Toxicology

Author(s):  
Robert Laumbach ◽  
Michael Gochfeld

This chapter describes the basic principles of toxicology and their application to occupational and environmental health. Topics covered include pathways that toxic substances may take from sources in the environment to molecular targets in the cells of the body where toxic effects occur. These pathways include routes of exposure, absorption into the body, distribution to organs and tissues, metabolism, storage, and excretion. The various types of toxicological endpoints are discussed, along with the concepts of dose-response relationships, threshold doses, and the basis of interindividual differences and interspecies differences in response to exposure to toxic substances. The diversity of cellular and molecular mechanisms of toxicity, including enzyme induction and inhibition, oxidative stress, mutagenesis, carcinogenesis, and teratogenesis, are discussed and the chapter concludes with examples of practical applications in clinical evaluation and in toxicity testing.

2020 ◽  
Vol 134 (17) ◽  
pp. 2243-2262
Author(s):  
Danlin Liu ◽  
Gavin Richardson ◽  
Fehmi M. Benli ◽  
Catherine Park ◽  
João V. de Souza ◽  
...  

Abstract In the elderly population, pathological inflammation has been associated with ageing-associated diseases. The term ‘inflammageing’, which was used for the first time by Franceschi and co-workers in 2000, is associated with the chronic, low-grade, subclinical inflammatory processes coupled to biological ageing. The source of these inflammatory processes is debated. The senescence-associated secretory phenotype (SASP) has been proposed as the main origin of inflammageing. The SASP is characterised by the release of inflammatory cytokines, elevated activation of the NLRP3 inflammasome, altered regulation of acetylcholine (ACh) nicotinic receptors, and abnormal NAD+ metabolism. Therefore, SASP may be ‘druggable’ by small molecule therapeutics targeting those emerging molecular targets. It has been shown that inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and adverse cardiac remodelling. Therefore, the pathomechanism involving SASP activation via the NLRP3 inflammasome; modulation of NLRP3 via α7 nicotinic ACh receptors; and modulation by senolytics targeting other proteins have gained a lot of interest within cardiovascular research and drug development communities. In this review, which offers a unique view from both clinical and preclinical target-based drug discovery perspectives, we have focused on cardiovascular inflammageing and its molecular mechanisms. We have outlined the mechanistic links between inflammageing, SASP, interleukin (IL)-1β, NLRP3 inflammasome, nicotinic ACh receptors, and molecular targets of senolytic drugs in the context of cardiovascular diseases. We have addressed the ‘druggability’ of NLRP3 and nicotinic α7 receptors by small molecules, as these proteins represent novel and exciting targets for therapeutic interventions targeting inflammageing in the cardiovascular system and beyond.


Author(s):  
G. S. Agzamova ◽  
M. M. Abdullaeva

The immunological profile of chronic liver lesions depending on the toxic agent was studied. It was revealed that chronic poisoning by industrial toxic substances causes changes in the functional state of the T-system of immunity, long-term contact with industrial chemicals leads to increased sensitization to autoantigens of the body.


2018 ◽  
Vol 24 (14) ◽  
pp. 1533-1550 ◽  
Author(s):  
Jong-Eun Kim ◽  
Ki Won Lee

Skin is a protective organ and the largest of the human body. Due to its pivotal role in aesthetic appearance, skin health has a significant impact on quality of life. Chronic inflammation of the skin often marks the beginning of various skin diseases. Immune-mediated responses serve to protect the body from external insults and require succinct control, and can lead to ongoing cellular damage and various skin conditions if left unchecked. Studies have shown that phytochemicals can alter processes involved in skin inflammation and alleviate the effects of aging, cancer, atopic dermatitis, psoriasis, and vitiligo. Direct molecular targets of some phytochemicals have been identified and their precise mechanisms of action investigated. In this review, we summarize recent findings on the effects of phytochemicals on skin inflammation and the mechanisms of action involved.


2020 ◽  
Vol 26 (44) ◽  
pp. 5720-5731 ◽  
Author(s):  
Arun Singh Lalotra ◽  
Vishesh Singh ◽  
Bharat Khurana ◽  
Shelly Agrawal ◽  
Shubham Shrestha ◽  
...  

