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Several disease-modifying osteoarthritis (OA) drugs have emerged, but none have been approved for clinical use due to their systemic side effects, short half-life, and rapid clearance from the joints. Nordihydroguaiaretic acid (NDGA), a reactive oxygen species (ROS) scavenger and autophagy inducer, could be a potential treatment for OA. In this report, we show for the first time that sustained delivery of NDGA through polymeric microparticles maintains therapeutic concentrations of drug in the joint and ameliorates post-traumatic OA (PTOA) in a mouse model. In vitro treatment of oxidatively stressed primary chondrocytes from OA patients using NDGA-loaded poly(lactic- co -glycolic acid) (PLGA) microparticles (NDGA-MP) inhibited 15-lipoxygenase, induced autophagy, prevented chondrosenescence, and sustained matrix production. In vivo intra-articular delivery of NDGA-MP was non-toxic and had prolonged retention time (up to 35 days) in murine knee joints. Intra-articular therapy using NDGA-MP effectively reduced cartilage damage and reduced pain in the surgery-induced PTOA mouse model. Our studies open new avenues to modulate the immune environment and treat post-traumatic OA using ROS quenchers and autophagy inducers.

The coronavirus infectious disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has been spreading rapidly worldwide, creating a pandemic. This article describes the evaluation of the antiviral activity of nordihydroguaiaretic acid (NDGA), a molecule found in Creosote bush ( Larrea tridentata ) leaves, against SARS-CoV-2 in vitro. A 35 µM concentration of NDGA was not toxic to Vero cells and exhibited a remarkable inhibitory effect on the SARS-CoV-2 cytopathic effect, viral plaque formation, RNA replication, and expression of the SARS-CoV-2 spike glycoprotein. The 50% effective concentration for NDGA was as low as 16.97 µM. Our results show that NDGA could be a promising therapeutic candidate against SARS-CoV-2.

In this study, we demonstrate that Raman microscopy combined with computational analysis is a useful approach to discriminating accurately between brain tumor bio-specimens and to identifying structural changes in glioblastoma (GBM) bio-signatures after nordihydroguaiaretic acid (NDGA) administration. NDGA phenolic lignan was selected as a potential therapeutic agent because of its reported beneficial effects in alleviating and inhibiting the formation of multi-organ malignant tumors. The current analysis of NDGA's impact on GBM human cells demonstrates a reduction in the quantity of altered protein content and of reactive oxygen species (ROS)-damaged phenylalanine; results that correlate with the ROS scavenger and anti-oxidant properties of NDGA. A novel outcome presented here is the use of phenylalanine as a biomarker for differentiating between samples and assessing drug efficacy. Treatment with a low NDGA dose shows a decline in abnormal lipid-protein metabolism, which is inferred by the formation of lipid droplets and a decrease in altered protein content. A very high dose results in cell structural and membrane damage that favors transformed protein overexpression. The information gained through this work is of substantial value for understanding NDGA's beneficial as well as detrimental bio-effects as a potential therapeutic drug for brain cancer.

Acute lung injury (ALI) is a continuum of pulmonary changes caused by various lung insults. Previously, we synthesized a series of nordihydroguaiaretic acid analogs; of these, compound 3a exhibited excellent antioxidant capacity in a murine model of middle cerebral artery occlusion. However, it remains unclear whether compound 3a can modulate lipopolysaccharide (LPS)-induced ALI. ALI was induced via tracheal LPS administration, and the pathological changes were assessed. The level of inflammation was verified by immunofluorescence and immunohistochemical analyses. Apoptosis was measured by terminal deoxynucleotidyl transferase dUTP nick-end labeling assays and Western blotting. Changes in the levels of mitogen-activated protein kinase (MAPK)/nuclear factor-κB (NF-κB) pathway proteins were assessed by immunofluorescence assays and Western blotting. In vitro, RAW 264.7 cells were treated with compound 3a prior to LPS challenge, and the intracellular level of inflammation was assessed by quantitative PCR (qPCR). Relevant proteins were detected via immunofluorescence assays and Western blotting. Mice developed extensive lung inflammation by 24 h after LPS challenge. Histological examination revealed signs typical of ALI. Preadministration of compound 3a markedly ameliorated the histopathological changes and reduced fluid exudation into the alveolar space. Compound 3a also greatly reduced the levels of inflammation and apoptosis both in vivo and in vitro. Moreover, compound 3a markedly reduced phosphorylation of MAPK/NF-κB pathway-related proteins and p65 translocation, consistent with the in vitro observations. In summary, administration of compound 3a prior to LPS suppressed ALI via inhibition of the MAPK/NF-κB pathway., (Copyright © 2022. Published by Elsevier B.V.)

Fingolimod (FTY720) inhibits Ca 2+ -permeable, Mg 2+ -sensitive channels called transient receptor potential melastatin 7 (TRPM7), but its effects on Ca 2+ paradox (CP) - induced myocardial damage has not been evaluated. We studied the effect of FTY720 on CP-induced myocardial damage and used other TRPM7 channel inhibitors nordihydroguaiaretic acid (NDGA) and Mg 2+ to test if any effect of FTY720 was via TRPM7 inhibition. Langendorff-perfused Wistar rat hearts were treated with FTY720 or NDGA and subjected to a CP protocol consisting of Ca 2+ depletion followed by Ca 2+ repletion. Hearts of rats pre-treated with MgSO 4 were also subjected to CP. Hemodynamic parameters were measured using an intraventricular balloon, and myocardial infarct size was quantified using triphenyltetrazolium chloride stain. TRPM7 proteins in ventricular tissue were detected using immunoblot analysis. FTY720, but not NDGA, decreased CP-induced infarct size. Both FTY720 and NDGA minimized the CP-induced elevation of left ventricular end-diastolic pressure, but only FTY720 ultimately improved ventricular developed pressure. Mg 2+ pre-treatment had no effect on CP-induced infarct size, nor hemodynamic parameters during CP, nor the level of TRPM7 protein expression in ventricular tissue. Overall, FTY720 attenuated CP-induced myocardial damage, with potential therapeutic implications on Ca 2+ -mediated cardiotoxicity; however, the cardioprotective mechanism of FTY720 seems to be unrelated to TRPM7 channel modulation.

Lignans are widely produced by various plant species; they are a class of natural products that share structural similarity. They usually contain a core scaffold that is formed by two or more phenylpropanoid units. Lignans possess diverse pharmacological properties, including their antiviral activities that have been reported in recent years. This review discusses the distribution of lignans in nature according to their structural classification, and it provides a comprehensive summary of their antiviral activities. Among them, two types of antiviral lignans-podophyllotoxin and bicyclol, which are used to treat venereal warts and chronic hepatitis B (CHB) in clinical, serve as examples of using lignans for antivirals-are discussed in some detail. Prospects of lignans in antiviral drug discovery are also discussed.

