Antioxidant properties of gingerol related compounds from ginger

Genoprotective Effect of the Chinese Herbal Decoction Xiao Jian Zhong Tang

The Chinese herbal decoction formula Xiao Jian Zhong Tang (XJZT) is one of the classic formulas from the classic traditional Chinese medicine (TCM). Previous studies on XJZT found that it is effective for treating peptic ulcer, irritable bowel syndrome, functional gastroenteritis and similar psychosomatic disorders of the digestive organs. It has also been shown that all the herbs used in XJZT contain antioxidants. In this study, we investigated the in vitro DNA protection effect of the individual herb extracts and the whole formula. Water extract of the herbs and XJZT were used to pre-treat human lymphocytes. The lymphocytes were then exposed to hydrogen peroxide. The in vitro DNA protection effect of the herbs was investigated by comet assay. No DNA protective effect ( P <0.05) was found for individual herb extracts, but XJZT showed protection of human lymphocytic DNA upon oxidative stress ( P<0.05). The in vitro DNA protection effect of XJZT was conferred by the synergistic effect of the herbs, while the individual herbs had no such effect.

In vitro antioxidant and anti-inflammatory activities of 1-dehydro-[6]-gingerdione, 6-shogaol, 6-dehydroshogaol and hexahydrocurcumin

Hexahydrocurcumin, 1-dehydro-[6]-gingerdione, 6-dehydroshogaol and 6-shogaol were evaluated for their antioxidant and anti-inflammatory activities in the present study. The relative antioxidant potencies of ginger compounds decreased in similar order of 1-dehydro-[6]-gingerdione, hexahydrocurcumin>6-shogaol>6-dehydroshogaol in both 1,1-diphenyl-2-picyrlhydrazyl (DPPH) radical-scavenging and trolox equivalent antioxidant capacity (TEAC) assays. All tested compounds could attenuate lipopolysaccharide (LPS)-elicited increase of prostaglandin E2 (PGE(2)) in murine macrophages (RAW 264.7) in a concentration-dependent manner but hexahydrocurcumin of 7μM and 6-shogaol of 7μM. The strongest inhibitory effect was observed for 6-dehydroshogaol and 6-shogaol at 14μM with the inhibition of 53.3% and 48.9%, respectively. Furthermore, both 6-dehydroshogaol and 1-dehydro-[6]-gingerdione significantly suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins in a concentration-dependent fashion. These results contribute to our theoretical understanding of the potential beneficial effects of consuming ginger as a food and/or dietary supplement.

Characterization of gingerol analogues in supercritical carbon dioxide (SC CO2) extract of ginger (Zingiber officinale, R.,)

Organically grown ginger rhizome (Zingiber officinale Roscoe) SC CO2 extract obtained at 280 bar and 40 °C and its column chromatographic fractions are characterised for its composition. The components in the extract and fractions are identified by HPLC and LC based MS and are used as standard for the estimation of gingerol analogues in the extract. HPLC and mass analysis of the extracts confirmed the various forms of gingerol constituents [4]-, [6]-, [10]-gingerols and [6]-, [8]-, [10]-shogaols in ginger extracts. SC CO2 extract of organic ginger was found to show 6-gingerol around 25.97 % of total extract. The estimation of [6]-gingerol, [6]-shogaols, [4]gingerol, [10]-gingerol and 6-gingediol content of the SC CO2 purified ginger extract was found to be 75.92 ± 1.14, 1.25 ± 0.04, 4.54 ± 0.04, 13.15 ± 0.30 and 0.37 ± 0.00 % respectively. Antioxidant activity was measured by 2, 2-diphenyl-1-pycryl-hydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) and the assay have shown 652 ± 0.37 mg TE/g and 3.68 ± 0.18 mg TE/100 g respectively, are significantly higher results with SC CO2 organic ginger extract. Paradol analogues are not detected in this study. Small quantities of [4]-, [10]gingediol and [6]-gingediacetate are also found in ginger extract.

Putative mycobacterial efflux inhibitors from the seeds of Aframomum melegueta

In order to identify new putative efflux pump inhibitors that represent an appropriate target in antimycobacterial chemotherapy, nine paradol- and gingerol-related compounds (1-9) isolated from the seeds of Aframomum melegueta were assessed for their potential to inhibit ethidium bromide (EtBr) efflux in a Mycobacterium smegmatis model. Five of the compounds from A. melegueta and NMR spectroscopic data of the diketone 6-gingerdione (2) and its enolic tautomers, methyl-6-gingerol (5) and rac-6-dihydroparadol (7), are presented herein for the first time. After determination of their antimycobacterial activities and modulatory effects on the MIC of antibiotics as well as their synergistic effects in combination with antibiotics against M. smegmatis mc(2) 155, their impact on EtBr accumulation and efflux was evaluated using a microtiter plate-based fluorometric assay. The compounds exhibited moderate to weak antimycobacterial activities, and the best modulators induced a 4- to 16-fold decrease of the MICs of EtBr and rifampicin as well as a reduction of the MIC of isoniazid with fractional inhibitory concentration index values indicating synergistic activities in some cases. 6-Paradol (3), 8-gingerol (6), and rac-6-dihydroparadol (7) were the most potent EtBr efflux inhibitors in M. smegmatis mc(2) 155, displaying EtBr efflux inhibiting activities comparable to reference inhibitors.

