Cedrol protects against chronic constriction injury-induced neuropathic pain through inhibiting oxidative stress and inflammation.

Injured somatosensory nervous system cause neuropathic pain which is quite difficult to treat using current approaches. It is therefore important to find new therapeutic options. We have analyzed cedrol effect on chronic constriction injury (CCI) induced neuropathic pain in rats. The mechanical and thermal hypersensitivity were evaluated using the von Frey filament, radiant heat and acetone drop methods. The changes in the levels of biomarkers of oxidative stress including malondialdehyde (MDA) and total thiol (SH), as well as inflammatory mediators including Tumour Necrosis Factor alpha (TNF-α) and Interleukin 6 (IL-6) were estimated in the lumbar portion (L4-L6) of neuropathic rats. Administration of cedrol attenuated the CCI-induced mechanical and thermal hypersensitivity. CCI produced an increase in MDA along with a reduction in SH levels in the spinal cord of the CCI rats. Reduced levels of SH were restored by cedrol. Also, the levels of MDA were reduced in the cedrol-treated CCI rats compared to the untreated CCI rats. Besides, level of TNF-α and IL-6 increased in the spinal cord of CCI group and cedrol could reverse it. The current study showed that cedrol attenuates neuropathic pain in CCI rats by inhibition of inflammatory response and attenuation of oxidative stress.

Nigella sativa and thymoquinone attenuate oxidative stress and cognitive impairment following cerebral hypoperfusion in rats.

Nigella sativa, a plant widely used in traditional medicine, possesses anti-inflammatory, antioxidant and neuroprotective properties. In the present study, we investigated the effect of hydroalcoholic extract of N. sativa seeds (NSE) and its active constituent, thymoquinone (TQ), on learning and memory deficits, hippocampal acetylcholine esterase (AChE) activity, and markers of redox status, mainly lipid peroxidation and superoxide dismutase (SOD) activity following cerebral hypoperfusion in rats. Cerebral hypoperfusion was induced by permanent occlusion of bilateral common carotid arteries (2VO). Male Wistar rats were administered either a vehicle (sham group: 10 ml/kg/day, ip), NSE (100, 200, and 400 mg/kg/day, ip), TQ (10, 20, and 40 mg/kg/day, ip), or donepezil (5 mg/kg/day, ip) for 10 days (three days before and seven days after ligation). Spatial learning and memory deficits were investigated using the Morris water maze (MWM) task. 2VO produced significant learning and memory deficits as evidenced by increased latency time to reach the hidden platform, increased swimming time, and decreased time spent in the target quadrant in the probe trial in the MWM task. There was also a significant increase in the lipid peroxidation level and AChE activity, and a significant decrease in SOD activity in the hippocampal portion of hypoperfused rats, as compared with the sham group. Treatment with NSE (400 mg/kg/day; p < 0.001) and TQ (40 mg/kg/day; p < 0.001), as well as donepezil significantly prevented learning and memory impairments and alleviated changes in the hippocampal lipid peroxide level and SOD and AChE activities in this model. In conclusion, our data suggest that N. sativa and thymoquinone have a beneficial role in cerebrovascular insufficiency states and dementia.

Terminalia chebula attenuates quinolinate-induced oxidative PC12 and OLN-93 cell death.