Nordihydroguaiaretic acid (NDGA) is a plant lignan obtained from creosote bush, Larrea tridentata and is known to possess antioxidant, anticancer activities and is used in traditional medicine in North America and Mexico. However, its prolonged consumption leads to liver damage and kidney dysfunction. Despite its toxicity and side effects, there is little awareness to forbid its consumption and its use in the treatment of medical ailments has continued over the years. Several reports discuss its therapeutic efficiency and its medical applications have tremendously been on the rise to date. There has been a recent surge of interest in the chemical synthesis of NDGA derivatives for therapeutic applications. NDGA derivatives have been developed as better alternatives to NDGA. Although several NDGA derivatives have been chemically synthesized as evidenced by recent literature, there is a paucity of information on their therapeutic efficacies. This review is to highlight the medicinal applications of NDGA, its toxicity evaluations and discuss the chemical derivatives of NDGA synthesized and studied so far and suggest to continue research interests in the development of NDGA analogs for therapeutic applications. We suggest that NDGA derivatives should be investigated more in terms of chemical synthesis with preferred conformational structures and exploit their biological potentials with future insights to explore in this direction to design and develop structurally modified NDGA derivatives for potential pharmacological properties., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Diabetic encephalopathy is a chronic complications of diabetes mellitus that affects the central nervous system. We evaluated the effect of ω3 and ω6 polyunsaturated fatty acids (PUFAs) supplementation plus the antioxidant agent nordihydroguaiaretic acid (NDGA) on the etiopathology of diabetic encephalopathy in eSS rats, a spontaneous model of type 2 diabetes., Methods: One hundred twenty spontaneous diabetic eSS male rats and 38 non-diabetic Wistar, used as healthy control, received monthly by intraperitoneal route, ω3 or ω6 PUFA (6.25 mg/kg) alone or plus NDGA (1.19 mg/kg) for 12 months. Diabetic rats had a worse performance in behavioural Hole-Board test. Histopathological analysis confirmed lesions in diabetic rats brain tissues. We also detected low expression of synaptophysin, a protein linked to release of neurotransmitters, by immunohistochemically techniques in eSS rats brain. Biochemical and histopathological studies of brain were performed at 12th month. Biochemical analysis showed altered parameters related to metabolism. High levels of markers of oxidative stress and inflammation were detected in plasma and brain tissues. Data were analysed by ANOVA test and paired t test was used by comparison of measurements of the same parameter at different times., Results: The data obtained in this work showed that behavioural, biochemical and morphological alterations observed in eSS rats are compatible with previously reported indices in diabetic encephalopathy and are associated with increased glucolipotoxicity, chronic low-grade inflammation and oxidative stress burden. Experimental treatments assayed modulated the values of studied parameters., Conclusions: The treatments tested with ω3 or ω3 plus NDGA showed improvement in the values of the studied parameters in eSS diabetic rats. These observations may form the basis to help in prevent and manage the diabetic encephalopathy.

Therapeutic natural products and medicinal herbs has gained popularity. The anti-antigenic action of the plant alkaloid nordihydroguaiaretic acid (NDGA) was studied in ovalbumin (OA)-sensitized guinea pigs. In one series of experiments conscious, non-sedated guinea pigs were challenged with OA aerosol. Specific airway resistance (SR AW ) was monitored using a two-chambered whole-body plethysmograph. OA aerosol increased SR AW above that produced by vehicle administration. Prior NDGA administration by a 1min 0.9% aerosol (w/vol) attenuated the increase in SR AW resulting from OA challenge. In the anesthetized guinea pig pretreated with indomethacin, pyrilamine and propranolol, intravenous OA injection increased intra-tracheal pressure above vehicle injection. Intravenous NDGA administration (5mg/kg) reduced the intra-tracheal pressure increases. In a third series of experiments plasma leukotriene C 4 was measured by radio-immunoassay in 3 groups challenged with OA aerosol: vehicle-treated OA-sensitized, OA-sensitized receiving NDGA and vehicle treated guinea pigs. NDGA pretreatment reduced plasma LTC 4 in response to OA challenge in OA sensitized guinea pigs. This study demonstrates that NDGA is an effective antigenic agent when given by aerosol or intravenous injection in either conscious or anesthetized guinea pigs, respectively. The mechanism of action of NDGA is presumed primarily be due to the blockage of 5-lipoxygenase and therefore the synthesis of leukotrienes., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Synthesized dl-Nordihydroguaiaretic acid (dl-NGDA or "Nordy") can inhibit the growth of malignant human tumors, especially the tumor angiogenesis. However, its liposoluble nature limits its in vivo efficacy in the hydrosoluble circulation of human., Purpose: We tried to use the ultrasonic microbubble as the carrier and the ultrasound-induced destruction for the targeted release of Nordy and evaluate its in vitro and in vivo anti-tumor effect., Methods: Nordy-loaded lipid microbubbles were prepared by mechanical vibration. Effects of ultrasound-induced Nordy-loaded microbubbles destruction on proliferation of human umbilical vein endothelial cells (HUVECs), tumor derived endothelial cells (Td-ECs), and rabbit transplanted VX2 tumor models were evaluated., Results: The ultrasound-induced Nordy-loaded microbubbles destruction inhibited the proliferations of HUVECs and Td-ECs in vitro, and inhibited the tumor growth and the microvasculature in vivo. Its efficacy was higher than those of Nordy used only and Nordy with ultrasound exposure., Conclusion: Ultrasonic microbubbles can be used as the carrier of Nordy and achieve its targeted release with improved anti-tumor efficacy in the condition of ultrasound-induced microbubbles destruction.

Pulmonary arterial hypertension (PAH) is a disease characterized by thickening of pulmonary artery walls, elevated pulmonary vascular resistance, pulmonary vascular thrombotic lesions, and right heart failure. Recent studies suggest that 15-lipoxygenase (15-LO)/15-hydroxyeicosatetraenoic acid (15-HETE) play an important role in PAH, acting on arterial walls. Here, we show evidence for the action of the 15-LO/15-HETE signaling in the pulmonary vascular thrombotic lesions in the experimental PAH models. Platelet deposition was augmented in rats exposed to hypoxia and Sugen 5416, which were both prevented by nordihydroguaiaretic acid (NDGA), a 15-LO inhibitor. Chronic hypoxic resulted in the platelet deposition specifically in pulmonary vasculature, which was reversed by 15-LO inhibitor. The 15-LO pathway mediated in the endothelial dysfunction induced by hypoxia in vivo. Meanwhile, 15-HETE positively regulated the generation of IL-6 and monocyte chemoattractant protein-1 (MCP-1). The coagulation and platelet activation induced by hypoxia were reversed by 15-LO inhibitor NDGA or the MCP-1 inhibitor synthesis inhibitor bindarit in rats. The 15-LO/15-HETE signaling promoted the coagulation and platelet activation, which was suppressed by MCP-1 inhibition. These results therefore suggest that 15-LO/15-HETE signaling plays a role in platelet activation and pulmonary vascular thrombosis in PAH, involving MCP-1., (Copyright © 2015 the American Physiological Society.)

