2. Introduction
■ Xenobiotic is a term used to describe chemical substances that are foreign to
animal life.
■ Examples as plant constituents, drugs, pesticides, cosmetics, flavorings,
fragrances, food additives, industrial chemicals and environmental pollutants.
■ Xenobiotic means ‘foreign to life’.
■ It can also cover the substances in which are present in higher concentrations
than usual in any product.
■ It’s not normally naturally produced.
3. Origin
■ Some organisms may also form them as a part of their defense system,
■ Examples; mycotoxins, bacterial and herbal toxins, etc.
■ Xenobiotics become harmful when entering the food chain.
■ Contemporary human exposure to xenobiotics is unavoidable, as they are
omnipresent.
■ Term xenobiotic is derived from the Greek words ξένος (xenos) = foreigner,
stranger and βίος (bios) = life.
■ Xenobiotics may be grouped as carcinogens, drugs, environmental pollutants,
food additives, hydrocarbons, and pesticides.
4. Purpose
■ Xenobiotic metabolism functions primarily to increase the polarity of
xenobiotics, making them easier to excrete.
■ With passive transport, molecules cross biological membranes without the
consumption of chemical energy.
5. Types
■ Environmental pollutants,
■ Hydrocarbons,
■ Food additives,
■ Oil mixtures,
■ Pesticides,
■ Synthetic polymers,
■ Carcinogens, drugs, and antioxidants are the major groups of xenobiotics
6. The role of xenobiotics in human
health:
■ XENobiotics may alter the microbiota composition, leading to
a state of dysbiosis, which is linked to multiple diseases and
adverse health outcomes, including increased toxicity of
some xenobiotics.
7. Sources
■ Ambient environment : Learn about the various sources of xenbiotics
present in our surrounding including Air pollutants, water Contaminants
and soil contaminants.
■ Dietary Exposure: Explore how Xenbiotics can enter into the human body
through the contaminated food.
■ Occupational exposure: Discover the Potential risks of Xenbiotics exposure
in specific environment , such as Factories, laboratories and agriculture
fields.
8. Effect on human Health
■ Acute Toxicity: Understand the immediate and severe harmful effects
xenobiotics can have on human health, ranging from poisoning to organ
damage.
■ Chronic Diseases: Explore how long-term exposure to xenobiotics can
contribute to the development of chronic diseases, including cancer,
neurological disorders, and respiratory conditions.
■ Reproductive health: Discover the impact of xenobiotics on reproductive
health, including fertility issues, developmental abnormalities in offspring,
and hormonal disruptions.
9. Metabolism of Xenobiotics
■ Phase I Reactions: Learn how xenobiotics are metabolized through oxidation,
reduction, and hydrolysis reactions to generate reactive intermediates.
■ Phase II Reactions: Explore the conjugation processes where reactive
intermediates are combined with molecules like glutathione and glucuronic
acid to facilitate their elimination.
■ Role of Enzymes: Discover the crucial role of enzymes, such as cytochrome
P450 and UDP-glucuronosyltransferase, in metabolizing and biotransforming
xenobiotics.