BACKGROUND: Quinolinic acid (QA) is a product of tryptophan degradation and its pathologic accumulation has been found to induce neuroinflammatory and demyelinating diseases such as multiple sclerosis via excessive free radicals generation. Recent studies showed that Terminalia chebula has several pharmacological effects such as antioxidant, anti-inflammatory and neuroprotective properties. The aim of this study was evaluation of the protective effect of T. chebula alcoholic extract (TCAE) on oxidative PC12 and OLN-93 cells death induced by QA. METHODS: The cells were pretreated with TCAE (6.25-50µg/mL) for 2h and then subjected to QA (8mM) for 24h. Cell viability and the parameters of redox status including the levels of intracellular reactive oxygen species (ROS), lipid peroxidation and oxidative DNA damage were measured using 2-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT), 2,7-dicholorofluorecin diacetate (DCF-DA), thiobarbituric acid and comet assays, respectively. RESULTS: Based on Folin-Ciocalteu method, the total phenolic compounds in TCAE were estimated about 1.18%. TCAE at concentration ranges of 6.25-50µg/mL had no toxic effect on cell viability (p>0.05). Treatment with TCAE significantly increased cell viability following QA insult at concentrations above 25µg/mL (p<0.01). Cytoprotective potential of TCAE also ameliorated ROS accumulation, lipid peroxidation and DNA damage induced by QA. CONCLUSION: These data suggest that TCAE exhibits neuroprotection and oligoprotection potential by means of alleviating oxidative stress parameters.

Aqueous and Ethanolic Extracts of Boswellia serrata Protect Against Focal Cerebral Ischemia and Reperfusion Injury in Rats.

Oxidative stress and cell apoptosis play major roles in neuronal injury after ischemia-reperfusion (I-R) injury. Boswellia serrata is a medicinal plant with antioxidant properties. Acetyl-11-keto-ß-boswellic acid (AKBA) is an active triterpenoid compound from B. serrate. In the current study, the neuroprotective effects of aqueous and ethanolic extracts of B. serrata (named ABS and EBS, respectively) and AKBA were investigated against middle cerebral artery occlusion-induced cerebral I-R injury in rats. ABS and EBS with doses of 125, 250 and 500 and AKBA with a dose of 50 mg/kg were administered (intraperitoneally) just after middle cerebral artery occlusion induction for 30 min and reperfusion for 24 h. HPLC analysis suggested that ABS and EBS had AKBA of 8.8% and 9.5% (w/w), respectively. B. serrata and AKBA significantly improved neurological deficit and reduced brain infarction, neuronal cell loss and apoptosis and also attenuated lipid peroxidation while increasing glutathione content and superoxide dismutase activity in the cerebral cortex following a stroke. Apoptosis suppression was found to be mediated through regulating caspase-3 and bax/bcl-2 expressions. In conclusion, our results demonstrated that B. serrata and AKBA attenuate oxidative damage and inhibit cell apoptosis, subsequently protecting cerebral I-R injury in rats. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of pomegranate seed oil on oxidative stress markers, serum biochemical parameters and pathological findings in kidney and heart of streptozotocin-induced diabetic rats.

PURPOSE: Oxidative stress due to hyperglycemia is a major cause of diabetes complications. The aim of this study was to evaluate the effects of pomegranate seed oil (PSO) on serum biochemical parameters, cardiomyopathy and nephropathy induced by diabetes mellitus. METHOD: W/A adult rats were divided into four groups (12 each): group 1, received saline (1 mL/kg), group 2, received streptozotocin (STZ, 65 mg/kg, a single dose as i.p.), groups 3 and 4, received STZ + PSO (0.4 and 0.8 mL/kg, daily by gavage, respectively). After three weeks, six rats of each group and one week later the remaining animals were anesthetized, blood samples were taken for measuring serum biochemical parameters. Sections of heart and kidneys were used for histopathological studies and the remaining tissues were homogenized for measuring malondialdehyde (MDA) and total sulfhydryl groups. RESULTS: Significant elevation of serum creatinine and urea, LDL, triglyceride, glucose levels as well as urine markers, MDA levels in tissue homogenates and a significant decrease in total thiol content and serum HDL were observed in STZ-treated group as compared with control group. PSO treatment resulted in a significant decrease in tissue MDA content, serum creatinine and urea levels as well as urine markers as compared with STZ-treated group. Lipid profile was ameliorated with PSO treatment. PSO also significantly reversed STZ-induced depletion in thiol content and histological abnormality. Effect of PSO was more specific at 28th than 21th days of study. CONCLUSION: The results showed that PSO has a protective effect against diabetes complications in rats.

