Antioxidants green tea extract and nordihydroguaiaretic acid confer species and strain-specific lifespan and health effects in Caenorhabditis nematodes.

The Caenorhabditis Intervention Testing Program (CITP) is an NIH-funded research consortium of investigators who conduct analyses at three independent sites to identify chemical interventions that reproducibly promote health and lifespan in a robust manner. The founding principle of the CITP is that compounds with positive effects across a genetically diverse panel of Caenorhabditis species and strains are likely engaging conserved biochemical pathways to exert their effects. As such, interventions that are broadly efficacious might be considered prominent compounds for translation for pre-clinical research and human clinical applications. Here, we report results generated using a recently streamlined pipeline approach for the evaluation of the effects of chemical compounds on lifespan and health. We studied five compounds previously shown to extend C. elegans lifespan or thought to promote mammalian health: 17α-estradiol, acarbose, green tea extract, nordihydroguaiaretic acid, and rapamycin. We found that green tea extract and nordihydroguaiaretic acid extend Caenorhabditis lifespan in a species-specific manner. Additionally, these two antioxidants conferred assay-specific effects in some studies-for example, decreasing survival for certain genetic backgrounds in manual survival assays in contrast with extended lifespan as assayed using automated C. elegans Lifespan Machines. We also observed that GTE and NDGA impact on older adult mobility capacity is dependent on genetic background, and that GTE reduces oxidative stress resistance in some Caenorhabditis strains. Overall, our analysis of the five compounds supports the general idea that genetic background and assay type can influence lifespan and health effects of compounds, and underscores that lifespan and health can be uncoupled by chemical interventions.

New insights into the antiviral activity of nordihydroguaiaretic acid: Inhibition of dengue virus serotype 1 replication.

BACKGROUND: Dengue virus (DENV) is considered one of the most important pathogens in the world causing 390 million infections each year. Currently, the development of vaccines against DENV presents some shortcomings and there is no antiviral therapy available for its infection. An important challenge is that both treatments and vaccines must be effective against all four DENV serotypes. Nordihydroguaiaretic acid (NDGA), isolated from Larrea divaricata Cav. (Zygophyllaceae) has shown a significant inhibitory effect on a broad spectrum of viruses, including DENV serotypes 2 and 4. PURPOSE: We evaluated the in vitro virucidal and antiviral activity of NDGA on DENV serotype 1 (DENV1), including the study of its mechanism of action, to provide more evidence on its antiviral activity. METHODS: The viability of viral particles was quantified by the plaque-forming unit reduction method. NDGA effects on DENV1 genome and viral proteins were evaluated by qPCR and immunofluorescence, respectively. Lysosomotropic activity was assayed using acridine orange and neutral red dyes. RESULTS: NDGA showed in vitro virucidal and antiviral activity against DENV1. The antiviral effect would be effective within the first 2 h after viral internalization, when the uncoating process takes place. In addition, we determined by qPCR that NDGA decreases the amount of intracellular RNA of DENV1 and, by immunofluorescence, the number of cells infected. These results indicate that the antiviral effect of NDGA would have an intracellular mechanism of action, which is consistent with its ability to be incorporated into host cells. Considering the inhibitory activity of NDGA on the cellular lipid metabolism, we compared the antiviral effect of two inhibitors acting on two different pathways of this type of metabolism: 1) resveratrol that inhibits the sterol regulatory element of binding proteins, and 2) caffeic acid that inhibits the 5-lipoxygenase (5-LOX) enzyme. Only caffeic acid produced an inhibitory effect on DENV1 infection. We studied the lysosomotropic activity of NDGA on host cells and found, for the first time, that this compound inhibited the acidification of cell vesicles which would prevent DENV1 uncoating process. CONCLUSION: The present work contributes to the knowledge of NDGA activity on DENV. We describe its activity on DENV1, a serotype different to those that have been already reported. Moreover, we provide evidence on which stage/s of the viral replication cycle NDGA exerts its effects. We suggest that the mechanism of action of NDGA on DENV1 is related to its lysosomotropic effect, which inhibits the viral uncoating process.