Radioprotective effects of Zingiber officinale Roscoe (ginger): past, present and future

Radiation is an important modality in treating people with cancer especially when surgical intervention is impracticable or might debilitate the patient. However, effective use of ionizing radiation is compromised by the side effects that result from radiation-induced damage to normal tissue. The use of radioprotective compounds, which can selectively protect normal tissues against radiation injury is of immense use because in addition to association with protecting the normal tissue, it will also permits use of higher doses of radiation to obtain better cancer control and possible cure. However, till date no ideal radioprotectors are available as most synthetic compounds are toxic at their optimal concentrations. Plants commonly used as dietary and or therapeutic agents have recently been the focus of attention since in most cases they are non-toxic and are easily accepted for human use. Ginger, the rhizomes of Zingiber officinale Roscoe (Zingiberaceae), has widely been used as both culinary and medicinal agent. Preclinical studies carried out in the last decade has shown that ginger and its phytochemicals dehydrozingerone, zingerone possess radioprotective effects in laboratory animals and in cultured cells in vitro. The hydroalcoholic extract of ginger rhizome when administered either through intraperitoneal or oral route was effective in protecting against gamma radiation-induced sickness and mortality. The phytochemicals dehydrogingerone and zingerone present in ginger are also shown to protect mice against radiation-induced sickness and mortality. Mechanistic studies have indicated that the free radical scavenging, antioxidant affects, anti-inflammatory and anti-clastogenic effects may contribute towards the observed protection. Additionally, studies with tumor bearing mice have also shown that zingerone selectively protects the normal tissues against the tumoricidal effects of radiation. This review for the first time summarizes the results related to the radioprotective properties and also emphasizes the aspects that warrant future research to establish its activity and utility as a radioprotective agent.

Effect of herbal preparation on heavy metal (cadmium) induced antioxidant system in female Wistar rats

Cadmium is one of the elements found to damage antioxidant systems in mammals. To ameliorate cadmium toxicity and to prevent oxidative stress, natural products may be useful. In Indian ethnobotanical practice, a mixture of 17 herbal products is used to fortify the reproductive system of women after parturition and to reverse ovarian oxidative stress. Oral administration of this extract to rats exposed to cadmium was useful in reversing oxidative stress. Two different doses of cadmium (50 ppm and 200 ppm) were given to Wistar rats aged 45 and 65 days. An herbal extract derived from 17 plants was administered orally every day at a dose level of 200 mg/kg of body weight to the rats exposed to cadmium. A battery of enzymes involved in antioxidant activity in the ovary, including superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and glutathione-s-transferase (GST) were measured in the control, cadmium-exposed rats without treatment and in the cadmium-exposed rats treated with herbal extract. The reduction in SOD, catalase, GPx and GST activity after cadmium exposure improved significantly in the rats treated with the herbal extract (p < 0.05). The decrease of antioxidant enzymes due to cadmium exposure was reversed significantly with herbal extract administration. The synergistic effect of each bioactive compound in different herbal extracts requires further study.

IN VITRO ANTIOXIDANT ACTIVITIES OF THE FERMENTED MARINE MICROALGA PAVLOVA LUTHERI (HAPTOPHYTA) WITH THE YEAST HANSENULA POLYMORPHA(1)

Microalgae are major primary producers of organic matter in aquatic environments through their photosynthetic activities. Fermented microalga (Pavlova lutheri Butcher) preparation (FMP) is the product of yeast fermentation by Hansenula polymorpha. It was tested for the antioxidant activities including lipid peroxidation inhibitory activity, free-radical-scavenging activity, inhibition of reactive oxygen species (ROS) on mouse macrophages (RAW264.7 cell), and inhibited myeloperoxidase (MPO) activity in human myeloid cells (HL60). FMP exhibited the highest antioxidant activity on free-radical scavenging, inhibitory intracellular ROS, and inhibited MPO activity. MTT [3-(4,5-dimethyl-2-yl)-2,5-diphenyltetrazolium bromide] assay showed no cytotoxicity in mouse macrophages (RAW264.7 cell), human myeloid cells (HL60), and human fetal lung fibroblast cell line (MRC-5). Furthermore, the antioxidative mechanism of FMP was evaluated by protein expression levels of antioxidant enzyme (superoxide dismutase [SOD] and glutathione [GSH]) using Western blot. The results obtained in the present study indicated that FMP is a potential source of natural antioxidant.

Ginger Rogers? No, Ginger Ale and its invisible proteome

The trace proteome of a Ginger drink, stated to be produced with a ginger root extract, has been investigated via capture with combinatorial peptide ligand libraries (ProteoMiner). Although in traces, we could confirm the presence of five grape proteins and one apple protein, but not even the faintest trace of any ginger root proteins. The first two findings are correct, as the producer stated that this beverage had been reinforced with 12% grape juice and 6% apple juice, but the absence of even traces of ginger proteins does not permit the classification of this beverage as a ginger extract on a proteomics scale. However, organoleptic tasting has confirmed the presence of a ginger extract, due to its piquant and tongue-biting taste. Nevertheless, any ginger root extract must be considered as a minor component as compared to the presence of grape and apple juice. At the light of these findings, it is hoped that the competent authorities will in the future make compulsory the proper labelling also of beverages so that all amounts of compounds utilized will be clearly stated in the label, including the presumptive main component.

Effects of [6]-shogaol on cholinergic signaling in HT22 cells following neuronal damage induced by hydrogen peroxide

Cholinergic neurons play a major role in memory and attention. The dysfunction and death of these neurons, especially in the hippocampus, are thought to contribute to the pathophysiology of memory deficits associated with Alzheimer's disease (AD). Therefore, studying the cholinergic properties and cell survival may help in treating this disease. We investigated the possible effects of [6]-shogaol on cholinergic signaling in HT22 hippocampal neuronal cells. HT22 cells express essential cholinergic markers, including choline acetyltransferase (ChAT) and choline transporter (ChTp). HT22 cells treated with H(2)O(2) for 3h showed an increase in ROS production (35%). These features were partly recovered by [6]-shogaol. Treating H(2)O(2)-treated HT22 cells with [6]-shogaol markedly increased the expression of ChAT and ChTp, an effect similar to that of brain-derived neurotrophic factor (BDNF). Furthermore, K-252a, an inhibitor of the BDNF receptor Trk B, attenuated the effects of both [6]-shogaol and BDNF. These data suggest that [6]-shogaol protects neurons by increasing ChAT and ChTp expression through a BDNF increase and thus may be useful for treating neurodegenerative diseases.

