Zingiberene, a non-zinc-binding class I HDAC inhibitor: A novel strategy for the management of neuropathic pain.

BACKGROUND: Even though numerous Histone deacetylase inhibitors (HDACi) have been approved for the treatment of different types of cancer, and others are in clinical trials for the treatment of neurodegenerative diseases, the main problem related to the clinical use of available HDACi is their low isoform selectivity which causes undesirable effects and inevitably limits their therapeutic application. Previously, we demonstrated that a standardized Zingiber officinalis Roscoe rhizome extract (ZOE) reduced neuroinflammation through HDAC1 inhibition in a mice model of neuropathy, and this activity was related to terpenes fraction. HYPOTHESIS/PURPOSE: The aim of this work was to identify the ZOE constituent responsible for the activity on HDAC1 and to study its possible application in trauma-induced neuropathic pain. METHODS: The ability of ZOE and its terpenes fraction (ZTE) to inhibit HDAC and SIRT isoforms activity and protein expression was assessed in vitro. Then, a structure-based virtual screening approach was applied to predict which constituent could be responsible for the activity. In the next step, the activity of selected compound was tested in an in vitro model of neuroinflammation and in an in vivo model of peripheral neuropathy (SNI). RESULTS: ZTE resulted to be more potent than ZOE on HDAC1, 2, and 6 isoforms, while ZOE was more active on HDAC8. Zingiberene (ZNG) was found to be the most promising HDAC1 inhibitor, with an IC50 of 2.3 ± 0.1 µM. A non-zinc-binding mechanism of inhibition was proposed based on molecular docking. Moreover, the oral administration of ZNG reduced thermal hyperalgesia and mechanical allodynia in animals with neuropathy after 60 min from administration, and decreased HDAC-1 levels in the spinal cord microglia. CONCLUSION: We found a new non-zinc-dependent inhibitor of HDAC class I, with a therapeutic application in trauma-related neuropathic pain forms in which microglia-spinal overexpression of HDAC1 occurs. The non-zinc-binding mechanism has the potential to reduce off target effects, leading to a higher selectivity and better safety profile, compared to other HDAC inhibitors.

Piscidin is highly active against carbapenem-resistant Acinetobacter baumannii and NDM-1-producing Klebsiella pneumonia in a systemic Septicaemia infection mouse model.

This study was designed to investigate the antimicrobial activity of two synthetic antimicrobial peptides from an aquatic organism, tilapia piscidin 3 (TP3) and tilapia piscidin 4 (TP4), in vitro and in a murine sepsis model, as compared with ampicillin, tigecycline, and imipenem. Mice were infected with (NDM-1)-producing K. pneumonia and multi-drug resistant Acinetobacter baumannii, and subsequently treated with TP3, TP4, or antibiotics for different periods of time (up to 168 h). Mouse survival and bacterial colony forming units (CFU) in various organs were measured after each treatment. Toxicity was determined based on observation of behavior and measurement of biochemical parameters. TP3 and TP4 exhibited strong activity against K. pneumonia and A. baumannii in vitro. Administration of TP3 (150 µg/mouse) or TP4 (50 µg/mouse) 30 min after infection with K. pneumonia or A. baumannii significantly increased survival in mice. TP4 was more effective than tigecycline at reducing CFU counts in several organs. TP3 and TP4 were shown to be non-toxic, and did not affect mouse behavior. TP3 and TP4 are able at potentiate anti-Acinetobacter baumannii or anti-Klebsiella pneumonia drug activity, reduce bacterial load, and prevent drug resistance, indicating their potential for use in combating multidrug-resistant bacteria.

Laminin-111 protein therapy reduces muscle pathology and improves viability of a mouse model of merosin-deficient congenital muscular dystrophy.

Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is a lethal muscle-wasting disease that is caused by mutations in the LAMA2 gene, resulting in the loss of laminin-α2 protein. MDC1A patients exhibit severe muscle weakness from birth, are confined to a wheelchair, require ventilator assistance, and have reduced life expectancy. There are currently no effective treatments or cures for MDC1A. Laminin-α2 is required for the formation of heterotrimeric laminin-211 (ie, α2, ß1, and γ1) and laminin-221 (ie, α2, ß2, and γ1), which are major constituents of skeletal muscle basal lamina. Laminin-111 (ie, α1, ß1, and γ1) is the predominant laminin isoform in embryonic skeletal muscle and supports normal skeletal muscle development in laminin-α2-deficient muscle but is absent from adult skeletal muscle. In this study, we determined whether treatment with Engelbreth-Holm-Swarm-derived mouse laminin-111 protein could rescue MDC1A in the dy(W-/-) mouse model. We demonstrate that laminin-111 protein systemically delivered to the muscles of laminin-α2-deficient mice prevents muscle pathology, improves muscle strength, and dramatically increases life expectancy. Laminin-111 also prevented apoptosis in laminin-α2-deficient mouse muscle and primary human MDC1A myogenic cells, which indicates a conserved mechanism of action and cross-reactivity between species. Our results demonstrate that laminin-111 can serve as an effective protein substitution therapy for the treatment of muscular dystrophy in the dy(W-/-) mouse model and establish the potential for its use in the treatment of MDC1A.

