Notoriety to respectability: a short history of arsenic prior to its present day use in haematology

Exploring antimicrobial interactions between metal ions and quaternary ammonium compounds toward synergistic metallo-antimicrobial formulations

Multi-target antimicrobial agents are considered a viable alternative to target-specific antibiotics, resistance to which emerged as a global threat. Used centuries before the discovery of conventional antibiotics, metal(loid)-based antimicrobials (MBAs), which target multiple biomolecules within the bacterial cell, are regaining research interest. However, there is a significant limiting factor-the balance between cost and efficiency. In this article, we utilize a checkerboard assay approach to explore antimicrobial combinations of MBAs with commonly used quaternary ammonium compound (QAC) antiseptics in order to discover novel combinations with more pronounced antimicrobial properties than would be expected from a simple sum of antimicrobial effects of initial components. This phenomenon, called synergy, was herein demonstrated for several mixtures of Al3+with cetyltrimethylammonium bromide (CTAB) and TeO32- with benzalkonium chloride (BAC) and didecyldimethylammonium bromide (DDAB) against planktonic and biofilm growth of Pseudomonas aeruginosa ATCC27853. Biofilm growth of Escherichia coli ATCC25922 was synergistically inhibited by the Cu2 +and benzalkonium chloride (BAC) mixture. Multiple additive mixtures were identified for both organisms. The current study observed unexpected species and growth state specificities for the synergistic combinations. The benefit of synergistic mixtures will be captured in economy/efficiency optimization for antimicrobial applications in which MBAs and QACs are presently used.

IMPORTANCE

We are entering the antimicrobial resistance era (AMR), where resistance to antibiotics is becoming more and more prevalent. In order to address this issue, various approaches are being explored. In this article, we explore for synergy between two very different antimicrobials, the antiseptic class of quaternary ammonium compounds and antimicrobial metals. These two antimicrobials have very different actions. Considering a OneHealth approach to the problem, finding synergistic mixtures allows for greater efficacy at lower concentrations, which would also address antimicrobial pollution issues.

Sodium arsenite and arsenic trioxide differently affect the oxidative stress of lymphoblastoid cells: An intricate crosstalk between mitochondria, autophagy and cell death

Although the toxicity of arsenic depends on its chemical forms, few studies have taken into account the ambiguous phenomenon that sodium arsenite (NaAsO2) acts as a potent carcinogen while arsenic trioxide (ATO, As2O3) serves as an effective therapeutic agent in lymphoma, suggesting that NaAsO2 and As2O3 may act via paradoxical ways to either promote or inhibit cancer pathogenesis. Here, we compared the cellular response of the two arsenical compounds, NaAsO2 and As2O3, on the Burkitt lymphoma cell model, the Epstein Barr Virus (EBV)-positive P3HR1 cells. Using flow cytometry and biochemistry analyses, we showed that a NaAsO2 treatment induces P3HR1 cell death, combined with drastic drops in ΔΨm, NAD(P)H and ATP levels. In contrast, As2O3-treated cells resist to cell death, with a moderate reduction of ΔΨm, NAD(P)H and ATP. While both compounds block cells in G2/M and affect their protein carbonylation and lipid peroxidation, As2O3 induces a milder increase in superoxide anions and H2O2 than NaAsO2, associated to a milder inhibition of antioxidant defenses. By electron microscopy, RT-qPCR and image cytometry analyses, we showed that As2O3-treated cells display an overall autophagic response, combined with mitophagy and an unfolded protein response, characteristics that were not observed following a NaAsO2 treatment. As previous works showed that As2O3 reactivates EBV in P3HR1 cells, we treated the EBV- Ramos-1 cells and showed that autophagy was not induced in these EBV- cells upon As2O3 treatment suggesting that the boost of autophagy observed in As2O3-treated P3HR1 cells could be due to the presence of EBV in these cells. Overall, our results suggest that As2O3 is an autophagic inducer which action is enhanced when EBV is present in the cells, in contrast to NaAsO2, which induces cell death. That's why As2O3 is combined with other chemicals, as all-trans retinoic acid, to better target cancer cells in therapeutic treatments.

Diabetes Mellitus across the Arabo-Islamic World: A Revolution

Background

Mankind continues to suffer from the ever-growing diabetes epidemic and the rapid rise of type 2 diabetes mellitus (T2DM). This metabolic disease has been studied since ancient civilizations. The Arabo-Islamic civilization excelled in establishing some of the most notable discoveries and teachings that remained the blueprint for years to come in the field of diabetology.