Antioxidant and inhibitory effect of red ginger (Zingiber officinale var. Rubra) and white ginger (Zingiber officinale Roscoe) on Fe(2+) induced lipid peroxidation in rat brain in vitro

Neurodegerative diseases have been linked to oxidative stress arising from peroxidation of membrane biomolecules and high levels of Fe have been reported to play an important role in neurodegenerative diseases and other brain disorder. Malondialdehyde (MDA) is the end-product of lipid peroxidation and the production of this aldehyde is used as a biomarker to measure the level of oxidative stress in an organism. The present study compares the protective properties of two varieties of ginger [red ginger (Zingiber officinale var. Rubra) and white ginger (Zingiber officinale Roscoe)] on Fe(2+) induced lipid peroxidation in rat brain in vitro. Incubation of the brain tissue homogenate in the presence of Fe caused a significant increase in the malondialdehyde (MDA) contents of the brain. However, the aqueous extract from both varieties of ginger caused a significant decrease in the MDA contents of the brain in a dose-dependent manner. However, the aqueous extract of red ginger had a significantly higher inhibitory effect on both Fe(2+)-induced lipid peroxidation in the rat brain homogenates than that of white ginger. This higher inhibitory effect of red ginger could be attributed to its significantly higher phytochemical content, Fe(2+) chelating ability, OH scavenging ability and reducing power. However, part of the mechanisms through which the extractable phytochemicals in ginger (red and white) protect the brain may be through their antioxidant activity, Fe(2+) chelating and OH scavenging ability. Therefore, oxidative stress in the brain could be potentially managed/prevented by dietary intake of ginger varieties (red ginger and white ginger rhizomes).

Antioxidant activity and protecting health effects of common medicinal plants

Medicinal plants are traditionally used in folk medicine as natural healing remedies with therapeutic effects such as prevention of cardiovascular diseases, inflammation disorders, or reducing the risk of cancer. In addition, pharmacological industry utilizes medicinal plants due to the presence of active chemical substances as agents for drug synthesis. They are valuable also for food and cosmetic industry as additives, due to their preservative effects because of the presence of antioxidants and antimicrobial constituents. To commonly used medicinal plants with antioxidant activity known worldwide belong plants from several families, especially Lamiaceae (rosemary, sage, oregano, marjoram, basil, thyme, mints, balm), Apiaceae (cumin, fennel, caraway), and Zingiberaceae (turmeric, ginger). The antioxidant properties of medicinal plants depend on the plant, its variety, environmental conditions, climatic and seasonal variations, geographical regions of growth, degree of ripeness, growing practices, and many other factors such as postharvest treatment and processing. In addition, composition and concentration of present antioxidants, such as phenolic compounds, are related to antioxidant effect. For appropriate determination of antioxidant capacity, the extraction technique, its conditions, solvent used, and particular assay methodology are important.

Protection by [6]-shogaol against lipopolysaccharide-induced toxicity in murine astrocytes is related to production of brain-derived neurotrophic factor

[6]-Shogaol has beneficial effects in spinal neuronal regeneration, but associated molecules and mechanisms are not identified. Neurotrophic factors, including brain-derived neurotrophic factor (BDNF), are associated with proliferation and differentiation of neuronal cells and exert a neuroprotective effect in neurodegenerative models. We investigated whether treatment with [6]-shogaol increases BDNF expression in lipopolysaccharide (LPS)-treated astrocytes, and examined the effect of [6]-shogaol on neuronal protection. [6]-Shogaol significantly attenuated the cell death induced by LPS. Western blotting showed that [6]-shogaol treatment reduced Bax expression and increased B-cell lymphoma (Bcl)-2 and BclxL expression in LPS-treated cells, consistent with the effects of BDNF treatment. Furthermore, K252a, a blocker of neurotrophic factors, attenuated the cellular protective effects of [6]-shogaol and BDNF. This study provides the first evidence that [6]-shogaol increases the expression of BDNF in LPS-treated astrocytes. Furthermore, these experimental results indicate that production of BDNF in astrocytes might be related to altered cell viability following [6]-shogaol treatment. Thus, the neuroprotective effects of [6]-shogaol is mediated by up-regulation of BDNF.

Effects of ginger root (Zingiber officinale) on laying performance and antioxidant status of laying hens and on dietary oxidation stability

To investigate the effects of ginger root (Zingiber officinale) on laying performance and antioxidant status of laying hens and on dietary oxidation stability, 675 Hy-Line brown laying hens at 27 wk of age were randomly allocated to 5 treatments with 5 replicates in a complete randomized design. Laying hens were fed corn-soybean meal based diets and supplemented with 0, 5, 10, 15, or 20 g of ginger powder/kg of diet for 10 wk. The ADFI, laying rate, average egg weight, egg mass, and feed conversion of each replicate were measured weekly. Blood samples from 10 laying hens and 15 egg samples/treatment were obtained on d 35 and 70 of the experiment to determine the serum or egg yolk antioxidant enzymatic activities. Three separate batches of each treatment diet were also made at the beginning of the experiment and stored at 20°C. Subsamples were taken at 10-d intervals to determine the dietary oxidation stability over a 60-d period. All laying hens had similar ADFI, laying rate, average egg weight, and feed conversion. However, laying hens supplemented with ginger powder had higher (P = 0.024) egg mass than the control group. Supplementation of ginger powder increased (P < 0.05) the serum and egg yolk antioxidant enzymatic activities of laying hens on d 35 and 70. Increasing ginger powder from 0 to 20 g/kg of diet linearly increased (P < 0.05) the peroxide value but linearly reduced (P < 0.05) the acid value of lipid extracted from stored diets for the first 30 d, but not for the second 30 d. Dietary supplementation of ginger powder improved laying performance and serum and egg yolk antioxidant status and enhanced dietary oxidation stability in a dose-dependent manner. The optimum supplementation rate of ginger powder in the diet of laying hens appeared to be between 10 and 15 g/kg of diet.