A Review on Potential Mechanisms of Terminalia chebula in Alzheimer's Disease.

The current management of Alzheimer's disease (AD) focuses on acetylcholinesterase inhibitors (AChEIs) and NMDA receptor antagonists, although outcomes are not completely favorable. Hence, novel agents found in herbal plants are gaining attention as possible therapeutic alternatives. The Terminalia chebula (Family: Combretaceae) is a medicinal plant with a wide spectrum of medicinal properties and is reported to contain various biochemicals such as hydrolysable tannins, phenolic compounds, and flavonoids, so it may prove to be a good therapeutic alternative. In this research, we reviewed published scientific literature found in various databases: PubMed, Science Direct, Scopus, Web of Science, Scirus, and Google Scholar, with the keywords: T. chebula, AD, neuroprotection, medicinal plant, antioxidant, ellagitannin, gallotannin, gallic acid, chebulagic acid, and chebulinic acid. This review shows that T. chebula extracts and its constituents have AChEI and antioxidant and anti-inflammatory effects, all of which are currently relevant to the treatment of Alzheimer's disease.

Water-soluble compounds of lettuce inhibit DNA damage and lipid peroxidation induced by glucose/serum deprivation in N2a cells.

Oxidative stress, increase of lipid peroxidation and resultant DNA damage are associated with pathophysiology of many human diseases such as acute and chronic CNS injuries and diseases, cancer, and also aging. This work was done to investigate whether water fraction from the hydroalcoholic extract of green leaf lettuce (Lactuca sativa L.) can protect N2a cells against glucose/serum deprivation (GSD)-induced lipid peroxidation and DNA fragmentation. The cells were cultivated for 12 h in GSD condition in the absence or presence of the lettuce fraction. The total antioxidant ability of the lettuce water fraction was determined using ferric reducing antioxidant power (FRAP) assay. The intracellular lipid peroxidation was evaluated by malondialdehyde (MDA) level. DNA damage was determined using single cell gel electrophoresis. Using FRAP assay, the antioxidant activity of lettuce water fraction was found to be 574 micromol/g, which is equivalent to 64.1 mg of pure ascorbic acid. Exposure of the cells to GSD condition led to a significant increase of MDA level and DNA fragmentation. Lettuce extract at 400 microg/mL could decrease the elevated intracellular lipid peroxidation and DNA damage. The present study demonstrates that lettuce exerts genoprotective effect through inhibition of oxidative stress.

Protective effect of Crocus sativus stigma extract and crocin (trans-crocin 4) on methyl methanesulfonate-induced DNA damage in mice organs.

This study was designed to examine the effect of aqueous extract of Crocus sativus stigmas (CSE) and crocin (trans-crocin 4) on methyl methanesulfonate (MMS)-induced DNA damage in multiple mice organs using the comet assay. Adult male NMRI mice in different groups were treated with either physiological saline (10 mL/Kg, intraperitoneal [ip]), CSE (80 mg/Kg, ip), crocin (400 mg/Kg, ip), MMS (120 mg/Kg, ip), and CSE (5, 20, and 80 mg/Kg, ip) 45 min prior to MMS administration or crocin (50, 200, and 400 mg/Kg, ip) 45 min prior to MMS administration. Mice were sacrificed about 3 h after each different treatment, and the alkaline comet assay was used to evaluate the effect of these compounds on DNA damage in different mice organs. The percent of DNA in the comet tail (% tail DNA) was measured. A significant increase in the % tail DNA was seen in nuclei of different organs of MMS-treated mice. In control groups, no significant difference was found in the % tail DNA between CSE- or crocin-pretreated and saline-pretreated mice. The MMS-induced DNA damage in CSE-pretreated mice (80 mg/Kg) was decreased between 2.67-fold (kidney) and 4.48-fold (lung) compared to those of MMS-treated animals alone (p < 0.001). This suppression of DNA damage by CSE was found to be depended on the dose, which pretreatment with CSE (5 mg/Kg) only reduced DNA damage by 6.97%, 6.57%, 7.27%, and 9.90% in liver, lung, kidney, and spleen, respectively (p > 0.05 as compared with MMS-treated group). Crocin also significantly decreased DNA damage by MMS (between 4.69-fold for liver and 6.55-fold for spleen, 400 mg/Kg), in a dose-dependent manner. These data indicate that there is a genoprotective property in CSE and crocin, as revealed by the comet assay, in vivo.