Aim

This article aimed to review the ancient history of diabetes mellitus, with its main focus on the Arabo-Islamic civilization, and to report our subjective views and analysis of some of the past recommendations based on modern-day findings. Discussion. It is natural to have the teachings of medicine dynamically inspired by one civilization to another, as various fields continue to expand and evolve. This also applies to diabetology as the Arabo-Islamic world used the outlines of prior civilizations to revolutionize the understanding of the disease. Al-Razi and Ibn Sina are probably two of the most renowned polymaths in history, and their contributions to diabetology are well documented. Ibn Maymun's postulation about the higher prevalence of diabetes in Egypt as compared to Andalusia is something to be carefully studied. It could be that diabetes mellitus' underdiagnosis and late-stage detection are some of the major reasons for the disparity between the two mentioned regions. Modern-day Arabo-Islamic scholars continue to excel in revolutionizing diabetology.

Conclusion

The Arabo-Islamic world houses an impressive bout of scholars who have contributed since the ancient times to diabetology. This scientific locomotion shows no signs of stopping, as it continues to shine during the present day, and likely in the future.

Arsenic in medicine: past, present and future

Arsenicals are one of the oldest treatments for a variety of human disorders. Although infamous for its toxicity, arsenic is paradoxically a therapeutic agent that has been used since ancient times for the treatment of multiple diseases. The use of most arsenic-based drugs was abandoned with the discovery of antibiotics in the 1940s, but a few remained in use such as those for the treatment of trypanosomiasis. In the 1970s, arsenic trioxide, the active ingredient in a traditional Chinese medicine, was shown to produce dramatic remission of acute promyelocytic leukemia similar to the effect of all-trans retinoic acid. Since then, there has been a renewed interest in the clinical use of arsenicals. Here the ancient and modern medicinal uses of inorganic and organic arsenicals are reviewed. Included are antimicrobial, antiviral, antiparasitic and anticancer applications. In the face of increasing antibiotic resistance and the emergence of deadly pathogens such as the severe acute respiratory syndrome coronavirus 2, we propose revisiting arsenicals with proven efficacy to combat emerging pathogens. Current advances in science and technology can be employed to design newer arsenical drugs with high therapeutic index. These novel arsenicals can be used in combination with existing drugs or serve as valuable alternatives in the fight against cancer and emerging pathogens. The discovery of the pentavalent arsenic-containing antibiotic arsinothricin, which is effective against multidrug-resistant pathogens, illustrates the future potential of this new class of organoarsenical antibiotics.

Realgar and arsenene nanomaterials as arsenic-based anticancer agents

Arsenic trioxide (ATO) is an approved therapy for the treatment of acute promyelocytic leukemia, but the extension of arsenic-based therapies to other types of malignancies, notably tumor-forming cancers, has been slow. Nanodelivery vehicles offer a means of effectively delivering ATO to tumors. Very recently, there has been a series of developments in the formulation of arsenic-based nanomedicines that are not simply loaded with ATO. Realgar nanoparticles are comprised of molecular As₄S₄ units. Current studies suggest that realgar nanoparticles ultimately act in a manner similar to ATO, but with greatly attenuated toxic side effects. A drastically different approach is taken with arsenene nanosheets, a 2-dimensional form of elemental As. The electronic properties of this material allow it to mediate both photothermal therapy and photodynamic therapy. The exploration of these nanomaterials is still in its infancy but is poised to allow arsenic-based therapy to make yet another significant impact on cancer treatment.

Interactions with Arsenic: Mechanisms of Toxicity and Cellular Resistance in Eukaryotic Microorganisms

Arsenic (As) is quite an abundant metalloid, with ancient origin and ubiquitous distribution, which represents a severe environmental risk and a global problem for public health. Microbial exposure to As compounds in the environment has happened since the beginning of time. Selective pressure has induced the evolution of various genetic systems conferring useful capacities in many microorganisms to detoxify and even use arsenic, as an energy source. This review summarizes the microbial impact of the As biogeochemical cycle. Moreover, the poorly known adverse effects of this element on eukaryotic microbes, as well as the As uptake and detoxification mechanisms developed by yeast and protists, are discussed. Finally, an outlook of As microbial remediation makes evident the knowledge gaps and the necessity of new approaches to mitigate this environmental challenge.

