Portulaca oleracea L. (purslane) improves the anti-inflammatory, antioxidant and autophagic actions of metformin in the hippocampus of diabetic demented rats.

Great body of evidence links cognitive decline to diabetes/insulin resistance. In this study the effect of Portulaca oleracea (PUR) (100 mg/kg), Metformin (MET) (200 mg/kg), a first line diabetes mellitus type 2 therapy, and their combination on cognitive function and hippocampal markers in diabetic rats were assessed. Male rats were injected with streptozotocin (30 mg/kg on two successive weeks) followed by 4 weeks of treatment. Possible antioxidant, anti-inflammatory, and autophagy enhancing mechanisms of these drugs were investigated in the hippocampal tissue using spectrophotometry, ELISA, and western blotting. Diabetic rats suffered significant cognitive impairment in Morris's water maze, hippocampal TBARS elevation, GSH depletion, and SOD upregulation. In addition, diabetes promoted the secretion of hippocampal inflammatory cytokines, TNF-α and IL-1ß, and depleted anti-inflammatory cytokines as IL-10. Such detrimental changes were reversed by MET and/or PUR. Notably, AMPK was upregulated by diabetes, then restored to normal by MET and/or PUR. The pattern of change in AMPK expression was concomitant with changes in oxidative and inflammatory burden. Hence, AMPK is believed to be a key mediator in most of the measured pre-AD markers in this study. However, from our results, PUR is believed to have non-AMPK dependent actions as well. In conclusion, antidiabetic agents as metformin and purslane extract proved to be invaluable in addressing the cognitive decline and hippocampal changes that arise as a complication of diabetes. They mainly acted through AMPK pathway; however, their usefulness was not limited to AMPK pathways since their combination was suggested to have a different mechanism.

The Impact of Trimetazidine on Cardiac Fibrosis, Inflammation, and Function in Ischemic Cardiomyopathy Patients.

BACKGROUND: Previous studies have shown that Trimetazidine (TMZ) improves vascular endothelial function and reduces the inflammatory process progression. However, limited data have been available regarding its effects on myocardial fibrosis following ischemia and causing left ventricular dysfunction. PURPOSE: To investigate the impact of TMZ adjuvant therapy for ischemic cardiomyopathy (ICM) on cardiac fibrosis, vascular endothelial function, inflammation, and myocardial functions. METHODS: This randomized, double-blind controlled clinical trial included 48 patients (aged 59.4 ± 9 years) with ICM who were randomly assigned to two groups: TMZ 35 mg twice daily and placebo in addition to conventional ICM medications. All patients received the tablets for 3 months. Both groups were then compared in terms of connective tissue growth factor (CTGF), endothelin-1 (ET-1), tumor necrosis factor-alpha (TNF-α), and some echocardiographic indices, weekly angina attacks and nitrate consumption before and after treatment. RESULTS: No significant differences between CTGF, ET-1, and TNF-α levels, in addition to some echocardiographic indices, were observed between both groups before treatment. After treatment, the TMZ group had significantly lower ET-1 than the placebo group, with both groups exhibiting a substantial decrease in TNF-α and CTGF. The TMZ group had lower mean ± SD levels for TNF-α and CTGF and showed significant improvement in echocardiographic indices and weekly angina attacks after treatment. CONCLUSION: Adjunctive TMZ therapy for ICM effectively improved vascular endothelial function and reduced inflammation. Furthermore, our exploratory findings may be used to provide new information on the potential effects of TMZ on myocardial fibrosis by downregulating CTGF.

Protective effects of melatonin and L-carnitine against methotrexate-induced toxicity in isolated rat hepatocytes.

The present study was designed to evaluate the possible protective effects of melatonin (MEL) and/or L-carnitine (L-CAR) against methotrexate (MTX)-induced toxicity in isolated rat hepatocytes. Hepatocytes were prepared using collagenase techniques of perfusion and digestion of rat liver. Trypan blue uptake, as well as, glutathione (GSH), lipid peroxidation (LPO), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-α) levels were measured. Caspase-3 activity was also assessed. Pre-incubation of hepatocytes with MEL (1 mM) and/or L-CAR (10 mM) 30 min prior to intoxication with MTX, significantly protected hepatocytes against toxicity. In addition, LPO, NO, TNF-α levels, and caspase-3 activity were decreased in comparison to the MTX-intoxicated group. Furthermore, the two drugs increased the MTX-depleted GSH level. MEL and L-CAR prevented MTX-induced hepatocytotoxicity, at least partly, by their antioxidative, antiinflammatory, and antiapoptotic effects. Further studies are recommended on the clinical pharmacologic and toxicologic effects of MEL and L-CAR in patients receiving MTX.

