Protective effect of Mesona procumbens against tert-butyl hydroperoxide-induced acute hepatic damage in rats

The protective effect of Hsian-tsao (Mesona procumbens Hemsl.) and its active compounds on liver damage was evaluated using the model of tert-butyl hydroperoxide (t-BHP)-induced acute hepatic damage in rats. Male Sprague-Dawley rats (200 +/- 10 g) were orally pretreated with a water extract of Hsian-tsao (WEHT) (0.1, 0.5, and 1.0 g/kg) or caffeic acid (0.1 g/kg of body weight) for 13 days before a single dose of t-BHP (0.2 mmol/kg, intraperitoneally) to each animal, and the rats were sacrificed 18 h later by decapitation; blood samples were collected for the assays of serum biochemical values. The livers were excised from the animals and assayed for oxidative injury, antioxidant enzyme, and pathological histology. The result showed that the oral pretreatment of WEHT (0.1, 0.5, and 1.0 g/kg) or caffeic acid (0.10 g/kg) before t-BHP (0.2 mmol/kg) treatment significantly lowered the serum levels of the hepatic enzyme markers (alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase) and reduced oxidative stress of the liver by evaluation of malondialdehyde, glutathione, 8-hydroxy-2'-deoxyguanosine, glutathione peroxidase, and glutathione reductase. The histopathological evaluation of the rat livers showed that WEHT and caffeic acid reduced the incidence of liver lesions including cloudy swelling, pyknosis, and cytolysis induced by t-BHP in rats. On the basis of the results of this study, it can be speculated that M. procumbens protects liver against t-BHP-induced hepatic damage in rats.     

Protective effect of ginseng on cytokine-induced apoptosis in pancreatic beta-cells

The effects of ginseng extracts (GE) and several ginsenosides on cytokine-induced apoptosis were evaluated. In pancreatic beta-cell line MIN6N8 cells, the inhibitory effect of GE was significantly observed at 25-100 microg/mL: an 86-100% decrease of cytoplasmic DNA fragments quantified by an ELISA. The inhibitory effect of red ginseng (RG) extract was greater than that of white ginseng (WG) extract (IC50, 3.633 vs 4.942 microg/mL). Screening of several known ginsenosides, which were present in ginseng extracts at 0.124-1.19% (w/w) by HPLC analysis, revealed that the ginsenosides were responsible for the inhibition of beta-cell apoptosis at 0.1-1.0 microg/mL. The molecular mechanism, by which GE inhibited beta-cell apoptosis, appeared to involve the reduction of nitric oxide (NO) and reactive oxygen species (ROS) production, inhibition on p53/p21 expression, and inhibition on cleavage of caspases and poly(ADP-ribose) polymerase (PARP). This study suggests that ginseng may inhibit cytokine-induced apoptosis in beta-cells and, thus, may contribute via this action to the antidiabetic influence in type 1 diabetes.     

Protective effect of structurally diverse grape procyanidin fractions against UV-induced cell damage and death

UV radiation leads to the generation of reactive oxygen species (ROS). These molecules exert a variety of harmful effects by altering key cellular functions and may result in cell death. Several studies have demonstrated that human skin can be protected against UV radiation by using plant-derived antioxidants. Here we evaluated the in vitro capacity of several antioxidant polyphenolic fractions from grape, which differ in their degree of polymerization and percentage of galloylation, to protect HaCaT human keratinocytes against UV-induced oxidative damage. These fractions inhibited both basal and UVB- or UVA-induced intracellular ROS generation in this cell line. Consequently, the same fractions inhibited p38 and JNK1/2 activation induced by UVB or UVA radiation. The highest protective effect was for fractions rich in procyanidin oligomers and gallate esters. These encouraging in vitro results support further research and should be taken into consideration into the clinical pharmacology of plant-derived polyphenolic extracts as novel agents for skin photoprotection.     