Soluble RAGE-modulating drugs: state-of-the-art and future perspectives for targeting vascular inflammation.

The expression of the Receptor for Advanced Glycation Endproducts (RAGE) is upregulated at sites of vascular inflammation and plays a crucial role in vessel homeostasis. Soluble RAGE (sRAGE), a truncated soluble form of the receptor, acts as a decoy and prevents the inflammatory response mediated by RAGE activation. sRAGE has recently emerged as a biomarker in several RAGE-mediated vascular disorders, including coronary artery disease, hypertension, diabetic vasculopathy and Kawasaki disease. Given the pivotal role played by RAGE and sRAGE in numerous vascular disorders, there is a growing need to understand how drugs can modulate the RAGE axis in different disease conditions. In this regard, there is evidence to suggest that traditional cardiovascular drugs (statins, thiazolidinediones, ACE-inhibitors, AT-1 receptor antagonists) as well as nutraceuticals (grape seed proanthocyanidin extract) could modulate RAGE expression and circulating sRAGE levels in cardiovascular disease states characterized by enhanced RAGE activation. Additionally, the production of genetically engineered sRAGE may hold promise for targeting the activation of RAGE by proinflammatory ligands in the setting of vascular inflammation. The present review considers current vascular drugs as modulators of the RAGE axis, and highlights future directions in the context of RAGE-directed therapy in cardiovascular disease.

Conjugated linoleic acids: are they beneficial or detrimental to health?

Conjugated linoleic acids (CLAs) comprise a family of positional and geometric isomers of linoleic acid (18:2n-6; LA) that are formed by biohydrogenation and oxidation processes in nature. The major dietary sources of these unusual fatty acids are foods derived from ruminant animals, in particular dairy products. The main form of CLA, cis-9, trans-11-18:2, can be produced directly by bacterial hydrogenation in the rumen or by delta-9 desaturation of the co-product vaccenic acid (trans-11-18:1) in most mammalian tissues including man. The second most abundant isomer of CLA is the trans-10, cis-12-18:2 form. Initially identified in grilled beef as a potential anti-carcinogen a surprising number of health benefits have subsequently been attributed to CLA mixtures and more recently to the main individual isoforms. It is also clear from recent studies that the two main isoforms can have different effects on metabolism and cell functions and can act through different cell signalling pathways. The majority of studies on body compositional effects (i.e. fat loss, lean gain), on cancer and cardiovascular disease attenuation, on insulin sensitivity and diabetes and on immune function have been conducted with a variety of animal models. Observations clearly emphasise that differences exist between mammalian species in their response to CLAs with mice being the most sensitive. Recent studies indicate that some but not all of the effects observed in animals also pertain to human volunteers. Reports of detrimental effects of CLA intake appear to be largely in mice and due mainly to the trans-10, cis-12 isomer. Suggestions of possible deleterious effects in man due to an increase in oxidative lipid products (isoprostanes) with trans-10, cis-12 CLA ingestion require substantiation. Unresponsiveness to antioxidants of these non-enzymatic oxidation products casts some doubt on their physiological relevance. Recent reports, albeit in the minority, that CLAs, particularly the trans-10, cis-12 isomer, can elicit pro-carcinogenic effects in animal models of colon and prostate cancer and can increase prostaglandin production in cells also warrant further investigation and critical evaluation in relation to the many published anti-cancer and anti-prostaglandin effects of CLAs.

Specific immunotherapy.

The prevalence of atopic allergic disease increased substantially towards the end of the 20th century and is set to rise further. This group of diseases now constitutes the most common cause of chronic ill health in industrialised countries. Despite considerable attention from the pharmaceutical industry, little progress has been made in the development of disease-modifying therapies. In contrast, recent activity has focused almost exclusively on treatment of symptoms (palliation) rather than cause. The failure of palliative approaches to address the issue of increasing incidence of disease is in evidence in the case of allergic diseases and is a continuing focus of concern. At present, the most frequently employed non-palliative form of disease-modifying therapy is specific allergen immunotherapy (SIT) in which increasing doses of whole allergen extract are administered in increasing dose in order to desensitise the allergic subject.