Standardization of zebrafish drug testing parameters for muscle diseases.

Skeletal muscular diseases predominantly affect skeletal and cardiac muscle, resulting in muscle weakness, impaired respiratory function and decreased lifespan. These harmful outcomes lead to poor health-related quality of life and carry a high healthcare economic burden. The absence of promising treatments and new therapies for muscular disorders requires new methods for candidate drug identification and advancement in animal models. Consequently, the rapid screening of drug compounds in an animal model that mimics features of human muscle disease is warranted. Zebrafish are a versatile model in preclinical studies that support developmental biology and drug discovery programs for novel chemical entities and repurposing of established drugs. Due to several advantages, there is an increasing number of applications of the zebrafish model for high-throughput drug screening for human disorders and developmental studies. Consequently, standardization of key drug screening parameters, such as animal husbandry protocols, drug compound administration and outcome measures, is paramount for the continued advancement of the model and field. Here, we seek to summarize and explore critical drug treatment and drug screening parameters in the zebrafish-based modeling of human muscle diseases. Through improved standardization and harmonization of drug screening parameters and protocols, we aim to promote more effective drug discovery programs.

DOCK3 regulates normal skeletal muscle regeneration and glucose metabolism.

DOCK (dedicator of cytokinesis) is an 11-member family of typical guanine nucleotide exchange factors (GEFs) expressed in the brain, spinal cord, and skeletal muscle. Several DOCK proteins have been implicated in maintaining several myogenic processes such as fusion. We previously identified DOCK3 as being strongly upregulated in Duchenne muscular dystrophy (DMD), specifically in the skeletal muscles of DMD patients and dystrophic mice. Dock3 ubiquitous KO mice on the dystrophin-deficient background exacerbated skeletal muscle and cardiac phenotypes. We generated Dock3 conditional skeletal muscle knockout mice (Dock3 mKO) to characterize the role of DOCK3 protein exclusively in the adult muscle lineage. Dock3 mKO mice presented with significant hyperglycemia and increased fat mass, indicating a metabolic role in the maintenance of skeletal muscle health. Dock3 mKO mice had impaired muscle architecture, reduced locomotor activity, impaired myofiber regeneration, and metabolic dysfunction. We identified a novel DOCK3 interaction with SORBS1 through the C-terminal domain of DOCK3 that may account for its metabolic dysregulation. Together, these findings demonstrate an essential role for DOCK3 in skeletal muscle independent of DOCK3 function in neuronal lineages.

DOCK3 regulates normal skeletal muscle regeneration and glucose metabolism.

DOCK (dedicator of cytokinesis) is an 11-member family of typical guanine nucleotide exchange factors (GEFs) expressed in the brain, spinal cord, and skeletal muscle. Several DOCK proteins have been implicated in maintaining several myogenic processes such as fusion. We previously identified DOCK3 as being strongly upregulated in Duchenne muscular dystrophy (DMD), specifically in the skeletal muscles of DMD patients and dystrophic mice. Dock3 ubiquitous KO mice on the dystrophin-deficient background exacerbated skeletal muscle and cardiac phenotypes. We generated Dock3 conditional skeletal muscle knockout mice (Dock3 mKO) to characterize the role of DOCK3 protein exclusively in the adult muscle lineage. Dock3 mKO mice presented with significant hyperglycemia and increased fat mass, indicating a metabolic role in the maintenance of skeletal muscle health. Dock3 mKO mice had impaired muscle architecture, reduced locomotor activity, impaired myofiber regeneration, and metabolic dysfunction. We identified a novel DOCK3 interaction with SORBS1 through the C-terminal domain of DOCK3 that may account for its metabolic dysregulation. Together, these findings demonstrate an essential role for DOCK3 in skeletal muscle independent of DOCK3 function in neuronal lineages.

Ribisins and Certain Analogues Exert Neuroprotective Effects through Activation of the Keap1-Nrf2-ARE Pathway.