Potential value of pharmacological agents acting on toll-like receptor (TLR) 7 and/or TLR8 in COVID-19.

The COVID-19 pandemic is an ongoing global pandemic of coronavirus disease 2019 as an atypical type of viral pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Many potential pharmacotherapies are currently being investigated against this disease. This article points to and justifies, the importance of investigating the potential therapeutic value of pharmacological agents acting on Toll-like Receptor (TLR) 7 and/or TLR8 as double-edged swords combating COVID-19. Induction of TLR7 and/or TLR8 may be investigated as a strategy to stimulate immunity and may be added to anti-COVID19 vaccines to cope with their current viral escape challenge. TLR7 stimulation may not only help viral clearance through Th1 antiviral responses but may also provide beneficial broncho- and vaso-dilatory, as well as, anti-inflammatory effects. Pharmacological compounds acting as TLR7 and/or TLR8 agonists may be of value if used by frontline healthcare workers with comorbidities who demonstrate mild symptoms of the disease. On the other hand, TLR7 and/or TLR8 antagonists may be used in combination with immune-modulatory/anti-inflammatory drugs in severe cases of the disease, with potential synergistic effects that could also help in reducing the doses of such therapies, and consequently their adverse effects.

Community pharmacists' needs, education, and readiness in facing COVID-19: Actions & recommendations in Egypt.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) outbreak is considered one of the most important public health crises all over the world and in Egypt. Community pharmacists represent the third largest health care professional group after physicians and nurses. Community pharmacists are expected to be fully prepared at the frontline of defending their community needs by limiting the spread of COVID-19 via different pharmaceutical care services. AIM: This study aimed to evaluate the sources of knowledge and readiness of community pharmacists in facing COVID-19 early outbreak in Egypt. METHODS: A descriptive cross-sectional study was performed via a self-administered online google form questionnaire during the early period from 14 April to 3 June 2020. The questionnaire focused on; evaluating education level, sources of information, and readiness of Egyptian community pharmacists in the COVID-19 pandemic crisis. RESULTS: A total of 318 community pharmacists from Egypt participated in this questionnaire. About half of the surveyed pharmacists reported that they were frequently consulted and that their patients were seeking consultation regarding COVID-19 management more than 10 times per day. More than half of the pharmacists reported using social media as a source of information and knew the right social distancing recommendations. Regarding protective measures, only a quarter of pharmacists disclosed the availability of personal protective equipment (PPE). Nevertheless, the majority of pharmacists significantly reported some initial lack of support either inform of recommendations or PPE supply. CONCLUSION: The study revealed the dependence of community pharmacists on social media as the main source of information and the lack of early awareness of evidence-based practice resources. Community pharmacists were in need of more initial support to achieve better satisfaction, patient counselling and infection control. Corrective measures were promptly undertaken to support and satisfy the Egyptian community pharmacists' initial awareness and readiness facing COVID-19.

Combinatorial antitumor effects of amino acids and epigenetic modulations in hepatocellular carcinoma cell lines.

Hepatocellular carcinoma (HCC) is a highly fatal form of liver cancer. Recently, the interest in using amino acids as therapeutic agents has noticeably grown. The present work aimed to evaluate the possible antiproliferative effects of selected amino acids supplementation or deprivation in human HCC cell lines and to investigate their effects on critical signaling molecules in HCC pathogenesis and the outcomes of their combination with the histone deacetylase inhibitor vorinostat. HepG2 and Huh7 cells were treated with different concentrations of L-leucine, L-glutamine, or L-methionine and cell viability was determined using MTT assay. Insulin-like growth factor 1 (IGF1), phosphorylated ribosomal protein S6 kinase (p70 S6K), p53, and cyclin D1 (CD1) protein levels were assayed using ELISA. Caspase-3 activity was assessed colorimetrically. L-leucine supplementation (0.8-102.4 mM) and L-glutamine supplementation (4-128 mM) showed dose-dependent antiproliferative effects in both cell lines but L-methionine supplementation (0.2-25.6 mM) only affected the viability of HepG2 cells. Glutamine or methionine deprivation suppressed the proliferation of HepG2 cells whereas leucine deprivation had no effect on cell viability in both cell lines. The combination between the effective antiproliferative changes in L-leucine, L-glutamine, and L-methionine concentrations greatly suppressed cell viability and increased the sensitivity to vorinostat in both cell lines. The growth inhibitory effects were paralleled with significant decreases in IGF-1, phospho p70 S6k, and CD1 levels and significant elevations in p53 and caspase-3 activity. Changes in amino acids concentrations could profoundly affect growth in HCC cell lines and their response to epigenetic therapy.