Phytosterol content in American ginseng seed oil

North American ginseng (Panax quinquefolium L.) oil was saponifed and the unsaponifiable matter trimethylsilylated. The phytosterol fraction of hexane-extracted, air-dried seed was quantified and identified by GC and GC-MS. Phytosterol contents (milligrams per 100 g of oil) were as follows: squalene (514-569), oxidosqualene (8.97-48.2), campesterol (9.96-12.4), stigmasterol (93.2-113), clerosterol (1.91-2.14), beta-sitosterol (153-186), beta-amyrin (11.7-19.5), delta(5)-avenasterol (12.4-20.5), delta(5,24(25))-stigmasterol (3.70-.76), lupeol (14.4-15.2), delta(7)-sitosterol (12.5-14.6), delta(7)-avenasterol (4.11-8.09), 24-methylenecycloartanol (1.94-4.76), and citrostadienol (2.50-3.81). Seed stratification lowered the phytosterol levels. Oven-drying gave mixed results, and phytosterols varied slightly between the 1999 and 2000 harvests.     

Protective activity of green tea against free radical- and glucose-mediated protein damage

Protein oxidation and glycation are posttranslational modifications that are implicated in the pathological development of many age-related disease processes. This study investigated the effects of green tea extract, and a green tea tannin mixture and its components, on protein damage induced by 2,2'-azobis(2-amidinopropane) dihydrochloride (a free radical generator) and glucose in in vitro assay systems. We found that green tea extract can effectively protect against protein damage, and showed that its action is mainly due to tannin. In addition, it was shown that the chemical structures of tannin components are also involved in this activity, suggesting that the presence of the gallate group at the 3 position plays the most important role in the protective activity against protein oxidation and glycation, and that there is also a contribution by the hydroxyl group at the 5' position in the B ring and the sterical structure. These findings demonstrate the mechanisms of the usefulness of green tea in protein oxidation- and glycation-associated diseases.     

Protection against oxidative stress in diabetic rats by wheat bran feruloyl oligosaccharides

Diabetes is one of the most costly of the chronic diseases and is increasing in epidemic proportions in developing countries. It has been found that some antioxidants play a role in protection against oxidative stress, which is associated with diabetes. In this study, enzyme-released feruloyl oligosaccharides from wheat bran were given intragastrically (ig) to test their effect on antioxidant capacity, body weight restoring capacity, and serum glucose level in alloxan-induced diabetic Sprague-Dawley (SD) rats, using sodium ferulate and vitamin C as positive control groups. The levels of blood glucose, total antioxidant capacity (TAOC), and malondiadehyde (MDA) and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and xanthine oxidase (XOD) were determined in rat serum, liver, and testes. Feruloyl oligosaccharides significantly increased TAOC level, GSH-Px, and SOD activities, but decreased blood glucose and MDA levels and XOD activity in serum, liver, and testes of diabetic rats compared to diabetic controls. Feruloyl oligosaccharides were, overall, more efficient in mitigating oxidative damage in diabetic rats than sodium ferulate and vitamin C. In this feruloyl oligosaccharide feeding study, the antioxidant restoring capacity varied across the tissues observed, and also the activity change of the various antioxidant enzymes varied within a single tissue. Feruloyl oligosaccharides showed greater antioxidant capacity in vivo than in vitro when compared with vitamin C.     

Protective effect of supplementation of fish oil with high n-3 polyunsaturated fatty acids against oxidative stress-induced DNA damage of rat liver in vivo

The present study was undertaken to know the effect of supplementation of fish oil with high n-3 polyunsaturated fatty acids (PUFA) on oxidative stress-induced DNA damage of rat liver in vivo. Male Wistar rats were fed a diet containing fish oil or safflower oil with high n-6 PUFA at 50 g/kg of diet and an equal amount of vitamin E at 59 mg/kg of diet for 6 weeks. Livers of rats fed fish oil were rich in n-3 PUFA, whereas those of rats fed safflower oil were rich in n-6 PUFA. Ferric nitrilotriacetate was intraperitoneally injected to induce oxidative stress. The degree of lipid peroxidation of the liver was assessed by the levels of phospholipid hydroperoxides and thiobarbituric acid-reactive substances (TBARS), and the degree of oxidative DNA damage was assessed by comet type characterization in alkaline single-cell gel electrophoresis and 8-hydroxy-2'-deoxyguanosine levels. The levels of TBARS of the livers of the fish oil diet group increased to a greater extent than those of the safflower oil diet group, whereas the levels of the hydroperoxides of the livers of both diet groups increased to a similar extent. The vitamin E level of livers of the fish oil diet group was remarkably decreased. The degree of DNA damage of both diet groups was increased, but the increased level of the fish oil diet group was remarkably lower than that of the safflower oil diet group. The above results indicate that fish oil supplementation does not enhance but appears to protect against oxidative stress-induced DNA damage and suggest that lipid peroxidation does not enhance but lowers the DNA damage.     

