Araroba powder explained

Araroba powder, also known as Bahia powder and Goa powder, is a drug occurring in the form of a yellowish-brown powder, varying considerably in tint, from the Portuguese colony of Goa, where it appears to have been introduced about the year 1852.^[1]

The tree which yields it is the Andira araroba of the family Fabaceae. It is abundant in certain forests in the province of Bahia in Brazil as well as imported into India, preferring as a rule low and humid spots. The tree ranges from 80 to 100 ft. high and has large imparipinnate, or feather shaped, leaves, the leaflets of which are oblong, about 12 in. long and 1 in. broad, and somewhat truncate at the apex. The flowers are papilionaceous, of a purple color and arranged in panicles.

The Goa powder or araroba is contained in the trunk, filling crevices in the heartwood. It is a morbid product in the tree, and yields to hot chloroform 50% of a substance known officially as chrysarobin. It occurs as a microcrystalline, odorless, tasteless powder, very slightly soluble in either water or alcohol; it also occurs in rhubarb root. This complex mixture contains pure chrysarobin, di-chrysarobin, and di-chrysarobin methylether. Chrysarobin is a methyl trioxyanthracene and exists as a glucoside in the plant, but is gradually oxidized to chrysophanic acid (a dioxy-methyl anthraquinone) and glucose. This strikes a blood-red color in alkaline solutions, and may therefore cause much alarm if administered to a patient whose urine is alkaline.

Medicinal uses

Dithranol and chrysophanic acid are therapeutic substances in araroba powder that are responsible for success in treatment of psoriasis and chronic eczema.^[2] It has been used as a treatment of ringworm. Generally, when used for skin conditions, the powder is mixed into a zinc or petrolatum ointment, paste, or cream base to contain it to the treatment area.^[3] The British Pharmacopoeia lists an ointment containing one part of chrysarobin and 24 parts of benzoated lard. The drug is a weak antiparasitic.

Adverse effects

Araroba powder stains skin, hair, and clothing a deep yellow or brown, a coloration which may be removed by caustic alkali in weak solution. Both internally and externally the drug is a powerful irritant. Reported adverse effects include inflammation of the eyes, gastrointestinal tract, and kidneys. Contact allergy has also been reported.^{[4] [5]}

Pharmacology

Mechanism of Action

The mechanism of action of araroba powder is not yet confirmed, but is believed to effect cell turnover. Anti-inflammatory properties are also present by neutrophil and monocyte function inhibition.^[6]

References

1. Web site: Kress . Henriette . Araroba.—Goa Powder. Henriette's Herbal Homepage . www.henriettes-herb.com . 24 May 2022 . en.
2. Coondoo . Arijit . Sengupta . Sujata . Serendipity and its role in dermatology. . Indian Journal of Dermatology . March 2015 . 60 . 2 . 130–5 . 10.4103/0019-5154.152504 . 25814699 . 2249-5673. Medknow Publications and Media Pvt. Ltd. . 4372903 . Dithranol has been derived from Goa powder extracted from the araroba tree which grew in the Bahia province in Brazil. It was imported from Brazil to India where it was used for centuries to treat ringworm. In 1876, a patient of Balmano Squire who had mistaken his psoriasis to be ringworm told him that he had used the powder to treat his "ringed" psoriasis and had got good results. Later, the active ingredient in the powder was identified as chrysarobin from which the first synthetic preparation, anthralin was derived. Anthralin was found to be an effective treatment for psoriasis by Galewsky in 1916. . free .
3. Busse . Kristine L . Alikhan . Ali . Feldman . Steven R . Optimizing topical therapy for psoriasis . Expert Review of Dermatology . 1 August 2009 . 4 . 4 . 385–402 . 10.1177/247553031117a00101. 24 May 2022 . Expert Reviews Ltd. . 79654867 . 1746-9880 . Anthralin is available in multiple formulations, including cream, ointment or paste..
4. Steele . Tace . Rogers . Cindy J. . Jacob . Sharon E. . Herbal remedies for psoriasis: what are our patients taking? . Dermatology Nursing . October 2007 . 19 . 5 . 448–50 . 18286859 . 1060-3441 . 23 May 2022 . Jannetti Publications, Inc. . en.
5. Wilkinson . Justin T. . Fraunfelder . Frederick W. . Peters . Dene . Use of herbal medicines and nutritional supplements in ocular disorders: an evidence-based review. . Drugs . 24 December 2011 . 71 . 18 . 2421–34 . 10.2165/11596840-000000000-00000 . 22141385 . 24 May 2022 . Wolters Kluwer Health, Inc. . 12028116 . en . 1179-1950.
6. Chen . Nancy . Cunningham . Bari B. . Psoriasis: Finding the right approach for your patients . Contemporary Pediatrics . August 2001 . 18 . 8 . 86 . 24 May 2022 . Intellisphere, LLC . en . 8750-0507 . Anthralin is a synthetic compound derived from chrysarophanic acid, which is an extract of the Vouacopoua araroba tree. Its mechanism of action has not been worked out, but it is thought to decrease cell turnover. It also exerts strong anti-inflammatory effects by inhibiting neutrophil and monocyte functions. A main advantage of this therapy is its lack of long-term side effects, which allows reintroduction of the medication as often as needed. Anthralin can, however, discolor hair, clothing, and surrounding skin and often causes irritant dermatitis when applied at a concentration that exceeds instructions. For plaque psoriasis, a low concentration of 0.05% to 1% anthralin incorporated into petrolatum or zinc paste can be applied once daily for 30 minutes. The application time can be slowly increased as tolerated..