Schisandrin B protects against solar irradiation-induced oxidative stress in rat skin tissue

Schisandrin B (Sch B) and schisandrin C (Sch C), but not schisandrin A and dimethyl diphenyl bicarboxylate, protected rat skin tissue against solar irradiation-induced oxidative injury, as evidenced by a reversal of solar irradiation-induced changes in cellular reduced glutathione and α-tocopherol levels, as well as antioxidant enzyme activities and malondialdehyde production. The cytochrome P-450-mediated metabolism of Sch B or Sch C caused ROS production in rat skin microsomes. Taken together, Sch B or Sch C, by virtue of its pro-oxidant action and the subsequent eliciting of a glutathione antioxidant response, may prevent photo-aging of skin.     

Schisandrin B protects against solar irradiation-induced oxidative injury in BJ human fibroblasts

The effects of schisandrin B (Sch B) and its analogs on solar irradiation-induced oxidative injury were examined in BJ human fibroblasts. Sch B and schisandrin C (Sch C) increased cellular reduced glutathione (GSH) level and protected against solar irradiation-induced oxidative injury. The photoprotection was paralleled by decreases in the elastases-type protease activity and matrix-metalloproteinases-1 expression in solar-irradiated fibroblasts. The cytochrome P-450-mediated metabolism of Sch B or Sch C caused ROS production. The results suggest that by virtue of its pro-oxidant action and the subsequent glutathione antioxidant response, Sch B or Sch C may offer the prospect of preventing skin photo-aging.     

沙棘叶子提取物对白化病白鼠由铬诱导氧化胁迫的抗氧化活性评估

本研究报道沙棘(胡颓子科)对雄性白化病白鼠由铬诱导氧化胁迫的抗氧化活性。氧化胁迫通过对小白鼠进行强制性喂养30 d,以浓度为30 m g/kg的铬相对体重比例的重铬酸钾盐实现。铬促使体重下降,而却明显增加了器官与体重比例。铬处理明显减少了谷胱甘肽的降低,增加了丙二醛和肌氨酸磷酸激酶的水平;而且它还加强了血清中谷氨酸草酰乙酸转移酶和谷氨酸丙酮酸转移酶的浓度。用不同剂量的沙棘叶子提取物(乙醇提取)对保护铬元素诱导的氧化胁迫进行了评估,结果表明叶子提取物在浓度为100到250 m g/kg铬与体重比的情况下可以明显保护动物避免由铬所诱导的氧化伤害。     

Gastroprotective potential of frutalin, a D-galactose binding lectin, against ethanol-induced gastric lesions

The present study was designed to verify whether frutalin (FTL) affords gastroprotection against the ethanol-induced gastric damage and to examine the underlying mechanism(s). Gastric damage was induced by intragastric administration of 0.2 ml of ethanol (96%). Mice in groups were pretreated with FTL (0.25, 0.5 and 1 mg/kg; i.p.), cimetidine (100 mg/kg; p.o.), or vehicle (0.9% of NaCl, 10 mL/kg; p.o.), 30 min before ethanol administration. They were sacrificed 30 min later, the stomachs excised, and the mucosal lesion area (mm2) measured by planimetry. Gastroprotection was assessed in relation to inhibition of gastric lesion area. To study the gastroprotective mechanism(s), its relations to capsaicin-sensitive fibers, endogenous prostaglandins, nitric oxide, sulphydryls, ATP-sensitive potassium channels, adrenoceptors, opioid receptors and calcium channels were analyzed. Treatments effects on ethanol-associated oxidative stress markers GSH and MDA were measured in gastric tissue. FTL afforded a dose-unrelated gastroprotection against the ethanol damage. However, it failed to prevent the ethanol-induced changes in the levels of GSH and MDA. It was observed that the gastroprotection by FTL was greatly reduced in animals pretreated with capsazepine, indomethacin, L-NAME or glibenclamide. Considering the results, it is suggested that the FTL could probably be a good therapeutic agent for the development of new medicine for the treatment of gastric ulcer.     