Removal of decidedly lethal metal arsenic from water using metal organic frameworks: a critical review

Water contamination is worldwide issue, undermining whole biosphere, influencing life of a large number of individuals all over the world. Water contamination is one of the chief worldwide danger issues for death, sickness, and constant decrease of accessible drinkable water around the world. Among the others, presence of arsenic, is considered as the most widely recognized lethal contaminant in water bodies and poses a serious threat not exclusively to humans but also towards aquatic lives. Hence, steps must be taken to decrease quantity of arsenic in water to permissible limits. Recently, metal-organic frameworks (MOFs) with outstanding stability, sorption capacities, and ecofriendly performance have empowered enormous improvements in capturing substantial metal particles. MOFs have been affirmed as good performance adsorbents for arsenic removal having extended surface area and displayed remarkable results as reported in literature. In this review we look at MOFs which have been recently produced and considered for potential applications in arsenic metal expulsion. We have delivered a summary of up-to-date abilities as well as significant characteristics of MOFs used for this removal. In this review conventional and advanced materials applied to treat water by adsorptive method are also discussed briefly.

Neurotoxicity in Marine Invertebrates: An Update

Invertebrates represent about 95% of existing species, and most of them belong to aquatic ecosystems. Marine invertebrates are found at intermediate levels of the food chain and, therefore, they play a central role in the biodiversity of ecosystems. Furthermore, these organisms have a short life cycle, easy laboratory manipulation, and high sensitivity to marine pollution and, therefore, they are considered to be optimal bioindicators for assessing detrimental chemical agents that are related to the marine environment and with potential toxicity to human health, including neurotoxicity. In general, albeit simple, the nervous system of marine invertebrates is composed of neuronal and glial cells, and it exhibits biochemical and functional similarities with the vertebrate nervous system, including humans. In recent decades, new genetic and transcriptomic technologies have made the identification of many neural genes and transcription factors homologous to those in humans possible. Neuroinflammation, oxidative stress, and altered levels of neurotransmitters are some of the aspects of neurotoxic effects that can also occur in marine invertebrate organisms. The purpose of this review is to provide an overview of major marine pollutants, such as heavy metals, pesticides, and micro and nano-plastics, with a focus on their neurotoxic effects in marine invertebrate organisms. This review could be a stimulus to bio-research towards the use of invertebrate model systems other than traditional, ethically questionable, time-consuming, and highly expensive mammalian models.

Drug Combination in Cancer Treatment-From Cocktails to Conjugated Combinations

It is well recognized today that anticancer drugs often are most effective when used in combination. However, the establishment of chemotherapy as key modality in clinical oncology began with sporadic discoveries of chemicals that showed antiproliferative properties and which as a first attempt were used as single agents. In this review we describe the development of chemotherapy from its origins as a single drug treatment with cytotoxic agents to polydrug therapy that includes targeted drugs. We discuss the limitations of the first chemotherapeutic drugs as a motivation for the establishment of combined drug treatment as standard practice in spite of concerns about frequent severe, dose limiting toxicities. Next, we introduce the development of targeted treatment as a concept for advancement within the broader field of small-molecule drug combination therapy in cancer and its accelerating progress that was boosted by recent scientific and technological progresses. Finally, we describe an alternative strategy of drug combinations using drug-conjugates for selective delivery of cytotoxic drugs to tumor cells that potentiates future improvement of drug combinations in cancer treatment. Overall, in this review we outline the development of chemotherapy from a pharmacological perspective, from its early stages to modern concepts of using targeted therapies for combinational treatment.

Heavy metal associated health hazards: An interplay of oxidative stress and signal transduction

Heavy metal-induced cellular and organismal toxicity have become a major health concern in biomedical science. Indiscriminate use of heavy metals in different sectors, such as, industrial-, agricultural-, healthcare-, cosmetics-, and domestic-sectors has contaminated environment matrices and poses a severe health concern. Xenobiotics mediated effect is a ubiquitous cellular response. Oxidative stress is one such prime cellular response, which is the result of an imbalance in the redox system. Further, oxidative stress is associated with macromolecular damages and activation of several cell survival and cell death pathways. Epidemiological as well as laboratory data suggest that oxidative stress-induced cellular response following heavy metal exposure is linked with an increased risk of neoplasm, neurological disorders, diabetes, infertility, developmental disorders, renal failure, and cardiovascular disease. During the recent past, a relation among heavy metal exposure, oxidative stress, and signaling pathways have been explored to understand the heavy metal-induced toxicity. Heavy metal-induced oxidative stress and its connection with different signaling pathways are complicated; therefore, the systemic summary is essential. Herein, an effort has been made to decipher the interplay among heavy metals/metalloids (Arsenic, Chromium, Cadmium, and Lead) exposures, oxidative stress, and signal transduction, which are essential to mount the cellular and organismal response. The signaling pathways involved in this interplay include NF-κB, NRF2, JAK-STAT, JNK, FOXO, and HIF.

