Maidenhair fern (Adiantum capillus-veneris) is native to the southern half of the United States through Mexico and Central America. They are also found worldwide in temperate climates from warm-temperate to tropical, where the moisture content is high. Traditionally, Native Americans used maidenhair fern for medicine. The Mahuna people used this plant to treat rheumatism while the Navajo people made this into an infusion and used for bumblebee or centipede stings. It was also widely used in traditional Iranian medicine as an ointment for anti-inflammatory agent or hair tonic for hair growth and anti-dandruff.

 

Phytochemical studies revealed that maidenhair contains diverse bioactive constituents such as tannins, terpenoids, flavonoids, alkaloids, and saponins, and tannins and flavonoids are present in high concentrations when compared to others. Quercetin, kaempferol-3-sulphate, kaempferol-3-rhamno- glucoside, and rutin are the main flavonoids isolated from polar fractions. It was reported that methanol extracts of maidenhair showed anti-oxidant activity by scavenging free radicals, anti-microbial activities against various strains, and anti-inflammatory activities by suppressing NF-κB activation.