Assessing Nordihydroguaiaretic Acid Therapeutic Effect for Glioblastoma Multiforme.

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.

Nordihydroguaiaretic acid reverses the antibacterial activity of colistin against MCR-1-positive bacteria in vivo/in vitro by inhibiting MCR-1 activity and injuring the bacterial cell membrane.

BACKGROUND: Colistin (polymyxin E) is an effective antibiotic for the treatment of most multidrug-resistant Gram-negative bacteria. However, some bacteria, including bacterial spp. belonging to the Enterobacteriaceae family, have an acquired resistance against polymyxins, which is attributed to they possess plasmid-carried resistance genes (mcr-1 and its variants). So, there is an urgent need to develop new therapeutic strategies to target broad spectrum resistant spp. from Enterobacteriaceae family in response to the loss of the protective barrier of last-line antibiotics. Here, we report the adjuvant capacity of nordihydroguaiaretic acid (NDGA) for restoring the antibacterial activity of colistin against MCR-1-positive E. coli ZJ487 in vivo/in vitro. METHODS: A checkerboard assay, time-killing analysis, isobolograms, growth curves and inducible resistance test showed the effect of NDGA combined with colistin in vitro. TLC was used to detect the inhibitory effect of NDGA on MCR-1. Colony determination and hematoxylin and eosin (HE) staining were used to assess the synergistic effect of NDGA and colistin in mice. RESULTS: Our results showed that NDGA in combination with colistin showed a synergistic bactericidal action without inducing resistance. NDGA directly inhibited MCR-1 activity and resulted in measurable injury to the bacterial cell membrane to recover the antibacterial effect of colistin. Most importantly, NDGA in combination with colistin exhibited an in vivo synergistic effect in murine peritonitis infection models, as evidenced by the survival rate of MCR-1-positive E. coli ZJ487-infected mice which increased from 6.67 to 50.0%. CONCLUSION: Our study demonstrated that NDGA effectively rescues the efficiency of colistin against MCR-positive E. coli ZJ487 by simultaneously inhibiting both, the MCR activity and the injury to the cell membrane of bacteria.

Facile synthesis and nanoscale features of a nanostructured nordihydroguaiaretic acid analog for therapeutic applications.

BACKGROUND: Nordihydroguaiaretic acid (NDGA) is a plant lignan obtained from creosote bush, known to possess anti-oxidant, anti-cancer and anti-viral activities and is being used in traditional medicine. However, toxicity studies indicated liver and kidney damage despite its immense medicinal properties. There has been a recent increase of curiosity in the chemical synthesis of NDGA derivatives for therapeutic applications. NDGA derivatives have been developed as better alternatives to NDGA and for targeted delivery to the site of tissue by chemical derivatives. In this regard, an analog of NDGA, Acetyl NDGA (Ac-NDGA), has been synthesized based on a previous procedure and formulated as a nanostructured complex with Polycaprolactone/Polyethylene glycol polymer matrices, by o/w solvent evaporation method. RESULTS: The drug-incorporated polymeric nanospheres exhibited a drug load of 10.0 ± 0.5 µg drug per mg of nanospheres in acetonitrile solvent with 49.95 ± 10% encapsulation efficiency and 33-41% drug loading capacity with different batches of nanospheres preparation. The in vitro drug release characteristics indicated 82 ± 0.25% drug release at 6 h in methanol. Further, the nanospheres have been characterized extensively to evaluate their suitability for therapeutic delivery. CONCLUSIONS: The present studies indicate a new and efficient formulation of the nanostructured AcNDGA with good therapeutic potential.

Nordihydroguaiaretic Acid in Therapeutics: Beneficial to Toxicity Profiles and the Search for its Analogs.

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.

Diabetic encephalopathy: beneficial effects of supplementation with fatty acids ω3 and nordihydroguaiaretic acid in a spontaneous diabetes rat model.

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.

