Predicting phase-I metabolism of piceatannol: an in silico study.

Piceatannol is a natural compound found in plants and can be derived from resveratrol. While resveratrol has been extensively researched for its effects and how the body processes it, there are concerns about its use. These concerns include its limited absorption in the body, the need for specific dosages, potential interactions with other drugs, lack of standardization, and limited clinical evidence to support its benefits. Interestingly, Piceatannol, another compound derived from resveratrol, has received less attention from researchers but appears to offer advantages. It has better bioavailability and seems to have a more favorable therapeutic profile compared to resveratrol. Surprisingly, no previous attempts have been made to explore or predict the metabolites of piceatannol when it interacts with the enzyme cytochrome P450. This study aims to fill that gap by predicting how piceatannol is metabolized by cytochrome P450 and assessing any potential toxicity associated with its metabolites. This research is interesting because it's the first of its kind to investigate the metabolic fate of piceatannol, especially in the context of cytochrome P450. The findings have the potential to significantly contribute to the field of piceatannol research, particularly in the food industry where this compound has applications and implications.

Structural dynamics and catalytic modulations of Aß regulating enzymes as future outlook for Alzheimer's.

Aß cascade hypothesis being considered most evident event in AD pathology and even today it holds good. Dysregulation of catalytic events of Aß regulating enzymes can possibly cause faulty Aß trafficking; inequity of Aß formation and clearance resulting in misfolded protein accumulation, neurodegeneration and cognitive impairment. Many novel approaches have been made on this pathway to discover new molecules, unfortunately couldn't reach the terminal phases of clinical trials. Over decades, studies have been more focused on enzyme chemistry and explored the relationship between structural features and catalytic function of Aß regulating enzymes. However, the modulations of catalytic mechanisms of those enzymes have not been imposed so far to reduce the Aß load. Hence, in this review, we have critically detailed the knowledge of basic structural dynamics and possible catalytic modulations of enzymes responsible for Aß formation and clearance that will impart new perspectives in drug discovery process.

Ameliorative potential of flavonoids of Aegle marmelos in vincristine-induced neuropathic pain and associated excitotoxicity.

Introduction: The objective of the study is to elucidate the effect of Aegle marmelos bark hydroalcoholic extract (AMHE) and the role of its constituents marmelosin, umbelliferone, and Para-coumaric acid in attenuating neuropathic pain.Methodology: Peripheral neuropathy was induced by vincristine 100 µg/ml. AMHE was administered in three dose levels (100, 200 and 300 mg/kg) for 21 days. Mechanical hyperalgesia and allodynia were assessed by Randall Sellitto and electronic Von-Frey test, respectively. Functional loss and recovery of the nerve were assessed by sciatic functional index test. The nerve conduction velocity and formalin test were done to assess the peripheral and central response of the extract. Inflammatory mediators in both sciatic nerve and brain and neurotransmitters glutamate and aspartate were measured to support the data.Results and discussion: The inflammatory mediators in both sciatic nerve and brain (TNF-α, IL-1ß, and IL-6) were found to be attenuated with AMHE-treated group in comparison to the group treated only with vincristine, which indicates the extract has anti-inflammatory property. AMHE treated rats were found to be active in all the behavioural tests, suggesting its activity could be mediated through a central and peripheral mechanism to attenuate the pain response. The levels of excitatory neurotransmitters were found to be reduced with AMHE treatment.Conclusion: It could be concluded that AMHE is active in attenuating the neuropathic pain caused by vincristine. The peripheral action would have mediated through lowering the inflammatory mediators as well as the excitotoxicity caused due to peripheral neuropathy and neuroinflammation.

Cytotoxicity and Synergistic Effect of Biogenically Synthesized Ternary Therapeutic Nano Conjugates Comprising Plant Active Principle, Silver and Anticancer Drug on MDA-MB-453 Breast Cancer Cell Line.

Drug delivery through biogenically synthesized silver nanoparticles (AgNPs) in cancer treatment is exerted by smaller size entailing high surface area and synergistic effects of embedded biomolecules.  In this study, prepared ternary conjugates of silver with plant active compound and anticancer drug towards reducing the dose through synergy, rendered by Electrostatic Attraction (EA) of functionalized drug on to the surface of biogenically synthesized AgNPs. The biogenic synthesis resulted in particles of nanometer range as well as serving reducing and capping agents. The cytotoxicity and synergistic effect of ternary therapeutic nano conjugates evaluated using MDA-MB-453 breast cancer cells were found to be superior than Doxorubicin (Dox). Quantitative HPTLC analysis showed 57.22 % inhibition by Dox-AP-AgNPs at a concentration of 2.5 µg/mL of Andrographolide and 0.95 µg/mL of Dox validating synergistic effect of the ternary conjugate.

