Charng-Cherng Chyau

Composition and antioxidant activity of the essential oil from Curcuma zedoaria

Abstract Curcuma zedoaria (Berg.) Rosc. (Zingiberaceae) has long been used as a folk medicine. The essential oil of its dried rhizome was isolated using simultaneous steam-distillation and solvent-extraction apparatus and its fractions were prepared by silica gel column chromatography. Totally, 36 compounds were identified in the essential oil, including 17 terpenes, 13 alcohols and 6 ketones. The yields of Fractions 2 and 3 were 83.66 and 10.71%, respectively. Epicurzerenone and curzerene were found in the first and second highest amounts (24.1 and 10.4%). At 20 mg ml −1 , the essential oil of C. zedoaria was moderate to good in antioxidant activities by three different methods, good in reducing power and excellent in scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radical but low in chelating effect on ferrous ion. However, after fractionation, with regard to all antioxidant properties assayed, fraction 4 showed consistently better effects than the essential oil did. The compound in fraction 4 responsible for better antioxidant properties might be 5-isopropylidene-3,8-dimethyl-1(5H)-azulenone.

Mulberry Water Extracts Possess an Anti-obesity Effect and Ability To Inhibit Hepatic Lipogenesis and Promote Lipolysis

Obesity plays a critical role in dyslipidemia and related disorders. Mulberry water extracts (MWEs) contain polyphenols, including gallic acid, chlorogenic acid, rutin, and anthocyanins. In this study, using 6-week-old male hamsters, we investigated the anti-obese effect of MWEs. After 12 weeks of treatment, MWEs lowered high-fat diet (HFD)-induced body weight and visceral fat, accompanied with hypolipidemic effects by reducing serum triacylglycerol, cholesterol, free fatty acid, and the low-density lipoprotein (LDL)/high-density lipoprotein (HDL) ratio (n=8 for each group). MWEs decreased hepatic lipids, thus protected livers from impairment. The hepatic peroxisome proliferator-activated receptor α and carnitine palmitoyltransferase-1 were elevated, while fatty acid synthase and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase were reduced by MWEs, indicating that MWEs regulated lipogenesis and lipolysis, which exerted the anti-obese and hypolipidemic effects. Noticeably, MWEs showed both efficacy and safety in vivo. In concluson, MWEs can be used to reduce body weight, serum, and liver lipids.

Supercritical fluid extracts of rosemary leaves exhibit potent anti-inflammation and anti-tumor effects

Supercritical fluid SF-CO2 treatment of Rosemarinus officinalis L. fresh leaves under optimum conditions (80 °C at 5,000 psi) yielded 5.3% of extract supercritical fluid extraction (SFE)-80, in which five major active principles were identified by liquid chromatography/mass spectrometry (LC/MS), viz., rosmarinic acid, carnosol, 12-methoxycarnosic acid, carnosic acid, and methyl carnosate. Total phenolic content was 155.8 mg/ gallic acid equivalent (GAE)/g in SFE-80, which showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging of 81.86% at 0.01 mg/ml. When treated in RAW 264.7, apparent dose-dependent NO inhibition occurred at dosages of 1.56 to 6.25 μg/ml, and more drastically at 12.5 and 25 μg/ml. At 0.5 to 5.0 μg/ml, SFE-80 exhibited dose-dependent viability suppression and significant tumor necrosis factor alpha (TNF-α) production in Hep 3B, whereas no effect was found in Chang liver cells. Furthermore, no effect was observed in RAW 264.7 at dosages of 3.13 to 25 μg/ml, indicating that SFE-80 exhibited a noncytotoxic character. Conclusively, rosemary can be considered an herbal anti-inflammatory and anti-tumor agent.

