Rutin from Begonia roxburghii modulates iNOS and Sep A activity in treatment of Shigella flexneri induced diarrhoea in rats: An in vitro, in vivo and computational analysis.

In developing countries, diarrhoea is a major issue of concern, where consistent use of antibiotics has resulted in several side effects along with development of resistance among pathogens against these antibiotics. Since natural products are becoming the treatment of choice, therefore present investigation involves mechanistic evaluation of antidiarrhoeal potential of Begonia roxburghii and its marker rutin against Shigella flexneri (SF) induced diarrhoea in rats following in vitro, in vivo and in silico protocols. The roots of the plant are used as vegetable in the North East India and are also used traditionally in treating diarrhoea. Phytochemically standardized ethanolic extract of B. roxburghii (EBR) roots and its marker rutin were first subjected to in vitro antibacterial evaluation against SF. Diarrhoea was induced in rats using suspension of SF and various diarrhoeagenic parameters were examined after first, third and fifth day of treatment at 100, 200 and 300 mg/kg, p.o. with EBR and 50 mg/kg, p.o. with rutin respectively. Additionally, density of SF in stools, stool water content, haematological and biochemical parameters, cytokine profiling, ion concentration, histopathology and Na+/K+-ATPase activity were also performed. Molecular docking and dynamics simulation studies of ligand rutin was studied against secreted extracellular protein A (Sep A, PDB: 5J44) from SF and Inducible nitric oxide synthase (iNOS, PDB: 1DD7) followed by network pharmacology. EBR and rutin demonstrated a potent antibacterial activity against SF and also showed significant recovery from diarrhoea (EBR: 81.29 ± 0.91% and rutin: 75.27 ± 0.89%) in rats after five days of treatment. EBR and rutin also showed significant decline in SF density in stools, decreased cytokine expression, potential antioxidant activity, cellular proliferative nature and recovered ion loss due to enhanced Na+/K+-ATPase activity, which was also supported by histopathology. Rutin showed a very high docking score of -11.61 and -9.98 kcal/mol against iNOS and Sep A respectively and their stable complex was also confirmed through dynamics, while network pharmacology suggested that, rutin is quite capable of modulating the pathways of iNOS and Sep A. Thus, we may presume that rutin played a key role in the observed antidiarrhoeal activity of B. roxburghii against SF induced diarrhoea.

Unlocking the potential of PROTACs: A comprehensive review of protein degradation strategies in disease therapy.

The technology known asPROTACs (PROteolysisTArgeting Chimeras) is a method of protein degradation. Utilising bifunctional small molecules, the ubiquitin-proteosome system (UPS) is used to induce the ubiquitination and degradation of target proteins. In addition to being novel chemical knockdown agents for biological studies that are catalytic, reversible, and rapid, PROTACs used in the treatment for disorders like cancer, immunological disorders, viral diseases, and neurological disorders. The protein degradation field has advanced quickly over the last two years, with a significant rise in research articles on the subject as well as a quick rise in smallmolecule degraders that are currently in or will soon enter the clinical stage. Other new degrading technologies, in addition to PROTAC and molecular glue technology, are also emerging rapidly. In this review article, we mainly focuses on various PROTAC molecules designed with special emphasis on targeted cellular pathways for different diseases i.e., cancer, Viral diseases Immune disorders, Neurodegenerative diseases, etc. We discussed about new technologies based on PROTACs such as Antibody PROTAC, Aptamers, Dual target, Folate caged, TF PROTAC, etc. Also, we listed out the PROTACs which are in clinical trials.

Design, synthesis and evaluation of novel enzalutamide analogues as potential anticancer agents.

The androgen receptor inhibitor, Enzalutamide, proved effective against castration resistance prostate cancer, has demonstrated clinical benefits and increased survival rate in men. However, AR mutation (F876L) converts Enzalutamide from antagonist to agonist indicating a rapid evolution of resistance. Hence, our goal is to overcome this resistance mechanism by designing and developing novel Enzalutamide analogues. We designed a dataset of Enzalutamide derivatives using Enzalutamide's shape and electrostatic features to match with pharmacophoric features essential for tight binding with the androgen receptor. Based on this design strategy ten novel derivatives were selected including 5,5-dimethyl-3-(6-substituted benzo[d]thia/oxazol-2-yl)-2-thioxo-1-(4-(trifluoromethyl)pyridin-2-yl)imidazolidin-4-one (6a-j) for synthesis. All the compounds were evaluated in-vitro on prostate cancer cell lines DU-145, LNCaP and PC3. Interestingly, two compounds 3-(6-hydroxybenzo[d]thiazol-2-yl)-5,5-dimethyl-2-thioxo-1-(4-(trifluoromethyl)pyridin-2-yl) imidazolidin-4-one (6c, IC50 - 18.26 to 20.31µM) and 3-(6-hydroxybenzo[d]oxazol-2-yl)-5,5-dimethyl -2-thioxo- 1- (4-(trifluoromethyl) pyridin-2-yl)imidazolidin-4-one (6h, IC50 - 18.26 to 20.31µM) were successful with promising in-vitro antiproliferative activity against prostate cancer cell lines. The binding mechanism of potential androgen receptor inhibitors was further studied by molecular docking, molecular dynamics simulations and MM-GBSA binding free energy calculations and found in agreement with the in vitro studies. It provided strong theoretical support to our hypothesis.