Protective effect of vanilloids against tert-butyl hydroperoxide-induced oxidative stress in vero cells culture

This study investigated the effect of synthetic capsiate, a simplified analogue of capsiate, and vanillyl alcohol on the oxidative stress induced by tert-butyl hydroperoxide (TBH) in a line of fibroblasts derived from monkey kidney (Vero cells). In response to the TBH-mediated oxidative stress, a reduction of the levels of total unsaturated fatty acids and cholesterol was observed, and a rise in the concentrations of conjugated dienes fatty acids hydroperoxides and 7-ketocholesterol. Pretreatment with both synthetic capsiate and vanillyl alcohol preserved Vero cells from oxidative damage and showed a remarkable protective effect on the reduction of the levels of total unsaturated fatty acids and cholesterol, inhibiting the increase of MDA, conjugated dienes fatty acids hydroperoxides, and 7-ketocholesterol. Both compounds were effective against peroxidation of cell membrane lipids induced by TBH, with synthetic capsiate essentially acting as a pro-drug of vanillyl alcohol, its hydrophilic hydrolytic derivative.     

Protective effect of apple polyphenols against stress-provoked influenza viral infection in restraint mice

This study was conducted to investigate the effects of apple polyphenol extract (APE) against influenza virus in mice loaded with restraint stress. The high-performance liquid chromatography (HPLC) fingerprint of APE was recorded, and the percentage composition of polyphenols was determined as 81.7%. Our results showed that restraint stress significantly promoted the mortality and duration of complications of mice infected with the H1N1 virus. However, oral administration of APE (100 and 200 mg/kg) improved the survival rates and prolonged living time of stressed mice infected with influenza virus in a dose-dependent manner. APE was further found to significantly improve the number of immunocytes, ratio of CD4 helper cells, secretion of IL-2, and capabilities of natural killer (NK) cytotoxicity (LU10/spleen) in spleens of restraint-stressed mice. In addition, APE also significantly decreased the level of lipid peroxidation and increased oxygen radical absorbance capacity (ORAC) in splenocytes. These results indicated that the protective effects of APE on mice infected with influenza virus were related to the alleviation of stress-induced impairment of immune functions and its antioxidant property might contribute to the immune recovery.     

西洋参分段式热风干燥动力学模型构建

针对直接将干燥时间带入干燥动力学模型无法准确得到分段式干燥各干燥阶段水分比的问题,提出了一种适用于分段式干燥的干燥动力学模型计算方法,可用于分析分段式干燥过程中水分比变化规律。对西洋参进行了干燥试验研究并对试验结果进行了非线性拟合,表明Modified Page模型适用于西洋参热风干燥的干燥动力学;通过对干燥条件和干燥常数的线性回归分析得到了偏回归系数,基于该偏回归系数对西洋参分段式干燥过程进行分析,得到了西洋参分段式热风干燥中各段的干燥动力学模型。利用所提出的计算方法对西洋参分段式干燥过程中水分比变化情况进行了计算,并将计算结果与西洋参分段式热风干燥试验结果进行了对比分析,发现计算结果与试验结果最大相对误差为7.44%,平均相对误差仅为1.78%。表明所提出的分段式干燥动力学模型计算方法可用于分析西洋参干燥过程中的水分比变化。     

Protective effect of the phenolic fraction from virgin olive oils against oxidative stress in human cells

This paper reports the protective effect of the phenolic fraction extracted from extra virgin olive oils (OOPEs) against the cytotoxic effects of reactive oxygen species in human erythrocytes and Caco-2 cells, employed as model systems. Pretreatment of cells with various OOPEs, indeed, provides a remarkable protection against oxidative damages: this effect was strictly dependent on the o-diphenolic content of the extracts. Moreover, the protective effects observable in cellular systems were compared with in vitro antioxidant properties, measured by using the FRAP (ferric reducing/antioxidant power) assay; the reducing ability of OOPEs strictly parallels their o-phenolic content. The linear relationship demonstrated between biological effects and antioxidant capacity measured by the FRAP assay allows us to propose the use of this rapid colorimetric method in assessing and certifying the antioxidant power of extra virgin olive oil.     