The synergistic anti-proliferative effect of the combination of diosmin and BEZ-235 (dactolisib) on the HCT-116 colorectal cancer cell line occurs through inhibition of the PI3K/Akt/mTOR/NF-κB axis.

One of the most lethal malignancies worldwide is colorectal cancer (CRC). Alterations in various signalling pathways, including PI3K-mTOR and NF-κB, have been reported in CRC with subsequent dysregulation of proliferation, apoptosis, angiogenesis and, questionably, autophagy processes. BEZ-235 (dactolisib) is a dual PI3K-mTOR inhibitor with potent anti-tumour activity. However, the observed toxicity of BEZ-235 necessitated the termination of its clinical trials. Hence, we aimed to evaluate the potential long-lasting anti-carcinogenic effects of adding diosmin (DIO, a natural NF-κB inhibitor) to BEZ-235 in HCT-116 CRC cells. The median inhibitory concentrations (IC50s) of BEZ-235 and/or DIO were evaluated in the HCT-116 CRC cell line. Caspase-3 activity was assessed colorimetrically, and p-Akt, NF-κB, CD1, VEGF and LC3B levels were assessed by ELISA. Additionally, LC3-II and P62 gene expression were assessed using qRT-PCR. The observed CIs (combination indices) and DRIs (dose reduction indices) confirmed the synergistic effect of DIO and BEZ-235. Co-administration of both drugs either in combination-1 (1 µM for BEZ-235, 250 µM for DIO) or in combination-2 (0.51 µM for BEZ-235 + 101.99 µM for DIO) inhibited the PI3K/Akt/mTOR/NF-κB axis, leading to the induction of apoptosis (via active caspase-3), and the inhibition of proliferation marker (CD1), angiogenesis marker (VEGF), autophagy protein (LC3B) and altered effects on LC3-IIandP62 gene expression. Our results reveal the synergistic chemotherapeutic effects of DIO combined with BEZ-235 in the HCT-116 CRC cell line and encourage future preclinical and clinical studies of this combination with reduced BEZ-235 concentrations to avoid its reported toxicity.

Synergistic antiproliferative effects of curcumin and celecoxib in hepatocellular carcinoma HepG2 cells.

Hepatocellular carcinoma (HCC) is still a leading cancer killer in the community. Molecular targeted therapy with celecoxib (CXB) has shown promising antitumor effects; however, its use may be limited due to serious side effects. Curcumin (CUR) has also shown beneficial effects against HCC. Then, it was aimed to investigate the effects of adding CUR to CXB on HCC HepG2 cells. HepG2 cells were treated with CXB and/or CUR at increasing concentrations to investigate synergistic drug interactions, as calculated combination index (CI). Combination treatment effects on cell viability and caspase-3 activation were assessed. The levels of Akt, nuclear factor-kappa B (NF-κB), prostaglandin E2 (PGE2), malondialdehyde (MDA), cyclin D1 (CD1), and vascular endothelial growth factor (VEGF) were also evaluated. CXB (3.13-100 µM) and/or CUR (1.25-40 µM) reduced HepG2 cell viability dose-dependently. Nevertheless, lower combined concentrations showed higher synergism (CI < 1) and higher CXB dose reduction index (DRI > 1). Also, the addition of CUR to CXB resulted in increased cytotoxicity and caspase-3 activation, as compared to CXB alone. In addition, the selected combination significantly reduced the levels of Akt, NF-κB, PGE2, MDA, CD1, and VEGF, as compared to either agent alone. In conclusion, CUR augmented the CXB-mediated antitumor effects in HepG2 cells through, at least in part, antiproliferative, antioxidant, and pro-apoptotic mechanisms. This may allow the further use of CXB at lower concentrations, combined with CUR, as a promising safer targeted strategy for HCC management.

Anti-Inflammatory and Antioxidant Activities of Salvia fruticosa: An HPLC Determination of Phenolic Contents.