Cisplatin is a widely used antineoplastic drug, but its clinical usefulness is limited due to dose dependent nephrotoxicity. Nordihydroguaiaretic acid (NDGA) is a natural compound with broad pharmacological properties like antioxidant, anti-inflammatory and anticancer activity. The present study was undertaken to evaluate the possible beneficial effects of NDGA on cisplatin induced nephrotoxicity as well as its anticancer activity in rats bearing DMBA induced mammary tumors. The effect of NDGA on cisplatin induced nephrotoxicity was evaluated by checking serum nephrotoxicity markers, antioxidant enzymes and inflammatory markers level and kidney histopathology. NDGA induced amelioration of cisplatin nephrotoxicity was clearly visible from significant reductions in serum blood urea nitrogen (86.51 g/dl) and creatinine (5.30 g/dl) levels and significant improvement in body weight change (-10.34 g) and kidney weight (728 mg/kg). The protective effect of NDGA against cisplatin induced nephrotoxicity in the rats was further confirmed by significant restoration of antioxidant enzymes like SOD (86.28% inhibition), inflammatory markers like TNF-α (34.6 pg/ml) and histopathological examination. Moreover, our results showed that NDGA potentiated anti-breast cancer activity of cisplatin through an increment in the expression of antioxidant enzymes like SOD (85.35% inhibition) in breast cancer tissue. These results indicated that NDGA potentiated the anti-breast cancer activity of cisplatin, which was clearly evident from the tumor volume and % tumor inhibition in breast cancer rats. The current study demonstrated that NDGA may modify the therapeutic effect of cisplatin in DMBA induced breast cancer in female Sprague-Dawley rats., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Drug and chemically-induced immunosuppression has been implicated as a confounding factor for cancer development. Management of cancer in such situation is often a challenging task. We tested the efficacy of nordihydroguiaretic acid (NDGA) against immunosuppressant tacrolimus-induced augmentation of mouse skin tumorigenesis. It was observed that topical administration of tacrolimus significantly accelerated the tumor promotion events in dimethylbenz(a)anthracene (DMBA)-initiated and 12-O-tetradecanoylphorbol-13-acetate (TPA) promoted two-stage mouse skin carcinogenesis, which were accompanied by reduced CD4(+)/CD8(+) ratio of lymph nodes and serum IL-2 level. NDGA pre-treatment before each TPA application reduced the tumor incidence, its multiplicity and volume together with improvement in histopathological alterations and decrease in proliferating cell nuclear antigen (PCNA) labeling index (LI). However, NDGA had no significant influence on the immunosuppressive effect of tacrolimus. The present study demonstrates chemopreventive effect of NDGA in normal as well as in the condition of immunosuppression. Thus, NDGA has the potential to inhibit or delay the onset of tumor development during immunosuppressive regimen., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Glioblastoma (GBM), one of the most malignant human neoplasias, responds poorly to current treatment modalities, with temozolomide (TMZ) being the drug most frequently used for its treatment. Tetra-O-methyl Nordihydroguaiaretic Acid (M4N) is a global transcriptional repressor of genes dependent on the Sp1 transcription factor, such as Survivin and Cdk1. In the present study we evaluated the gene expression of Survivin, its spliced variants and Cdk1 in GBM samples and cell lines. Moreover, we investigated the effects of M4N combined or not with TMZ and/or radiation on GBM primary cultures and cell lines. qRT-PCR assays were performed to determine the Survivin-spliced variants and Cdk1 gene mRNA expression in GBM tumor samples and cell lines. Cell proliferation was measured by XTT assay and cell cycle and apoptosis were determined by flow cytometry. Drug combination analyses using different schedules of administration (simultaneous and sequential) were performed on GBM cell lines and primary cultures based on the Chou-Talalay method. For clonogenic survival, doses of 2, 4, and 6 Gy of gamma radiation. were used. All Survivin-spliced variants and the Cdk1 gene were expressed in GBM samples (n = 16) and cell lines (n = 6), except the Survivin-2B variant that was only expressed in GBM cell lines. M4N treatment down regulated the expression of Cdk1, Survivin and the Survivin-ΔEx3 variant, while the Survivin-2B variant was up-regulated. M4N decreased the cell proliferation separately and synergistically with TMZ, and enhanced the effects of radiation, mainly when associated with TMZ. M4N also induced apoptotic cell death, decreased the mitotic index and arrested the cell cycle mainly in the G2/M phase. Our results suggest a potential clinical application of M4N in combination with TMZ and radiation for GB treatment.

It has been shown that the pretreatment with nordihydroguaiaretic acid (NDGA), a lignan with direct and indirect antioxidant properties, protects against the ischemia-reperfusion (I/R)-induced renal oxidant damage. Although it has been shown that NDGA induces Nrf2 nuclear translocation in renal epithelial LLC-PK1 cells in culture, it is unknown if NDGA may induce Nrf2 translocation in vivo. In this work was explored if NDGA is able to induce in vivo Nrf2 nuclear translocation in kidneys of rats submitted to uni-nephrectomy (U-NX) or I/R injury. Four groups of male Wistar rats were used: U-NX, NDGA, I/R, and I/R+NDGA. NDGA was injected i.p. (10mg/kg/day) starting 48 h before I/R. Kidney samples were obtained at 3 h of reperfusion after to measure Nrf2 translocation. Additional groups of rats were studied at 24 h of reperfusion to measure histological damage and apoptosis. NDGA was able to induce Nrf2 translocation in vivo in kidneys of rats submitted to both U-NX and I/R injury and to protect against renal histological damage and apoptosis. It is concluded that the pretreatment of NDGA is able to induce in vivo nuclear Nrf2 translocation in kidney of rats suggesting that this may be involved in the renoprotection against I/R., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

After spinal cord injury (SCI), a series of complex pathophysiological processes follows the initial injury. Because inflammation plays a key role in this secondary pathology damage, anti-inflammatory drug treatment may reduce secondary damage and protect neurons after SCI. Though nordihydroguaiaretic acid (NDGA) can inhibit inflammatory responses, its potential roles in neuroprotection and anti- inflammation in an SCI model have not been studied. In this study, we investigated the anti-inflammatory effects of NDGA in SCI. First, histopathological alterations were evaluated with hematoxylin/eosin (HE) and Nissl staining, showing an increased number of neurons after NDGA administration. Additionally, the extent of secondary damage was assessed by TUNEL assay and measurement of astrocyte proliferation. The data showed that the numbers of apoptotic cells and the proliferative extent of astrocytes were significantly decreased by the use of NDGA. The anti-inflammatory effect of NDGA was evaluated by measuring myeloperoxidase (MPO) levels as an indicator of neutrophil activity, macrophage/microglia numbers, and expression of inflammatory cytokines including IL-1β and TNF-α. NDGA treatment significantly decreased the MPO level and the number of macrophages/microglia. In addition, NDGA also suppressed the expression of IL-1β and TNF-α after SCI. These data suggest that anti-inflammatory action by NDGA can reduce secondary damage after SCI., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Creosote bush-derived nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor, possesses antioxidant properties and functions as a potent antihyperlipidemic agent in rodent models. Here, we examined the effect of chronic NDGA treatment of ob/ob mice on plasma dyslipidemia, hepatic steatosis, and changes in hepatic gene expression. Feeding ob/ob mice a chow diet supplemented with either low (0.83 g/kg diet) or high-dose (2.5 g/kg diet) NDGA for 16 wk significantly improved plasma triglyceride (TG), inflammatory chemokine levels, hyperinsulinemia, insulin sensitivity, and glucose intolerance. NDGA treatment caused a marked reduction in liver weight and TG content, while enhancing rates of fatty acid oxidation. Microarray analysis of hepatic gene expression demonstrated that NDGA treatment altered genes for lipid metabolism, with genes involved in fatty acid catabolism most significantly increased. NDGA upregulated the mRNA and nuclear protein levels of peroxisome proliferator-activated receptor α (PPARα), and the activated (phosphorylated) form of AMP-activated kinase. NDGA increased PPARα promoter activity in AML12 hepatocytes and also prevented the fatty acid suppression of PPARα expression. In contrast, PPARα siRNA abrogated the stimulatory effect of NDGA on fatty acid catabolism. Likewise, no stimulatory effect of NDGA on hepatic fatty acid oxidation was observed in the livers of PPARα-deficient mice, but the ability of NDGA to reverse fatty liver conditions was unaffected. In conclusion, the beneficial actions of NDGA on dyslipidemia and hepatic steatosis in ob/ob mice are exerted primarily through enhanced fatty acid oxidation via PPARα-dependent pathways. However, PPARα-independent pathways also contribute to NDGA's action to ameliorate hepatic steatosis.

Several natural polyphenols have been reported to act on different amyloidogenic proteins inhibiting amyloid formation therefore we decided to test their effect on transthyretin (TTR) amyloid formation. We found that epigallocatechin-3-gallate (EGCG), curcumin and nordihydroguaiaretic acid (NDGA) bind to TTR and modulate its amyloidogenicity, in vitro, although through different mechanisms of action. Based on these in vitro studies, we decided to test EGCG in vivo using mice models for familial amyloidotic polyneuropathy (FAP). Therefore, we performed a subchronic administration of EGCG to mice, for 6 weeks. Next, we assessed the effects of EGCG treatment by immunohistochemistry (IHC) and western blot analysis of mice tissues. The results obtained demonstrate that EGCG inhibits TTR aggregates deposition in about 50% along the gastrointestinal (GI) tract and peripheral nervous system (PNS) and lowered the levels of several FAP associated biomarkers. Furthermore, treatment of old FAP mice with EGCG resulted not only in the decrease of nonfibrillar TTR deposition but also in the disaggregation of congophilic amyloid deposits. The dual effect as inhibitor of aggregation and as disruptor of amyloid together with its low toxicity indicates that EGCG presents a therapeutic application in FAP.

