Current Medicinal Chemistry - Volume 28, Issue 41, 2021

Mitochondrial dysfunction and oxidative stress are prominent features of a plethora of human disorders. Dysregulation of mitochondrial functions represents a common pathogenic mechanism of diseases such as neurodegenerative disorders and cancer. The maintenance of the Nicotinamide adenine dinucleotide (NAD+) pool, and a positive NAD+/NADH ratio, are essential for mitochondrial and cell functions. The synthesis and degradation of NAD+ and transport of its key intermediates among cell compartments play an important role in maintaining optimal NAD levels, for the regulation of NAD+-utilizing enzymes, such as sirtuins (Sirt), poly-ADP-ribose polymerases, and CD38/157 enzymes, either intracellularly as well as extracellularly. In this review, we present and discuss the links between NAD+, NAD+-consuming enzymes, mitochondria functions, and diseases. Attempts to treat various diseases with supplementation of NAD+ cycling intermediates and inhibitors of sirtuins and ADP-ribosyl transferases may highlight a possible therapeutic approach for therapy of cancer and neurodegenerative diseases.

The oxidative stress response is critical for malignant cells. It plays a dual role by helping cancer cells survive and proliferate but also causing apoptosis and apoptosis-- like cell death. The oxidative stress response is characterized by tight regulation of gene expression by a series of transcription factors (OSRts; oxidative stress response transcription factors). In this communication, we review the role of OSRts, notably NRF2 and p53 as well as other transcription factors that modulate the response. We discuss how hierarchal the oxidative stress response is and controls ‘live or die’ signals. This is followed by a discussion on how plant-derived molecules, including polyphenols, which are described both as prooxidants and antioxidants within the cancer cells, have been reported to affect the activities of OSRts. Deriving an example from preliminary data from our group, we discuss how plant-derived molecules might modulate the oxidative stress response by causing structural perturbations in the proteinaceous transcription factors, notably Nrf2 and p53. We look at this information in the light of understanding how plant derived molecules may be used as lead compounds to develop modulators of the oxidative stress response.

Objective: Serrated colorectal lesions are a group of colonic lesions with a serrated (saw-tooth) profile of the surface epithelium and crypts, and peculiar molecular and genetic developmental mechanisms that are incompletely understood. These formations cause concern due to their premalignant potential. Aim: The review is dedicated to serrated lesions of colon and appendix. We focused on modern classification, role in carcinogenesis, as well as new approaches to morphological diagnosis. Methods: A literature search was performed using PubMed, Scopus, ResearchGate, Google, MEDLINE, and ScienceDirect databases to find studies of serrated colorectal lesions related cancer published between 2000 and 2020 that address epidemiological risk factors, underlying pathophysiological mechanism and enable our review of these factors as well as molecular, genetics, and structural patterns. Results: Serrated colorectal lesions take one third of all benign neoplasms of the colon in the pathologist’s practice. The active study of serrated lesions began in the 1900s. Terminology and diagnostic criteria changed in the updated classification in 2019. Morphological criteria, immunohistochemical and molecular profile, endoscopic and clinical characteristics are reviewed. Conclusion: Although significant efforts were made in attempt to improve our understanding and diagnostic criteria of serrated polyps of colorectum, very little has changed since the original morphologic description of preneoplastic serrated lesions in early 2000s. There remains a need for more research in order to develop more definitive immuophenotypic and molecular biomarkers in order to distinguish between non-neoplastic and neoplastic serrated lesions.

Objective: The molecular mechanisms of bladder cancer development and progression are not clear. Bladder cancer is an important focus for epidemiological studies and understanding clinical implications. Goal: The primary aim of prevention is achieved by limiting exposure to non-genetic risk factors, such as smoking, diet, arsenic in drinking water, or aromatic amines at work or elsewhere. Current therapies for bladder cancer are affected by tumor morphology and associated acquired genetic mutations. Methods: A literature search was performed using PubMed, Scopus, ResearchGate, Google, MEDLINE, and ScienceDirect databases to find studies of bladder cancer published between 1984 and early 2020. The focus was articles that address epidemiological risk factors and underlying pathophysiological mechanisms. Articles were selected that enabled our review of these factors as well as molecular and structural patterns. Results: There are multiple views of bladder cancer. The literature offers several novel insights regarding the development and progression of bladder cancer and possible biomarkers that may be useful in clinical and diagnostic practice. Conclusion: There are several molecular pathways associated with bladder cancer that are frequently updated. In addition, genetic subtypes of bladder tumors are not distinguished clearly which requires future more detailed analysis.