Variations in the content of stress proteins in the needles of common pine (Pinus sylvestris L.) within an annual cycle

This investigation has focused on the content of heat shock proteins (Hsps) and dehydrins (dhn) in the needles of Pinus sylvestris L. (common pine) depending on environmental conditions and on adaptation of photosynthetic activity. Unlike the case of photosynthetic activity, no relationships have been revealed between variations in environmental conditions over 2 years of observations and variations in Hsps content. It has been discovered that constitutive and stress forms of Hsp70, Hsp60 and dhn are accumulated in the cold season of the year, whereas for Hsp17.6 and Hsp101 this accumulation occurs in the warm season. Seasonal air temperature variations influenced the content of Hsps; variations of temperature and moisture conditions influenced the content of dhn. The supposition is made that accumulation of Hsp70, Hsp60 and dhn in the needles may be the factor and/or the marker of the autumn and spring adaptation of the photosynthetic apparatus, while accumulation of Hsp17.6 and Hsp101 is the marker of summer “heat” adaptation.     

Interactions of water stress and solar irradiance on the physiology and biochemistry of Ligustrum vulgare

We studied the interactive effects of water stress and solar irradiance on physiological and biochemical traits in Ligustrum vulgare L., with special emphasis on antioxidant enzymes and flavonoids. Water relations, photosynthetic performance, plant growth, activities of antioxidant enzymes and of phenylalanine-ammonia-lyase, and concentrations of nonstructural carbohydrates and phenylpropanoids were measured in plants growing in 12% (shade) or 100% (sun) sunlight and supplied with 100 or 40% of daily evapotranspiration-demand over a 4-week period. The mild water stress treatment caused leaf water potential and relative water content to decline on average by -0.22 MPa and 4.5%, respectively. In response to the water stress treatment, photosynthetic rates decreased more in sun plants than in shade plants, likely because of declines in photosystem II photochemistry, apparent maximum rate of carboxylation and apparent maximum electron transport rate coupled with significant reductions in stomatal conductance. Antioxidant enzymatic activities, which were much greater in sun leaves than in shade leaves under well-watered conditions, increased (particularly the enzymatic activities associated with hydrogen peroxide removal) in response to water stress only in shade leaves. Antioxidant phenylpropanoids, particularly quercetin and luteolin derivatives, markedly increased in response to full sunlight irrespective of water treatment; however, antioxidant phenylpropanoid concentrations increased in response to water stress only in shade leaves. We suggest that: (1) assimilated carbon in sun plants was used largely to support an effective antioxidant system capable of countering water-stress-induced oxidative damage--an example of cross tolerance; and (2) in shade plants, carbon was also diverted from growth to counter oxidative damage driven by the mild water-stress treatment. Both findings are consistent with the nearly exclusive distribution of L. vulgare in well-watered, partially shaded Mediterranean areas.     

Stereospecific antioxidant effects of ginsenoside Rg3 on oxidative stress induced by cyclophosphamide in mice

Ginsenoside Rg3 is one of the active ingredients isolated from Panax ginseng C.A. Meyer. Previous investigation demonstrated that Rg3 was stereospecific in promotion of the immune response. The present study was designed to evaluate Rg3 and its epimers, 20(R)-Rg3 and 20(S)-Rg3, for their effects on oxidative stress induced by cyclophosphamide (Cy) in mice. Forty-eight mice were randomly distributed into 6 groups and intraperitoneally administered saline solution, Cy, 20(R)-Rg3, 20(S)-Rg3, 20(R)-Rg3+Cy or 20(S)-Rg3+Cy. After that, the spleen, thymus and serum were collected to measure the indices of the organs and oxidative parameters. The results showed that Rg3 significantly inhibited Cy-induced oxidative stress in mice by increasing the indices of the spleen and thymus and total antioxidant capacity, elevating the activities of catalase, superoxidase dismutase and lysozyme as well as decreasing the activity of xanthine oxidase and the levels of malondialdehyde and nitric oxide. Rg3 was stereospecific in antioxidant activities as R form exhibited significantly higher antioxidant effects than S form. Therefore, R form should be used when Rg3 is considered to be used as an antioxidant agent.     