Design, Synthesis, and Biological Evaluation of 2-(2-Bromo-3-nitrophenyl)-5-phenyl-1,3,4-oxadiazole Derivatives as Possible Anti-Breast Cancer Agents.

Breast Cancer (BCa) is the most often diagnosed cancer among women who were in the late 1940's. Breast cancer growth is largely dependent on the expression of estrogen and progesterone receptor. Breast cancer cells may have one, both, or none of these receptors. The treatment for breast cancer may involve surgery, hormonal therapy (Tamoxifen, an aromatase inhibitor, etc.) and oral chemotherapeutic drugs. The molecular docking technique reported the findings on the potential binding modes of the 2-(2-bromo-3-nitrophenyl)-5-phenyl-1,3,4-oxadiazole derivatives with the estrogen receptor (PDB ID: 3ERT). The 1,3,4-oxadiazole derivatives 4a-4j have been synthesized and described by spectroscopic method. 2-(2-Bromo-6-nitrophenyl)-5-(4-bromophenyl)-1,3,4-oxadiazole (4c) was reconfirmed by single-crystal XRD. All the compounds have been tested in combination with generic Imatinib pharmaceutical drug against breast cancer cell lines isolated from Caucasian woman MCF-7, MDA-MB-453 and MCF-10A non-cancer cell lines. The compounds with the methoxy (in 4c) and methyl (in 4j) substitution were shown to have significant cytotoxicity, with 4c showing dose-dependent activation and decreased cell viability. The mechanism of action was reported by induced apoptosis and tested by a DNA enzyme inhibitor experiment (ELISA) for Methyl Transferase. Molecular dynamics simulations were made for hit molecule 4c to study the stability and interaction of the protein-ligand complex. The toxicity properties of ADME were calculated for all the compounds. All these results provide essential information for further clinical trials.

Corrigendum: Design, Synthesis, and Biological Evaluation of (E)-N'-((1-Chloro-3,4-Dihydronaphthalen-2-yl)Methylene)Benzohydrazide Derivatives as Anti-prostate Cancer Agents.

[This corrects the article DOI: 10.3389/fchem.2019.00474.].

In Silico Molecular Docking, Synthesis of 4-(4-benzoylaminophenoxy) Phenol Derivatives as Androgen Receptor Antagonists.

AIM AND OBJECTIVE: To study the structural difference, optimization, molecular docking and development of new benzoyl amino phenoxy phenol derivatives as anti-prostate cancer agents. MATERIALS AND METHODS: Strategies towards the identification of novel benzoyl amino phenoxy phenol (BAPP), molecular docking was performed with the designed Androgen Receptor (AR) blockers. Pharmacophore-based studies revealed that the nitro- or cyano-substituted anilide groups have influenced the activity profiles of non-steroidal AR antagonists, followed by the molecular docking studies with five AR receptors. Molecular docking studies were carried out using Maestro from Schrödinger. Absorption, Distribution, Metabolism, and Excretion (ADME) properties of the BAPP derivatives were evaluated for the predictive bioavailability/drug-likeness. These studies supported vital information for designing new anti-prostate cancer agents. RESULTS AND DISCUSSION: There are 125 compounds were screened and best fit compounds (12 entries) were well-synthesized in good to excellent yields and anticancer activities were evaluated. The compounds, 6i showed the highest activities of this series (14.65 ± 1.35 µM). CONCLUSION: The present approach is simple and efficient for the synthesis of BAPP derivatives and the observed IC50 values of BAPPs were in good agreement with the glide scores obtained from the molecular docking. We, further, intend to carry out in vitro and in vivo AR binding studies for the active compounds.

Design, Synthesis, and Biological Evaluation of (E)-N'-((1-Chloro-3,4-Dihydronaphthalen-2-yl)Methylene)Benzohydrazide Derivatives as Anti-prostate Cancer Agents.