Objectives. Salvia fruticosa Mill. (S. fruticosa) is widely used in folk medicine. Accordingly, the present study was designed to evaluate the antioxidant and anti-inflammatory activities of S. fruticosa, and to determine the phenolic constituents of its extracts. Methods. The antioxidant activity was determined using 2,2-diphenylpicrylhydrazyl assay. Total phenolic contents were estimated using Folin-Ciocalteu reagent, and high-performance liquid chromatography was performed to identify phenolic constituents. To evaluate the anti-inflammatory activity, carrageenan-induced mouse paw edema was determined plethysmographically. Key Findings. Different plant extracts demonstrated strong radical scavenging activity, where the ethyl acetate extract had the highest value in the roots and the lowest in the aerial parts. This antioxidant activity was correlated to the total phenolic content of different extracts, where rutin and luteolin were the most abundant constituents. Interestingly, both the roots and aerial parts revealed a significant anti-inflammatory activity comparable to diclofenac. Conclusions. This study is the first to demonstrate pharmacologic evidence of the potential anti-inflammatory activity of S. fruticosa. This activity may partly be due to the radical scavenging effects of its polyphenolic contents. These findings warrant the popular use of the East Mediterranean sage and highlight the potential of its active constituents in the development of new anti-inflammatory drugs.

Synthesis of some new amide-linked bipyrazoles and their evaluation as anti-inflammatory and analgesic agents.

Four series of new bipyrazoles comprising the N-phenylpyrazole scaffold linked to polysubstituted pyrazoles or to antipyrine moiety through different amide linkages were synthesized. The synthesized compounds were evaluated for their anti-inflammatory and analgesic activities. In vitro COX-1/COX-2 inhibition study revealed that compound 16b possessed the lowest IC50 value against both COX-1 and COX-2. Moreover, the effect of the most promising compounds on inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) protein expression in lipopolysaccharide (LPS)-activated rat monocytes was also investigated. The results revealed that some of the synthesized compounds showed anti-inflammatory and/or analgesic activity with less ulcerogenic potential than the reference drug diclofenac sodium and are well tolerated by experimental animals. Moreover, they significantly inhibited iNOS and COX-2 protein expression induced by LPS stimulation. Compounds 16b and 18 were proved to display anti-inflammatory activity superior to diclofenac sodium and analgesic activity equivalent to it with minimal ulcerogenic potential.

Novel microstructured sildenafil dosage forms as wound healing promoters.

PURPOSE: Study the possible benefit of combining biodegradable polymers with sildenafil citrate (SC) in wound healing. METHOD: Biodegradable micronized powdered formulations of SC were prepared by spray drying using chitosan (P1) or chitosan/gum Arabic (P2). Powders were characterized by differential scanning calorimetry, Scanning electron microscope, particle size analysis, flow and swelling behavior. The powders were also incorporated into microstructured gels and in vitro SC release from powders and gels was tested. In vivo wound healing acceleration was tested by measuring area contraction of excision wounds and histologically. Post-healing tensile strength (TS) for incision wounds in rats receiving powder formulations was tested. RESULTS: The powders were in the micron-size range showing no SC-polymers interaction. Powders had poor flow with angle of repose (θ) of 41 - 48°, and high moisture uptake reaching 107% for placebo powder P1. Good excision wound healing was seen with P1 and G1 formulations showing 98.4 and 98.5% reduction in wound area, respectively, compared with 83% for the control. Incision wounds were improved with P1 showing TS value of 6.9 compared with 3.7 kg/cm² for control. Histological examinations supported. CONCLUSION: Spray-dried chitosan/SC powder (P1) and its gel form (G1) could be promising wound healing promoters as supported by the histological examinations.

Hepatoprotective effects of Astragalus kahiricus root extract against ethanol-induced liver apoptosis in rats.

The hepatoprotective activity of the ethanol extract of Astragalus kahiricus (Fabaceae) roots against ethanol-induced liver apoptosis was evaluated and it showed very promising hepatoprotective actions through different mechanisms. The extract counteracted the ethanol-induced liver enzymes leakage and glutathione depletion. In addition, it demonstrated anti-apoptotic effects against caspase-3 activation and DNA fragmentation that were confirmed by liver histopathological examination. Moreover, the phytochemical study of this extract led to the isolation of four cycloartane-type triterpenes identified as astrasieversianin II (1), astramembrannin II (2), astrasieversianin XIV (3), and cycloastragenol (4). The structures of these isolates were established by HRESI-MS and 1D and 2D NMR experiments. The antimicrobial, antimalarial, and cytotoxic activities of the isolates were further evaluated, but none of them showed any activity.