Effect of safranal on extracellular hippocampal levels of glutamate and aspartate during kainic Acid treatment in anesthetized rats.

In this study, the effect of safranal, a constituent of CROCUS SATIVUS L., pretreatment on concomitant changes in the extracellular hippocampal levels of EAA (glutamate and aspartate) following systemic administration of KA was investigated in anesthetized rats. Safranal (72.75 mg/kg or 291 mg/kg, I. P.) was injected 40 min before KA (15 mg/kg, I. P.). A group of rats also received DZP (15 mg/kg, I. P.) 20 min prior to KA administration. The basal hippocampal concentrations of glutamate and aspartate were estimated to be 0.51 +/- 0.02 microM and 0.28 +/- 0.01 microM, respectively. Basal EAA levels were not affected by pretreatment with safranal. Following KA injection, there was a significant increase (p < 0.001) in the extracellular glutamate and aspartate levels (about 5-fold and 3-fold, respectively) at 80 min after injection. However, the kainite-evoked release of EAA was significantly reduced by DZP (p < 0.001) and safranal (291 mg/kg, I. P.; p < 0.001). The results of this study show that acute systemic injection of safranal reduces the extracellular concentrations of glutamate and aspartate in the rat hippocampus following KA administration.

Effect of thymoquinone and Nigella sativa seeds oil on lipid peroxidation level during global cerebral ischemia-reperfusion injury in rat hippocampus.

It has been previously reported that Nigella sativa oil (NSO) and thymoquinone (TQ), active constituent of N. sativa seeds oil, may prevent oxidative injury in various models. Therefore, we considered the possible effect of TQ and NSO on lipid peroxidation level following cerebral ischemia-reperfusion injury (IRI) in rat hippocampus. Male NMRI rats were divided into nine groups, namely, sham, control, ischemia and ischemia treated with NSO or TQ. TQ (2.5, 5 and 10 mg/kg), NSO (0.048, 0.192 and 0.384 mg/kg), phenytoin (50 mg/kg, as positive control) and saline (10 ml/kg, as negative control) were injected intraperitoneally immediately after reperfusion and the administration was continued every 24h for 72 h after induction of ischemia. The transient global cerebral ischemia was induced using four-vessel-occlusion method for 20 min. Lipid peroxidation level in hippocampus portion was measured as malondialdehyde (MDA) based on its reaction with thiobarbituric acid (TBA) following ischemic insult. The transient global cerebral ischemia induced a significant increase in TBA reactive substances (TBARS) level (p<0.001), in comparison with sham-operated animal. Pretreatment with TQ and NSO were resulted a significant decrease in MDA level as compared with ischemic group (66.9+/-1.5 vs. 297+/-2.5 nmol/g tissue for TQ, 10 mg/kg; p<0.001 and 153.5+/-1.3 nmol/g tissue for NSO, 0.384 mg/kg; p<0.001). Using a reversed-phase HPLC system, the amount of TQ in NSO was also quantified and was 0.58% w/w. These results suggest that TQ and NSO may have protective effects on lipid peroxidation process during IRI in rat hippocampus.

Safranal, a constituent of Crocus sativus (saffron), attenuated cerebral ischemia induced oxidative damage in rat hippocampus.

