**Mallanagoud S. Biradar, MD**

Professor of Medicine, BLDE (Deemed to be University), Vijayapura, Karnataka, India

### **Dr. Varaprasad Bobbarala, PhD**

Chief Scientist and Director, Adhya Biosciences Pvt. Ltd., India

#### **Dr. S. Subba Tata**

**1**

Section 1

Redox Biology

and Medicine

Assistant Professor, Department of Botany, Andhra University, India

Section 1

Redox Biology and Medicine

**3**

**Chapter 1**

of Antioxidants

*Mallanagouda S. Biradar*

cal, hydroxyl radical, and nitric oxide [7].

**1. Introduction**

studies [6].

process [8, 9].

**2. Metal toxicities**

Introductory Chapter: Free Radical

Industrial revolution imparts a high level of metal contamination in this world [1–3]. Although technology advances to control pollution, it fails to check environmental heavy metal pollution. As metals used not always leads to biodegradation, hence, these heavy metals circulate in human life chains and accumulate in living organisms [4]. Some metals like zinc and iron are physiologically essential, but they may also alter the function of organisms when the exposure dose exceeds a critical threshold, which is species specific, and can depend on multiple factors including age, sex, and functional norms of physiological system [5]. Rodents are as sensitive and near similar to human monitoring system against metal toxicity

In the last few decades there has been a tremendous interest on oxygen-free radicals, more generally known as "reactive oxygen species," (ROS) and of "reactive nitrogen species" (RNS) in experimental and clinical studies on various environmental pollutants [6]. ROS and RNS are found to be generated during irradiation or metal catalyzed reaction or its presence in atmosphere as pollutants or simply generates due to inflammation in the physiological system. Some examples of free radicals are hydrogen peroxide, singlet oxygen, hypochlorous acid, superoxide radi-

It has generated interest that oxygen metabolism induces over production of free radicals due to altered pathophysiology in the system. Another hypothesis is that inadequate antioxidants in the body also impairs body defense system and ability to fight against pollutants especially heavy metal pollutants. Antioxidants can prevent cellular damage by interacting with free radicals and terminating chain reaction

Metals play an important role by conjugating at the active sites of enzymes and participate directly in catalysis, stabilize macromolecular structures of proteins and

The molecular mechanisms including enzymatic functions of metal induced bio-toxicities have been established. Possible recognition of essential biological

nucleic acids, thereby affecting structural and functional integration.

Biology in Metal Toxicities—Role

*Swastika Das, Shrilaxmi Bagali, Sayandeep K. Das,* 

*Aravind V. Patil, Ishwar B. Bagoji, Kusal K. Das and* 