Protective Effect of Ginger oil on Aspirin and Pylorus Ligation-Induced Gastric Ulcer model in Rats

The present investigation was performed in aspirin and pylorus ligation-induced ulcer model in Wistar rats, in which ability of ginger oil to provide gastric protection was studied at two different doses, 0.5 and 1 g/kg po. Gastric protection was evaluated by measuring the ulcer index, serum γ-GTP levels, total acidity of gastric juice and gastric wall mucus thickness. The results obtained in the present study indicated that ginger oil has a protective action against gastric ulcers induced by aspirin plus pylorus ligation in Wistar rats.

Update on the chemopreventive effects of ginger and its phytochemicals

The rhizomes of Zingiber officinale Roscoe (Zingiberaceae), commonly known as ginger, is one of the most widely used spice and condiment. It is also an integral part of many traditional medicines and has been extensively used in Chinese, Ayurvedic, Tibb-Unani, Srilankan, Arabic, and African traditional medicines, since antiquity, for many unrelated human ailments including common colds, fever, sore throats, vomiting, motion sickness, gastrointestinal complications, indigestion, constipation, arthritis, rheumatism, sprains, muscular aches, pains, cramps, hypertension, dementia, fever, infectious diseases, and helminthiasis. The putative active compounds are nonvolatile pungent principles, namely gingerols, shogaols, paradols, and zingerone. These compounds are some of the extensively studied phytochemicals and account for the antioxidant, anti-inflammatory, antiemetic, and gastroprotective activities. A number of preclinical investigations with a wide variety of assay systems and carcinogens have shown that ginger and its compounds possess chemopreventive and antineoplastic effects. A number of mechanisms have been observed to be involved in the chemopreventive effects of ginger. The cancer preventive activities of ginger are supposed to be mainly due to free radical scavenging, antioxidant pathways, alteration of gene expressions, and induction of apoptosis, all of which contribute towards decrease in tumor initiation, promotion, and progression. This review provides concise information from preclinical studies with both cell culture models and relevant animal studies by focusing on the mechanisms responsible for the chemopreventive action. The conclusion describes directions for future research to establish its activity and utility as a human cancer preventive and therapeutic drug. The above-mentioned mechanisms of ginger seem to be promising for cancer prevention; however, further clinical studies are warranted to assess the efficacy and safety of ginger.

Zingiber officinale Mitigates Brain Damage and Improves Memory Impairment in Focal Cerebral Ischemic Rat

Cerebral ischemia is known to produce brain damage and related behavioral deficits including memory. Recently, accumulating lines of evidence showed that dietary enrichment with nutritional antioxidants could reduce brain damage and improve cognitive function. In this study, possible protective effect of Zingiber officinale, a medicinal plant reputed for neuroprotective effect against oxidative stress-related brain damage, on brain damage and memory deficit induced by focal cerebral ischemia was elucidated. Male adult Wistar rats were administrated an alcoholic extract of ginger rhizome orally 14 days before and 21 days after the permanent occlusion of right middle cerebral artery (MCAO). Cognitive function assessment was performed at 7, 14, and 21 days after MCAO using the Morris water maze test. The brain infarct volume and density of neurons in hippocampus were also determined. Furthermore, the level of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in cerebral cortex, striatum, and hippocampus was also quantified at the end of experiment. The results showed that cognitive function and neurons density in hippocampus of rats receiving ginger rhizome extract were improved while the brain infarct volume was decreased. The cognitive enhancing effect and neuroprotective effect occurred partly via the antioxidant activity of the extract. In conclusion, our study demonstrated the beneficial effect of ginger rhizome to protect against focal cerebral ischemia.

Effect of combined administration of ginger (Zingiber officinale Roscoe) and atorvastatin on the liver of rats

Ginger is known to possess hypolipidemic, antioxidant and hepatoprotective properties. Combination therapy often takes advantage of complementary effects of different agents. This study investigated the combined effect of ginger extract (GE) and atorvastatin on lipid profile and on atorvastatin-induced hepatic injury. Rats were randomized into: control; GE (400 mg/kg); atorvastatin (20 mg/kg) alone or with GE or vitamin E, and atorvastatin (80 mg/kg) alone or with GE or vitamin E. Administration of 80 mg/kg atorvastatin for 4 weeks had major hepatotoxic effect whereas the lower dose (20 mg/kg) seems to cause mild liver injury. Besides lowering serum total cholesterol and hepatic superoxide dismutase (SOD) and catalase (CAT), atorvastatin significantly increased serum aminotransferases, hepatic malondialdehyde (MDA) and nitric oxide (NO). Concurrent administration of GE and atorvastatin had the opposite effect. Histopathological study revealed that GE reduced liver lesions induced by atorvastatin. The results indicate that the ability of ginger to lower serum cholesterol and to decrease aminotransferases, MDA and NO is clinically important, because its chronic administration will neither lead to side-effects nor to hepatic changes as occurs with high atorvastatin doses. Therefore, combination regimens containing GE and low dose of statins could be advantageous in treating hypercholesterolemic patients which are susceptible to liver function abnormalities.