Anti-apoptotic effects of tamarind leaves against ethanol-induced rat liver injury.

OBJECTIVES: The leaf decoctions of Tamarindus indica (TI) have long been traditionally used in liver ailments. The aim of this study was to investigate the anti-apoptotic activity of TI leaf extract against acute ethanol (EtOH)-induced liver injury. The major constituents of the extract were also examined for standardization purposes. METHODS: Rats (n = 5-7) were orally pretreated with TI leaf extract (25, 50 and 100 mg/kg) for seven days. Silymarin was used as a positive control. Liver tissue biochemical assays included key markers of apoptosis and its redox signalling. Serum enzyme levels were also determined. KEY FINDINGS: All graded doses of TI leaf extract mitigated the EtOH-induced liver caspase-3 activation (42, 57 and 64%) as well as DNA fragmentation (32, 47 and 50%), respectively. The highest dose of the extract demonstrated membrane-stabilizing (38%) in addition to glutathione-replenishing (88%) effects. Also, the leaves improved the liver histopathological alterations. Moreover, major plant bioactive polyphenolics, that might be responsible for the extract's observed effects, were isolated and identified. CONCLUSIONS: TI leaf extract demonstrated promising anti-apoptotic hepatoprotective effects in rats. The use of TI leaves in different liver diseases, having apoptosis as the underlying pathology, hence warrants further clinical investigation.

Dichloroacetonitrile induces oxidative stress and developmental apoptotic imbalance in mouse fetal brain.

Dichloroacetonitrile (DCAN) is one of the disinfection by-products of chlorination of drinking water. Limited mechanistic studies exist on the developmental toxicity of haloacetonitriles (HANs). The present study was designed to investigate the potential adverse effects of maternal exposure to DCAN on mouse fetal brain. Based on initial dose-response experiment, DCAN (14 mg/kg/day) was administered orally to pregnant mice at gestation day (GD) 6, till GD 15. Maternal exposure to DCAN resulted in redox imbalance in fetal cortex and cerebellum, characterized by significant decrease in reduced glutathione (GSH), and elevation of malondialdehyde (MDA) level and superoxide dismutase (SOD) activity. Further, DCAN induced apoptosis indicated by significant enhancement of DNA fragmentation and active caspase-3 level in fetal cortex and cerebellum. Neuronal degeneration was indicated by positive cupric silver staining. In conclusion, maternal exposure to DCAN adversely affects mouse fetal brain as evidenced by induction of oxidative stress, apoptotic imbalance and neurodegeneration.

Rubus sanctus protects against carbon tetrachloride-induced toxicity in rat isolated hepatocytes: isolation and characterization of its galloylated flavonoids.

OBJECTIVES: Rubus sanctus Schreb., known from the Bible as 'holy thorn bush', grows wild in Egypt. Rubus sanctus aqueous alcoholic extract (RE) contains a complicated phenolic mixture (ellagitanins, flavonoids and caffeic acid derivatives). In this study, the phytochemical investigation of the plant was re-evaluated. Herein, we report on the isolation and identification of three galloylated flavonoids, namely kaempferol-3-O-(6''-O-galloyl)-(4)C(1)-beta-d-galactopyranoside, quercetin-3-O-(6''-O-galloyl)-(4)C(1)-beta-d-galactopyranoside and myricetin-3-O-(6''-O-galloyl)-(4)C(1)-beta-d-galactopyranoside for the first time from the Rubus genus. We further aimed at evaluating the potential protective effects of RE against carbon tetrachloride (CCl(4))-induced toxicity in isolated rat hepatocytes. METHODS: Based on an initial concentration-response experiment, a concentration of 100 mug/ml was selected to investigate the hepatoprotective activity of RE. KEY FINDINGS: Pretreatment with RE afforded protection as indicated by counteracting CCl(4)-induced cell death, and reduced glutathione depletion. In addition, RE ameliorated CCl(4)-induced enzyme leakage by 40% for lactate dehydrogenase, 30% for alanine aminotransferase and 20% for aspartate aminotransferase as compared with CCl(4)-treated cells. Moreover, RE counteracted CCl(4)-induced lipid peroxidation and inhibited spontaneous lipid peroxidation in the control group. CONCLUSIONS: In conclusion, RE protects against CCl(4)-induced toxicity in isolated rat hepatocytes.