Terameprocol is a global transcription inhibitor that affects cell division apoptosis, drug resistance, hypoxia responsive genes, and radiation resistance in hypoxia. A multicenter, dose-escalation study was conducted in heavily pretreated patients with recurrent, measurable, high-grade gliomas. Terameprocol was administered intravenously for 5 consecutive days each month and discontinued for toxicity or progression. Patients taking enzyme-inducing antiseizure drugs (EIASDs) were escalated independently. Thirty-five patients with a median Karnofsky performance status of 80, median age of 46 years, and median of 2 prior treatment regimens were accrued. Doses of 750, 1100, 1700, and 2200 mg/day were administered. Terameprocol was reformulated to avoid acidosis related to the excipient and was well tolerated at 1700 mg/day. Hypoxia and interstitial nephritis were noted at 2200 mg/day. Concurrent administration of EIASD did not significantly affect the serum pharmacokinetics of the terameprocol. Although no responses were seen, stable disease was noted in 9 (28%) of 32 evaluable patients, with 5 (13%) continuing treatment for >6 months (≥6, 8, 10, 10, and ≥21 months). The overall median survival was 5.9 months. This phase I study defined the toxicity of terameprocol, determined that EIASDs do not affect its pharmacokinetics, and identified 1700 mg/day as the dose for future studies. Preclinical and human data suggest that this novel transcription inhibitor is worthy of further study. The long-term stability noted in some patients and the lack of associated myelosuppression suggest that terameprocol could be safely combined with radiation and temozolomide in newly diagnosed high-grade gliomas.

Nordihydroguaiaretic acid (NDGA) is a powerful antioxidant and/or lipoxygenase (LOX) inhibitor which is isolated from Larrea tridentate. NDGA has been shown to have neuroprotective effects both in vitro and in vivo experiments. However, little is known regarding NDGA's protective mechanism in ischemia/reperfusion (I/R) injury. We therefore investigated the potential protective effects of NDGA and explored the underlying mechanisms. Oxygen-glucose deprivation (OGD) was performed in cultured rat cortical neurons for 60min. The effect of NDGA on OGD induced cell death and apoptosis was examined at 24h after reperfusion. Western blot was used to analyze the expression of p-c-jun and p-JNK. Exogenous 5-, 12-, 15-hydroxyeicosatetraenoic acid (HETE) was added respectively to the cells to investigate the contribution of the products of LOX to the c-Jun N-terminal protein kinase (JNK) pathway. Rats were injected intraperitoneally with NDGA before being subjected to middle cerebral artery occlusion (MCAO). At 24h after reperfusion, neurological deficit, brain infarct volume and the expression of p-c-jun and p-JNK were measured. The results showed that NDGA increased cell viability and inhibited apoptosis after OGD in neurons. NDGA suppressed the expression of p-c-jun and p-JNK in cortical neurons, whereas exogenous 12-, 15-HETE attenuated this effect. NDGA improved neurological deficit, reduced infarct volumes, and downregulated the overexpression of p-c-jun and p-JNK after MCAO and reperfusion. In conclusion, these results suggest that NDGA's protective effect against I/R injury is mediated by the suppression of JNK pathway. This effect is probably due to its 12/15-LOX inhibitor property., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic neurons and the aggression of alpha Synuclein (αS) in the brain. Drosophila mutants and transgenes have provided a platform to understand the mechanistic insight associated with the degenerative diseases. A number of polyphenols have been reported to inhibit the αS aggregation resulting in the possible prevention of PD. The involvement of free radicals in mediating the neuronal death in PD has also been implicated. In the present study, the effect of Nordihydroguaiaretic acid (NDGA) was studied on the climbing ability of the PD model Drosophila expressing normal human alpha synuclein (h-αS) in the neurons. These flies exhibit locomotor dysfunction as the age progresses. NDGA at final concentration of 0.01, 0.1, 0.5, and 1μl/ml was supplemented with the diet and the flies were allowed to feed for the 24 days. NDGA at 0.01 μl/ml did not showed any significant delay in the loss of climbing ability of PD model flies. However, NDGA doses at 0.1, 0.5, and 1.0 μl/ml showed a dose dependent significant (p < .05) delay in the loss of climbing ability of PD model flies as compared to the untreated PD flies. The results suggest that the NDGA is potent in delaying the climbing disability of PD model flies and also supports the utility of this model in studying PD symptoms.

Insulin-like growth factor (IGF)-mediated signaling is a newly recognized clinical target in prostate cancer, and it is hypothesized that blockade of the IGF receptor (IGF1R) will impair downstream signaling and slow tumor growth. In this study the efficacy of nordihydroguaiaretic acid (NDGA), a small molecule inhibitor of the IGF-1R, was prospectively evaluated in patients with non-metastatic hormone-sensitive prostate cancer (HSPC). Eligible patients had non-metastatic HSPC with a rising prostate-specific antigen (PSA) and a normal testosterone level. NDGA 2000 mg was given orally daily in 28 day cycles and treatment continued until PSA progression or toxicity. Accrual was stopped early after a pre-planned interim analysis showed no significant PSA declines after 3 cycles of treatment among the first 12 patients enrolled. Median time on treatment was 9 cycles (range 2-19) for 11 patients now off study; 1 patient continues to receive therapy and has been on study for 29 months. Seven patients experienced non-sustained declines in PSA ranging from 1.9 to 15.8% of baseline. PSADT lengthened by a median of 1.4 months for all evaluable patients when compared to pretreatment PSADT (range -6.1 to +19.8 months). Grade 3 events were rare and included nausea/vomiting, syncope due to dehydration, and elevated liver function tests in 1 patient, and cognitive disturbance in another patient. NDGA therapy lengthens median PSADT but does not induce significant PSA declines. Further study may require a placebo-control to determine if changes in PSADT are drug related.

Reactive oxygen radicals, pro-inflammatory mediators and cytokines have been implicated in caerulein induced acute pancreatitis. Nordihydroguaiaretic acid (NDGA), a plant lignin, has marked anti-inflammatory properties. The present study aimed to investigate the possible protective effect of NDGA against caerulein induced pancreatitis. Acute pancreatitis was induced by intraperitoneal administration of eight doses of caerulein in male swiss albino mice. NDGA was administered after 9 h of acute pancreatitis induction. Pancreatic damage and the protective effect of NDGA were assessed by oxidative stress parameters and histopathology of pancreas. The mRNA expression of heat shock proteins (DNAJ C15 and HSPD1) was examined by real-time RT-PCR analysis. Expression of HSP 27, NF-κB, TNF-α, p-p38, Bcl-2, p-PP2A, procaspase-3, caspase-3 and histone modifications were examined by western blotting. NDGA attenuated the oxidative stress, led to increased plasma α-amylase and decreased IGF-1 in AP mice. It modulated the mRNA and protein levels of heat shock proteins and reduced the expression of NF-κB, TNF-α and p-p38. It increased the number of TUNEL positive apoptotic cells in the pancreas of AP mice. In addition, NDGA prevented the changes in modifications of histone H3 in acute pancreatitis. To best of our knowledge, this is the first report which suggests that NDGA prevents the progression of acute pancreatitis by involving alteration of histone H3 modifications and modulating the expression of genes involved in inflammatory/apoptotic cascade, which may be responsible for decreased necrosis and increased apoptosis in this model of acute pancreatitis.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder. Oxidative damage has been associated with pathological neuronal loss in HD. The therapeutic modulation of oxidative stress and mitochondrial function using low molecular weight compounds may be an important strategy for delaying the onset and slowing the progression of HD. In the present study, we found a marked increase of 4-hydroxy-2-nonenal (4-HNE) adducts, a lipid peroxidation marker, in the caudate and putamen of HD brains and in the striatum of HD mice. Notably, 4-HNE immunoreactivity was colocalized with mutant huntingtin inclusions in the striatal neurons of R6/2 HD mice. Administration of nordihydroguaiaretic acid (NDGA), an antioxidant that functions by inhibiting lipid peroxidation, markedly reduced 4-HNE adduct formation in the nuclear inclusions of R6/2 striatal neurons. NDGA also protected cultured neurons against oxidative stress-induced cell death by improving ATP generation and mitochondrial morphology and function. In addition, NDGA restored mitochondrial membrane potential, mitochondrial structure, and synapse structure in the striatum of R6/2 mice and increased their lifespan. The present findings suggest that further therapeutic studies using NDGA are warranted in HD and other neurodegenerative diseases characterized by increased oxidative stress and altered mitochondrial function.