Oral Cancer Treatment Through the Ages: Part 1

PURPOSE

Understanding how oral cancer treatment evolved can pave the way for future management. The literature holds an expansive collection of historical findings regarding oral cancer, yet the authors were unable to find a comprehensive review of oral cancer treatment throughout the ages.

METHODS

A thorough literature review was carried out using multiple scientific databases and languages, as well as examination of historical archives. Articles were included for their relevance and their findings were assimilated.

RESULTS

Part one of this article reveals a rich history of oral cancer treatment commencing in ancient times, with discussion of Egyptian, Greek and Roman practices, and travelling through the age of discovery to arrive at the dawn of scientific medicine in the 19th century.

CONCLUSION

Part one demonstrates how fundamental concepts of oral cancer were discovered, and the significant impact medical innovation had on the success of oral cancer treatment.

Therapeutic and analytical applications of arsenic binding to proteins

Knowledge of arsenic binding to proteins advances the development of bioanalytical techniques and therapeutic drugs.

Arsenic trioxide and other arsenical compounds inhibit the NLRP1, NLRP3, and NAIP5/NLRC4 inflammasomes

Inflammasomes are large cytoplasmic multiprotein complexes that activate caspase-1 in response to diverse intracellular danger signals. Inflammasome components termed nucleotide-binding oligomerization domain-like receptor (NLR) proteins act as sensors for pathogen-associated molecular patterns, stress, or danger stimuli. We discovered that arsenicals, including arsenic trioxide and sodium arsenite, inhibited activation of the NLRP1, NLRP3, and NAIP5/NLRC4 inflammasomes by their respective activating signals, anthrax lethal toxin, nigericin, and flagellin. These compounds prevented the autoproteolytic activation of caspase-1 and the processing and secretion of IL-1β from macrophages. Inhibition was independent of protein synthesis induction, proteasome-mediated protein breakdown, or kinase signaling pathways. Arsenic trioxide and sodium arsenite did not directly modify or inhibit the activity of preactivated recombinant caspase-1. Rather, they induced a cellular state inhibitory to both the autoproteolytic and substrate cleavage activities of caspase-1, which was reversed by the reactive oxygen species scavenger N-acetylcysteine but not by reducing agents or NO pathway inhibitors. Arsenicals provided protection against NLRP1-dependent anthrax lethal toxin-mediated cell death and prevented NLRP3-dependent neutrophil recruitment in a monosodium urate crystal inflammatory murine peritonitis model. These findings suggest a novel role in inhibition of the innate immune response for arsenical compounds that have been used as therapeutics for a few hundred years.

Arsenic trioxide (ATO) influences the gene expression of metallothioneins in human glioblastoma cells

Arsenic trioxide (As(2)O(3); ATO, TRISENOX®) is used to treat patients with refractory or relapsed acute promyelocytic leukaemia while its application for treatment of solid cancers like glioblastoma is still under evaluation. In the present study, we investigated the interaction of arsenic trioxide with metallothionein (MT) isoforms as a possible (protective response) resistance of glioblastoma cells to arsenic-induced cytotoxicity. Special attention was focused on MT3, the isoform expressed mainly in the brain. MT3 has low metal inducibility, fast metal binding/releasing properties and outstanding neuronal inhibitory activity. The human astrocytoma (glioblastoma) cell line U87 MG was treated with 0.6, 2 and 6-7 μM arsenic (equivalent to 0.3, 1 and 3-3.5 μM As(2)O(3)) for 12, 24 or 48 h and gene expression for different MT isoforms, namely MT2A, MT1A, MT1F, MT1X, MT1E and MT3, was measured by real time qPCR using SYBR Green I and Taqman® gene expression assays. TfR, 18S rRNA, GAPDH and AB were tested as reference genes, and the last two evaluated to be appropriate in conditions of low (GAPDH) and high (AB) arsenic exposure. The gene expression of MT3 gene was additionally tested and confirmed by restriction enzyme analysis with PvuII. In the given conditions the mRNAs of six MT isoforms were identified in human glioblastoma cell line U87 MG. Depending on arsenic exposure conditions, an increase or decrease of MT gene expression was observed for each isoform, with the highest increase for isoforms MT1X, MT1F and MT2A mRNA (up to 13-fold) and more persistent decreases for MT1A, MT1E and MT3 mRNA. Despite the common assumption of the noninducibility of MT3, the evident MT3 mRNA increase was observed during high As exposure (up to 4-fold). In conclusion, our results clearly demonstrate the influence of As on MT isoform gene expression. The MT1X, MT1F and MT2A increase could represent brain tumour acquired resistance to As cytotoxicity while the MT3 increase is more enigmatic, with its possible involvement in arsenic-related induction of type II cell death.