Hibiscus sabdariffa Polyphenolic Extract Inhibits Hyperglycemia, Hyperlipidemia, and Glycation-Oxidative Stress while Improving Insulin Resistance

H. sabdariffa polyphenolic extract (HPE) was demonstrated to inhibit high glucose-stimulated cellular changes. In this study, we analyzed the composition of HPE and used a type 2 diabetic rat model to test its protective effect. At least 18 phenolic compounds were found in HPE. Treatment with HPE reduced hyperglycemia and hyperinsulinemia, especially at the dose of 200 mg/kg. HPE decreased serum triacylglycerol, cholesterol, and the ratio of low density lipoprotein/high density lipoprotein (LDL/HDL). Diabetes promoted plasma advanced glycation end product (AGE) formation and lipid peroxidation, while HPE significantly reduced these elevations. Immunohistological observation revealed that HPE inhibited the expression of connective tissue growth factor (CTGF) and receptor of AGE (RAGE), which was increased in type 2 diabetic aortic regions. Furthermore, HPE recovered the weight loss found in type 2 diabetic rats. In conclusion, we demonstrated the anti-insulin resistance properties of HPE and its effect on hypoglycemia, hypolipidemia, and antioxidation. HPE has the potential to be an adjuvant for diabetic therapy.

Antioxidant properties of solvent extracts from Terminalia catappa leaves

Solvent extracts were prepared from green, yellow fallen and red fallen leaves of Terminalia catappa L. and their antioxidant activities were evaluated. Other antioxidant properties of methanolic extracts, including reducing power, scavenging and chelating effects, were also determined. The yields were consistently in the order of yellow fallen (6.34–10.50%)> red fallen (5.12–9.98%)> green leaf extracts (2.36–6.08%) for four solvents used. Higher yields were obtained from extraction with ethyl acetate or methanol than with dichloromethane or pentane. For three different leaves, the antioxidant activities were in the order methanol > ethyl acetate >dichloromethane > pentane extracts and all showed a parabolic-like curve with the maximum at 0.1–0.5 mg ml 1 of solvent extract. Reducing powers of three methanolic extracts and their scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radicals were excellent at 0.5 and 0.1 mg ml 1 , respectively. At 30 mg ml 1 , chelating effects of methanolic extracts from green, yellow fallen and red fallen leaves on ferrous ions were 77.3, 48.6 and 48.3%, respectively. # 2002 Elsevier Science Ltd. All rights reserved.

Antimicrobial Activity and Cytotoxicity of the Essential Oil of Curcuma zedoaria

The chemical compositions of the essential oil of Curcuma zedoaria (Berg.) Rosc. were analyzed by gas chromatography-mass spectrometry (GC-MS) and showed a high content of epicurzerenone and curdione representing 46.6% and 13.7% of the total oil, respectively. The essential oil was evaluated for potential antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonasa aeruginosa, Vibrio parahaemolyticus, Salmonella typhimurium and Bacillus cereus. V. parahaemolyticus was sensitive to the presence of the essential oil, while the most resistant strain appeared to be E. coli. Based on 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay, nitroblue tetrazolium (NBT) reduction and cell morphology, the essential oil of C. zedoaria could inhibit the proliferation of human promyelocytic leukemia HL-60 cells. These results suggest that the essential oil has the antimicrobial activity against some of Gram- positive and negative pathogenic microorganisms and the components of the extract lead to the apoptosis of human cancer cell line.

Effects of mulberry (Morus alba L.) extracts on lipid homeostasis in vitro and in vivo.

The objective of this study was to investigate the lipid-lowering effects of mulberry water extracts (MWEs). To evaluate the hypolipidemic effect of MWEs, hamsters were fed with either high fat/cholesterol diets (HFCD) or HFCD supplemented with 1 and 2% MWEs for 12 weeks. Plasma total cholesterol (TC) and triglyceride (TG) levels of hamsters fed HFCD with MWEs were significantly reduced by about 30-37% and 16-35%, respectively, as compared to those without MWEs. Similar results were also measured in hepatic TC and TG of hamsters fed HFCD with MWEs. Low-density lipoprotein receptor (LDLR) gene expression and the uptake ability of low-density lipoprotein (LDL) in HepG2 cells were also upregulated by additions of MWEs. MWEs also decreased the gene expressions of enzymes involved in the TG and TC biosyntheses. Results suggest that hypolipidemic effects of MWEs are via an enhancement of LDLR gene expression and the clearance ability of LDL and a decrease in the lipid biosynthesis. Therefore, MWEs could be used as a natural agent against hyperlipidemia.

