCJ) in RAW 264.7 macrophages and an animal model. PSCJ induced mRNA expressions of inducible nitric oxide synthase and tumor necrosis factor-α (TNF-α) by activating nuclear factor-κB, and subsequently increased the productions of nitric oxide (NO) and TNF-α in murine recombinant interferon-γ-primed RAW 264.7 macrophages. Furthermore, after daily oral administration of PSCJ, immobility time decreased significantly in the PSCJ-administered group (200 or 400 mg/kg) on day 10. Taken together, these results suggest that the PSCJ has a possible role improving immune function through regulatory effects on immunological parameters, such as NO and TNF-α productions and changes in indicators related to fatigue.

Cheonggukjang polysaccharides enhance immune activities and prevent cyclophosphamide-induced immunosuppression.

Cheonggukjang is a traditional Korean fermentation product prepared from soybean that is reported to have various biological functions. We previously reported that the polysaccharides from Cheonggukjang (PSCJ) have immunostimulatory activities in RAW 264.7 macrophages and primary cultured splenocytes. In this study, the immunostimulatory activities of the PSCJ were investigated further using various experimental models such as in vitro, ex vivo, and in vivo. The PSCJ was able to stimulate the complement system (ITCH50: 30.6%). In primary cultured mouse peritoneal macrophages, the PSCJ was found to significantly increase nitric oxide and immunostimulatory cytokines (IL-6 and IL-12) production in a concentration-dependent manner (1-100 μg/mL). In the normal mice model, the oral administration of the PSCJ increased the weight of spleen (p < 0.05 at 100 and 200 mg/kg) and improved the phagocytic rates of peritoneal macrophages (p < 0.05 at 200 mg/kg) and lymphocytes proliferation (p < 0.05 at 100 and 200 mg/kg). Similarly, the PSCJ markedly restored the decreased lymphocytes proliferation (p < 0.01 at 200 mg/kg), natural killer cell activity (p < 0.01 at 200mg/kg), and white blood cell count (p<0.01 at 100 and 200 mg/kg) in the cyclophosphamide-induced immunosuppressed mice model. These results suggest that the PSCJ could be utilized as an effective immunostimulatory agent.

Hypolipidemic and Antioxidant Properties of Phenolic Compound-Rich Extracts from White Ginseng (Panax ginseng) in Cholesterol-Fed Rabbits

In this study, the effect of low-molecular weight white ginseng compounds on various biochemical indices, including blood lipid concentrations and antioxidant enzyme activities and morphological changes was investigated in rabbits with high cholesterol diet-induced hypercholesterolemia. The experimental animals were 16-week-old male New Zealand white rabbits divided into normal control diet, high cholesterol diet, and high cholesterol with 0.05% white ginseng low-molecule compound groups, treated for 4 weeks. Blood lipid concentrations were higher in the high cholesterol groups compared to the normal control group but were not improved by the white ginseng low-molecular weight compound. We note however that antioxidant enzyme activities and morphological changes of the aorta showed that white ginseng small compounds had a positive effect on hypercholesterolemia. Based on such results, low-molecular weight compounds rich in phenolic compounds in white ginseng can be said to be effective in part in improving hyperlipidemia and atherosclerosis induced by a high cholesterol diet among New Zealand white rabbits.

Antioxidant Activities of Ginseng Seeds Treated by Autoclaving

Ginseng seeds were treated with different autoclaving temperatures and autoclaving times, and extracted with 80% methanol to measure changes in antioxidant activity. The antioxidant activity of ginseng seeds treated by autoclaving was measured by 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, 2,2’-aziono-bis(3-ethylbenzthiazoline)-6-sulfonic acid radical scavenging activity, superoxide dismutase SOD-like activity, ferric reducing antioxidant power (FRAP), and total phenolic compound content. As autoclaving temperature and time were increased, the L lightness value decreased and the redness value tended to increase. Total phenolic compound content was about three times higher in ginseng seeds treated with autoclaving at 130℃ than in ginseng seeds that were not treated. DPPH radical scavenging activity and ABTS radical scavenging activity increased as autoclaving temperature and time were increased. In particular, when the concentration was 100 ppm, the ABTS radical scavenging activity was 91.80% in ginseng seeds treated by autoclaving at 130℃, which was the highest antioxidant activity. FRAP and SOD-like antioxidant activity tended to increase significantly as autoclaving temperature and time were increased.

Green and gold kiwifruit peel ethanol extracts potentiate pentobarbital-induced sleep in mice via a GABAergic mechanism.