Prostate Cancer (PCa) is the most frequently diagnosed cancer in men in their late '50s. PCa growth is mainly due to the activation of the androgen receptor by androgens. The treatment for PCa may involve surgery, hormonal therapy, and oral chemotherapeutic drugs. A structural based molecular docking approach revealed the findings of (E)-N'-((1-chloro-3,4-dihydronaphthalen-2-yl)methylene)benzohydrazide derivatives, where the possible binding modes of the compounds with protein (PDB ID: 3V49) are shown. The compounds (6a-k) were synthesized and characterized by using conventional methods. The compounds, 6g, 6j, and 6k were reconfirmed through single crystal X-ray diffraction (XRD). Further, the compounds (6a-k) and standard drug were evaluated against human prostate cancer cell lines, LNCaP and PC-3 and the non-cancerous cell line, 3T3. Among these compounds, 6g and 6j showed higher cytotoxicity, and 6g exhibited dose-dependent activity and reduced cell viability. The mechanism of action was observed through the induced apoptosis and was further confirmed by western blot and ELISA. Molecular dynamics simulation studies were carried out to calculate the interaction and the stability of the protein-ligand complex in motion. ADME properties were predicted for all the tested compounds. These findings may give vital information for further development.

Molecular mechanism of tuberoinfundibular peptide of 39 on glucocorticoid receptor mediated glutamate/GABA imbalance and cerebral abnormalities against cognitive deficit model.

OBJECTIVES: This study is designed to evaluate the role of tuberoinfundibular peptide of 39 (TIP39) in connection with glucocorticoid receptor-mediated glutamate/GABA abnormalities in chronic unpredictable mild stress (CUMS) model. METHODS: Male Sprague-Dawley rats were treated with TIP39 (1 and 10 nmol, i.c.v) and diazepam 2 mg/kg throughout the stress period (28 days) in alternate days. Then, rats were subjected for different behavioural activity followed by biochemical, gene expression and histological examinations. KEY FINDINGS: Chronic unpredictable mild stress rats showed significant cognitive impairment in Morris water maze, Novel object recognition and Y maze test. This was reversed after TIP39 administration. Moreover, TIP39 significantly decreased the brain glutamate and acetyl cholinesterase levels in CUMS rats, whereas it increases the level of GABA after TIP39 treatment. These changes were evident with increased glutamic acid decarboxylase enzyme activity by TIP39. TIP39 significantly decreased the brain glucocorticoid and mineralocorticoid receptor expression ratio in comparison with CUMS rats. Moreover, histological abnormalities in prefrontal cortex and hippocampus were markedly improved after TIP39 administration in CUMS rats. CONCLUSIONS: Tuberoinfundibular peptide of 39 can be a potent neuroendocrine modulator in treating cognitive impairment induced by CUMS rats by controlling glucocorticoid receptor-mediated glutamate/GABA abnormalities in brain.

Tribulusterine Containing Tribulus terrestris Extract Exhibited Neuroprotection Through Attenuating Stress Kinases Mediated Inflammatory Mechanism: In Vitro and In Vivo Studies.

The present study has been aimed to explore the different secondary messengers of the inflammatory pathway NF-κB, kinases (JNK, P38MAPK, GSK3ß/ßcatenin), apoptosis pathway (Caspase-3 and AIF), and neuronal survival pathway (BDNF) in order to understand the neuroprotective mechanism of aqueous extract of Tribulus terrestris (AQTT). In primary cortical neurons, the ischemic condition was induced through oxygen-glucose deprivation (OGD). Anti-inflammatory activity of AQTT was evaluated in formalin induced inflammation model and carrageenan-induced paw edema test. The bilateral common carotid artery occlusion model was employed for whole animal studies. Treatment of AQTT (100 mg/kg) significantly reduced the inflammation induced by formalin and carrageenan. The neuroprotective mechanism of AQTT (50 and 100 mg/kg) was assessed by pre- and post-administration. The results indicate down regulation of kinases and NFkB, suggesting possible anti-inflammatory activity of AQTT. Additionally, AQTT down regulated both caspase dependent and independent apoptotic pathways suggesting its possible anti-apoptotic activity. The treatment of AQTT also reduced GSK3ß levels and increased p-Ser9 GSK3ß levels; stabilizing the unphosphorylated form of ß-catenin and its translocation into the nucleus suggesting role of AQTT in neuronal survival and GSK3ß mediated anti-inflammatory property. In comparison to pretreatment, post treatment of AQTT had lesser effects indicating tribulusterine standardized AQTT may have prophylactic effect. This study can be concluded with the thesis that AQTT has neuroprotective effect through alternating neuroinflammation, apoptosis, and promoting neuron survival. Being that it produced better effect with pretreatment, exploring this with thrombolytic drugs will be beneficial. For the first time AQTT has been reported for this indication.