Enhanced anti-inflammatory activities of Monascus pilosus fermented products by addition of ginger to the medium

Hypercholesterolemia initiates the atherogenic process; however, chronic inflammation promotes atherogenesis. Monascus spp. fermented products are recognized for their anti-hypercholesterolemic effect, but their anti-inflammatory activity is not as significant as that of many plant-derived foods. To enhance the anti-inflammatory function of Monascus pilosus fermented products, ginger was added to the PDB medium at a ratio of 20% (v/v). The mycelia and broth were collected, freeze-dried, and extracted by ethanol for assays. Macrophage RAW264.7 was challenged with lipopolysaccharide (LPS) and coincubated with the extracts of fermented product cultured in ginger-supplemented medium (MPG) or extracts of fermented product cultured in regular PDB medium (MP) for 18 h. Human umbilical vein endothelial cell HUVEC was challenged with tumor necrosis factor (TNF)-α and coincubated with the extracts of either MPG or MP for 6 h. The results showed that MPG significantly (p<0.05) lowered the production of macrophage pro-inflammatory cytokines TNF-α, nitric oxide (NO), interleukin (IL)-1, IL-6, and prostaglandin E2 (PGE2) by 68.53%, 84.29%, 32.55%, 84.49%, and 69.49%, respectively; however, MP had no inhibitory effect. MPG significantly downregulated the expression of p-IκB, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in macrophage by 42.16%, 50.87%, and 51.35%, respectively, while MP had no inhibition on COX-2 expression and only 16.64% and 19.22% downregulatory effect on iNOS and phosphorylated-IκB (p-IκB), respectively. Moreover, MPG significantly suppressed the expression of vessel cell adhesion molecule-1 (VCAM-1) and p-IκB in endothelial cell by 63.48% and 63.41%, respectively. LC/MS/MS analysis indicated that 6-gingerdiol was formed in the ginger-modified medium during fermentation. The results of this study will facilitate the development of Monascus spp. fermented products as antiatherosclerotic nutraceuticals.

Effect of DHU001, a Polyherbal Formula, on Dinitrofluorobenzene-induced Contact Dermatitis (Type I allergy)

The effect of DHU001, a mixed herbal formula consisted of 7 types aqueous extracts for various respiratory disorders were evaluated on 2,4-dinitrofluorobenzene (DNFB) -induced contact dermatitis, type I allergic model. Contact dermatitis was induced by sensitization with dinitrophenyl-derivatized ovalbumin (DNP-OVA) and DNFB challenge as antigen. Two different dosages of DHU001 (300 and 150 mg/kg) were orally administered to DNP-OVA sensitization mice once a day for 7 days with reference material, dexamethasone (15 mg/kg, intraperitoneal treatment) . End of 7 days oral administration of DHU001 extracts or intraperitoneal treatment of dexamethasone, the changes on the edematous changes and scratching behavior were measured. Immediate after DNFB challenge on ear or paw of DNP-OVA sensitized mice, increases of ear and paw thicknesses and weights were detected with anterior ear skin (dermis to epidermis) thickness and paw scratching behavior increases. However, these contact dermatitis signs induced by DNFB treatment were reduced by treatment of the both different dosages of DHU001 and dexamethasone, respectively. The results obtained in this study suggest that oral treatment of DHU001 extracts also has relatively favorable effects on contact dermatitis.

RP-thin layer chromatographic method for the quantification of three gingerol homologs of ultrasonic-assisted fresh rhizome extracts of Zingiber officinale collected from North Western Himalayas

A rapid and sensitive RP high-performance thin-layer chromatographic (RP-HPTLC) methodology was developed and validated for the quantitative estimation of gingerols in methanolic extract of fresh ginger rhizome. The samples were chromatographed on RP-TLC glass plates pre-coated with RP-18 60F(254) as the stationary phase. Linear ascending development was carried out in twin trough glass chamber saturated with ternary-solvent system consisting of acetonitrile-water-formic acid (7:2:1 v/v/v) at room temperature (25+/-2 degrees C) and plates were scanned at 500 nm. The system was found to give compact spots for gingerols (R(f) values of 6-gingerol 0.73+/-0.04, 8-gingerol 0.59+/-0.08 and 10-gingerol 0.36+/-0.05). Linearity was found to be in the range of 140-840 ng/spot for 6-gingerol, 168-1008 ng/spot for 8-gingerol and 136-816 ng/spot for 10-gingerol with significantly high value of correlation coefficient. The linear regression analysis data for the calibration plots showed linear relationship (r(2)) and ranged from 0.9992 to 0.9937 for 6-, 8- and 10-gingerol. The method was used for routine analyses and to obtain relative amounts of the gingerols in the fresh rhizomes of the ginger cultivated in different locations of Uttarakhand and Himachal Pradesh of North Western Himalayas (India).

Inhibitors of oxidation and matrix metalloproteinases, floridoside, and D-isofloridoside from marine red alga Laurencia undulata

In the exploration of abundant marine biological resources, edible red alga Laurencia undulata led to two bioactive isolates: floridoside (1) and D-isofloridoside (2). For the first time, the antioxidant properties of both derivatives (1 and 2) were characterized via free radical scavenging using the ESR technique, reactive oxygen species (ROS) inhibition, membrane protein oxidation, myeloperoxidase (MPO) inhibition, gene expression levels of glutathione (GSH) and superoxide dismutase (SOD), and protein expression of MMP-2 and MMP-9. The results demonstrate that floridoside and D-isofloridoside possess significant antioxidant capacity and are potential inhibitors of MMP-2 and MMP-9. These results clarified that these components may be responsible for the relative activities of crude extract from this genus, which is used as folk medicine. Furthermore, the structure-activity relationships were also suggested. Both isomers could be effective candidates for applications in food and pharmaceutical fields as natural marine antioxidants.