Kiwifruit is one of the most popular fruits worldwide, and it has various biological properties, including antioxidant, anti-allergic, and cardiovascular protective effects. The peel of kiwifruit, which is a by-product of processing, is a good source of flavonoids; however, its bioactivity has not been widely investigated. In this study, we evaluated the hypnotic effects of green (GRPE, Actinidia deliciosa) and gold (GOPE, Actinidia chinensis) kiwifruit peel ethanol extracts and their solvent fractions, and the possible underlying mechanisms. Oral GRPE and GOPE administration (125-1000mg/kg) produced a dose-dependent decrease in sleep latency and an increase in sleep duration in pentobarbital-treated mice. Among three different solvent fractions of GRPE and GOPE, ethyl acetate (EA) fractions had the greatest effect on sleep duration at 250mg/kg. The total flavonoid contents of solvent fractions were proportional to sleep duration. Like diazepam (a GABA(A)-benzodiazepine (BZD) receptor agonist), the hypnotic effects of GRPE, GOPE, and their EA fractions were fully inhibited by flumazenil (a GABA(A)-BZD receptor antagonist). These results suggest that potentiation effects of GRPE and GOPE on pentobarbital-induced sleep in mice may be modulated by a GABAergic mechanism.

Inhibitory Effect of a Cirsium setidens Extract on Hepatic Fat Accumulation in Mice Fed a High-Fat Diet via the Induction of Fatty Acid β-Oxidation

Cirsium setidens is a perennial medicinal herb that is rich in flavonoids. We investigated in this study the effect of a C. setidens ethanol extract (CSE) on the development of nonalcoholic fatty liver in mice fed a high-fat diet (HF). C57BL/6J mice were fed either a control diet (CON) or HF for 8 weeks, and then fed CON, HF, or HF with 100 mg/kg of BW CSE (HF+CSE) for an additional 7 weeks. The final body weight and adipose tissue weight of the mice in the HF+CSE group were significantly lower than those in the HF group. CSE also markedly diminished both the lipid droplets in the liver tissues and decreased the hepatic and serum triglycerides (TG) concentrations. CSE strongly increased the hepatic mRNA levels of carnitine palmitoyltransferase (CPT1) and medium-chain acyl-CoA dehydrogenase (MCAD), the fatty acid β-oxidation enzymes. The hepatic levels of phosphorylated-AMP-activated protein kinase (AMPK) were significantly higher in the HF+CSF group than in the HF group. These results suggest that CSE inhibited hepatic fat accumulation by up-regulating the expression of the fatty acid β-oxidation genes.

Comparison of Ginsenoside and Phenolic Ingredient Contents in Hydroponically-cultivated Ginseng Leaves, Fruits, and Roots

In this study, hydroponically-cultivated ginseng leaves, fruits, and roots were respectively extracted with ethanol. The contents of 12 ginsenosides and three phenolics in the extracts were quantitatively analyzed and the free radical scavenging activities were measured and compared. Hydroponically-cultivated ginseng leaves contained higher levels of gensenosides (Rg1, Rg2+Rh1, Rd, and Rg3) and p-coumaric acid than the other parts of the ginseng plants. The 2,2’-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid radical scavenging activities of leaves were also the highest. Accordingly, hydroponically-grown ginseng leaves were shown to hold promise for use as an environmentally-friendly natural anti-oxidant.

Quality and characteristics of ginseng seed oil treated using different extraction methods

Ginseng seed oil was prepared using compressed, solvent, and supercritical fluid extraction methods of ginseng seeds, and the extraction yield, color, phenolic compounds, fatty acid contents, and phytosterol contents of the ginseng seed oil were analyzed. Yields were different depending on the roasting pretreatment and extraction method. Among the extraction methods, the yield of ginseng seed oil from supercritical fluid extraction under the conditions of 500 bar and 65℃ was the highest, at 17.48%. Color was not different based on the extraction method, but the b-value increased as the roasting time for compression extraction was increased. The b-values of ginseng seed oil following supercritical fluid extraction were 3.54 to 15.6 and those following compression extraction after roasting treatment at 200℃ for 30 min, were 20.49, which was the highest value. The result of the phenolic compounds composition showed the presence of gentisic acid, vanillic acid, ferulic acid, and cinnamic acid in the ginseng seed oil. No differences were detected in phenolic acid levels in ginseng seed oil extracted by compression extraction or solvent extraction, but vanillic acid tended to decrease as extraction pressure and temperature were increased for seed oil extracted by a supercritical fluid extraction method. The fatty acid composition of ginseng seed oil was not different based on the extraction method, and unsaturated fatty acids were >90% of all fatty acids, among which, oleic acid was the highest at 80%. Phytosterol analysis showed that β-sitosterol and stigmasterol were detected. The phytosterol content of ginseng seed oil following supercritical fluid extraction was 100.4 to 135.5 mg/100 g, and the phytosterol content following compression extraction and solvent extraction was 71.8 to 80.9 mg/100 g.