Saponins of Tribulus terrestris attenuated neuropathic pain induced with vincristine through central and peripheral mechanism.

The study comprises exploring the effects of saponins from Tribulus terrestris (TT) in attenuating the neuropathic pain caused by vincristine (100 µg/ml i.p.) for 10 days (in two 5 day cycles with 2 days pause). Mechanical hyperalgesia and allodynia were assessed by Randall-Sellitto and electronic von Frey tests, respectively. Chemical- induced nociception was assessed by formalin test. Neurophysiological effect of the extract was evaluated by recording sciatic functional index (SFI) on the test days (7, 10, 14, and 21) and sciatic nerve conduction velocity test (SNCV) on the last day. Inflammatory mediators (TNF-α, IL-1ß, and IL-6) in both sciatic nerve and brain and brain neurotransmitters, glutamate and aspartate, were measured to support the behavioral response. The saponins of TT-treated group were found to be effective in the behavioral experiments, implying its activity both centrally and peripherally in attenuating pain. The inflammatory mediators in both sciatic nerve and brain (TNF-α, IL-1ß, and IL-6) were found to be attenuated with TT saponin treatment in comparison to vincristine-treated group, indicating its anti-inflammatory property. The excitatory neurotransmitters, L-glutamic acid and L-aspartic acid, were also found to be attenuated with TT saponins, implying restoration of neuronal damage and synaptic activity caused by high amount of glutamate due to excess TNF-α in brain and reversing the nociceptive threshold lowered due to aspartate. Thus, TT(S) is peripherally and centrally active in lowering the inflammatory mediators, reversing the neuronal damage and increasing the nociceptive threshold caused due to peripheral neuropathy.

Design, Synthesis and Biological Evaluation of Novel 1, 3- thiazolidine-2, 4-diones as Anti-prostate Cancer Agents.

BACKGROUND: Androgen receptor is an attractive target for the treatment of prostate cancer. The 1,3- thiazolidine-2,4-diones possess a wide diversity of important biochemical effects and interesting pharmacological properties. OBJECTIVE: The aim of the study is to find the experimental and computational methods to investigate the interference of 1,3-thiazolidine-2,4-diones with androgen receptor against prostate cancer. METHOD: Structural modification and molecular docking-based virtual screening approaches were imposed to identify the novel 1,3-thiazolidine-2,4-diones by using Schrödinger (Maestro 9.5). The best fit molecules (3-12 & 23-31) were synthesized and characterized using spectroscopic techniques, then in vitro antioxidant and antiprostate cancer activities were evaluated. Further, the structure of the intermediate (18) was confirmed by single crystal XRD analysis. The mechanism studies were performed through the gene expression for the compounds, 29, 30, and 31, the standards, dihydrotestosterone and R-bicalutamide. RESULTS: The compounds, 29, 30 and 31 showed comparatively significant antioxidant activity and better antiproliferative activity against PC-3 and LNCaP cell lines. Also, very low cytotoxicity was observed in the noncancerous cell (3T3). The compounds, 29, 30 and 31 significantly decreased the mRNA expression of ARstimulated genes, PSA and TMPRSS2, which demonstrated their anti-prostate cancer activities. ADME/T properties prediction of the compounds (3-12 and23-31) showed the promising drug-likeness and pharmacokinetic parameters without toxicity. Moreover, DFT calculations apparently confirmed the stable conformer of the compound, 31. CONCLUSION: These findings may provide the essential information for the development of anti-prostate cancer agents.

Bioactive Fraction of Annona reticulata Bark (or) Ziziphus jujuba Root Bark along with Insulin Attenuates Painful Diabetic Neuropathy through Inhibiting NF-κB Inflammatory Cascade.