DNA G-Quadruplex and i-Motif Structure Formation Is Interdependent in Human Cells.

Guanine- and cytosine-rich nucleic acid sequences have the potential to form secondary structures such as G-quadruplexes and i-motifs, respectively. We show that stabilization of G-quadruplexes using small molecules destabilizes the i-motifs, and vice versa, indicating these gene regulatory controllers are interdependent in human cells. This has important implications as these structures are predominately considered as isolated structural targets for therapy, but their interdependency highlights the interplay of both structures as an important gene regulatory switch.

Generation of Phenothiazine with Potent Anti-TLK1 Activity for Prostate Cancer Therapy.

Through in vitro kinase assays and docking studies, we report the synthesis and biological evaluation of a phenothiazine analog J54 with potent TLK1 inhibitory activity for prostate cancer (PCa) therapy. Most PCa deaths result from progressive failure in standard androgen deprivation therapy (ADT), leading to metastatic castration-resistant PCa. Treatments that can suppress the conversion to mCRPC have high potential to be rapidly implemented in the clinics. ADT results in increased expression of TLK1B, a key kinase upstream of NEK1 and ATR and mediating the DNA damage response that typically results in temporary cell-cycle arrest of androgen-responsive PCa cells, whereas its abrogation leads to apoptosis. We studied J54 as a potent inhibitor of this axis and as a mediator of apoptosis in vitro and in LNCaP xenografts, which has potential for clinical investigation in combination with ADT. J54 has low affinity for the dopamine receptor in modeling and competition studies and weak detrimental behavioral effects in mice and C. elegans.

Identification of potential cruzain inhibitors using de novo design, molecular docking and dynamics simulations studies.

Communicated by Ramaswamy H. Sarma.

Development and Validation of HPLC and HPTLC Methods for Therapeutic Drug Monitoring of Capecitabine in Colorectal Cancer Patients.

Capecitabine is a prodrug of 5-fluorouracil, employed as a monotherapy or combination chemotherapy agent for treatment of colorectal cancer. Combination therapy of capecitabine consists of oxaliplatin, and hence, it becomes essential to determine that co-administration does not affect its metabolism. High-performance liquid chromatography and high-performance thin-layer chromatography methods were developed and validated to determine the plasma concentration of capecitabine. In this study, blood samples from 12 patients with colorectal cancer were collected and analyzed by both methods with a reference internal standard. Two groups consisting of six patients each were formed: the first group was treated with capecitabine monotherapy, the second group with capecitabine + oxaliplatin combination therapy. The results of analysis from both the methods indicated that there is no significant drug-drug interaction. The co-administration of oxaliplatin did not affect the metabolism of capecitabine. Both assay methods were compared for their sensitivity, robustness and specificity. It was found that both the assay methods were suitable for therapeutic drug monitoring of capecitabine.

A rapid and simple HPTLC assay for therapeutic drug monitoring of capecitabine in colorectal cancer patients.

Capecitabine is a prodrug of 5-flurouracil, employed as a broad spectrum chemotherapeutic agent. It is also used as monotherapy or a combination chemotherapy agent for the treatment of colorectal cancer. Capecitabine is administered in combination with oxaliplatin and hence it is essential to determine that co-administration does not affect its metabolism. To determine the plasma concentration of capecitabine a simple HPTLC method was developed and validated. Blood samples from 12 patients with colorectal cancer were collected and analyzed by the HPTLC method with a reference internal standard. Out of these 12 patients, six were treated with capecitabine monotherapy and another six were treated with capecitabine + oxaliplatin combination therapy. The results of analysis indicated that there was no significant drug-drug interaction and the co-administration of oxaliplatin did not affect the metabolism of capecitabine. This method is sensitive, robust and specific and allows analysis of multiple samples simultaneously, making it suitable for therapeutic drug monitoring of capecitabine.