Increased oxidative stress has been implicated in the mechanisms of delayed neuronal cell death following cerebral ischemic insult. In this study, we investigated whether safranal, an active constituent of Crocus sativus L. stigmas, may ameliorate ischemia-reperfusion injury (IRI)-induced oxidative damage in rat hippocampus. Male NMRI rats were divided into six groups, namely, sham, control, ischemia and ischemia treated with safranal (four groups). The transient global cerebral ischemia was induced using four-vessel-occlusion method for 20 min. Safranal was injected intraperitoneally (727.5 mg/kg, 363.75 mg/kg, 145.5 mg/kg, and 72.75 mg/kg body weight) 5 min. prior to reperfusion and the administration was continued every 24 hours for 72 hours after induction of ischemia. The markers of oxidative stress including thiobarbituric acid reactive substances (TBARS), total sulfhydryl (SH) groups and antioxidant capacity of hippocampus (using FRAP assay) were measured. The transient global cerebral ischemia induced a significant increase in TBARS levels (p<0.001), decrement in both antioxidant power (FRAP value) (p<0.05) and total sulfhydryl (SH) concentrations (p<0.001) in comparison with sham-operated animals. Following safranal administration the total SH contents (3.2 vs. 0.7micromol/g, p<0.001, safranal 727.5 mg/kg) and antioxidant capacity (4.12 vs. 1.16 micromol/g, p<0.001; 727.5 mg/kg) were elevated in hippocampus in comparison with ischemic group. The MDA level was declined significantly in hippocampus (52.31 vs. 159.70 nmol/g, p<0.001; 727.5 mg/kg). It is concluded that safranal have some protective effects on different markers of oxidative damage in hippocampal tissue from ischemic rats.

Protective effect of aqueous saffron extract (Crocus sativus L.) and crocin, its active constituent, on renal ischemia-reperfusion-induced oxidative damage in rats.

PURPOSE: The generation of reactive oxygen species and lipid peroxidation are associated with tissue injury following ischemic insult; therefore, the use of antioxidants appears rational in the improvement of kidney diseases therapy. The aim of the present study was to assess the effect of aqueous saffron extract (Crocus sativus L.) and its active constituent, crocin, on oxidative stress following renal ischemia-reperfusion injury (IRI) in rats. METHODS: The cellular redox status (thiobarbituric acid reactive species (TBARS) and total thiol levels) and antioxidant power (using ferric reducing/antioxidant power test) were assessed in control and ischemic groups. The left kidney was exposed to warm ischemia for 60 min followed by reperfusion for 90 min. The macerated aqueous extract of saffron (with doses of 5, 20 and 80 mg/kg, i.p.) and crocin (with doses of 50, 200 and 400 mg/kg, i.p.) were administrated prior to induction of ischemia. Normal saline (10 ml/kg, i.p.) was injected to control group and a sham group that did not have ischemia-reperfusion. RESULTS: Ischemia-reperfusion (IR) caused a significant increase in TBARS levels (p<0.001) and decrement in both antioxidant power (FRAP value) (p<0.05) and total thiol concentration (p<0.001) in kidney homogenate samples. In crocin pretreated groups, a reduction in TBARS levels (from 85.8 +/- 5.4 to 20.9 +/- 1.5 nmol/g tissue, p<0.001; 400 mg/kg) and elevation in antioxidant power (FRAP value) (from 3.05 +/- 0.16 to 4.15 +/- 0.16 micromol/g tissue, p<0.001; 400 mg/kg) and total thiol concentrations (from 0.38 +/- 0.03 to 0.62 +/- 0.03 mM, p<0.001; 200 mg/kg), as compared with control group, were observed. The aqueous extract also reduced lipid peroxidation products (from 85.8 +/- 5.4 to 15.9 +/- 2.6 nmol/g tissue, p<0.001; 80 mg/kg) and increased antioxidant power (from 2.98 +/- 0.11 to 5.97 +/- 0.56 micromol/g tissue, p<0.001; 80 mg/kg) in ischemia-reperfusion injured rat kidneys. CONCLUSION: This study therefore suggests that the aqueous saffron extract (Crocus sativus L.) and its active constituent, crocin, may be useful agents for the prevention of renal ischemia-reperfusion (IR)-induced oxidative injury in rats.