盐胁迫对‘南林895’杨组培再生芽生根及抗氧化能力的影响

以‘南林895’杨经组培获得的2 cm长再生芽为试验材料,研究不同浓度NaCl处理下再生芽不定根发生能力及其耐盐能力。结果表明:‘南林895’杨再生芽在75 mmol/L以下能够正常产生不定根,100 mmol/L完全抑制不定根的形成。25～50 mmol/L盐处理能够促进‘南林895’杨再生芽不定根的伸长,增加根数,提高叶绿素a及总叶绿素的含量。25 mmol/L处理的SOD、CAT、POD、GR 4种保护酶与对照之间没有显著性差异,MDA含量和电导率也低于对照;而在高浓度盐处理下(75～100 mmol/L),SOD、CAT、GR保护酶活性下降,导致膜透性加大,MDA含量增加,POD和AsA-POD酶活性的提高有助于缓解盐胁迫对‘南林895’杨造成的氧化损伤。     

Ionic homeostasis and reactive oxygen species control in leaves and xylem sap of two poplars subjected to NaCl stress

We investigated the effects of increasing soil NaCl concentration on intracellular compartmentalization of salt and on the activities of antioxidant enzymes (superoxide dismutase (SOD), ascorbic peroxidase (APX), catalase (CAT) and glutathione reductase (GR)) and their role in the regulation of reactive oxygen species (ROS; O(2)(-*) and H(2)O(2)) in leaves and xylem sap of salt-tolerant Populus euphratica Oliv. and salt-sensitive P. popularis cv. 35-44. Mesophyll cells of P. euphratica exhibited a high capacity for NaCl exclusion and compartmentalization of salt in vacuoles compared with P. popularis. In P. popularis, the salt treatment resulted in large accumulations of Na(+) and Cl(-) in leaves that induced significant increases in O(2)(-*) and H(2)O(2) production despite marked increases in the activities of antioxidant enzymes in leaves and xylem sap. Separation of the isoforms of leaf SOD, APX and CAT by polyacrylamide gel electrophoresis followed by in-gel activity staining revealed that the salt-induced activities of APX and CAT were the result of increases in activities of all the isoenzymes. Leaf injury and shedding of aged leaves occurred following the oxidative burst in P. popularis, indicating that the increased activities of antioxidant enzymes in P. popularis were insufficient to counter the harmful effects of ROS at high soil NaCl concentrations. Unlike P. popularis plants, P. euphratica plants did not exhibit an oxidative burst in response to the NaCl treatments, because of (1) a high salt exclusion capacity and effective compartmentalization of salt in vacuoles, and (2) up-regulation of antioxidant enzymatic activities after the onset of salt stress. We conclude that P. euphratica plants subjected to saline conditions control ROS homeostasis through two pathways: (1) by maintaining cellular ionic homeostasis and thereby limiting the NaCl-induced enhancement of ROS production under long-term saline conditions; and (2) by rapidly up-regulating antioxidant defenses to prevent oxidative damage.     

Hepatoprotective effect of Ginkgoselect Phytosome in rifampicin induced liver injury in rats: evidence of antioxidant activity

The protective effects of Ginkgoselect Phytosome((R)) (GBP) on Rifampicin (RMP) induced hepatotoxicity and the probable mechanism(s) involved in this protection were investigated in rats. Liver damage was induced in Wistar rats by administering rifampicin (500 mg/kg, p.o.) daily for 30 days. Simultaneously, GBP at 25 mg/kg and 50 mg/kg, and the reference drug silymarin (100 mg/kg) were administered orally for 30 days/daily to RMP treated rats. Levels of marker enzymes (SGOT, SGPT and SALP), albaumin (Alb) and total proteins (TP) were assessed in serum. The effects of GBP on lipid peroxidation (LPO), reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GR) were assayed in liver homogenates to evaluate antioxidant activity. GBP (25 and 50 mg/kg) and silymarin elicited a significant hepatoprotective activity by lowering the levels of serum marker enzymes and lipid peroxidation and elevated the levels of GSH, SOD, CAT, GPX, GR, Alb and TP in a dose dependant manner. The present findings suggest that the hepatoprotective effect of GBP in RMP induced oxidative damage may be related to its antioxidant and free radical scavenging activity.     

Effect of salt on ROS homeostasis, lipid peroxidation and antioxidant mechanisms in Pinus pinaster suspension cells

? In the Pinus genus, information on the effectiveness of oxidative defence mechanisms during exposure to salt is lacking. The effect of salt stress imposition on ROS homeostasis was investigated using maritime pine (Pinus pinaster Ait.) suspension cells as a model system.

