Agriculture Reference
In-Depth Information
The plant produces fruits that vary enormously in shape and size; most are oblong, globular, or
round, often five angled and narrowed to the stigma tip, although flask-shaped fruits narrow at the
base are not uncommon. The ripe fruit is yellow or bright orange in color. The pulp is thick and
yellow-orange in color. The seeds are small, dark green or brown, enclosed in a mucilaginous mass.
The whole plant yields copious white latex when cut.
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Habitat and Distribution —
This is cultivated and grows wide in most parts of the continent.
It is native of tropical Africa.
Ethnomedicinal Uses —
Pawpaw is used in traditional medicine for a variety of purposes.
The green fruit is applied on ringworm and is claimed to effect a cure if rubbed hard until the skin
bleeds. The ripe fruit is edible and rich in vitamin A and has some vitamin C. A weak decoction
of the leaves is taken for malaria, and the mixture with lemongrass and guava leaves is used in the
treatment of hypertension. The three plants are also used with leaves of neem,
Azadirachta indica,
in steam therapy for malaria,
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in which the patients are covered with a thick blanket and made to
bathe in and inhale the vapor from the cook pot.
The leaves and seeds are used for the treatment of amebiasis and as an anthelmintic. The fresh
fruits are carminative and administered for digestive conditions and used as a diuretic, stomachic,
and antiseptic. The sap of the plant contains a ferment, which has the property of coagulating milk
and of softening or digesting the fibrous tissues of flesh; hence, it is used to make meat tender, either
by adding a piece of unripe fruit to the water when cooking, by wrapping the meat in the leaves to
roast or bake, or as a preliminary treatment for some hours before cooking.
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The seeds are used as
an oxytocic and externally as an antifungal agent.
Constituents —
The principal constituents of papaya are the proteolytic enzymes found in the
latex, which abounds in all parts of the plant but is obtained mainly from the fruit, seeds, and leaf.
The two major enzymes in the mixture are papain and chymopapain, with less papain occurring
but with twice the proteolytic activity of chymopapain. Commercially available “purified papain”
usually consists of a mixture of the two enzymes and small amounts of other enzymes. An alkaloid
carpaine occurs in the seeds and leaf, with traces in the unripe fruit. The air-dried seeds yield 660
to 760 mg/100 g of the aglycone of glucotropaeolin, benzyl isothiocyanate (BITC). The fruit is rich
in vitamins B and C and traces of vitamin A and has a high content of potassium and other miner-
als. The leaves and the root yield the alkaloids carpaine, isocarpaine, and dihydrocarpaine I and
II.
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In the young leaves, the alkaloid content is about 0.28%.
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The seeds also contain fixed oils,
carbohydrates, glycosides, carpasemine, and benzene senevol.
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The bark contains a pentalcohol,
xylitol, and saponins.
Pharmacological Studies —
The proteolytic activity of the enzymes has been exploited as an
aid in digestive disorders and malabsorption syndrome. The crude enzyme preparation is used in
wounds and surgical incisions to promote healing and prevent sloughing in infected wounds.
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A
related enzyme, leucopaine, has been shown to aid the regenerative processes of the injured tissue of
rabbits and in treatment of purulent wounds in 303 patients under clinical conditions.
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The papaya
enzymes are used as a topical debriding agent, sometimes in conjunction with urea, in wound heal-
ing to facilitate wound cleaning from necrotic tissues, and to arrest local inflammation and purulent
exudation. They are also applied in eye and spinal disorders.
The fruit is edible and rich in vitamin A and has some vitamin C; it is used in a variety of
ways as a food and as a meat tenderizer. Chymopapain has been employed, with remarkable suc-
cess, as an intervertebral disk injection in the lumbar spine (chemonucleolysis). For this purpose,
it is recommended that the drug should be administered under local anesthesia rather than under
general anesthesia.
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The leaves have been shown to possess antiplasmodial activity against both
chloroquine-sensitive and chloroquine-resistant
P. falciparum
.
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Aqueous extract of
Carica papaya
(CP) leaves exhibited antitumor activity and immunomodu-
latory effects.
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In human peripheral blood mononuclear cells (PBMCs), the production of IL-2
and IL-4 was reduced following the addition of CP extract, whereas that of IL-12p40, IL-12p70,