Hexane fraction of Zingiberis Rhizoma Crudus extract inhibits the production of nitric oxide and proinflammatory cytokines in LPS-stimulated BV2 microglial cells via the NF-kappaB pathway

Excessive production of inflammatory mediators such as nitric oxide (NO), prostaglandin E(2) (PGE2), and proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) from activated microglia contributes to uncontrolled inflammation in neurodegenerative diseases. It seems possible that treatment with anti-inflammatory agents, including plants used in Oriental medicine, might delay the progression of neurodegeneration through the inhibition of microglial activation. The present study is focused on the inhibitory effect of the rhizome hexane fraction extract of Zingiber officinale Roscoe (ginger hexan extract; GHE) on the production of inflammatory mediators such as NO, PGE(2), and proinflammatory cytokines in lipopolysaccharide (LPS)-stimulated BV-2 cells, a mouse microglial cell line. GHE significantly inhibited the excessive production of NO, PGE(2), TNF-alpha, and IL-1beta in LPS-stimulated BV2 cells. In addition, GHE attenuated the mRNA expressions and protein levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and proinflammatory cytokines. The molecular mechanisms that underlie GHE-mediated attenuation are related to the inhibition of the phosphorylation of three mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinases 1 and 2 (ERK1/2), p38 MAPK, and c-Jun N-terminal kinase (JNK), and the activation of nuclear factor-kappaB (NF-kappaB). Our results indicate that GHE exhibits anti-inflammatory properties by suppressing the transcription of inflammatory mediator genes through the MAPK and NF-kappaB signaling pathways. The anti-inflammatory properties of GHE may make it useful as a therapeutic candidate for the treatment of human neurodegenerative diseases.

Use of conventional and -omics based methods for health claims of dietary antioxidants: a critical overview

This article describes the principles and limitations of methods used to investigate reactive oxygen species (ROS) protective properties of dietary constituents and is aimed at providing a better understanding of the requirements for science based health claims of antioxidant (AO) effects of foods. A number of currently used biochemical measurements aimed of determining the total antioxidant capacity and oxidised lipids and proteins are carried out under unphysiological conditions and are prone to artefact formation. Probably the most reliable approaches are measurements of isoprostanes as a parameter of lipid peroxidation and determination of oxidative DNA damage. Also the design of the experimental models has a strong impact on the reliability of AO studies: the common strategy is the identification of AO by in vitro screening with cell lines. This approach is based on the assumption that protection towards ROS is due to scavenging, but recent findings indicate that activation of transcription factors which regulate genes involved in antioxidant defence plays a key role in the mode of action of AO. These processes are not adequately represented in cell lines. Another shortcoming of in vitro experiments is that AO are metabolised in vivo and that most cell lines are lacking enzymes which catalyse these reactions. Compounds with large molecular configurations (chlorophylls, anthocyans and polyphenolics) are potent AO in vitro, but weak or no effects were observed in animal/human studies with realistic doses as they are poorly absorbed. The development of -omics approaches will improve the scientific basis for health claims. The evaluation of results from microarray and proteomics studies shows that it is not possible to establish a general signature of alterations of transcription and protein patterns by AO. However, it was shown that alterations of gene expression and protein levels caused by experimentally induced oxidative stress and ROS related diseases can be normalised by dietary AO.

The effect of dietary ginger (Zingiber officinals Rosc) on renal ischemia/reperfusion injury in rat kidneys

Oxidative stress has been considered as one of the possible mechanisms of ischemia/ reperfusion (I/R) injury in the kidney. The aim of this study was to analyze the possible protective effect of dietary ginger (Zingiber officinals Rosc), a free radical scavenger, on renal I/R injury in rats. The protective effect of ginger against the damage inflicted by reactive oxygen species (ROS) during renal I/R was investigated in Wistar albino rats using histopathological and biochemical parameters. Thirty rats were randomly divided into five experimental groups (i.e., control, sham-operated, ginger, I/R, and I/R + ginger groups, n = 6 each). The ginger and I/R + ginger groups were fed on the test diet containing 5% ginger. The rats were subjected to bilateral renal ischemia followed by reperfusion in I/R and I/R + ginger groups. At the end of the reperfusion period, rats were sacrificed, and kidney function tests, serum and tissue oxidants and antioxidants, and renal morphology were evaluated. Serum urea, creatinine, and cystatin C (CYC) levels were significantly elevated in the ischemia group, but these levels remained unchanged in the ginger + I/R group compared to the I/R group. Reduction of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) enzyme activity was significantly improved by the treatment with ginger compared to I/R group. Administration of ginger resulted in significant reduction levels of tissue malondialdehyde (MDA), NO, protein carbonyl contents (PCC) in the ginger + I/R group compared with the I/R group. Ginger supplementation in the diet before I/R injury resulted in higher total antioxidant capacity (TAC) and lower total oxidant status (TOS) levels than I/R group. The ginger supplemented diet prior to I/R process demonstrated marked reduction of the histological features of renal injury. The findings imply that ROS play a causal role in I/R-induced renal injury, and ginger exerts renoprotective effects probably by the radical scavenging and antioxidant activities.

Protective effect of Zingiber officinale roscoe against anticancer drug doxorubicin-induced acute nephrotoxicity

Oxidative stress due to abnormal production of reactive oxygen species has been implicated in the nephrotoxicity induced by a commonly used anticancer antibiotic doxorubicin (DXN). The nephroprotective effect of aqueous ethanol extract of Zingiber officinale (200 and 400mg/kg, p.o) was evaluated against doxorubicin-induced (15mg/kg, i.p) acute renal damage in rat. Serum urea and creatinine levels were evaluated as the markers of renal failure. Renal antioxidant status such as activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and level of reduced glutathione (GSH) were determined. Level of lipid peroxidation as equivalents of malondialdehyde (MDA), and glutathione-S-transferase (GST) activity were determined in the kidneys. Serum urea and creatinine levels were reduced in the Z. officinale (200 and 400mg/kg, p.o) plus DXN treated groups. The renal antioxidant enzymes activities such as SOD, CAT GPx, levels of GSH and GST activity were restored and that of MDA declined significantly (p<0.001) in the Z. officinale (400mg/kg) plus DXN treated group. The nephroprotection is mediated by preventing the DXN-induced decline of renal antioxidant status, and also by increasing the activity of GST.

