Current medicinal chemistry
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Centrally acting opioids, such as morphine, are the most frequently used analgesic agents for the treatment of severe pain. However, their usefulness is limited by the production of a range of adverse effects such as constipation, respiratory depression, tolerance and physical dependence. In addition, opioids generally exhibit poor efficacy against neuropathic pain. ⋯ In this review we describe various strategies that have been adopted so far to conquer the major drawbacks associated with endomorphins. They include chemical modifications to produce locally or globally-restricted peptide analogs in addition to application of peptidase inhibitors, which is of minor importance compared to the former strategy. Diverse approaches that resulted in the design and synthesis of pharmacologically active endomorphin analogs with less adverse effects are also discussed giving an insight into the development of opioid peptides with an improved side effect profile.
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Sphingolipids are a class of lipids that have important functions in a variety of cellular processes such as, differentiation, proliferation, senescence, apoptosis and chemotherapeutic resistance. The most widely studied bioactive shingolipids include ceramides, dihydroceramide (dhCer), ceramide-1-phosphate (C1P), glucosyl-ceramide (GluCer), sphingosine and sphingosine-1-phosphate (S1P). Although the length of fatty acid chain affects the physiological role, ceramides and sphingosine are known to induce apoptosis whereas C1P, S1P and GluCer induce proliferation of cells, which causes the development of chemoresistance. ⋯ These approaches mainly aim to up-regulate the levels of apoptotic shingolipids while the proliferative ones are down-regulated, or to directly deliver cytotoxic sphingolipids like short-chain ceramide analogs to tumor cells. It is suggested that a combination therapy with conventional cytotoxic approaches while preventing the conversion of ceramide to S1P and consequently increasing the ceramide levels would be more beneficial. This review compiles the current knowledge about sphingolipids, and mainly focuses on novel agents modulating sphingolipid pathways that represent recent therapeutic strategies for the treatment of cancer.
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Chronic obstructive pulmonary disease (COPD) is an increasing global health problem and cause of death. COPD is a chronic inflammatory disease predominantly affecting small airways and lung parenchyma that leads to progressive airway obstruction. However, current therapies fail to prevent either disease progression or mortality. ⋯ A new promising approach is reversal of corticosteroid resistance through increasing histone deacetylase-2 (HDAC2) activity. This might be achieved by existing treatments such as theophylline, nortriptyline and macrolides, or more selectively by PI3 kinase-δ inhibitors. Thus although there have been major advances in the development of long-acting bronchodilators for COPD, it has proved difficult to find anti-inflammatory treatments that are safe and effective.
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Tuberculosis (TB), an ongoing public health threat, is worsened by the emergence of drug resistance. With an estimated 630000 cases per year of multidrug resistant (MDR)-TB, and 9% of those being extensively drug resistant (XDR)-TB, there is an urgent need for new and more effective anti-TB drugs. ⋯ In spite of the difficulties and alleged lack of interest from the pharmaceutical industry for the discovery and development of new antibiotics, several new or repurposed drugs are being evaluated in clinical trials. This review article summarizes the information available and presents an update on the drugs currently in clinical trials for TB and briefly introduces some new compounds in pre-clinical development.
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The progression and exacerbations of chronic obstructive pulmonary disease (COPD) are intimately associated with tobacco smoke/biomass fuel-induced oxidative and aldehyde/carbonyl stress. Alterations in redox signaling proinflammatory kinases and transcription factors, steroid resistance, unfolded protein response, mucus hypersecretion, extracellular matrix remodeling, autophagy/apoptosis, epigenetic changes, cellular senescence/aging, endothelial dysfunction, autoimmunity, and skeletal muscle dysfunction are some of the pathological hallmarks of COPD. In light of the above it would be prudent to target systemic and local oxidative stress with agents that can modulate the antioxidants/ redox system or by boosting the endogenous levels of antioxidants for the treatment and management of COPD. ⋯ This includes specific spin traps like α-phenyl-N-tert-butyl nitrone, a catalytic antioxidant (ECSOD mimetic), porphyrins (AEOL 10150 and AEOL 10113), and a superoxide dismutase mimetic M40419, lipid peroxidation and protein carbonylation blockers/inhibitors, such as edaravone and lazaroids/tirilazad, myeloperoxidase inhibitors, as well as specialized pro-resolving mediators/inflammatory resolving lipid mediators, omega-3 fatty acids, vitamin D, and hydrogen sulfide. According to various studies it appears that the administration of multiple antioxidants could be a more effective mode used in the treatment of COPD. In this review, various pharmacological and dietary approaches to enhance lung antioxidant levels and beneficial effects of antioxidant therapeutics in treating or intervening the progression of COPD have been discussed.