Description

Lichen extracts containing usnic acid have been utilized in medicine, perfumery, cosmetics, and ecology. Usnic acid possess a wide range of interesting biological properties. It is a potent antibiotic effective against gram positive bacteria, including Mycobacterium tuberculosis, Staphylococcus, Streptococcus, and Pneumococcus, as well as some pathogenic fungi. It also exhibits antiviral, antiprotozoal, antimitotic, anti-inflammatory and analgesic activity. Other characteristics, like ultraviolet absorption, preserving properties, antigrowth, antiherbivore and anti-insect properties, have also been demonstrated. Usnic acid has been included as an ingredient in creams, powders, toothpastes, mouthwash, deodorants, hair shampoos and sunscreen products. In some of these preparations, usnic acid is employed as an active principle, in others as a preservative. Usnic acid and its salt form, sodium usniate, have been marketed in the US as an ingredient in food supplements for use in weight reduction, although unsupported by solid scientific proof. There have been unconfirmed reports of liver damage caused by the consumption of usnic acid.