15 research outputs found

    Identification and characterization of antibacterial compound(s) of cockroaches (Periplaneta americana)

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    Infectious diseases remain a significant threat to human health, contributing to more than 17 million deaths, annually. With the worsening trends of drug resistance, there is a need for newer and more powerful antimicrobial agents. We hypothesized that animals living in polluted environments are potential source of antimicrobials. Under polluted milieus, organisms such as cockroaches encounter different types of microbes, including superbugs. Such creatures survive the onslaught of superbugs and are able to ward off disease by producing antimicrobial substances. Here, we characterized antibacterial properties in extracts of various body organs of cockroaches (Periplaneta americana) and showed potent antibacterial activity in crude brain extract against methicillin-resistant Staphylococcus aureus and neuropathogenic E. coli K1. The size-exclusion spin columns revealed that the active compound(s) are less than 10 kDa in molecular mass. Using cytotoxicity assays, it was observed that pre-treatment of bacteria with lysates inhibited bacteria-mediated host cell cytotoxicity. Using spectra obtained with LC-MS on Agilent 1290 infinity liquid chromatograph, coupled with an Agilent 6460 triple quadruple mass spectrometer, tissues lysates were analyzed. Among hundreds of compounds, only a few homologous compounds were identified that contained isoquinoline group, chromene derivatives, thiazine groups, imidazoles, pyrrole containing analogs, sulfonamides, furanones, flavanones, and known to possess broad-spectrum antimicrobial properties, and possess anti-inflammatory, anti-tumour, and analgesic properties. Further identification, characterization and functional studies using individual compounds can act as a breakthrough in developing novel therapeutics against various pathogens including superbugs

    Targeting the Zinc-Dependent Histone Deacetylases (HDACs) for Drug Discovery

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    In humans, the zinc-dependent histone deacetylases (HDACs) are a family of 11 nonredundant isoforms that catalyze the dynamic reversal of posttranslationally modified acyl-lysine residues back to lysine. At the epigenetic level, HDACs have a critical gene silencing effect, promoting the compaction of histone tails with DNA to prevent transcription. In addition, HDACs deacylate many nonhistone substrates in diverse cellular compartments to profoundly influence protein structure and function. While the action of HDACs is indispensable to normal physiology, their abnormal overexpression is linked to the majority of human diseases. Consequently, the inhibition of HDACs has become a valuable target for therapeutic applications. Numerous potent small molecules are known, of both natural product and synthetic origin, that inhibit HDACs, primarily by reversibly interacting with the zinc cation within the enzyme active site. At the present time, five such HDAC inhibitors have received regulatory approval for the treatment of hematological cancers. This review focuses on the typical zinc-binding groups employed in HDAC inhibitors and the major advances within each class in terms of potency, isoform selectivity, and clinical applications

    Structure–Activity Relationships and Mechanism of Action of Small Molecule Smoothened Modulators Discovered by High-Throughput Screening and Rational Design

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    Smoothened (Smo) is the signal transducer of the Hedgehog (Hh) pathway and its stimulation or inhibition is considered a potential powerful tool in regenerative medicine and for the treatment of cancer. In the last years, many natural and nonnatural small molecules have been identified that are able to modulate the Hh pathway. Most of them target Smo, while only a few compounds are able to interact directly with upstream and downstream Hh pathway components. Although several compounds showed a remarkable potency and selectivity, their use induced emergence of mutated and resistant cell lines. In an attempt to find new chemical entries able to affect the Hh pathway and overcome limitation imposed by mutations and resistance, academic researchers and pharmaceutical companies are making further efforts to identify new drug-like small molecules to be included in the currently available therapeutic protocols for several types of cancers or in regenerative medicine and tissue repair
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