Three perglycosylated nordihydroguaiaretic acids (NDGA) were synthesized through the Huiseng 1,3-dipolar cycloaddition reaction. These sugar-NDGA conjugates containing triazole-linkages possessed good solubility in water. NDGA-(triazol-galactose)(4) (12b) and NDGA-(triazol-glucose)(4) (12c) were found to act as inhibitors against human hepatocellular carcinoma Hep3B cells in culture., (Copyright © 2010. Published by Elsevier Ltd.)

Creosote bush, Larrea tridentata, is known as chaparral or greasewood in the United States and as gobernadora or hediondilla in Mexico. Nordihydroguaiaretic acid (NDGA), the main metabolite of the creosote bush, has been shown to have promising applications in the treatment of multiple diseases, including cardiovascular diseases, neurological disorders and cancers. Creosote bush is a promising agent of North American herbal medicine, and it has extensive pharmacological effects and specific mechanisms of actions. This review provides an update of recent in vitro and in vivo research about NDGA and describes experimental studies using NDGA as antioxidant. Also, potential medical uses based on the effects of NDGA on the cardiovascular, immune and neurological systems; cancer; tissue engineering; as well as pharmacokinetics and toxicity are discussed.

In a recent issue of Experimental Neurology, Boston-Howes and colleagues used an assay of glutamate transport to screen 1040 FDA approved drugs in an attempt to identify compounds that would increase glutamate transport, a central function of astrocytes, and a potential biological target for neuroprotection for a variety of neurological disorders. They identified the compound nordihydroguaiaretic acid (NDGA) as a particularly good candidate for inducing glutamate transport. Pharmacological increases in glutamate transport could have a number of potential applications to diseases of the nervous system where glutamate excitotoxicity is thought to be a contributing factor to pathogenesis including Amyotrophic Lateral Sclerosis, Alzheimer's disease, Parkinson's disease, stroke, and epilepsy among others. They chose to test this compound in a model of Amyotrophic Lateral Sclerosis (ALS)--the SOD1G93A mouse. In both human ALS and rodent models of the disease, glutamate excitotoxicity and abnormalities in glutamate transporter biology more specifically, have been implicated in ALS disease propagation. Interestingly, while the authors nicely demonstrate that NDGA has a biological effect on glutamate transport in normal (wild type) central nervous system tissues both in vitro and in vivo, it was the somewhat unexpected (and often overlooked) findings in the ALS mouse model that makes this manuscript notable and suggests that rethinking translational approaches to drug therapies in ALS may be on the horizon.

5-lipoxygenase inhibitor and human recombinant erythropoietin might accelerate renal recovery in cisplatin-induced acute renal failure rats. Male Sprague-Dawley rats were randomized into four groups: 1) normal controls; 2) Cisplatin group-cisplatin induced acute renal failure (ARF) plus vehicle treatment; 3) Cisplatin+nordihydroguaiaretic acid (NDGA) group-cisplatin induced ARF plus 5-lipoxygenase inhibitor treatment; 4) Cisplatin+erythropoietin (EPO) group-cisplatin induced ARF plus erythropoietin treatment. On day 10 (after 7 daily injections of NDGA or EPO), urea nitrogen and serum Cr concentrations were significantly lower in the Cisplatin+NDGA and Cisplatin+EPO groups than in the Cisplatin group, and 24 hr urine Cr clearances were significantly higher in the Cisplatin+EPO group than in the Cisplatin group. Semi-quantitative assessments of histological lesions did not produce any significant differences between the three treatment groups. Numbers of PCNA(+) cells were significantly higher in Cisplatin, Cisplatin+NDGA, and Cisplatin+EPO groups than in normal controls. Those PCNA(+) cells were significantly increased in Cisplatin+NDGA group. These results suggest that EPO and also NDGA accelerate renal function recovery by stimulating tubular epithelial cell regeneration.

Purpose: Arachidonic acid metabolism via the cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) pathways modulates cell growth and apoptosis. Many studies have examined the effects of COX inhibitors on human colorectal cancer, but the role of 5-LOX in colonic cancer development has not been well studied. The purpose of this study was to evaluate the expression of 5-LOX in colonic polyps and cancer and the effect of 5-LOX inhibition on colon cancer cell proliferation., Experimental Design: Colonic polyps, cancer, and normal mucosa were evaluated for 5-LOX expression by immunohistochemistry. Reverse transcription-PCR was used to establish 5-LOX expression in colon cancer cells. Thymidine incorporation and cell counts were used to determine the effect of the nonspecific LOX inhibitor Nordihydroguaiaretic Acid and the 5-LOX inhibitor Rev5901 on DNA synthesis. A heterotopic xenograft model in athymic mice using HT29 and LoVo human colon cancer cells was used to evaluate the effect of the 5-LOX inhibitor zileuton on tumor growth., Results: 5-LOX is overexpressed in adenomatous polyps and cancer compared with that of normal colonic mucosa. LOX inhibition and 5-LOX inhibition decreased DNA synthesis in a concentration- and time-dependent manner in the Lovo cell line (P < 0.05). Inhibition of 5-LOX in an in vivo colon cancer xenograft model inhibited tumor growth compared with that of controls (P < 0.05)., Conclusions: This study showed that 5-LOX is up-regulated in adenomatous colon polyps and cancer compared with normal colonic mucosa. The blockade of 5-LOX inhibits colon cancer cell proliferation both in vitro and in vivo and may prove a beneficial chemopreventive therapy in colon cancer.

Acoustic injury is a common cause of hearing loss for people in industrial societies. Cyclooxygenase (COX) and lipoxygenase (LOX) are two important enzymes involved in arachidonic acid metabolism. Two COX isozymes are characterized, COX-1 and COX-2, that differ in terms of regulatory mechanisms of expression. Although COX-1, COX-2, and LOX are expressed in cochlea, their roles played in cochlear acoustic injury have not fully been evaluated. Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit either COX or LOX, or both. This study evaluated the effects of NSAIDs on the functional recovery of the cochlea after acoustic injury. Mice were exposed to a 4-kHz pure tone of 128 dB SPL (sound pressure level) for 4 hours and received one of the following drugs for two weeks after acoustic overexposure: indomethacin (COX-1 inhibitor), meloxicam, SC58125, and CAY10404 (COX-2 inhibitors), and nordihydroguaiaretic acid (LOX inhibitor). The hearing ability was evaluated using an auditory brainstem response (ABR) before and after overexposure. The ABR threshold shifts, defined as subtraction between ABR thresholds before and after overexposure, were compared among the control and the medication groups at one and two weeks after acoustic overexposure. Treatment of mice with either indomethacin or nordihydroguaiaretic acid decreased the ABR threshold shifts after overexposure, indicating that COX-1 and LOX inhibitors exhibited protective effects against acoustic injury. In contrast, COX-2 inhibitors, meloxicam, SC58125, and CAY10404, showed no noticeable effects on the ABR threshold shifts. These findings suggest that COX-1 and LOX are involved in the pathogenesis of acoustic injury in cochlea.