Saponins composition in American ginseng leaf and berry assayed by high-performance liquid chromatography

The root of American ginseng is a commonly used herbal medicine in the United States. However, the compositions of American ginseng leaves and berries are not clear to date. In this study, we improved a method for the analysis of 12 ginsenosides based on solid phase extraction and high-performance liquid chromatography-ultraviolet. Good resolution was obtained for all tested ginsenosides: Rb1, Rb2, Rb3, Rc, Rd, Re, Rg1, Rg2, 20(R)-Rg2, Rg3, Rh1, and Rh2. Ginsenosides Rh1, Rg2, and 20(R)-Rg2 were easily separated with this column. The modified gradient elution program resulted in satisfactory linearity and precision. Solid phase extraction made the analysis accurate and efficient. Other investigators recently observed that ginsenoside Rb3 is a potent neuroprotective compound; it can promote learning and memory. In this report, we found that the major ginsenoside in American ginseng leaves and berries was ginsenoside Rb3, while Rb3 only had limited amounts in the root of American ginseng and other species of the Panax genus. Ginsenoside Rb3 was quantified as 4.71% in American ginseng leaves and 5.35% in berries, suggesting that American ginseng leaves and berries are new sources of ginsenoside Rb3.     

Protective effects of fermented filtrate from Antrodia camphorata in submerged culture against CCl4-induced hepatic toxicity in rats

The protective effects and the possible mechanisms of dry matter of fermented filtrate (DMF) from Antrodia camphorata in submerged culture (ACSC) on H(2)O(2)-induced cytotoxicity in HepG2 and carbon tetrachloride (CCl(4))-induced hepatotoxicity in Sprague-Dawley rats were investigated. The results showed that the inhibitory effect of DMF and its crude triterpenoids on lipid peroxidation occurred in a dose-response manner in an AAPH/linoleic acid system. When HepG2 cells were pretreated with DMF at the concentration of 0.10 mg/mL for 4 h and then induced by 1 h of treatment with H(2)O(2) (100 microM), lipid peroxidation was significantly (p < 0.05) decreased, as measured by the formation of malondialdehyde. The oral pretreatment with DMF [0.25 and 0.50 mg/kg of body weight (bw)] for 5 consecutive days prior to the administration of a single dose of 40% CCl(4) (0.10 mL/100 g of bw, ip) significantly prevented the increase in serum levels of hepatic enzyme markers (alanine and aspartate aminotransferase) and liver lipid peroxidation (p < 0.05). Histopathological evaluation of the rat liver revealed that DMF reduced the incidence of liver lesions, including neutrophil infiltration, hydropic swelling, and necrosis induced by CCl(4) in rats. Moreover, reduced glutathione (GSH)-dependent enzymes (glutathione peroxidase, glutathione reductase, and glutathione S-transferase) and the GSH/GSSG ratio were significantly improved in the oral pretreatment DMF of rats (p < 0.01). The results suggest that DMF may play a role in preventing oxidative damage in living systems by up-regulating hepatic GSH-dependent enzymes to preserve the normal GSH/GSSH ratio and scavenging free radicals formed during CCl(4) metabolism.     

