Salicin vs Salicylic Acid: Relationship, Difference & Uses
In 1534 BC, the ancient Egyptians recorded the use of willow trees for anti-inflammatory and pain-relieving purposes. Later, people from different regions gradually discovered other benefits of willow bark. With the advancement of chemistry, two active components were identified: salicylic acid and salicin.
What Is The Relationship Between Salicin and Salicylic Acid
They shared a chemical foundation and metabolic connection. Salicin is a natural compound found primarily in the bark of willow trees and certain other plants. It serves as a prodrug, meaning that it metabolizes into its active form within the human body.
When ingested, salicin undergoes enzymatic conversion to salicylic acid, a process that primarily occurs in the liver. This biochemical transformation underscores the historical significance of salicin as the precursor to salicylic acid, which eventually became the inspiration for modern aspirin.
In essence, salicin can be considered a natural, plant-derived source of salicylic acid, forming a direct biochemical link between the two.
Fig 1. The molecular structure and origin
What Is Their Difference
Although salicin and salicylic acid are chemically related, they differ in molecular structure, source, bioactivity, solubility, and toxicity.
Structurally, salicin is composed of salicylic acid bound to a glucose molecule, while salicylic acid is a standalone organic acid.
Strictly speaking, their sources are also different. Salicin is primarily found in certain plants, such as birch bark and willow leaves. In contrast, salicylic acid is obtained through the hydrolysis of salicin or artificial synthesis.
They exhibit distinct bioactivities. Salicin needs to be enzymatically hydrolyzed into salicylic acid in the body to take effect, whereas salicylic acid directly exhibits anti-inflammatory, analgesic, and antipyretic properties.
Generally, salicin has poor solubility in water, while salicylic acid is highly soluble.
Additionally, their toxicity levels differ. Salicin is relatively less toxic, while salicylic acid can cause gastrointestinal irritation, toxicity, or even death when taken in high doses.
In summary, salicin is usually milder and less irritating to the stomach lining because it requires metabolic conversion to exert its effects. Salicylic acid, on the other hand, is an active compound with stronger potency, often used topically for its immediate therapeutic properties.
A reminder: many people use salicylic acid to combat acne, but it should not be applied extensively (over more than 30% of the body surface area), as it may lead to symptoms of toxicity, such as dizziness, tinnitus, or confusion.
What Are Their Uses
Salicin has a long history in traditional medicine as a natural pain reliever and anti-inflammatory agent. Salicylic acid has carved its niche in modern medicine and skincare.
–Applications of Salicin
Salicin is widely found in plants such as willow bark and birch bark. In traditional herbal medicine, it is used as a natural anti-inflammatory, analgesic, and antipyretic agent. It requires metabolic conversion into salicylic acid in the body to exert its effects, making it milder and less irritating to the gastrointestinal tract.
It is also used in herbal extracts and dietary supplements to relieve mild headaches, joint pain, inflammation, and fever, serving as a natural alternative to aspirin. Given its antioxidant properties, salicin has also been studied for its potential to prevent oxidative stress-related diseases, such as cardiovascular diseases and neurodegenerative disorders.
–Applications of Salicylic Acid
Salicylic acid has the ability to exfoliate and dissolve keratin, making it an important medicinal ingredient. It is widely used in the treatment of acne, psoriasis, corns, warts, and other keratinization-related skin conditions.
It is commonly used in cosmetics and skincare products. With its mild exfoliating and anti-inflammatory properties, salicylic acid is included in cleansers, toners, and creams to help clear pores, improve skin texture, and reduce inflammation.
In industrial applications, it also serves as a precursor for synthesizing aspirin and other pharmaceuticals, showcasing its versatility beyond topical and oral remedies.
Stanford Chemicals Company (SCC) specializes in providing pharmaceutical and cosmetic raw ingredients, as well as various herbal extracts, to enterprises and research institutions. Our product offerings include sodium hyaluronate, salicin, capryloyl salicylic acid, dihydromyricetin, chondroitin sulfate, and more. If you have related needs, feel free to contact us for inquiries.
