Bitter Melon Drug Information - Precautions to be kept in mind while using Bitter Melon

Taxonomic Class

Cucurbitaceae

Common Trade Names

None known.

Common Forms

Available in a decoction or tincture and as juice or a whole fruit.

Source

Bitter melon is derived from the tropical tree Momordica charantia, which is native to Asia, East Africa, South America, and parts of the Caribbean. Seeds, vines, and leaves are used medicinally, but the fruit of the tree is most commonly used and generally thought to be the safest.

Chemical Components

Bitter melon contains the proteins alpha- and beta-momorcharin, along with serine protease inhibitors BGIA (bitter gourd inhibitor against amino acid-specific proteins) and BGTI (bitter gourd trypsin inhibitor). Also present is the plant protein MAP30; charantin, which is a mixture of steroidal saponins; and insulin-like peptides and alkaloids.

Actions

Recombinant MAP30 has been shown to inhibit HIV-1 and to have antitumorigenic effects with no untoward effects on normal human cells. MAP30 also may enhance the activity of dexamethasone and indomethacin as weak HIV antagonists by causing inactivation of viral DNA and specific cleavage of 28 S ribosomal RNA .

A crude extract of bitter melon was reported to be both cytostatic and cytotoxic to human leukemic lymphocytes and yet had no harmful effect on normal human lymphocytes in vitro . These effects were observed within 2 hours, and the researchers theorize that the effect may result from quick entrance of the factor into the cells.

A later study in mice led to the conclusion that the antileukemic properties exhibited by bitter melon may be caused, at least in part, by the activation of natural killer cells in the host .

Reported Uses

Bitter melon has been used as a food substance and to treat cancer, diabetes, and some types of infections. Beer, soups, and teas have been made from both the leaves and the fruit. Wax produced by the berries has been used in candlemaking.

A 1981 study measured the effect of a fruit extract of bitter melon on nine patients with type 2 diabetes. The extract was given and followed by a glucose tolerance test, which revealed an improvement in glucose tolerance that was small but possibly clinically significant. No increase in serum insulin levels was noted in these patients.

Dosage

The typical dose is one small unripe melon, the equivalent of about

50 ml of juice in divided doses b.i.d. or t.i.d. Up to 100 ml of the decoction or 5 ml of the tincture may be consumed daily, also in divided doses. No dosing information for patients with renal or hepatic impairment is available.

Adverse Reactions

GI: diarrhea, stomach pain (overdose).

Interactions

Antidiabetics: May cause additive effects, resulting in excessive hypoglycemia. Monitor blood glucose levels and patient closely.

Contraindications And Precautions

Bitter melon is contraindicated in patients with hypoglycemia because it may exacerbate this condition, causing dangerously low blood glucose levels. It is also contraindicated in young children, who may be overly sensitive to the hypoglycemic effect. Avoid using bitter melon in women who are pregnant because alpha- and beta-momorcharin have abortifacient properties . Data regarding the use of bitter melon in women who are breast-feeding are lacking.

Special Considerations

No dosage form can effectively mask the extremely bitter taste of bitter melon and its preparations.

Monitor the patient for adverse GI reactions because they may be signs of overdose.

Monitor the patient’s blood glucose levels if he is taking bitter melon for its hypoglycemic effect.

Commentary

The best-substantiated use for bitter melon is as an antidiabetic agent. Without clinical data on effective dosing and predictability of response, bitter melon should be used with care and probably not with other antidiabetic drugs until more is known about its potency. Bitter melon may show some value as adjunctive therapy for HIV-infected or leukemic patients in the future, but additional studies are needed to fully evaluate its efficacy and clinical relevance. Use of bitter melon as an anti-infective remains unsubstantiated.