Iodine: Its Role in Thyroid Hormone Biosynthesis and Beyond.

Area of Science:

• Biochemistry
• Endocrinology
• Microbiology

Background:

• Iodine is primarily known for its essential role in synthesizing thyroid hormones (THs).
• Emerging research highlights additional significant biological functions of iodine.
• Understanding these diverse roles is critical for appreciating iodine's overall physiological impact.

Purpose of the Study:

• To review the multifaceted functional roles of iodine and its metabolism.
• To consolidate evidence on iodine's antioxidant, antimicrobial, and antineoplastic activities.
• To emphasize iodine's conserved physiological functions beyond thyroid hormone synthesis.

Main Methods:

• Literature review of studies on iodine's biological functions.
• Analysis of research on iodine's antioxidant properties (ROS scavenging).
• Examination of data on iodine's antimicrobial (bactericidal, antiviral, antifungal) effects.
• Review of studies investigating iodine's antineoplastic activity in cancer cell lines.

Main Results:

• Iodine is a key component in thyroid hormone biosynthesis.
• Iodine exhibits significant reactive oxygen species (ROS) scavenging activity, acting as an antioxidant.
• Iodine oxidation products (hypoiodite) demonstrate potent bactericidal, antiviral, and antifungal properties.
• Iodine has shown antineoplastic effects against human cancer cell lines.

Conclusions:

• Iodine possesses diverse, evolutionarily conserved physiological functions.
• Beyond TH production, iodine serves critical roles in antioxidant defense and pathogen resistance.
• Iodine's antineoplastic potential warrants further investigation for cancer therapy.