Reactive oxygen species (ROS) performs a pivotal function as a signaling mediator in receptor-mediated signaling. However, the sources of ROS in this signaling have yet to be determined, but may include lipoxygenases (LOXs) and NADPH oxidase. The stimulation of lymphoid cells with TNF-alpha, IL-1beta, and LPS resulted in significant ROS production and NF-kappaB activation. Intriguingly, these responses were markedly abolished via treatment with the LOXs inhibitor nordihydroguaiaretic acid (NDGA). We further examined in vivo anti-inflammatory effects of NDGA in allergic airway inflammation. Both intraperitoneal and intravenous NDGA administration attenuated ovalbumin (OVA)-induced influx into the lungs of total leukocytes, as well as IL-4, IL-5, IL-13, and TNF-alpha levels. NDGA also significantly reduced serum levels of OVA-specific IgE and suppressed OVA-induced airway hyperresponsiveness to inhaled methacholine. The results of our histological studies and flow cytometric analyses showed that NDGA inhibits OVA-induced lung inflammation and the infiltration of CD11b+ macrophages into the lung. Collectively, our findings indicate that LOXs performs an essential function in pro-inflammatory signaling via the regulation of ROS regulation, and also that the inhibition of LOXs activity may have therapeutic potential with regard to the treatment of allergic airway inflammation.

The effects of nordihydroguaiaretic acid (NDGA) and its tetraacetylated derivative (NDGATA) on the growth, oxygen consumption, adenosine 5'-triphosphate (ATP) level and viability of mouse mammary adenocarcinoma TA3 and its multiresistant variant TA3-MTX-R cell lines were determined. NDGA inhibited mitochondrial carbonyl cyanide m-chlorophenylhydrazone (CCCP)-stimulated oxygen consumption in mouse liver and tumor cells when glutamate plus malate or succinate was added as substrate. The effects were considerably weaker when respiration was supported by duroquinol, indicating that NDGA inhibited primarily mitochondrial electron flow located at some point before ubiquinone. Although NDGATA only inhibited the electron flow through complex I, it was more efficient and selective than NDGA because mouse liver mitochondria were significantly less sensitive to it than both tumor cell lines tested. NDGA and NDGATA inhibited mitochondrial ATP synthesis and, consequently, cell viability and growth rate were also decreased. NDGA and NDGATA inhibited the growth of intramuscularly implanted tumor cells, indicating that NDGATA was also antineoplastic in vivo. In conclusion, NDGATA is cytotoxic to tumor cells, provoking selective induction of mitochondrial dysfunctions, which could be interesting as potential antitumoral agent.

Induction of apoptosis and pro-inflammatory cytokine gene expression in influenza virus-infected cells activates production of toxic superoxide by macrophages. Pyrrolidine dithiocarbamate and nordihydroguaiaretic acid inhibit influenza virus proliferation and scavenge superoxide. These results suggest that they can be potential candidates for a drug of choice for influenza chemotherapy.

Terameprocol, a novel, semisynthetic derivative of a naturally occurring plant lignan, is under development by Erimos Pharmaceuticals LLC for the potential treatment of cancer. The antitumor activity of terameprocol is based on the selective inhibition of specificity protein 1 (Sp1)-regulated proteins, including cyclin-dependent kinase 1, survivin and VEGF. With this mechanism of action, terameprocol potentially inhibits the cell cycle, triggers apoptosis and decreases angiogenesis. Several preclinical studies have demonstrated the potent anticancer activity of terameprocol in tumor cell lines and animal models. In addition, terameprocol prevented the proliferation of HIV, HSV and HPV by a deactivation of viral Sp1-dependent promoters in preclinical studies. In a phase I clinical trial in patients (25 evaluable) with solid tumors administered intravenous terameprocol, 8 patients exhibited stable disease and 17 had progressive disease; the drug was generally well tolerated. A good safety and efficacy profile has also been observed with the intratumoral and intravaginal administration of terameprocol in patients with head and neck or squamous cell carcinoma and in patients with cervical dysplasia, respectively. At the time of publication, terameprocol was in phase I or I/II clinical development for the treatment of glioma, treatment-refractory solid tumors and cervical dysplasia; a phase I clinical trial was also planned in patients with hematological cancers. Thus, the favorable tolerability and efficacy profile demonstrated for terameprocol to date suggests that the further investigation of this drug is warranted.

Objective: To assess the tolerability of the effects of nordihydroguareacetic acid (NDGA) and its effect on prostate-specific antigen (PSA) kinetics in patients with relapsed prostate cancer, as among the many biological effects of NDGA is the inhibition of the insulin-like growth factor 1 receptor (IGF-1R) tyrosine kinase., Patients and Methods: Eligible patients were those with an increasing PSA level after definitive local therapy, in either the non-castrate (androgen-dependent prostate cancer, ADPC) or the castrate state (castration-resistant prostate cancer, CRPC) with no evidence of metastatic disease by bone scan or computed tomography of the abdomen or pelvis. Treatment consisted of continuous oral daily dosing according to a planned dose escalation of 750, 1250, 1750, 2250 and 2500 mg of NDGA. PSA levels were measured every 28 days. Serial levels of testosterone, dihydrotestosterone, oestradiol and sex hormone-binding globulin were measured at baseline and monthly while on study therapy., Results: Fifteen patients were enrolled, including 11 with ADPC and four with CRPC. There were asymptomatic increases in transaminase in six patients, two of which were grade 3, all occurring at >or=3 months. The increases in transaminase resolved after stopping NDGA but recurred with repeated dosing. Doses of NDGA up to 2500 mg/day caused no other toxicities. A median (range) of 5.5 (1-13) cycles were delivered. Of the 11 patients with ADPC, one had a decline in PSA level of >50% of the baseline value and one a decline of <50%. Three patients with ADPC had a greater than three-fold increase in PSA doubling time while on therapy, one from 11 to 46 months (750 mg), one from 9.5 to 49.5 months (1750 mg), and one from 5.9 to 46.2 months (2500 mg). There were no reductions in PSA level in patients with CRPC. There were no significant effects on levels of testosterone, dihydrotestosterone, oestradiol or sex hormone-binding globulin., Conclusions: Continuous daily dosing with NDGA is reasonably well tolerated but is associated with transaminitis in some patients, that occurs after several months on therapy. There were apparent effects on the rate of increase in PSA. Further study is required to determine the optimum pharmacokinetics and antitumour effects of this therapy.

Recent epidemiological studies have demonstrated that consumption of certain natural products can lower cancer risk in humans. For example, plant-derived lignans have been shown to exert chemopreventive effects against cancer in vitro and in vivo. In the present study, the effects of three such lignans, termed arctiin, arctigenin, and nordihydroguaiaretic acid (NDGA), on the proliferation of Helicobacter pylori and the prevention of H. pylori-associated gastric cancer were investigated in Mongolian gerbils. To examine the effects of arctigenin and NDGA on stomach carcinogenesis, specific pathogen-free male, 5-week-old gerbils were infected with H. pylori, administered 10 p.p.m. N-methyl-N-nitrosourea in their drinking water and fed diets containing various concentrations of lignans until they were killed after 52 weeks. At a dietary level of 0.25%, NDGA significantly decreased the incidence of gastric adenocarcinomas. Arctigenin, in contrast, failed to attenuate neoplasia at a level of 0.1%. Both NDGA and arctigenin significantly reduced serum 8-hydroxy-2'-deoxyguanosine levels at doses of 0.25 and 0.05% (NDGA), and 0.1% (arctigenin). Administration of 0.25% NDGA significantly suppressed the formation of intestinal metaplasia both in the antrum and the corpus. Although all three lignans dose-dependently inhibited the in vitro proliferation of H. pylori, there were no differences in the titers of anti-H. pylori antibodies or the amount of the H. pylori-specific urease A gene among all H. pylori-infected groups. These results suggest that NDGA might be effective for prevention of gastric carcinogenesis. The possible mechanisms appear to be related to inhibitory effects on progression of gastritis and antioxidative activity rather than direct antimicrobial influence.