Long chain polyunsaturated fatty acids (LCPUFAs) and nordihydroguaiaretic acid (NDGA) modulate metabolic and inflammatory markers in a spontaneous type 2 diabetes mellitus model (Stillman Salgado rats).

BACKGROUND: Diabetes mellitus (DM) is a complex disease with alterations in metabolic and inflammatory markers. Stillman Salgado rats (eSS) spontaneously develop type 2 DM by middle age showing progressive impairment of glucose tolerance with hyperglycemia, hypertriglyceridemia and hyperinsulinemia. We analyzed the effects of supplementation of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) with or without nordihydroguaiaretic acid (NDGA) added, an antioxidant and lipoxygenase inhibitor, on metabolic and inflammatory parameters in eSS rats to evaluate whether they can delay development and/or prevent progression of DM. METHODS: After weaning, eSS rats received, intraperitoneally, once a month ω-3 (EPA 35% and DHA 40%-6.25 mg/Kg) or ω-6 (90% arachidonic acid- 6. 25 mg/Kg) for twelve months. Two additional groups of rats received 1.9 mg/kg NDGA added to ω-3 and ω-6 fatty acids. Blood samples were collected at day 40, and at the end of the 6th month and 12th month of age to determine plasma triglycerides (TGs), total plasma fatty acids (FA), A1C hemoglobin (HbA1C), C-reactive protein (CRP), gamma glutamyl transpeptidase (GGT), lipo and hydro peroxides, nitrites and IL-6 (in plasma and liver, kidney, and pancreas) and underwent oral glucose tolerance test (OGTT) as well. Wistar and eSS rats that received saline solution were used as controls. RESULTS: Plasma lipids profile, TG, fasting and post-prandial blood glucose levels, and glycosylated HbA1C showed significant improvements in ω-3 and ω-3 + NDGA treated animals compared to eSS control group. ω-3 and ω-3 + NDGA groups showed an inverse correlation with fasting blood glucose and showed lower plasma levels of GGT, TG, and CRP. eSS rats treated with ω-3 LCPUFAs showed reduced level of inflammatory and oxidative indices in plasma and liver, kidney and pancreas tissues in comparison with eSS control (non-treated) and ω-6 treated groups. CONCLUSIONS: eSS rats are a useful model to study type 2 DM pathophysiology and related inflammatory indices. ω-3 + NDGA supplementation, at the doses tested, ameliorated inflammatory, metabolic and oxidative stress markers studied.

Anti-anaphylactic action of nordihydroguaiaretic acid in antigen sensitized guinea pigs.

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 (SRAW) was monitored using a two-chambered whole-body plethysmograph. OA aerosol increased SRAW above that produced by vehicle administration. Prior NDGA administration by a 1min 0.9% aerosol (w/vol) attenuated the increase in SRAW 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 C4 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 LTC4 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.

Nordihydroguaiaretic acid (NDGA) and α-mangostin inhibit the growth of Mycobacterium tuberculosis by inducing autophagy.

Tuberculosis (TB) remains as a global health problem. The prevalence of this infection is related to the association with other diseases, such as HIV, neglect treatment and misuse of antibiotics. Hence, the identification of new drugs is required to eradicate TB. Possible alternatives to existing antibiotics include pure compounds extracted from medicinal plants, which are an important source of antimicrobial agents. The aim of this study was to evaluate the effect of nordihydroguaiaretic acid (NDGA) and α-mangostin on Mycobacterium tuberculosis growth and bacterial survival in infected macrophages derived from the human THP-1 cell line and monocytes. Our results show that both compounds directly inhibit M. tuberculosis growth in liquid medium with Minimal Inhibitory Concentrations (MIC) of 250 and 62 µg/mL respectively, likely through preventing bacterial replication. In addition, NDGA and α-mangostin were able to induce autophagy in human cells at lower concentrations (7 and 6 µg/mL, respectively) and contributed to the elimination of intracellular bacteria. NDGA and α-mangostin could be candidates for coadjuvant therapy in cases of drug-resistant TB, and their ability to enhance the immune response by promoting autophagy might contribute to TB treatment.