? Cells were maintained in MS-based medium, exposed to salt (50, 100 and 150 mM NaCl) and analysed for biomass production, evidencing a decreasing growth capacity. Use of 100 mM NaCl imposed severe salt stress without affecting cell viability, being chosen for subsequent studies on the ROS homeostasis of salt shock-treated suspension cells.

? Increased total ROS levels were evident on the second day of salt exposure, but a superoxide ion transient burst was immediately noticeable. Additionally, lipid peroxide formation seemed to correlate with superoxide ion breakdown. In-gel superoxide dismutase activity evidenced a FeSOD homodimer with strongly increasing activity between hours 12–48 of salt stress imposition. Subsequently, P. pinaster Fe-Sod1 and csApx1 genes were isolated from a cDNA library and expression was shown to increase within 12–24 h.

? Results show that severe salt treatment generates oxidative stress in P. pinaster cells despite the induction of antioxidant systems, and suggest a putative involvement of ROS in salt stress signalling.

     

Celastrus paniculatus seed water soluble extracts protect cultured rat forebrain neuronal cells from hydrogen peroxide-induced oxidative injury

The effects of aqueous extracts of Celastrus paniculatus (CP) seeds were shown to have antioxidant properties in rats. In the study reported here, we have investigated the free radical scavenging capacity of three aqueous extracts (WSEs) obtained from CP seeds: a room temperature extract (WF); a hot water extract (HF); an acid extract (AF). All the WSEs exhibited a dose-dependent free radical scavenging capacity for 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) and also for superoxide-generated assays (in vitro assays). In addition, we used enriched forebrain primary neuronal cell (FBNC) cultures to evaluate the neuroprotective effects of the three CP-WSE extracts on H(2)O(2)-induced toxicity. FBNC were pre-treated with the CP-WSE and then with H(2)O(2) to evaluate the protection afforded against H(2)O(2)-induced toxicity. The criteria for neuroprotection by the WSEs were based on a mitochondrial function test following the H(2)O(2)-induced neurotoxicity. All the WSEs significantly attenuated H(2)O(2)-induced neuronal death, and AF was the most effective in protecting the neuronal cells against oxidative injury caused by H(2)O(2). In 10 day FBNC, cellular superoxide dismutase activity was not affected by the WSEs or H(2)O(2), but catalase activity was decreased and levels of malondialdehyde were increased by H(2)O(2) treatment. When the neuronal cells were treated with WSEs prior to H(2)O(2) exposure, catalase activity was increased and levels of malondialdehyde were decreased significantly. The data presented here suggest that CP seed WSEs protected neuronal cells in part by their free radical scavenging properties, by reducing lipid peroxidation, and also by their ability to induce the antioxidant enzyme catalase. Our results indicate that WSEs might exert neuroprotective effects against increased oxidative stress resulting from free radical damage that is associated with a number of neurodegenerative diseases.     

Effects of the commercial extract of aronia on oxidative stress in blood platelets isolated from breast cancer patients after the surgery and various phases of the chemotherapy

Since the extract from berries of Aronia melanocarpa presents antioxidative properties in plasma and in blood platelets, not only from healthy group, but also from patients with benign breast diseases and in patients with invasive breast cancer before surgery, the aim of our present study was to evaluate the oxidative stress by measuring the level of various biomarkers of this process such as the generation of superoxide anion radicals (O(2)(-·)), the amount of carbonyl groups and 3-nitrotyrosine in proteins or the amount of glutathione in blood platelets isolated from breast cancer patients after the surgery and after various phases of the chemotherapy in the presence of A. melanocarpa extract (Aronox) in vitro. We demonstrated in platelet proteins from patients with invasive breast cancer (after the surgery and after various phases of the chemotherapy) higher level of carbonyl groups than in control healthy group. The level of 3-nitrotyrosine in platelet proteins from patients with invasive breast cancer was also significantly higher than in healthy subject group. We observed an increase of other biomarkers of oxidative stress such as O(2)(-·) and a decrease of GSH in platelets from patients with breast cancer (after the surgery and after various phases of the chemotherapy) compared to the healthy group. In model system in vitro our results showed that the commercial extract from berries of A. melanocarpa due to antioxidant action, significantly reduced the oxidative/nitrative stress in platelets from patients with invasive breast cancer caused by the surgery and various phases of the chemotherapy.     