The present study explains the neuroprotective ability of bioactive fractions of Annona reticulata bark (ARB) and Ziziphus jujuba root bark (ZJ) along with insulin against diabetic neuropathy. By using different solvents of increasing polarity ARB and ZJ were undergone for bioactive guided fractionation. The neuroprotective ability of the all the plant fractions were tested against H2O2 induced toxicity in SHSY5Y neuroblastoma cell lines and DRG neuronal cells. Among all the fractions tested, the methanol extract of ARB and ZJ (ARBME and ZJME) and its water fractions (ARBWF and ZJWF) exhibited significant neuroprotection against H2O2 induced toxicity in SHSY5Y cells and DRG neuronal cells. Further both the active fractions were tested against streptozotocin (55 mg/kg i.p.) induced diabetic neuropathy in male Wistar rats. Body weight changes, blood glucose levels and pain threshold through hot plate, tail immersion, cold plate and Randall-Sillitto methods were measured throughout the study at weekly interval. After completion of the drug treatment period, all the animals were sacrificed to measure the sciatic nerve lipid peroxidation, antioxidative enzyme levels (SOD, catalase, and GSH) and cytokine levels (IL-1ß, IL-6, IL-10, TNF-α, iNOS, and NFκB) through ELISA and western blotting analysis. Results of this study explain that ARBME, ZJME, ARBWF, and ZJWF along with insulin potentially attenuate the thermal, mechanical hyperalgesia and cold allodynia in diabetic neuropathic rats, where insulin treatment alone failed to diminish the same. Reduction of sciatic nerve oxidative stress, NF-κB and iNOS mediated inflammatory cascade and normalization of abnormal cytokine release confirms the possible mechanism of action. The present study confirms the neuroprotective ability of ARB and ZJ against painful diabetic neuropathy through inhibiting oxidative stress and NF-κB inflammatory cascade.

Low dose of L-glutamic acid attenuated the neurological dysfunctions and excitotoxicity in bilateral common carotid artery occluded mice.

Glutamate, an excitatory neurotransmitter in the brain, produces excitotoxicity through its agonistic action on postsynaptic N-methyl-D-aspartate receptor, resulting in neurodegeneration. We hypothesized that the administration of low doses of glutamate in cerebral ischemia could attenuate the excitotoxicity in neurons through its autoreceptor regulatory mechanism, and thereby control neurodegeneration. To test the hypothesis, the effect of L-glutamic acid (L-GA) 400 µmol/l/kg was evaluated in a bilateral common carotid artery occlusion-induced global ischemic mouse model. Memantine was used as a positive control. Global ischemia in mice was induced by occlusion of both the common carotid artery (bilateral common carotid artery occlusion) for 20 min, followed by reperfusion injury. L-GA was infused slowly through the tail vein 30 min before the surgery and every 24 h thereafter until the end of the experiment. The time-dependent change in cerebral blood flow was monitored using a laser Doppler image analyzer. The neurotransmitters glutamate and γ-aminobutyric acid (GABA) and the neurobiochemicals ATP, glutathione, and nitric oxide were measured in the different regions of brain at 0, 24, 48, and 72 h after reperfusion injury. L-GA increased locomotor activity, muscle coordination, and cerebral blood flow in ischemic mice at 72 h after ischemic insult. L-GA reduced glutamate levels in the cortex, striatum, and hippocampus at 72 h, whereas GABA levels were elevated in all three brain regions studied. Further, L-GA elevated glutathione levels and attenuated nitric oxide levels, but failed to restore ATP levels 72 h after ischemia-reperfusion. We conclude that the gradual reduction of glutamate along with elevation of GABA in different brain regions could have contributed toward the neuroprotective effect of L-GA. Hence, a slow infusion of a low dose of L-GA could be beneficial in controlling excitotoxicity-induced neurodegeneration following ischemia.

Telmisartan attenuated LPS-induced neuroinflammation in human IMR-32 neuronal cell line via SARM in AT1R independent mechanism.