Persistent infection with oncogenic human papillomaviruses (HPVs) is the most important factor in the induction of uterine cervical cancer, a leading cause of cancer mortality in women worldwide. Upon cell transformation, continual expression of the viral oncogenes is required to maintain the transformed phenotype. The viral E6 protein forms a ternary complex with the cellular E6-AP protein and p53 protein which promotes the rapid degradation of p53. Recent studies have revealed that lignans from the creosote bush (3'-O-methyl-nordihydroguaiaretic acid) can repress the viral promoter responsible for E6 gene expression. Work reported here shows that the lignan can subvert viral oncogene function resulting in stabilized p53 protein within treated HPV-containing tumor cells. The stabilized p53 is transcriptionally active as demonstrated by a luciferase reporter vector and induction of genes for Bax and PUMA proteins. Apoptosis is detected by annexin V binding to treated cells as analyzed by flow cytometry. Programmed cell death is confirmed by the induction of active caspases and TUNEL assay. Initiator caspase-9 is activated first, followed later by the effector caspase-3 enzyme. The stabilization and induced apoptosis are not observed within treated HPV-negative cervical tumor cells. Quantitative real time RT-PCR analysis of endogenous E6 gene transcription from the integrated HPV 16 promoter shows at least a fivefold repression of expression as compared to untreated cells. These results indicate that the loss of E6 protein in treated cells could be, in part, responsible for the stabilization of p53 within the lignan treated cells., ((c) 2007 Wiley-Liss, Inc.)

This study examined the combinatory effect on graft survival of neonatal pig pancreatic cell clusters (NPCC) with nordihydroguaiaretic acid (NDGA), a 5-lipoxygenase inhibitor, with systemic CTLA4Ig expression, with local CTLA4Ig and with interleukin-1 (IL-1) receptor antagonist (IL-1ra) expression using a pig to mouse model. About 2000 NPCCs, which were infected with both adenoviruses carrying CTLA4Ig and IL1-1ra genes (each 500 pfu/NPCC), were transplanted beneath the kidney capsule of diabetic BALB/c mice. Two days before transplantation, the recipient mice were either injected with (group C, n = 4; group D, n = 6) or without (group A, n = 7; group B, n = 9) 1 x 10(13) pfu/kg body weight of adenovirus carrying the CTLA4Ig gene. Mice in groups B and D received daily injections of NDGA (20 mg/kg body weight) subcutaneously for 4 weeks. Blood glucose levels less than 200 mg/dL were defined to be normoglycemic and the transplant termed as a functioning graft for the purpose of calculating mean graft function time (MFT). Four weeks posttransplantation, an intraperitoneal glucose tolerance test (IPGTT) was performed to calculate the area under the curve (AUC). Blood glucose levels in groups C and D were significantly lower than groups A and B at 1, 2, and 3 weeks after transplantation. Graft MFT and AUC of IPGTT in group D were significantly different from those in groups A and B. Our data suggested that a high dosage of systemic expression of CTLA4Ig was effective to enhance xenograft survival and that in it was reinforced by a combination with the macrophage inhibitor NDGA.

As Pseudomonas aeruginosa ExoU possesses two functional blocks of homology to calcium-independent (iPLA(2)) and cytosolic phospholipase A(2) (cPLA(2)), we addressed the question whether it would exhibit a proinflammatory activity by enhancing the synthesis of eicosanoids by host organisms. Endothelial cells from the HMEC-1 line infected with the ExoU-producing PA103 strain exhibited a potent release of arachidonic acid (AA) that could be significantly inhibited by methyl arachidonyl fluorophosphonate (MAFP), a specific PLA(2) inhibitor, as well as significant amounts of the cyclooxygenase (COX)-derived prostaglandins PGE(2) and PGI(2). Cells infected with an isogenic mutant defective in ExoU synthesis did not differ from non-infected cells in the AA release and produced prostanoids in significantly lower concentrations. Infection by PA103 induced a marked inflammatory response in two different in vivo experimental models. Inoculation of the parental bacteria into mice footpads led to an early increase in the infected limb volume that could be significantly reduced by inhibitors of both COX and lipoxygenase (ibuprofen and NDGA respectively). In an experimental respiratory infection model, bronchoalveolar lavage (BAL) from mice instilled with 10(4) cfu of PA103 exhibited a marked influx of inflammatory cells and PGE(2) release that could be significantly reduced by indomethacin, a non-selective COX inhibitor. Our results suggest that ExoU may contribute to P. aeruginosa pathogenesis by inducing an eicosanoid-mediated inflammatory response of host organisms.

Although controversial, Creosote bush, Larrea tridentata (Sesse and Moc. ex DC) Coville, is used to treat a variety of illnesses including infertility, rheumatism, arthritis, diabetes, gallbladder and kidney stones, pain and inflammation. Recently, it has been used as a nutritional supplement. The primary product extracted from this common plant of the arid regions of northern Mexico and Southwestern United States is the potent antioxidant nordihydroguaiaretic acid (NDGA). It was widely used during the 1950s as a food preservative and to preserve naturals fibers. Later it was banned after reports of toxicity during the early 1960s. Renal and hepatotoxicity are also reported for chronic use of creosote bush and NDGA. This article reviews traditional and contemporary uses and pharmacology, including toxicology of this plant widely used in Mexican traditional medicine.

Purpose: Inflammation, in general, causes the release of a variety of inflammatory mediators that in turn induce cyclooxygenase (COX) 2, nitric oxide synthase (iNOS) and 5-lipoxygense (LP) synthesis, producing large amounts of inflammatory prostaglandins (PG), nitric oxide (NO), and leukotriene (LT) B4. Therefore, inhibition of these enzymes may abrogate intraocular inflammation in experimental autoimmune anterior uveitis (EAAU)., Methods: Lewis rats were immunized with melanin-associated antigen (MAA) isolated from bovine iris and ciliary body. These animals were divided into three groups. The first group of rats received subcutaneous injection of COX 2 inhibitor CS 236 at different time points. The second and third groups of animals received subcutaneous aminoguanidine (AG), an iNOS inhibitor, and nordihydroguaiaretic acid (NDGA), a 5-LP inhibitor, respectively. Control animals received vehicle. Rat eyes were examined daily by slit-lamp biomicroscopy from Day 7 to 30 post injection for uveitis. Animals were also sacrificed at various time points for histologic analysis., Results: Control animals developed severe EAAU in both eyes. The disease started in these animals on Day 12 post immunization and lasted for ten days. Interestingly, CS 236, a potent COX 2 inhibitor, completely abrogated EAAU when the animals were treated daily from the Day 0 to 14 or Day 0 to 20 after MAA injection. Furthermore, daily CS 236 treatment after the onset of EAAU (Day 14-20) significantly reduced the severity (both clinical and histologic) of EAAU and shortened the duration of disease. iNOS inhibitor (AG) and 5-LP inhibitor (NDGA) partially attenuated EAAU., Conclusions: Our results show that EAAU was partially attenuated by AG and NDGA. Interestingly, CS 236, a potent COX 2 inhibitor, completely inhibited EAAU in male Lewis rats most likely by inhibiting the initial phase and onset of the disease.

