TOSSICOLOGIA GENERALE ED AMBIENTALE

The General Toxicology course consists of lectures and aims to provide students with basic knowledge of toxicology and of the molecular and cellular mechanisms underlying the toxicity of the main classes of xenobiotics and toxic agents.

At the end of the course, students will have achieved the following learning outcomes:

1. Knowledge and understanding. Students will be able to describe the fundamental principles of toxicology, the main classes of xenobiotics and toxic agents, the molecular and cellular mechanisms of toxicity, and the toxic effects of major environmental pollutants.

2. Applying knowledge and understanding. Students will be able to apply the concepts of toxicokinetics and toxicodynamics to the interpretation of the toxicological profiles of xenobiotics and toxic agents and to interpret the main toxicity tests.

3. Making judgements. Students will be able to critically evaluate data concerning the toxicity of chemical substances and apply the principles of risk assessment and risk management.

4. Communication skills. Students will be able to clearly and appropriately present the main toxicological concepts, using the technical and scientific terminology specific to the discipline.

5. Learning skills. Students will be able to independently retrieve and use up-to-date scientific and bibliographic information concerning the toxicity of xenobiotics and environmental pollutants.

Face-to-face lectures

If the course is delivered in blended or remote mode, appropriate adjustments may be made to the above, in order to ensure consistency with the syllabus.

Students may use AI as a tool to support their studies, in compliance with applicable legislation, including legislation concerning copyright and the use of intellectual works, as described in Section 5.1 of the guidelines (https://www.unict.it/it/ateneo/cidia-centro-l%E2%80%99informatica-la-digitalizzazione-e-l%E2%80%99intelligenza-artificiale).

According to the RDA, Art. 12 – University Educational Credits (CFU), within the standard workload of 25 hours of overall student commitment corresponding to one credit, the following activities may be included: a) 7 hours devoted to lectures or equivalent teaching activities, with the remaining hours assigned to individual study;b) no fewer than 12 and no more than 15 hours devoted to classroom exercises or equivalent supervised activities (laboratories), with the remaining hours assigned to individual study and independent work.

Attendance is mandatory, as provided for in the degree programme regulations. Absences are permitted for no more than 30% of the total number of teaching hours, regardless of the mode of delivery  (https://www.dsf.unict.it/it/corsi/l-29_sfa/regolamento-didattico).

Principles of toxicology 
Pharmacokinetic and pharmacodynamic concepts that characterize the toxicological profile and mechanism of action of xenobiotics. 

GENERAL PRINCIPLES OF TOXICOLOGY - Areas of toxicology. Classification of toxic agents. Classification of toxic effects. Allergic reactions, idiosyncrasy; immediate and delayed toxicity reversible, irreversible, local, and systemic toxicity. Factors influencing the response to toxins.

PREDICTIVE TOXICOLOGY AND RISK ASSESSMENT - Exposure to toxic agents: routes and sites, duration and frequency of exposure. Acute, subchronic, and chronic toxicity. Risk assessment. Toxicity threshold, effects without a threshold. LOEL, LOAEL, NOEL, NOAEL, NEL. Dose-response relationship. Dose-response curves. Margin of safety, ADI.

TOXICOKINETICS: ABSORPTION, DISTRIBUTION, METABOLISM, AND ELIMINATION OF TOXIC SUBSTANCES - Cell membranes, passive transport, filtration, active transport, facilitated diffusion. Absorption through the gastrointestinal tract. Absorption through the lungs (gases and vapors, aerosols). Absorption through the skin. Distribution, deposition sites. Blood-brain barrier, placenta. Apparent volume of distribution. Clearance. Half-life. Excretion: urinary, fecal, biliary, intestinal, cerebrospinal fluid, milk, sweat, saliva, and hair. Toxicological consequences of xenobiotic biotransformation. The cytochrome P450 system. Production of toxic metabolites through phase I and phase II metabolic reactions. Induction and inhibition of metabolism.

TOXICODYNAMICS: TOXIC-RECEPTOR INTERACTION - General information on receptors. Chemical bonds involved in ligand/receptor binding. Binding studies. Characteristics of the interaction. Reversible and irreversible interactions. Interactions between chemicals (additive effect, synergy, potentiation, antagonism, tolerance). Analysis of dose-response curves. Major classes of receptors and signal transduction mechanisms. Interaction with functional targets.

MOLECULAR AND CELLULAR MECHANISMS OF TOXICITY - Major neurotransmitter systems. Morphological, functional, and biochemical alterations produced by xenobiotics. General mechanisms of cell damage. Free radicals. Mechanisms of toxicity: genotoxicity, mutagenesis, carcinogenesis, and teratogenesis.

MAJOR ENVIRONMENTAL POLLUTANTS - Pesticides. Polycyclic aromatic hydrocarbons. Dioxins. Phthalates

1. Casaret and Doull's TOXICOLOGY: The Basic Science of Poisons, Ed. McGraw-Hill

Learning is assessed through an oral examination aimed at evaluating students’ knowledge and understanding of the main concepts of general and environmental toxicology, toxicokinetic and toxicodynamic mechanisms, and the molecular and cellular mechanisms underlying toxicity. The oral examination also assesses students’ ability to apply the knowledge acquired to the interpretation of toxicological phenomena, critically evaluate data concerning toxicity and risk, and establish connections between the different topics covered in the syllabus.

The relevance and accuracy of the answers, the quality and completeness of the content, the ability to establish connections between topics, the ability to provide appropriate examples, the use of appropriate technical and scientific terminology, and overall communication skills will be assessed. Students’ ability to independently retrieve and use up-to-date scientific and bibliographic information will also be evaluated.

The examination is considered passed with a minimum of 18/30 when the student demonstrates, for each question, adequate knowledge of the essential concepts and fundamental content relevant to the specific topic. The final evaluation, ranging from 18/30 to 30/30 cum laude, is based on the depth and accuracy of the student’s responses, the ability to establish connections between different topics and concepts, and the level of complexity of the questions addressed.

The assessment may also be conducted remotely, if circumstances so require.

Exam schedule: https://www.dsf.unict.it/it/corsi/l-29_sfa/calendario-esami

Information for students with disabilities and/or SLD:

To ensure equal opportunities and in compliance with current legislation, students with disabilities and/or Specific Learning Disorders (SLD) may request a personal interview with the instructor in order to agree on any appropriate compensatory and/or dispensatory measures, in accordance with the learning objectives of the course and the student’s specific needs.

Students may contact Prof. Santina Chiechio, also in her capacity as the CInAP (Centro per l’Inclusione Attiva e Partecipata – Services for Disabilities and/or Specific Learning Disorders) contact person for the Department of Drug and Health Sciences, at santina.chiechio@unict.it

Describe the main mechanisms of toxicity.

Describe the primary pathways of exposure to xenobiotics.

Risk assessment.

Interaction between xenobiotics and biological targets.

Metabolic interactions.