AIM: The aim of this study was to find the protective role of Telmisartan (TS) in LPS intoxicated neuronal cells and elucidate the possible neuroprotective mechanism of action. MAIN METHODS: TLR4 and AT1R specific primers were designed and used in rtPCR to confirm the receptor expression in IMR-32 and Neuro2A cell lines. The protective effect of TS was assayed by MTT assay. The mechanism of action of TS was elucidated by assessing the expression and activation of TLR4 specific adaptor proteins SARM and MyD88, phosphorylated NFκB, PPARγ, MAPK p38, c-JNK, ERK by Western blotting. Selective PPARγ antagonist GW9662 was used to confirm the link between PPARγ activation and TLR4 mediated NFκB inflammatory mechanisms. The pro-inflammatory cytokines TNFα, IL1ß, and IL-6 and anti-inflammatory cytokine IL10 release were measured by ELISA. KEY FINDINGS: IMR-32 cells expressed TLR4 receptor and Neuro2A cells expressed both AT1R and TLR4 receptors. TS significantly protected both the cell lines from LPS intoxication. TS significantly suppressed the TLR4 mediated inflammatory response by PPARγ and SARM protein activation and the effect was reversed significantly by selective PPARγ antagonist GW9662, confirming the existence of link between PPARγ activation and TLR4 mediated inflammation via SARM. SIGNIFICANCE: LPS intoxicated human neuronal IMR-32 cells can be a good in vitro model to study inflammatory mediated neurodegeneration due to TLR4 receptor expression. Our study strongly recommends that the PPARγ activating pleiotropic effect of TS is responsible for the protective effect in LPS induced TLR4 mediated inflammation via SARM adaptor protein in the IMR-32 cell line.

Preparation, characterization and in vitro cytotoxicity assay of curcumin loaded solid lipid nanoparticle in IMR32 neuroblastoma cell line.

Curcumin (diferuloylmethane) possesses low bioavailability due to its poor solubility, permeability and rapid metabolism. Solid Lipid Nanoparticle of curcumin was prepared by high-speed homogenization technique. Stearic acid was used as a lipid, tween 80 as surfactant and various co surfactants were used for the preparation of SLN. The prepared SLN was characterized using zeta sizer, TEM analysis and the average particle size was found to be in the range of 80 nm - 200nm. The entrapment efficiency of the SLN was ~58 to 85%. The characteristic FTIR peaks suggest that the stearic acid is compatible with curcumin. MTT assay was performed on the optimized formulation and the results are indicative that curcumin SLN showed better cytotoxicity in low dose while compared to plain curcumin. The developed Cu-SLN can find its better place in the anticancer therapy.

Discovery of potential and selective COX-1 inhibitory leads using pharmacophore modelling, in silico screening and in vitro evaluation.

Cyclooxygenase -1 (COX-1) selective inhibitors are anticipated to be potential therapeutic agents for thrombosis, tumorigenesis, atherosclerosis, neuroprotection, and oxidative stress. In this study, a 3D-QSAR pharmacophore model was developed for potent and selective COX-1 inhibition based on 44 compounds from four different scaffolds using Phase, Schrödinger. One (hydrogen-bond) acceptor, one hydrophobic, and two aromatic sites (AHRR) contribute to COX-1 inhibitory activity. Test and decoy sets were used to corroborate the best hypothesis and the validated hypothesis was used to screen the SPECS database. The resultant hits were filtered by standard precision (SP) and extra precision (XP) modes of docking using Glide, Schrödinger which yielded five hits. Free energy calculations were carried out to quantify the affinity differences of the hits towards COX enzymes. These five hits were subjected to in vitro COX (ovine) inhibitory activity studies. The hits displayed potent COX-1 inhibitory activity and good selectivity versus COX-2 enzyme. The compounds also protected the nitric oxide (NO) induced cell death mediated by COX-1 in mouse macrophages cell line. Hence, we hypothesize that these compounds could be promising leads for the design of superior COX-1 inhibitors and insights gained from further exploration of the same could provide pertinent clues for the treatment of the conditions mentioned above.

Quercetin protected isolated human erythrocytes against mancozeb-induced oxidative stress.

Mancozeb is a fungicide belonging to the ethylene-bisdithiocarbamate group and is widely used in agriculture. The aim of this study was to examine the protective effect of quercetin (QRN) against oxidative stress induced by mancozeb in human erythrocytes. In order to verify this, 5 ml of venous blood was collected and the erythrocytes were separated and divided into equal parts. One part was incubated with different concentrations of mancozeb (0, 10, 30, 100 µM) for 4 h at 37°C. The other part was preincubated with QRN (40 and 80 µM) for 30 min, followed by mancozeb (0, 10, 30, 100 µM) incubation for 4 h. We found reduction in the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) along with elevated levels of lipid peroxide (LPO) in erythrocytes incubated with 30 and 100 µm of mancozeb. Pre-incubation with QRN (80 µM) reversed oxidative stress induced by mancozeb (30 µM) and inhibited LPO induced at 100 µM by 64.36%. QRN also reduced the haemolytic effect on erythrocytes but could not prevent the induction of haemolysis by mancozeb. Therefore, these results suggest that QRN may play a role in preventing the oxidative stress induced by mancozeb in human erythrocytes.