一株人参根区解磷细菌的筛选、鉴定及对人参生长的影响

人参是我国传统名贵中药材,也是吉林省对外交往中的代名词。吉林参畦土壤有效磷含量低,但大量施用磷肥又会导致人参品质的下降,因此,本研究从人参根区土壤中筛选高效解磷细菌,接种到人参根部,研究其对人参生长、品质、土壤速效养分、土壤酶活性的影响,以期为人参解磷微生物肥料提供优良菌株,从而促进人参产业绿色发展。采用PKO平板初筛及摇瓶复筛从野山参根区土壤筛选高效解磷细菌。盆栽试验以3年生人参种苗为材料,每盆种植6棵单株重相同的人参种苗,设对照(CK)和处理组,待完全展叶后间苗,留取4棵长势一致的人参苗,采用滴灌的方式将菌液接种在人参苗根部附近,生长至红果期(90 d)取样,测定植物生长量和叶绿素含量、土壤速效养分、参根和参叶中NPK的含量、土壤酶活性、参根中微量元素和8种皂苷的含量。结果表明,1)平板初筛和摇瓶复筛得到P1、P7菌株,摇瓶培养中,P1可溶性磷为472.85μg/m L,P7可溶性磷为437.33μg/m L。2)P1处理的人参参根鲜重、干重显著高于P7、BM、CK处理,株高显著高于对照,叶绿素含量显著高于P7、BM、CK(P0.05)。3)P1处理促进人参对土壤钾元素的吸收,提高磷素在参根中的积累量。4)接种菌剂可以不同程度的提高土壤酶活性,以P1处理的效果最显著,P1处理人参根际土壤脲酶、酸性磷酸酶、过氧化物酶活性均为最高。5)P1处理显著提高了人参根中Fe、Mn、Cu的含量,分别较对照增加了52.74%、127.03%、28.96%,P1处理Zn与对照相比增加19.96%;人参根中8种单体皂苷P1处理均显著高于P7、BM、CK。6)经16S rRNA分析结合P1形态初步鉴定为假单胞菌。     

Activity of (-)-epigallocatechin 3-O-gallate against oxidative stress in rats with adenine-induced renal failure

Methylguanidine (MG) is widely recognized as a strong uremic toxin. The hydroxyl radical (*OH) specifically plays an important role in the pathway of MG production from creatinine (Cr). In this study, we investigated whether oral administration of (-)-epigallocatechin 3-O-gallate (EGCg) suppresses MG production in rats with chronic renal failure after intraperitoneal Cr injection. MG production from Cr was significantly increased in rats with adenine-induced renal failure, which was more vulnerable to oxidative stress, compared with that in normal rats. However, oral administration of EGCg 30 min before and after Cr injection effectively inhibited MG production. Our findings suggest that EGCg, an excellent antioxidant from green tea, exerts protective activity in rats with chronic renal failure, resulting in suppression of Cr oxidation influenced by *OH.     

Protective effect of ascorbic acid against the browning developed in apple fruit treated with high hydrostatic pressure.

Apple Reineta variety was used as an apple dessert. The 1-1.5-cm cubes were immersed in a sucrose solution (30% w/v) and subjected to high pressure (HP) of 400 MPa for 30 min at 5 degrees C. Different ascorbic acid concentrations were used to protect the fruit from the browning developed after the HP treatment. After 2 months of storage at 5 degrees C, no brown color was observed in the samples treated with 20 mM ascorbic acid, and they were acceptable to consumers. However, untreated samples presented fermentation, and they were not acceptable to consumers. The electric conductivity and potassium content were found to be good indicators of the metabolites released from the fruit to the solution in samples treated with high pressure. HP did not affect the peroxidase activity but eliminated the microbial population.     

Protective effects of dietary chamomile tea on diabetic complications

Matricaria chamomilla L., known as "chamomile", has been used as an herbal tea or supplementary food all over the world. We investigated the effects of chamomile hot water extract and its major components on the prevention of hyperglycemia and the protection or improvement of diabetic complications in diabetes mellitus. Hot water extract, esculetin (3) and quercetin (7) have been found to show moderate inhibition of sucrase with IC50 values of 0.9 mg/mL and 72 and 71 microM, respectively. In a sucrose-loading test, the administration of esculetin (50 mg/kg body weight) fully suppressed hyperglycemia after 15 and 30 min, but the extract (500 mg/kg body weight) and quercetin (50 mg/kg body weight) were less effective. On the other hand, a long-term feed test (21 days) using a streptozotocin-induced rat diabetes model revealed that the same doses of extract and quercetin showed significant suppression of blood glucose levels. It was also found that these samples increased the liver glycogen levels. Moreover, chamomile extract showed potent inhibition against aldose reductase (ALR2), with an IC50 value of 16.9 microg/mL, and its components, umbelliferone (1), esculetin (3), luteolin (6), and quercetin (7), could significantly inhibit the accumulation of sorbitol in human erythrocytes. These results clearly suggested that daily consumption of chamomile tea with meals could contribute to the prevention of the progress of hyperglycemia and diabetic complications.     