Lactoperoxidase catalyzes in vitro activation of acrylonitrile to cyanide.

Acrylonitrile (ACN) is a widely used industrial chemical. Although it is a well reported animal carcinogen, its current designation to humans is "possibly carcinogenic". The present study aimed at investigating the ability of LPO enzyme system to oxidize ACN to cyanide (CN(-)) in vitro. Detection of CN(-) served as a marker for the possible generation of free radical intermediates implicated in ACN induced toxicity in the activation process. Optimum conditions for the oxidation of ACN to CN(-) were characterized with respect to pH, temperature and time of incubation as well as ACN, LPO and H(2)O(2) concentrations in incubation mixtures. Maximum reaction velocity (V(max)) and Michaelis-Menten constant (K(m)) were assessed. Addition of nitrite (NO(2)(-)) salts to the reaction mixtures significantly enhanced the rate of the reaction. Free radical scavengers (quercetin and trolox C), LPO enzyme inhibitor (resorcinol) and competitors for LPO binding (sodium azide and indomethacin) were found to reduce the rate of CN(-) production. Inclusion of the sulfhydryl compounds glutathione (GSH), NAC (N-acetylcysteine), D-penicillamine or L-cysteine enhanced the rate of ACN oxidation. The present results demonstrate the ability of LPO enzyme system to oxidize ACN to CN(-) and provide insight for the elucidation of ACN chronic toxicity.

Effects of curcumin on ethanol-induced hepatocyte necrosis and apoptosis: implication of lipid peroxidation and cytochrome c.

Ethanol-induced hepatocyte necrosis and apoptosis are valid in vitro models to investigate the modulatory effects of hepatoprotective/toxic agents such as curcumin. In this study, suspension and monolayer cultures of isolated rat hepatocytes were used. Levels of trypan blue uptake, reduced glutathione, and lipid peroxidation were quantified. Chromatin condensation, caspase-3 activity, and cytochrome c extramitochondrial translocation were also evaluated. Results revealed that curcumin did not protect against either ethanol-induced necrosis or glutathione depletion. Neither did curcumin reduce caspase-3 activation nor chromatin condensation. In contrast, curcumin induced glutathione depletion, caspase-3 activation, necrosis, and apoptosis. Fortunately, all tested curcumin concentrations (1 microM-10 mM) diminished the ethanol-induced lipid peroxidation. In addition, 1 microM curcumin decreased cytochrome c translocation in hepatocyte monolayers. In conclusion, low concentrations of curcumin may protect hepatocytes by reducing lipid peroxidation and cytochrome c release. Conversely, higher concentrations provoke glutathione depletion, caspase-3 activation, and hepatocytotoxicity.

Protective effects of curcumin against ischaemia/reperfusion insult in rat forebrain.

Oxidative stress is believed to be implicated in the pathogenesis of postischaemic cerebral injury. Many antioxidants were shown to be neuroprotective in experimental models of cerebral ischaemia/reperfusion (I/R). The present study was designed to investigate the potential protective effects of curcumin (CUR) against I/R insult in rat forebrain. The model adopted was that of surgically-induced forebrain ischaemia, performed by means of bilateral common carotid artery occlusion (BCCAO) for 1 h, followed by reperfusion for another 1h. The effects of a single i.p. dose of CUR (50, 100 or 200 mg kg(-1)), administered 0.5 h after the onset of ischaemia, were investigated by assessing oxidative stress-related biochemical parameters in rat forebrain. CUR, at the highest dose level (200 mg kg(-1)), decreased the I/R-induced elevated xanthine oxidase (XO) activity, superoxide anion (O(2)*(-)) production, malondialdehyde (MDA) level and glutathione peroxidase (GPx), superoxide dismutase (SOD), and lactate dehydrogenase (LDH) activities. On the other hand, CUR did not affect the declined reduced glutathione (GSH) content due to I/R insult. Worth mentioning is that the activity of catalase (CAT) did not change in response to either I/R insult or drug treatment. In conclusion, CUR was found to protect rat forebrain against I/R insult. These protective effects may be attributed to its antioxidant properties and/or its inhibitory effects on xanthine dehydrogenase/xanthine oxidase (XD/XO) conversion and resultant O(2)*(-) production.