There is a causal relationship between cancer (including colorectal cancer), chronic systemic inflammation and persistent infections, and the presence of dysregulated circulating inflammatory markers. It is known that aberrant clot formation and coagulopathies occur in systemic inflammation. In colorectal cancer, there is a close link between gut dysbiosis and an inflammatory profile. In this review, we present evidence of the connection between gut dysbiosis, the entry of bacteria into the internal environment, and the presence of their highly potent inflammagenic molecules, such as lipopolysaccharide and lipoteichoic acid, in circulation. These bacterial components may act as one of the main drivers of the inflammatory process (including hypercoagulation) in colorectal cancer. We review literature that points to the role of these bacterial inflammagens and how they contribute to colorectal carcinogenesis. Insight into the factors that promote carcinogenesis is crucial to effectively prevent and screen for colorectal cancer. Early diagnosis of an activated coagulation system and the detection of bacterial components in circulation and also in the tumour microenvironment, could therefore be important, and may also, together with modulation of the gut microbiota, serve as potential therapeutic targets.

Low-temperature plasma (LTP) is a partially ionized gas that contains electrons, ions, radicals, light, etc. Recently, the bio-medical application of LTP has become a hot topic in plasma science and biological science. Cancer treatment with plasma is the most challenging topic in plasma bio-medical applications. Many in vitro and in vivo experiments have been conducted to investigate the anti-tumor effects of LTP. Extracellular reactive oxygen and nitrogen species (RONS) in plasma-activated solutions are key factors for the anti-tumor effects, and amino acid modifications by LTP may affect cellular responses. Intracellular RONS are also key factors for the anti-tumor effects. Various signaling pathways, such as p53 signaling pathways, survival and proliferation signaling pathways, and oxidative stress-dependent signaling pathways are activated by LTP.

There is a new public health crisis threatening the world with the emergence and spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease was later named novel coronavirus disease or COVID-19. It was then declared a pandemic by the World Health Organization on March 11, 2020. The virus originated in bats and was transmitted to humans through unknown intermediary animals in Wuhan, Hubei province, China, in December 2019.

As of February 5, 2021, 103 million laboratory-confirmed cases and nearly 2.3 million deaths were reported globally. The number of death tolls continues to rise, and a large number of countries have been forced to maintain social distance in public place and enforce lockdown. As per literature, coronavirus is transmitted human to human or human to animal via airborne droplets. Coronavirus enters the human cell through the membrane ACE-2 exopeptidase receptor. WHO, ECDC, and ICMR advised avoiding public places and close contact with infected persons and pet animals. To date, there is no evidence of any effective treatment for COVID-19. The main therapies being used to treat the disease are antiviral drugs, chloroquine/hydroxychloroquine, and respiratory therapy. Although several therapies have been proposed, quarantine is the only intervention that appears to be effective in decreasing the contagion rate. We conducted a literature review of publicly available information to summarize knowledge about the pathogen and the current epidemic. In the present literature review, the causative agent of the pandemic, epidemiology, pathogenesis, and diagnostic techniques are discussed. Further, currently used treatment, preventive strategies along with vaccine trials and computational tools are all described in detail.

Background: Abdominal aortic aneurysms (AAAs) are a leading cause of death in older adults due to aortic rupture. There are currently no effective medical therapies for AAA, with surgery being the only acceptable treatment. There is frequently an extended period between AAA diagnosis and treatment by corrective surgery, during which an effective drug therapy could prevent or delay the need for AAA repair. Objective: This review aimed to critically summarize prior research investigating the potential benefits of phytochemicals in preventing or treating AAA. Methods: In vitro, in vivo, and human studies examining the effect of phytochemicals in AAA models and patients were critically summarised. Results: Some preliminary data support the further investigation of curcumin, radix astragali, grape seed polyphenols, resveratrol, Ginkgo biloba extract (EGb 761), Ginsenoide Rb1, Dan Hong, Epigallocatechin-3-gallate, Baicalein, Fucoidan, Quercetin, and Salvianolic acid as potential treatments for AAA. Conclusion: Experimental in vivo and in vitro studies suggest the potential benefits of a number of medicinal herbs and phytochemicals in preventing or reducing the progression of AAA. In order to assess whether these findings can be translated into proven treatments, adequately designed double-blind randomized clinical trials will be required.

The liver is one of the significant regenerative organs in the body. Nevertheless, underlying molecular mechanisms regulating liver repair and regeneration following resection or damage remain largely unknown. The Notch signaling pathway is a profoundly evolutionarily well-conserved cell signaling system that mostly involves developing multicellular organisms. Malfunctions in this pathway lead to the progression of several liver disorders, including hepatoblastoma (HB), cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC). The Notch pathway plays a fundamental role in cell fate during the embryonic stage's progression to the adult stage in liver tissue. Modulation of Notch signaling may be used in many patients who succumb to cirrhosis due to chronic hepatitis by virus infection. This review describes the underlying mechanisms of the Notch signaling pathway in liver development and regeneration briefly and discusses how this pathway leads to the betterment of liver disorders in the clinic.