Protective activities of stilbene glycosides from Acer mono leaves against H2O2-induced oxidative damage in primary cultured rat hepatocytes

In our previous study, we isolated two new hepatoprotective stilbene glycosides, 5-O-methyl-(E)-resveratrol 3-O-beta-D-glucopyranoside (MRA) and 5-O-methyl-(E)-resveratrol 3-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (MRAG), from the methanolic extract of Acer mono leaves. Thereby, we have attempted to elucidate the hepatoprotective mechanism of these compounds, focusing on antioxidative effects, using hydrogen peroxide (H2O2)-injured primary cultures of rat hepatocytes. Both MRA and MRAG showed potent hepatoprotective activities in pretreatment but showed little effects in posttreatment. In addition, they increased the glutathione (GSH) level in the normal control cultures and significantly prevented the depletion of GSH in H2O2-injured primary cultured rat hepatocytes. Moreover, these compounds significantly restored the level of GSH depleted by buthionine sulfoximine or diethylmaleate in the presence or absence of H2O2. Furthermore, these compounds preserved the activities of antioxidant enzymes such as superoxide dismutase, glutathione reductase, and glutathione peroxidase reduced by H2O2 insults. Meanwhile, MRA and MRAG showed moderate scavenging effects with IC50 values of 103.6 and 80.5 microM, respectively, as determined by 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging activity. Taken together, these results suggest that MRG and MRAG exert significant hepatoprotective activities against H2O2-induced hepatotoxicity by maintaining the antioxidative defense system rather than scavenging free radicals.     

Phytochemistry of wild populations of Panax quinquefolius L. (North American ginseng)

A survey of the phytochemistry of Panax quinquefolius L. (North American ginseng) collected from wild populations in Ontario, Quebec, Maine, Vermont, and Wisconsin was undertaken. Reverse-phase HPLC was used to determine the natural variation of levels of ginsenosides Rg1, Re, Rf, Rb1, Rc, Rb2, and Rd and their total in leaf, stem, and root of authentic wild-grown material. The totals in roots varied from 1 to 16%, with the greatest number of individual samples having 4-5% total ginsenosides. The lack of ginsenoside Rf in roots of authentic wild populations confirmed its status as a phytochemical marker differentiating American and Asian ginseng. Ten geographically isolated wild populations were collected, and several showed significant variation in the levels of major ginsenosides. There was no statistical difference in mean ginsenoside content between wild and cultivated P. quinquefolius roots at 4 years of age, suggesting there is no phytochemical justification for wild crafting. Baseline data on total ginsenoside levels for authentic wild P. quinquefolius reported here provide reference levels for quality assurance programs.     

Degradation of ginsenosides in American ginseng (Panax quinquefolium) extracts during microwave and conventional heating

The degradation of ginsenosides in American ginseng (Panax quinquefolium) extracts during microwave and water (oil) bath heating (conventional heating) was investigated. Both the 50% ethanol-water extracts and the aqueous extracts were boiled in a modified laboratory microwave oven and in a water (or oil) bath, respectively. The neutral ginsenosides (Rb(1), Rc, Rd, and Re) and malonyl ginsenosides (m-Rb(1), m-Rc, and m-Rd) were determined by reverse-phase high-performance liquid chromatography. The results showed that the degradation of ginsenosides in 50% ethanol-water extracts was a first-order reaction. The malonyl ginsenosides were much less stable than the corresponding neutral ginsenosides, with the rate constant value of the malonyl ginsenosides being 3-60 times that of the neutral ginsenosides. At the same temperature, the effect of microwave heating on the degradation of ginsenosides was the same as that of conventional heating.