Pre-treatment of Syndrex® protects mice from becoming diabetic after streptozotocin injection

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia due to either insufficiency of insulin or inability of cells to respond to insulin. Many clinical and experimental evidence have suggested the strong association between hyperglycemia, oxidative stress and diabetic complications. Therefore, the antidiabetic drugs with antioxidant potential would have a higher therapeutic value. To check its antidiabetic and antioxidant properties in vivo, experiments were done wherein mice were fed with Syndrex^® in different schedules and/or made diabetic by intraperitoneal injection of streptozotocin. Animals fed with Syndrex^® prior to the induction of diabetes by streptozotocin injection showed resistance to an increase in blood glucose levels. This treatment increased the activities of antioxidant enzymes namely, catalase, glutathione reductase and superoxide dismutase and reduced serum triglyceride and cholesterol levels as compared to those found in uncontrolled diabetic mice. Among the three different schedules used for Syndrex^® treatment, the best effect was seen in the case of mice pretreated with Syndrex^® prior to STZ injection. In our opinion, Syndrex^® given along with insulin may reduce the amount of insulin dose required and because of its strong antioxidant activity would certainly help to reduce the development of diabetic complications.     

Protective effects of Picrorrhiza kurroa against HCl/ethanol-induced ulceration in rats

The antiulcerogenic effects of the ethanol extract of Picrorrhiza kurroa rhizomes and roots (PK) on HCl/ethanol-induced ulceration in rats with respect to acid/pepsin, lipid peroxidation, antioxidant status, proteins and glycoproteins in the gastric mucosa have been investigated. Oral pre-treatment with PK (100 mg/kg/day for 10 days) significantly prevented the induced ulceration and maintained the rats at near normal status.     

Antihyperglycemic and antioxidant activities of total alkaloids from Catharanthus roseus in streptozotocin-induced diabetic rats

We evaluated the hypoglycemic and antioxidant effects of the total alkaloids of leaves and twigs of Catharanthus roseus Linn.(CTA) in streptozotocin(STZ)-induced diabetic rats. The hypoglycemic effect was measured by blood glucose and plasma insulin level. Oxidative stress was measured in heart, liver and kidney by levels of antioxidant markers, free radical scavengers and lipid peroxides i.e. superoxide dismutase(SOD), catalase(CAT), glutathione(GSH) and thiobarbituric acid reactive substances(TBARS). Biochemical parameters, i.e. aspartate aminotransferase(AST), alanine aminotransferase(ALT), alkaline phosphate(ALP) were observed in diabetic control and treated rats. Oral administration of CTA for30 days was followed by a significant(P \ 0.05) decrease in fasting blood glucose and increase in insulin level as compared with untreated diabetic rats. Also it significantly(P \ 0.05) reduced ALT, AST and ALP. The treatment also resulted in significant(P \ 0.05) reductions in GSH,SOD, CAT, and decrease in TBARS in the heart, liver and kidney of diabetic rats. The results suggest that CTA can effectively normalize the impaired antioxidant status in STZ-induced diabetes in a dose-dependent manner.CTA exerted rapid protective effects against lipid peroxidation by scavenging of free radicals and reducing the risk of diabetic complications.     

An HPLC-ESI-MS method for analysis of loureirin A and B in dragon's blood and application in pharmacokinetics and tissue distribution in rats

A sensitive HPLC-ESI-MS method for the simultaneous determination of loureirin A (LA) and loureirin B (LB) in rat plasma and tissues was developed, and the pharmacokinetic and tissue distribution characteristics of LA and LB were investigated after gavage administration. The samples were pretreated by protein precipitation with ethyl acetate and then separated on a Welch Ultimate XB-C18 column with water-acetonitrile (42:58, v/v) containing 0.1% glacial acetic acid as the mobile phase. The analytes were detected with no interference in multiple reaction monitoring (MRM) mode on an electrospray ionization ion trap mass spectrometer. The analytes showed good linearity over a wide concentration range and the lowest limit of quantification (LLOQ) was 5 ng/mL for LA and 2 ng/mL for LB in matrices. The pharmacokinetic curves of both analytes were best fitted to one-compartment model. It suggested that the analytes absorbed and distributed very quickly in rats. Tissue distribution results showed that the analytes had a wide distribution in tissues and the highest levels for LA and LB were observed in liver followed by kidney, lung, spleen, heart and cerebrum. This work provided the pharmacokinetics and tissue distribution characteristics of LA and LB, which would be instructive for their clinical regiment design.     