Effects of DHU001, a Mixed Herbal Formula on Acute Inflammation in Mice

The effects of DHU001, a mixed herbal formula consisted of 7 types aqueous extracts for treating respiratory disorders were observed on xylene-induced acute inflammation. The xylene was topically applied 60 min after administration of 500, 250 and 125 mg/kg of DHU001, and all animals were sacrificed 2 hrs after xylene application. The changes on ear weights, histolopathological analyses of ear were evaluated and compared to those of indomethacin and dexamethasone (15 mg/kg treated) - Both of drugs are well-known by anti-inflammatory agents. Xylene application resulted in marked increases in induced ear weights as compared with intact control ear. Severe vasodilation, edematous changes of ear skin and increase in the thickness of the ear tissues, neutrophil infiltration as acute inflammation were detected in xylene-treated control ears at histopathological observation. However, these xylene-induced acute inflammatory changes were dose-dependently decreased by oral treatment of DHU001. Therefore, it is concluded that DHU001 has favorable anti-inflammatory effects on xylene-applicated acute ear inflamed mice.

Modulating effect of ginger extract on rats with ulcerative colitis

ETHNOPHARMACOLOGICAL RELEVANCE

Ginger rhizomes are used traditionally for management of different gastrointestinal disturbances. Several studies proved that the rhizome possesses diverse biological activities such as cytotoxic, antioxidant, and anti-inflammatory effects. Recently, interest in ginger for treatment of chronic inflammatory conditions has been renewed.

AIM OF THE STUDY

The purpose of the present study is to evaluate the potential role of ginger extract [GE] in modulating the extent and severity of ulcerative colitis (UC), a chronically recurrent inflammatory bowel disease of unknown origin.

MATERIALS AND METHODS

Male Wistar rats received 3 different doses of GE, sulfasalazine, or vehicle for 3 consecutive days before induction of UC by intra-rectal acetic acid administration, and continued further for 7 days after the induction. The colonic mucosal injury was assessed by macroscopic scoring, and histological examination. Furthermore, the mucosal content of malondialdehyde (MDA), protein carbonyl (PCO), and reduced glutathione (GSH) with the catalase (CAT) and superoxide dismutase (SOD) activity, were appraised as parameters of the redox state. Acute inflammatory response was determined by measuring myeloperoxidase (MPO), tumor necrosis factor (TNF-alpha), and prostaglandin E2 (PGE2).

RESULTS

All parameters were altered in ulcerated rats, and improved in animals receiving GE, an effect that was comparable to that of the standard sulfasalazine, especially at the highest dose level. Colonic mucosal injury parallels with the histological and biochemical evaluations.

CONCLUSIONS

Results showed a valuable effect of ginger extract against acetic acid-induced ulcerative colitis possibly by its antioxidant and anti-inflammatory properties.

The effects of methanolic extracts of ginger (Zingiber officinale) on human sperm parameters; an in vitro study

This study was conducted on Zingiber officinale or ginger on motility, grading and morphological aspects of human sperm. Thirty human semen samples were obtained from the local hospital. The samples were swim up by Ham's F10. The samples (0.9 mL) were treated by 0.1 mL of ginger methanolic extracts (0.1, 0.2, 0.4 and 0.6% concentration). Sperm motility, grading and morphology parameters were assessed using light microscope at 0, 2, 4, 8 and 24 h after treatment. Dose and time-dependent decreases in motility accompanied by concomitant decrease in grading 3 and 4 were noticed. Morphologic profiles of the sperms were changed under different doses of ginger on the basis of time of assess. These data indicate that some exhibits a lower percentage of motility and grading when methanolic ginger is added to semen fluid. According to the results it would be concluded that ginger can induce the toxic effects on sperm parameters.

Protective effects of dietary ginger (Zingiber officinales Rosc.) on lindane-induced oxidative stress in rats

The protective effect of dietary feeding of Zingiber officinales Rosc. (ginger) against lindane-induced oxidative stress was investigated in male albino rats. Oxidative stress was monitored by estimating the extent of lipid peroxidation, activities of the oxygen free radical (OFR) scavenging enzymes superoxide dismutase (SOD) and catalase (CAT) and the status of the glutathione redox cycle antioxidants. Lindane administration (30 mg/kg bw orally for 4 weeks) was associated with enhanced lipid peroxidation and compromised antioxidant defenses in rats fed a normal diet. Concomitant dietary feeding of ginger (1%w/w) significantly attenuated lindane-induced lipid peroxidation, accompanied by modulation of OFR scavenging enzymes as well as reduced glutathione (GSH) and the GSH dependent enzymes glutathione peroxidase (Gpx), glutathione reductase (GR) and glutathione-S-transferase (GST) in these rats. These findings suggest that a diet containing naturally occurring compounds is effective in exerting protective effects by modulating oxidative stress.

Cytotoxic components from the dried rhizomes of Zingiber officinale Roscoe

Five compounds were isolated from the chloroform-soluble fraction of the methanolic extract of the dried rhizomes of Zingiber officinale (Zingiberaceae) through repeated column chromatography. Their chemical structures were elucidated as 4-, 6-, 8-, and 10-gingerols, and 6-shogaol using spectroscopic analysis. Among the five isolated compounds, 6-shogaol exhibited the most potent cytotoxicity against human A549, SK-OV-3, SK-MEL-2, and HCT15 tumor cells. 6-shogaol inhibited proliferation of the transgenic mouse ovarian cancer cell lines, C1 (genotype: p53(-/-), c-myc, K-ras) and C2 (genotype: p53(-/-), c-myc, Akt), with ED(50) values of 0.58 microM (C1) and 10.7 microM (C2).

