Oxidative Stress Associated With Arsenic Exposure: An Overview

What Is Oxidative Stress?

Oxidative stress is mainly caused by the disruption between the generation and lodgement of the free radicals or reactive oxygen species (ROS) and the inhibition of the detoxification process that neutralizes its effect. The human body produces both free radicals and antioxidants during metabolic processes. If free radical production is high, it can damage the cell’s regenerative and repair process, which causes aging and many diseases in the body.

What Are Free Radicals?

Free radicals are unequal or odd numbers of electrons in oxygen molecules that can interact with cell membrane molecules and cause chemical reactions to form large chains in the body. This process is called an oxidation reaction in the human body.

How does Arsenic Metal Exposure Cause Oxidative Stress?

Arsenic is a metalloid that occurs naturally, and studies show that during the biotransformation process or disturbance in the cellular pathway, arsenic has the potential to produce free radicals or reactive oxygen species (ROS) in humans and animals. It can also disrupt the detoxification process in the body, leading to an increase in ROS or free radicals, thus causing oxidative stress.

How Does Oxidative Stress Affect the Body?

In normal body functioning, free radicals help fight pathogens causing infection. Still, in case of disruption, oxidative stress is generated, causing damage to DNA (deoxyribonucleic acid), fatty cells, tissues, and protein levels. This leads to several diseases that occur over time.

• Heart disease.

• Neurodegenerative diseases like Alzheimer's and Parkinson's disease.

• Diabetes.

• Hypertension (high blood pressure).

• Cancer.

• Atherosclerosis (blood vessels get hardened).

• Inflammations.

What Are the Symptoms of Oxidative Stress?

• Headache.

• Aging or wrinkles.

• Joint and muscle pain.

• Fatigue.

• Loss of memory.

• Gray hair.

• Eyesight gets weak.

• Fluctuating blood sugar levels.

• Noise sensitivity.

What Are the Symptoms of Arsenic Poisoning?

• Diarrhea.

• Nausea.

• Vomiting.

• Muscle cramps.

• Abdominal pain.

• Skin redness and swelling.

How Can We Get Exposed to Free Radicals in the Environment?

Our body produces free radicals naturally, but one can also get exposed to them through environmental risk factors, such as:

• Cigarettes.

• Radiation.

• Pollution.

• Ozone.

• A diet containing alcohol, sugar, or fat.

• Disinfectants and pesticides.

• High blood sugar levels.

• Amount of iron, manganese, zinc, and copper in the body.

• Toxins.

What Are the Other Human Diseases Caused by Arsenic Exposure?

• Skin Diseases - Skin lesions like hyperpigmentation and hyperkeratosis develop due to arsenic exposure. In addition, some studies show keratosis in female workers due to arsenic toxicity and precancerous dermatitis due to severe exposure.

• Cardiovascular Effect - inorganic arsenic can cause cardiac arrhythmia or myocardial infarction due to prolonged exposure.

• Cancer - Arsenic has carcinogenic properties and can cause lung, kidney, bladder, and liver cancer.

• Liver Disease - Many studies show the effect of arsenic poisoning on the liver causing hepatic injury on oral exposure.

• Neurological Disorders - Arsenic exposure shows changes in dopamine levels and other neurotransmitters, thus producing alterations in neurobehavioral.

• Reproductive Health Effects - Studies have proved that arsenic affects reproductive health by changing the weight of the ovary and uterus and altering the fertility index.

• Renal Disease - At high levels of arsenic toxicity in the body, arsenic can cause an increase in creatinine and bilirubin levels in the body.

How do Antioxidants Work to Fight Against Oxidative Stress and Free Radicals?

The human body produces many antioxidant enzymes to neutralize the effects of free radicals causing oxidative stress and damaging the cell. Antioxidants fight against these radicals in many ways, such as by decreasing the energy levels of these free radicals, inhibiting the formation of the free radicals in the body, causing a disturbance in the oxidation reaction, and reducing the effect of free radicals, therefore protecting cells from damage.

How Can We Diagnose Arsenic Exposure in the Human Body?

• A urine test within one to two hours of arsenic exposure can help diagnose its presence in the body.

• Fingernails and hair can be used to diagnose arsenic exposure over 12 months.

How Can We Prevent Oxidative Stress?

Oxidative stress can be prevented with the help of the natural defense mechanism of the body to protect cells from damage; This includes:

• First, antioxidants can repair the damage caused by free radicals.

• Second, oxygen-neutralizing enzymes can fight against the action of free radicals.

• Finally, a physical barrier like intact skin keeps the free radicals away from the cell periphery.

Oxidative stress can be managed by taking dietary antioxidants for detoxification, such as:

• Vitamin E.

• Vitamin C.

• Melatonin.

• Green tea.

• Onion.

• Turmeric.

• Garlic.

We can also prevent oxidative stress by changing our lifestyle habits, like:

• Avoid smoking and also passive exposure to smoke.

• Alcohol intake should also be decreased.

• Avoid chemical exposures.

• Regular exercising produces antioxidants naturally.

• Environment-friendly practices to lower the production of free radicals in the air.

How Can We Treat Chronic Arsenic Exposure?

• Fluid replacement therapy can be given intravenously to cope with severe toxicity.

• If ingestion of arsenic metal occurs, gastric lavage can help to reduce the effect and further absorption in the body.

• In case of diarrhea due to exposure, cathartic drugs must be given.

• Renal involvement can be treated with hemodialysis.

• Administration of chelating agents (Dimercaprol 2, 3 dimercaptopropanol) can also be helpful in severe cases.

• In some cases, vitamin A (retinoids) can be used to treat arsenical keratosis.

Conclusion

Arsenic exposure causes health issues worldwide, and arsenic-induced oxidative stress disrupts biological and cellular pathways. DNA repair, growth factors, apoptosis promotion and resistance, and antioxidant imbalance are all caused by prolonged exposure to arsenic. It causes damage to the cells and is associated with many health-related problems, such as renal, cardiovascular, developmental, and liver disorders.