Background: Skin is the largest organ of the body and helps to regulate several physiological functions. It acts as a barrier that protects the body against UV-radiation, toxic substances, infections, etc. The abnormal growth of the skin cells is called skin cancer. Different types of skin cancer can be classified as Basal Cell Carcinoma (BCC) and Squamous Cell Carcinoma (SCC); which mainly occur due to chronic exposure to UV- sunlight and pollution. Methods: The conventional topical treatments of skin cancer such as cream, gel, ointment, etc., are more occlusive and thus they do not penetrate deep into the skin (dermal layer) and remain at the upper part of the skin (epidermal layer). The stratum corneum acts as a physiological barrier for the drug-loaded in the conventional formulation. The novel carrier systems have the potential to facilitate the penetration of the drug deep into the skin (dermal layer) because these have less size and higher flexibility than conventional treatment. Conclusion: In the present review, we have discussed various novel carrier systems being investigated for the topical application of chemotherapeutic agents for efficient skin targeting and better dermatological as well as therapeutic benefits with minimal systemic exposure and toxicity.


2020 ◽  
Vol 14 ◽  
Author(s):  
Abhishek Kumar ◽  
Neeraj Masand ◽  
Vaishali M. Patil

Abstract: Breast cancer is the most common and highly heterogeneous neoplastic disease comprised of several subtypes with distinct molecular etiology and clinical behaviours. The mortality observed over the past few decades and the failure in eradicating the disease is due to the lack of specific etiology, molecular mechanisms involved in initiation and progression of breast cancer. Understanding of the molecular classes of breast cancer may also lead to new biological insights and eventually to better therapies. The promising therapeutic targets and novel anti-cancer approaches emerging from these molecular targets that could be applied clinically in the near future are being highlighted. In addition, this review discusses some of the details of current molecular classification and available chemotherapeutics


Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 794
Author(s):  
Cullen Horstmann ◽  
Victoria Davenport ◽  
Min Zhang ◽  
Alyse Peters ◽  
Kyoungtae Kim

Next-generation sequencing (NGS) technology has revolutionized sequence-based research. In recent years, high-throughput sequencing has become the method of choice in studying the toxicity of chemical agents through observing and measuring changes in transcript levels. Engineered nanomaterial (ENM)-toxicity has become a major field of research and has adopted microarray and newer RNA-Seq methods. Recently, nanotechnology has become a promising tool in the diagnosis and treatment of several diseases in humans. However, due to their high stability, they are likely capable of remaining in the body and environment for long periods of time. Their mechanisms of toxicity and long-lasting effects on our health is still poorly understood. This review explores the effects of three ENMs including carbon nanotubes (CNTs), quantum dots (QDs), and Ag nanoparticles (AgNPs) by cross examining publications on transcriptomic changes induced by these nanomaterials.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Raphael Severino Bonadio ◽  
Larissa Barbosa Nunes ◽  
Patricia Natália S. Moretti ◽  
Juliana Forte Mazzeu ◽  
Stefano Cagnin ◽  
...  

AbstractMost biological features that occur on the body after death were already deciphered by traditional medicine. However, the molecular mechanisms triggered in the cellular microenvironment are not fully comprehended yet. Previous studies reported gene expression alterations in the post-mortem condition, but little is known about how the environment could influence RNA degradation and transcriptional regulation. In this work, we analysed the transcriptome of mouse brain after death under three concealment simulations (air exposed, buried, and submerged). Our analyses identified 2,103 genes differentially expressed in all tested groups 48 h after death. Moreover, we identified 111 commonly upregulated and 497 commonly downregulated genes in mice from the concealment simulations. The gene functions shared by the individuals from the tested environments were associated with RNA homeostasis, inflammation, developmental processes, cell communication, cell proliferation, and lipid metabolism. Regarding the altered biological processes, we identified that the macroautophagy process was enriched in the upregulated genes and lipid metabolism was enriched in the downregulated genes. On the other hand, we also described a list of biomarkers associated with the submerged and buried groups, indicating that these environments can influence the post-mortem RNA abundance in its particular way.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Hamed Nosrati ◽  
Reza Aramideh Khouy ◽  
Ali Nosrati ◽  
Mohammad Khodaei ◽  
Mehdi Banitalebi-Dehkordi ◽  
...  