Free and glycosidically bound aroma compounds in lychee (Litchi chinensis Sonn.)

Free and glycosidically-bound volatile compounds were isolated and separated from fresh clear lychee juice using an Amberlite XAD-2 column. The volatile compounds from the bound fraction were released by hydrolysis with almond b-glucosidase. Volatile components of both free and bound fractions were then determined by GC and GC–MS, and they showed similar volatile profiles. Totally, 25 compounds were identified in both fractions, including one ester, 14 alcohols, two aldehydes, four acids, two ketones and two terpenes. In the free fraction (2907 mg kg � 1 ), the major volatile compounds found were acetoin (30.1%), geraniol (15.6%), 3-methyl-2-buten-1-ol (15.3%), octanoic acid (7.28%), 2-phenylethanol (4.91%), cis-ocimene (4.32%), and butyric acid (3.40%). In the bound fraction (1576 mg kg � 1 ), the latent major volatile compounds found were geraniol (73.7%) and geranial (7.95%). In aroma evaluation, the free volatile fraction showed a fresh-fruity, lychee-like aroma whereas the bound fraction was odourless. The characteristic lychee-like aroma was noted in the bound fraction after enzymatic hydrolysis. On combination of the free and hydrolysed bound fractions, a strongly fruity, lychee-like aroma was perceived. # 2002 Elsevier Science Ltd. All rights reserved.

Relevance of phenolic diterpene constituents to antioxidant activity of supercritical CO2 extract from the leaves of rosemary

Isolation of phenolic diterpene constituents from the freeze-dried leaves of Rosmarinus officinalis has been obtained by supercritical extraction with carbon dioxide. To determine the ideal conditions for the maximum yield of extract, nine different conditions using three levels of pressures (3000, 4000 and 5000 psi) in combination with three temperatures at 40, 60 and 80°C, respectively, in combination with the analyses of the corresponding antioxidant activities and constituents which existed in extracts has been investigated. The antioxidant activity of each obtained extract was determined by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals test. GC/MS method was used as an alternative to conventional HPLC method for the determination of the principal antioxidant constituents in extract, including phenolic diterpenes carnosic acid (CA) and carnosol (CAL). The confirmation of CA and CAL in extract was forward performed by subjecting HPLC isolates from extract into an ion trap mass spectrometer through an electrospray ionization (ESI) interface for MS/MS analysis. These results indicate that an ideal extraction process was obtained at 5000 psi and 80°C with an extraction yield of 4.27% (w/w) and rich in phenolic antioxidants CA and CAL as contents of 35.23 and 0.46 mg g−1 in extract, respectively.

Trapping of Methylglyoxal by Curcumin in Cell-Free Systems and in Human Umbilical Vein Endothelial Cells

Curcumin, the most active compound of curcuminoids, has been shown to inhibit formation of advanced glycation end products (AGEs) in streptozotocin-induced diabetic rats. However, little is known on whether curcumin may trap methylglyoxal (MGO), a major reactive dicarbonyl compound, to inhibit AGE formation. We found that one molecule of curcumin effectively trapped one molecule of MGO at a 1:3 ratio at 24 h of incubation under physiological conditions (pH 7.4, 37 °C). Curcumin decreased N(ε)-(carboxymethyl)lysine (CML) expression in human umbilical vein endothelial cells. We further used two curcumin analogues, dimethoxycurcumin (DIMC) and ferulic acid, to investigate the possible MGO-trapping mechanism of curcumin. Results reveal that DIMC, but not ferulic acid, exhibited MGO-trapping capacity, indicating curcumin traps MGO at the electron-dense carbon atom (C10) between the two keto carbon groups. Thus, curcumin may prevent MGO-induced endothelial dysfunction by directly trapping MGO.