Standardized Aqueous Tribulus terristris (nerunjil) extract attenuates hyperalgesia in experimentally induced diabetic neuropathic pain model: role of oxidative stress and inflammatory mediators.

The present study aimed to evaluate standardized aqueous Tribulus terristris (nerunjil) extract on the pain threshold response in streptozotocin (STZ)-induced diabetic neuropathic pain model in rats. After a single injection of STZ (40 mg/kg; i.p.), Wistar male rats were tested by the thermal and chemical-induced pain models. Diabetic rats exhibited significant hyperalgesia, and these rats were left untreated for the first four weeks. Thereafter, treatment was initiated and continued up to week-8. All the rats except the vehicle-treated group received insulin 5 IU/kg/day to maintain plasma glucose levels. Treatment with nerunjil (100 and 300 mg/kg; p.o.) for 4 weeks significantly attenuated the nociception in behavioural models. Nerunjil also inhibited the tumour necrosis factor-α and interleukin-1 beta levels. The effect of nerunjil (300 mg/kg) is comparable to the standard drug Pregabalin (100 mg/kg). Nerunjil increased the superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, and decreased the lipid peroxide levels in dose-dependent manner. Insulin alone-treated rats failed to attenuate hyperalgesic response. In comparison to insulin alone-treated rats, nerunjil exhibited significant increase in the pain threshold response. It could be concluded that in controlled diabetic states, nerunjil attenuated the neuropathic pain through modulation of oxidative stress and inflammatory cytokine release.

Post-ischemic administration of nimodipine following focal cerebral ischemic-reperfusion injury in rats alleviated excitotoxicity, neurobehavioural alterations and partially the bioenergetics.

The present study focuses on the temporal calcium significance in middle cerebral artery occluded (2 h ischemia)-reperfused (70 h reperfusion) rats treated with nimodipine (NM) through concurrent measurements of excitotoxicity, bioenergetics and neurobehavioural paradigms. Further, the suitable therapeutic time window of calcium channel antagonism in stroke was also ascertained. NM (5 mg/kg, i.p.) was administered at pre (30 min before the induction of ischemia), during (1 h following occlusion of MCA) and post-ischemic (3 h after begin of reperfusion) states. The magnitude of neuroprotection in terms of excitotoxicity (glutamate, glutamine synthetase, Na(+)K(+)ATPase), bioenergetics (ATP, NAD(+)) and neurobehavioural paradigms (neurological score and open field exploratory behaviour) were measured and compared to ensure the therapeutic time-window of NM in stroke. Middle cerebral artery occlusion-reperfusion (MCAO/R) was found to elevate glutamate, glutamine synthetase levels and deplete Na(+)K(+)ATPase activity in the vehicle treated group (IR group). Significant decrease in bioenergetics such as ATP and NAD(+) levels was also observed. Further, IR group demonstrated grievous oxidative stress (increase in lipid peroxidation, protein carbonyl content, nitrite/nitrate levels and decrease in superoxide dismutase and glutathione levels) along with anxiogenic behaviour, neurological deficits and neuronal damage and decreased nuclear to cytoplasm ratio in CA1 hippocampal region. Post-ischemic NM administration reversed the excitotoxicity, neurobehavioural and histopathological alterations significantly, but it restored bioenergetics level in MCAO/R rats only partially. These findings were further confirmed with the combination treatment (CT) of post-ischemic NM and pre-ischemic memantine (MN) administration, since MN showed protective effect in the pre-ischemic administration (Babu and Ramanathan, 2009). The failure of NM to forefend the neurodegeneration on pre- and during-ischemic administration suggests that the initial phase damages in ischemic-reperfusion (IR) might be mediated through other mechanism(s) such as glutamergic overstimulation or reverse operation of glutamate transporters. From the present study, it is concluded that calcium plays a crucial role in post-ischemic status and the suitable therapeutic time window of calcium antagonism is the post-ischemic state.