Familial forms of amyotrophic lateral sclerosis (ALS) can be caused by mutations in copper, zinc-superoxide dismutase (SOD1). Mice expressing SOD1 mutants demonstrate a robust neuroinflammatory reaction characterized, in part, by up-regulation of tumor necrosis factor alpha (TNFalpha) and its primary receptor TNF-RI. In an effort to identify small molecule inhibitors of neuroinflammation useful in treatment of ALS, a microglial culture system was established to identify TNFalpha antagonists. Walker EOC-20 microglia cells were stimulated with recombinant TNFalpha, with or without inhibitors, and the cell response was indexed by NO2- output. Three hundred and fifty-five rationally selected compounds were included in this bioassay. The arachidonic acid 5-lipoxygenase (5LOX) and tyrosine kinase inhibitor nordihydroguaiaretic acid (NDGA), a natural dicatechol, was one of the most potent non-cytotoxic antagonists tested (IC50 8 +/- 3 microm). Investigation of the G93A-SOD1 mouse model for ALS revealed increased message and protein levels of 5LOX at 120 days of age. Oral NDGA (2500 p.p.m.) significantly extended lifespan and slowed motor dysfunction in this mouse, when administration was begun relatively late in life (90 days). NDGA extended median total lifespan of G93A-SOD1 mice by 10%, and life expectancy following start of treatment was extended by 32%. Disease-associated gliosis and cleaved microtubule-associated tau protein, an indicator of axon damage, were likewise reduced by NDGA. Thus, TNFalpha antagonists and especially 5LOX inhibitors might offer new opportunities for treatment of ALS.

Recent evidences indicate a pivotal role of reactive oxygen species in etiology of diabetic nephropathy, an important microvascular complication of diabetes mellitus. Moreover, oxidative stress leads to an increased production of lipoxygenase derivatives which also play a role in diabetic nephropathy. The present study was thus designed to examine the effect of an antioxidant and a lipoxygenase inhibitor, nordihydroguairetic acid (NDGA), on renal function and oxidative stress in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by a single intraperitoneal injection of streptozotocin (65 mg/kg) in rats. After the 4th week of STZ injection, NDGA (5 and 10 mg/kg) was given subcutaneously (s.c.) for another 4 weeks to both control and diabetic rats. At the end of the 8th week, diabetic rats exhibited renal dysfunction as evidenced by reduced creatinine and urea clearance along with enhanced albumin excretion rate as compared with control rats. Biochemical analysis of kidneys revealed a marked increase in oxidative stress demonstrated by increased lipid peroxidation and decreased activities of key antioxidant enzymes, glutathione (GSH), superoxide dismutase (SOD) and catalase in diabetic rats. Chronic treatment with NDGA in diabetic rats significantly prevented both renal dysfunction and oxidative stress as compared with vehicle-treated diabetic rats. The kidneys of diabetic rats showed morphological changes such as hyaline casts, glomerular thickening and moderate interstitial fibrosis and arteriolopathy, whereas NDGA administration in diabetic rats markedly prevented renal morphological alterations. These results emphasize the role of oxidative stress in the pathophysiology of diabetic nephropathy and point towards the potential of NDGA as a complementary therapy for the prevention/treatment of diabetic nephropathy., (Copyright 2004 S. Karger AG, Basel)

Plant-derived lignans caused cell loss by apoptosis in colorectal adenoma and carcinoma cells. Nordihydroguaiaretic acid (NDGA), commonly used for the inhibition of lipoxygenase isoenzymes, showed the strongest growth inhibition with an IC50 of 1.9+/-0.5 microg followed by epiashantin (IC50=9.8+/-4.5 microM) and arctigenin (IC50=16.5+/-8.5 microM). The lignans caused a time- and dose-dependent loss of mitochondrial membrane potential (MMP), down regulation of the anti-apoptotic protein bcl(xl) and an increase of the apoptotic index. The time interval until loss of MMP and down modulation of bcl(xl) became evident correlated with the efficiency of growth inhibition by NDGA, epiashantin and yangambin. Bcl2 and caspase 3 were not involved. NDGA also induced a shift of the culture population to the G2/M phase of the cell cycle. With respect to these results, naturally occurring lignans could be useful in the therapy and chemoprevention of colorectal tumors.

tetra-O-methylnordihydroguaiaretic acid is a derivative of a naturally-occurring lignan, nordihydroguaiaretic acid, that has previously been shown to inhibit various cancer types in vitro and in vivo. Additionally, nordihydroguaiaretic acid has been shown to have nephrotoxic effects in the rat. Here we show that tetra-O-methylnordihydroguaiaretic acid inhibits the growth of a number of tumor cell lines in vitro by inducing apoptosis in a non-schedule-dependent manner. Further, this compound inhibits the synthesis of DNA by melanoma cells and causes cell cycle arrest in G0/G1 and G2/M phases of the cell cycle. tetra-O-Methylnordihydroguaiaretic acid also inhibits the growth of both murine and human melanomas and human colon cancer in vivo without apparent hepatic or renal toxicity.

The purpose of this study was to evaluate the neuroprotective effect of nordihydroguaiaretic acid (NDGA), an antioxidant and/or 5-lipoxygenase inhibitor, on ischemia-reperfusion injury behavioral pharmacologically and histologically in vivo. First, the antioxidant activity of NDGA was evaluated in vitro by measuring the production of thiobarbituric acid reactive substances (TBARS) in rat brain homogenate. Second, the effect of NDGA on learning and memory impairment induced by rat four-vessel occlusion transient ischemia was investigated with the Morris water-maze task. Third, the effect of NDGA on pyramidal cell loss in the hippocampus after transient ischemia was examined. NDGA inhibited the production of TBARS with an IC(50) of 0.1 microM, and significantly attenuated postischemic learning and memory impairment at 10 mg/kg. Furthermore, consecutive 4-day administration of NDGA at 10 mg/kg significantly reduced the postischemic neuronal death. NDGA was found to be potent and effective as an anti-ischemia-reperfusion injury agent in terms of behavioral pharmacology and histology. The present results suggest that NDGA has beneficial effects on behavioral deficits and histological injury caused by ischemia-reperfusion.

Objective: To study the effect of nordihydroguaiaretic acid (NDGA), zafirlukast and indomethacin on the size of the size of the allergic prick-test wheal., Method: In the first part of the study, NDGA and indomethacin, as well as the mepyramine control (10 micrograms/ml and 100 micrograms/ml), were injected intracutaneously 10 min before prick-testing with the cow dander allergen in 51 sensitised atopic subjects. In the second part, five other subjects were prick-tested with several allergens followed by administration of 40 mg zafirlukast or 100 mg indomethacin and re-prick-testing 2 h or 4 h later., Results: The intracutaneous indomethacin at both concentrations enlarged the wheal by 27 +/- 50% and 29 +/- 51% (P < 0.02, n = 51), respectively. Likewise, the peroral indomethacin significantly increased the wheal area by 17 +/- 30% (P = 0.035, n = 5). Neither intracutaneous NDGA in 51 subjects nor peroral zafirlukast in 5 subjects had marked effects on the size of the prick-test wheal. As expected, mepyramine (10 micrograms/ml) decreased the wheal area by 33 +/- 32% (P < 0.001, n = 51), but 14 subjects did not show any decrease after administration of this H1-antihistamine., Conclusion: The prostaglandin synthesis inhibitor (indomethacin) augments the prick-test wheal, but the leukotriene synthesis inhibitor (NDGA) and leukotriene C4 antagonist (zafirlukast) have no marked effects on the size of the prick-test wheal.

In this paper, we report the effect of standard NDGA, as compared to that of an aqueous extract of Larrea divaricata Cav., on BW 5147 lymphoma cell-line proliferation. To determine the mechanism of action, the effects of both on the level of intracellular cAMP, protein kinase C activity and calcium influx were studied. Moreover, the NDGA present in the aqueous extract of the plant was quantified. The aqueous extract and the standard NDGA showed antiproliferative action against these cells. While the antiproliferative activity of the aqueous extract was mediated by an increase in cAMP levels, and inhibition of PKC and calcium influx, the antiproliferative activity of NDGA was related only to the inhibition of PKC. Considering the amount of NDGA detected in the aqueous extract of the plant, at the concentrations analyzed in this case, antiproliferative activity of Larrea divaricata cannot be attributed to this compound, but could have an additive effect on the activity of other compounds.