Oxidative stress contributes to the pathogenesis of various neurodegenerative diseases and induction of the Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) pathway is a validated neuroprotective strategy. Synthetically-derived samples of members of the ribisin class of natural product together with a range of analogues were evaluated for their neuroprotective capacities. Four of the twenty-four compounds tested were found to strongly stimulate antioxidant response element-dependent transcriptional activity in human-derived SH-SY5Y cells. Further, in rat pheochromocytoma PC12 cells and mouse brain cortical cultures these compounds upregulated levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target gene products, namely heme oxygenase (HO-1) and NAD(P)H quinone reductase 1 (NQO1). Functionally speaking, the compounds conferred protection in these cell models challenged with H2 O2 . In silico molecular modeling suggests that certain of the ribisins can dock in the Nrf2-binding Kelch domain in Keap1, while cysteine labeling by biotinylated iodoacetamide suggest that cysteine residues within Keap1 react with the ribisins. It is thus proposed that the most active compounds exert their neuroprotective activities by targeting Keap1, thereby activating Nrf2 and so increasing transactivation of Nrf2-responsive genes that encode for detoxifying and antioxidant enzymes.

Therapeutic Potential of Semaglutide, a Newer GLP-1 Receptor Agonist, in Abating Obesity, Non-Alcoholic Steatohepatitis and Neurodegenerative diseases: A Narrative Review.

INTRODUCTION: Semaglutide, a peptidic GLP-1 receptor agonist, has been clinically approved for treatment of type 2 diabetes mellitus and is available in subcutaneous and oral dosage form. Diabetes, insulin resistance, and obesity are responsible for the pathological manifestations of non-alcoholic steatohepatitis (NASH). Similarly, insulin resistance in brain is also responsible for neurodegeneration and impaired cognitive functions. BACKGROUND: Observations from phase-3 clinical trials like SUSTAIN and PIONEER indicated anti-obesity potential of semaglutide, which was established in STEP trials. Various pre-clinical and phase-2 studies have indicated the therapeutic potential of semaglutide in non-alcoholic steatohepatitis and neurodegenerative disorders like Parkinson's and Alzheimer's disease. DISCUSSION: Significant weight reduction ability of semaglutide has been demonstrated in various phase-3 clinical trials, for which recently semaglutide became the first long-acting GLP-1 receptor agonist to be approved by the United States Food and Drug Administration for management of obesity. Various pre-clinical and clinical studies have revealed the hepatoprotective effect of semaglutide in NASH and neuroprotective effect in Parkinson's and Alzheimer's disease. CONCLUSION: Many GLP-1 receptor agonists have shown hepatoprotective and neuroprotective activity in animal and human trials. As semaglutide is an already clinically approved drug, successful human trials would hasten its inclusion into therapeutic treatment of NASH and neurodegenerative diseases. Semaglutide improves insulin resistance, insulin signalling pathway, and reduce body weight which are responsible for prevention or progression of NASH and neurodegenerative diseases.

Semaglutide, a glucagon like peptide-1 receptor agonist with cardiovascular benefits for management of type 2 diabetes.

Semaglutide, a glucagon like peptide-1 (GLP-1) receptor agonist, is available as monotherapy in both subcutaneous as well as oral dosage form (first approved oral GLP-1 receptor agonist). It has been approved as a second line treatment option for better glycaemic control in type 2 diabetes and currently under scrutiny for anti-obesity purpose. Semaglutide has been proved to be safe in adults and elderly patients with renal or hepatic disorders demanding no dose modification. Cardiovascular (CV) outcome trials established that it can reduce various CV risk factors in patients with established CV disorders. Semaglutide is well tolerated with no risk of hypoglycaemia in monotherapy but suffers from gastrointestinal adverse effects. A large population affected with COVID-19 infection were diabetic; therefore use of semaglutide in diabetes as well as CV patients would be very much supportive in maintaining health care system during this pandemic situation. Hence, this peptidic drug can be truly considered as a quintessential of GLP-1 agonists for management of type 2 diabetes.