Intestinal antiinflammatory activity of a lyophilized infusion of Turnera ulmifolia in TNBS rat colitis

Turnera ulmifolia is a plant popularly known in Brazil and South America as chanana. Some species of Turnera are widely used in folk medicine for different types of inflammatory diseases. In this study, the preventive intestinal antiinflammatory activity of a lyophilized infusion obtained from the aerial parts of T. ulmifolia was tested in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis. The results obtained revealed that pretreatment to colitic rats with the extract, at 250 and 500 mg/kg, significantly attenuated the colonic damage induced by TNBS. This beneficial effect was associated with an improvement in the colonic oxidative status, since the infusion prevented the glutathione depletion that occurred as a consequence of the colonic inflammation. On the other hand, this antioxidant activity was confirmed in in vitro studies. In conclusion, the preventive effect exerted by the lyophilized infusion of T. ulmifolia in the TNBS model of rat colitis is probably related to its antioxidant properties, due to its flavonoids content.     

Type 2 antidiabetic activity of bergenin from the roots of Caesalpinia digyna Rottler

Bergenin, a major constituent of Caesalpinia digyna Rottler (Leguminosae) was isolated from its roots and was characterized by comparing its melting point and spectroscopic data (IR, (1)H, (13)C, Mass Spectra) with standard bergenin. Isolated bergenin was then evaluated for antidiabetic (Type 2) activity in streptozotocin (STZ)-nicotinamide induced diabetic rats. Bergenin was administered at doses of 2.5, 5, and 10 mg/kg; p.o. to normal rats which were subjected to oral glucose tolerance test (OGTT). Bergenin at same dose level was given to diabetic rats and fasting blood glucose level was estimated on 0th, 7th and 14th day of treatment while plasma lipids, antioxidant enzymes and liver glycogen level in diabetic rats were estimated on 14th day of treatment followed by histopathological studies of pancreas. Bergenin at 10mg/kg; p.o. was found to reduce blood glucose level significantly in OGTT (P<0.01) while it showed a significant reduction in fasting blood glucose level in diabetic rats at same dose level only on 14th day of treatment. Bergenin in all dose levels reversed plasma lipid (reduced elevated TC, LDL-C and increased HDL-C level) profile to normal values except TG. However, bergenin showed no significant effect on liver glycogen at all dose level. The decrease in lipid peroxides and increase in superoxide dismutase (SOD) and catalase (CAT) in liver illustrated the antioxidant potential of bergenin. Histopathological studies demonstrated the regenerative effect of bergenin on pancreatic β cells. Hence, bergenin isolated from C. digyna possesses significant antidiabetic, hypolipidemic and antioxidant activity in Type 2 diabetic rats.     

Germination,osmotic adjustment,and antioxidant enzyme activities of gibberellin-pretreated <Emphasis Type="Italic">Picea asperata</Emphasis> seeds under water stress

Germination of dragon spruce (Picea asperata Mast.) seeds pretreated with gibberellin (GA) in response to water stress and changes in the levels of osmotic adjustments as well as in activities of antioxidant enzymes were investigated. With decreasing water potential caused by increasing concentrations of PEG 6000, germination percentage and germination index decreased gradually; the decrease was especially prominent under the serious water stress from PEG −0.6 MPa. In contrast, osmotic regulation substances (free proline and soluble sugar contents), lipid peroxidation (MDA), and activities of antioxidant enzyme (ascorbate peroxidase, catalase, and peroxidase) increased markedly with decreased water potential. Similarly, the values in all parameters under −0.6 MPa PEG treatment were markedly higher than the control and −0.2 MPa PEG treatment. These results suggested that P. asperata seed germination was insensitive to water stress. In addition, seeds pretreated with GA had increased tolerance to water stress as measured by germination percentage and germination index, osmotic regulation substance, and antioxidant enzyme activities.