AbstractSkin is the body’s first barrier against external pathogens that maintains the homeostasis of the body. Any serious damage to the skin could have an impact on human health and quality of life. Tissue engineering aims to improve the quality of damaged tissue regeneration. One of the most effective treatments for skin tissue regeneration is to improve angiogenesis during the healing period. Over the last decade, there has been an impressive growth of new potential applications for nanobiomaterials in tissue engineering. Various approaches have been developed to improve the rate and quality of the healing process using angiogenic nanomaterials. In this review, we focused on molecular mechanisms and key factors in angiogenesis, the role of nanobiomaterials in angiogenesis, and scaffold-based tissue engineering approaches for accelerated wound healing based on improved angiogenesis.


Biomolecules ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 79
Author(s):  
Svetlana N. Morozkina ◽  
Thi Hong Nhung Vu ◽  
Yuliya E. Generalova ◽  
Petr P. Snetkov ◽  
Mayya V. Uspenskaya

For a long time, the pharmaceutical industry focused on natural biologically active molecules due to their unique properties, availability and significantly less side-effects. Mangiferin is a naturally occurring C-glucosylxantone that has substantial potential for the treatment of various diseases thanks to its numerous biological activities. Many research studies have proven that mangiferin possesses antioxidant, anti-infection, anti-cancer, anti-diabetic, cardiovascular, neuroprotective properties and it also increases immunity. It is especially important that it has no toxicity. However, mangiferin is not being currently applied to clinical use because its oral bioavailability as well as its absorption in the body are too low. To improve the solubility, enhance the biological action and bioavailability, mangiferin integrated polymer systems have been developed. In this paper, we review molecular mechanisms of anti-cancer action as well as a number of designed polymer-mangiferin systems. Taking together, mangiferin is a very promising anti-cancer molecule with excellent properties and the absence of toxicity.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
M Company-Morales ◽  
A Fontalba-Navas ◽  
M F Rubio-Jimenez ◽  
V Gil-Aguilar ◽  
J P Arrebola

Abstract Introduction Persistent Toxic Substances (PTS) are substances that are characterized by the cumulative effect at low doses inside the body. Exposure to PTS in pregnant and breastfeeding women, through food consumption, shows various harmful effects on the health of the mother, the fetus and the baby. The objective of this article is to analyze how pregnant and breastfeeding women perceive the presence of chemical substances in food and reflect on the accumulation, transmission and elimination of these substances. Methodology Descriptive and interpretive study under the qualitative research paradigm following a phenomenological and ethnographic perspective. As instruments to obtain the primary data we rely on 111 semi-structured interviews with pregnant and breastfeeding women, 4 focused ethnographies, 8 focus groups (63 women), 71 feeding diaries, 71 free listings. To encode the content of the speeches of pregnant and nursing women we rely on the N-Vivo 12 software. Results Pregnant and breastfeeding women are concerned about food quality controls. Women trust on local and seasonal foods such as fresh fruits and vegetables from non-extensive crops and close to their home. Foods that produce distrust in women are processed, packaged foods, red meat and large fish. The latter foods promote in women a perception of risk of contamination by chemical substances, manifesting a defenseless situation to maintain a diet without contaminants. Conclusions Pregnant and breastfeeding women in Spain have no information on the risk and danger of synthetic chemicals or PTS, with the exception of certain toxic substances such as mercury present in large fish. Women maintain a duality in their own care and that of the fetus or child. This circumstance implies that the women interviewed believe that PTS and synthetic chemicals may have different harmful effects on the mother and the degree of growth of the fetus and, subsequently, of the baby. Key messages Future mothers are worried about the type of product they eat, knowing that food influences healthy growth and development of the fetus. Pregnant and breastfeeding women often distrust “processed” or “industrial” foods, which they tend to associate with low quality and large amounts of additives and chemical substances.


Sign in / Sign up

Export Citation Format

Share Document