Zingiber officinale Roscoe prevents acetaminophen-induced acute hepatotoxicity by enhancing hepatic antioxidant status

A large number of xenobiotics are reported to be potentially hepatotoxic. Free radicals generated from the xenobiotic metabolism can induce lesions of the liver and react with the basic cellular constituents - proteins, lipids, RNA and DNA. Hepatoprotective activity of aqueous ethanol extract of Zingiber officinale was evaluated against single dose of acetaminophen-induced (3g/kg, p.o.) acute hepatotoxicity in rat. Aqueous extract of Z. officinale significantly protected the hepatotoxicity as evident from the activities of serum transaminase and alkaline phosphatase (ALP). Serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT) and ALP activities were significantly (p<0.01) elevated in the acetaminophen alone treated animals. Antioxidant status in liver such as activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase and glutathione-S-transferase (GST), a phase II enzyme, and levels of reduced glutathione (GSH) were declined significantly (p<0.01) in the acetaminophen alone treated animals (control group). Hepatic lipid peroxidation was enhanced significantly (p<0.01) in the control group. Administration of single dose of aqueous extract of Z. officinale (200 and 400mg/kg, p.o.) prior to acetaminophen significantly declines the activities of serum transaminases and ALP. Further the hepatic antioxidant status was enhanced in the Z. officinale plus acetaminophen treated group than the control group. The results of the present study concluded that the hepatoprotective effect of aqueous ethanol extract of Z. officinale against acetaminophen-induced acute toxicity is mediated either by preventing the decline of hepatic antioxidant status or due to its direct radical scavenging capacity.

Zingiber officinale Roscoe alone and in combination with alpha-tocopherol protect the kidney against cisplatin-induced acute renal failure

Oxidative stress due to abnormal production of reactive oxygen molecules (ROM) is believed to be involved in the etiology of toxicities of many xenobiotics. Evidences suggested that ROM is involved in the nephrotoxicity of a widely used synthetic anticancer drug cisplatin. The nephroprotective effects of ethanol extract of Zingiber officinale alone and in combination with vitamin E (alpha-tocopherol) were evaluated using cisplatin (single dose of 10 mg/kg body wt, i.p) induced acute renal damage in mice. The results of the study indicated that Z. officinale significantly and dose dependently protected the nephrotoxicity induced by cisplatin. The serum urea and creatinine levels in the cisplatin alone treated group were significantly elevated (P<0.01) with respect to normal group of animals. The levels were reduced in the Z. officinale (250 and 500 mg/kg, p.o) plus cisplatin, vitamin E (250 mg/kg) plus cisplatin, and Z. officinale (250 mg/kg) with vitamin E plus vitamin E treated groups. The renal antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities and level of reduced glutathione (GSH) were declined; level of malondialdehyde (MDA) was elevated in the cisplatin alone treated group. The activities of SOD, CAT GPx and level of GSH were elevated and level of MDA declined significantly (P<0.05) in the Z. officinale (250 and 500 mg/kg) plus cisplatin and Z. officinale (250 mg/kg) with vitamin E plus cisplatin treated groups. The protective effect of Z. officinale (250 mg/kg body wt) was found to be better than that of vitamin E (250 mg/kg body wt). The results also demonstrated that combination of Z. officinale (250 mg/kg) with vitamin E (250 mg/kg) showed a better protection compared to their 250 mg/kg alone treated groups. This study concluded that ethanol extract of Z. officinale alone and in combination with vitamin E partially ameliorated cisplatin-induced nephrotoxicity. This protection is mediated either by preventing the cisplatin-induced decline of renal antioxidant defense system or by their direct free radical scavenging activity.

Inhibition of gastric H+, K+-ATPase and Helicobacter pylori growth by phenolic antioxidants of Zingiber officinale

Ulcer is a common global problem characterized by acute gastric irritability, bleeding, etc. due to either increased gastric cell proton potassium ATPase activity (PPA) or perturbation of mucosal defence. Helicobacter pylori has been identified as a major ulcerogen in addition to oxidative stress and nonsteroidal anti-inflammatory drugs. In this paper, we report ginger-free phenolic (GRFP) and ginger hydrolysed phenolic (GRHP) fractions of ginger (Zingiber officinale) as potent inhibitors of PPA and H. pylori growth. GRFP and GRHP inhibited PPA at an IC(50) of 2.9 +/- 0.18 and 1.5 +/- 0.12 microg/mL, exhibiting six- to eight-fold better potency over lansoprazole. GRFP is constituted by syringic (38%), gallic (18%) and cinnamic (14%) acids and GRHP by cinnamic (48%), p-coumaric (34%) and caffeic (6%) acids as major phenolic acids. GRFP and GRHP further exhibited free radical scavenging (IC(50) 1.7 +/- 0.07 and 2.5 +/- 0.16), inhibition of lipid peroxidation (IC(50) 3.6 +/- 0.21 and 5.2 +/- 0.46), DNA protection (80% at 4 microg) and reducing power abilities (80-338 U/g) indicating strong antioxidative properties. GRFP and GRHP may thus be potential in-expensive multistep blockers against ulcer.

Characterization and identification of diarylheptanoids in ginger (Zingiber officinale Rosc.) using high-performance liquid chromatography/electrospray ionization mass spectrometry

In our continuing investigation of diarylheptanoids in Zingiberaceae plants using liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS/MS), 26 diarylheptanoids were identified from fresh ginger rhizome. Of the 26 compounds, 15 diarylheptanoids appear to be new compounds. In addition, the majority of these compounds (18) were acetylated, which is different from our investigation of diarylheptanoids from turmeric, another member of the Zingiberaceae, which did not possess any acetylated diarylheptanoids. In all, five distinct groups (homologous series) of diarylheptanoids were found in extracts from ginger rhizome. These groups were differentiated by structural differences on the heptane skeletons, whereas homologs within each group differed by substitution patterns on the aromatic rings. Diagnostic fragmentation behavior in (+)- and (-)ESI-MS/MS analyses for each group of homologs, as well as information regarding polarity obtained from retention time data, allowed us to classify compounds by group and identify them based on key structural features.