Novel dual-targeting anti-proliferative dihydrotriazine-chalcone derivatives display suppression of cancer cell invasion and inflammation by inhibiting the NF-κB signaling pathway.

Chalcones present in edible plants possess anti-cancer and anti-inflammatory properties, with the Michael acceptor moiety reported to be responsible for their biological activities. In this study, two novel dihydrotriazine-chalcone compounds previously identified to exert anti-proliferative effects through dual-targeting of dihydrofolate reductase (DHFR) and thioredoxin reductase (TrxR), were evaluated for their anti-invasive and anti-inflammatory abilities. At non-lethal concentrations, the compounds suppressed in vitro migration of MDA-MB-231 breast carcinoma cells, which was correlated with a dose-dependent downregulation of phorbol 12-myristate 13-acetate (PMA)-induced matrix metalloproteinase-9 (MMP-9) expression and secretion. At similar concentrations, these chalcone-based compounds suppressed expression of inflammatory mediators inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharides (LPS)-stimulated murine macrophage-like RAW 264.7 cells, as well as tumor necrosis factor alpha (TNF-α) in LPS-stimulated human monocytes isolated from healthy donors. Mechanistically, inhibition of cancer cell invasion and inflammation by the compounds were mediated through suppression of the nuclear factor-kappaB (NF-κB) signaling pathway, which corroborated with the reported mechanism of action of chalcones. Their abilities to target multiple biological mediators relevant to multi-step carcinogenesis and with bioactivities stronger than those of the parent chalcone scaffold have warranted dihydrotriazine-chalcone compounds as promising candidates for use in pharmacological intervention of aggressive cancers.

Evaluation of wound healing and antimicrobial potentials of Ixora coccinea root extract.

OBJECTIVE: To evaluate the wound healing and antimicrobial activity of root extracts of Ixora coccinea (I. coccinea). METHODS: To investigate the wound healing efficacy of root extract of I. coccinea Linn, five groups of animals were divided each containing six animals. Two wound models including incision and excision wound models were used in this study. The parameters studied were tensile strength on incision wound model and in terms of wound contraction for excision wound model were compared with standard Nitrofurazone (NFZ) ointment (0.2% w/w). Six extracts (ethanol, aqueous, petroleum ether, benzene, chloroform and ethyl acetate) of I. coccinea were screened for in vitro growth inhibiting activity against different bacterial strains viz, Staphylococcus aureus, Bacillus pumilius, Enterococcus faecalis, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa and fungi Candida albicans and Aspergillus niger were compared with the standard drugs ciprofloxacin and chloramphenicol for antibacterial and griseofulvin for antifungal screening. The serial dilution and cup (or) well plate methods were used for the antimicrobial study and MIC was determined. RESULTS: The ethanolic extract showed significant (P<0.001) wound healing activity when compared to standard drug NFZ with respect to normal control group. Amongst all, ethanolic extract showed highly significant antibacterial activity against all bacterial strains used in this study when compared to standard. The aqueous extract showed moderate significant inhibition against all bacterial strains when compared to standard. All the extracts were shown negligible activity against the fungal strains used in this study. CONCLUSIONS: The ethanolic root extract of I. coccinea showed pronounced wound healing and antibacterial activity. The probable reason to heal the wound was that the external application of the extract prevented the microbes to invade through the wound thus the protection of wound occurs against the infection of the various organisms.

Development of selective and reversible pyrazoline based MAO-A inhibitors: Synthesis, biological evaluation and docking studies.

3,5-Diaryl pyrazolines analogs were synthesized and evaluated for their monoamine oxidase (MAO) inhibitory activity. The compounds were found reversible and selective towards MAO-A with selectivity index in the magnitude of 10(3)-10(5). The docking studies were carried out to gain further structural insights of the binding mode and possible interactions with the active site of MAO-A. Interestingly, the theoretical (K(i)) values obtained by molecular docking studies were in congruence with their experimental (K(i)) values.