Creosote bush lignans for human disease treatment and prevention: Perspectives on combination therapy.

The medicinal properties of the most successful plant in the deserts of the western hemisphere, the creosote bush (Larrea tridentata), are evidenced by the long traditional usage of the plants by the Native Americans Indian tribes in Southwestern North America and the Amerindians from South America. The plant is rich in simple bisphenyl lignans and tricyclic lignans known as cyclolignans. These compounds are responsible for many of the pharmacological activities of extracts of the plants. Some of these activities, namely antiherpes, antioxidant, antifungal, and anti-inflammatory, were known a century ago. Only recently have further studies revealed other crucial activities of the same plant molecules as powerful agents against human immunodeficiency virus, human papillomavirus, cancer, neurodegenerative diseases, and symptoms of aging. Molecular mechanisms underlying the antiviral and anticancer activities have been elucidated and involve the inhibition of SP1 dependent gene transcription. This review summarizes the recent findings on creosote bush lignans. We introduce the concept of a cocktail of safe well-characterized natural products from the creosote bush that would represent a bridge between oriental herbal medicines and Western drug-based therapies.

Paradoxical cellular effects and biological role of the multifaceted compound nordihydroguaiaretic acid.

Nordihydroguaiaretic acid (NDGA) is a phenolic compound obtained from the leaves of the evergreen desert shrub Larrea tridentata (Creosote bush), which has been used anciently in folk medicine for the treatment of multiple diseases. At the molecular level, NDGA is a potent scavenger of reactive oxygen species. Lipoxygenase inhibition by NDGA has been broadly studied over several cell models; however, NDGA exerts other antioxidant properties and cytoprotective effects in non-tumor cells, which are related with its role as modulator of the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) antioxidant pathway. In contrast, in tumor cells NDGA exerts pro-apoptotic activity and anti-tumor effects. Different effects of NDGA have been observed in mitochondria, where NDGA prevents mitochondrial damage in non-tumor cells and induces loss of mitochondrial function in tumor cells. Moreover, NDGA exerts beneficial effects in diverse diseases like cancer, renal damage, Huntington's disease, Alzheimer's disease, and other neurodegenerative pathologies. This work represents a critical review about relevant NDGA mechanisms, cellular effects, and signal pathways involved with possible useful effects.

Effects of Lipoxygenase Inhibitor on Diabetic Nephropathy in Rats: Decreasing Proteinuria and Preserving Renal Function / 대한신장학회지

PURPOSE: Oxidative stress leads to an increased production of lipoxygenase derivatives in diabetic nephropathy. Thus, we hypothesized that lipoxygenase inhibitor, nordihydroguaiaretic acid (NDGA), ha the effects of decreasing proteinuria and preserving renal function in streptozotocin (STZ)-induced diabetic rats. METHODS: 45 Sprague-Dawley rats were divided into three groups; (A) treatment with lipoxygenase inhibitor, NDGA in diabetic nephropathy rats, (B) treatment with dimethyl sulfoxide (DMSO) as a vehicle in STZ-induced diabetic rats, (C) normal control group with subcutaneous injection of normal saline. Diabetes was induced by a single intraperitoneal injection of STZ (65 mg/kg) in rats of group A and B. After the 4th week of STZ injection, NDGA (10 mg/kg) and DMSO were given subcutaneously for another 4 weeks in group A and B respectively. RESULTS: The NDGA-treated diabetic rats exhibited significantly decreased urinary albumin excretion. Serum creatinine and blood urea nitrogen concentrations were increased in both group A and B, and tend to be higher in group B than group A. Twenty-four-hour urine creatinine clearances were increased in both group A and B after injection of STZ. Pathologic alterations of kidney were observed after injection of STZ, and then attenuated after administration of NDGA. CONCLUSION: These results suggest the potential of lipoxygenase inhibitor as a complementary therapy for the prevention and treatment of diabetic nephropathy.