Papaya

Uses

The decoction of the leaves is used locally in sores and atonic ulcers, followed by a poultice of the boiled and mashed leaves. The natives use the cold infusion of the leaves to wash clothes spotted with blood and the spots disappear rapidly by virtue of the ferment papain which digests the fibrin. The infusion is also very useful as a wash for sores and gangrenous ulcers, modifying their appearance very rapidly.

Before proceeding further it is desirable to give a description of papain, a digestive ferment which exists throughout the whole plant, fruit, trunk, leaves and petioles; it is contained in the milky juice which exudes from all these parts when cut. This juice was studied simultaneously by Wurtz in France and Peckolt in Brazil. The best method of collecting it is to make several superficial, longitudinal incisions in the green fruit without removing it from the tree; immediately an abundance of juice appears in the incisions and coagulates rapidly. The best time to do this is the early morning. The fruit does not suffer by this process but continues developing and ripens perhaps more rapidly, at the same time improving in flavor, becoming sweeter; the seeds, however, atrophy and lose their power of germination. Peckolt gives the following as the composition of the juice:

[table omitted; see the source text]

The milky juice is neutral and coagulates rapidly, separating in two parts: a kind of insoluble pulp and a limpid colorless serum. If combined with fibrin, raw meat, white of egg or gluten it gradually softens them and completely dissolves them in 3 or 4 hours in vitro at 40° C. Combined with milk it coagulates it and soon precipitates the casein which is also dissolved a little later. It digests lumbricoids and tape-worms and the false membrane of croup, in a few hours. According to Wurtz and Bouchut papain is prepared as follows:

The fluid juice or the aqueous solution of the milky exudate is precipitated by the addition of ten times the volume of alcohol. The precipitate, after treating again with concentrated alcohol, is dissolved in water and the addition of sub-acetate of lead eliminates the albuminoids and peptones but does not precipitate the papain. The liquid is filtered and the lead salts separated by means of a current of hydrogen sulphide. It is filtered again and alcohol added gradually, which process first precipitates whatever sulphate of lead may have passed through the filter, and then the papain.

Papain is an amorphous substance, perfectly white, soluble in water, insipid, odorless. An aqueous solution, if shaken violently, foams like a solution of soap. Boiling makes it turbid and when concentrated it has a slightly astringent taste. It is precipitated by hydrochloric, nitric, picric and the metaphosphoric acids. Trommer’s test gives it a beautiful blue violet color which, on boiling, changes to a red violet.

It is an extremely active digestive ferment, comparable with pepsin, but superior to the latter because it does not require an acid medium, as its digestive action takes place even in the presence of an alkaline medium and of antiseptic substances such as boric acid, phenol, etc. It is given in doses of 10–40 centigrams in different vehicles such as water, wine, etc. It should be given after meals carefully and properly diluted, in order that its action may not be exerted upon the gastric mucous membrane itself. Its use is contraindicated in gastric ulcer.

A watery solution prepared by macerating the green fruit has been used effectively to remove blemishes from the face, leaving the skin clean and smooth. The natives use little pieces of the green fruit to remove freckles (which they call pecas). The ripe fruit is edible and its taste quite agreeable; in some of the Malay Islands it is given for dysentery, but it must be remembered that the ripe fruit does not contain papain.

The pure exudate is given to children as an anthelmintic in doses of 2–6 grams with a little molasses, but it is not so harmless that it may be used with impunity in this form, Moncorvo and others having reported cases of peritonitis with symptoms suggestive of cholera following its use. It is drastic and digestive in addition to its anthelmintic action, but according to Rabuteau, boiling destroys the first property without affecting the others. Dr. Lemarchand of the island of Mauritius gives the following anthelmintic prescription:

[table omitted; see the source text]

Add gradually while shaking the mixture.

[table omitted; see the source text]

Cool and administer in one dose followed immediately by 30 grams of castor oil. For a child, one-half dose.

This treatment frequently causes colic, for the relief of which the author advises an injection of sweetened water. Sir O’Shaughnessy’s prescription is preferable:

[table omitted; see the source text]

This dose cannot cause any untoward symptoms and is efficient in expelling both lumbricoids and tæniæ.

The triturated seeds may be given internally in doses of 1–2 grams with milk or molasses to expel lumbricoids. Analysis has revealed in the seeds the presence of a resinous oil, an oleaginous material of disagreeable odor and taste called by Peckolt caricin, a fatty acid, papayic acid and a resin. In India the seeds are considered emmenagogue. In some countries they wrap meat in papaya leaves for several hours before eating in order to soften it. For the same purpose they sometimes boil the meat in water containing a few leaves or pieces of the green fruit; some even go to the length of saying that it is only necessary to hang a piece of meat in a papaya tree for a time in order to soften it.

The decoction of the green fruit is given internally for indigestion, a treatment common in the provinces of Bulacan and Pampanga. The milky juice is used to remove corns and Dr. Daruty offers the following prescription for eczema and psoriasis:

[table omitted; see the source text]

Mix.

Paint the affected part with feather or brush, 2–3 times a day. The same solution may be used for softening corns.

Botanical description

Trees 15° in height, trunk covered with large leaf scars, wood soft and brittle, the long-petioled, palmately-lobed leaves growing in a crown and giving the tree the general appearance of a palm. Flowers diœcious. Staminate tree: Flowers loosely clustered on long, hanging stems. Calyx, 5–6 teeth. Corolla tubular, 1′ long, limb divided into 5 oval parts. Stamens 10, inserted in the throat. Style short, awl-shaped. Pistillate tree: Flowers much larger, sessile, in axils of leaves. Calyx 5-toothed. Corolla large, 5 lanceolate petals curved outward, fleshy. Stigmas 5, fringed. Fruit about size of child’s head or smaller, somewhat pear-shaped, juicy, pulp melon-like, 1 compartment with numerous seeds, each in a mucilaginous aril.