Nicotiana species: Tobacco

Family

Cucurbitaceae

Common Name

Balsam pear, balsam apple, bitter gourd, bitter cucumber, balsamina. Two species are naturalized in North America; M. balsamina and M. charantia.

Plant Description

Comprising a genus of 35 - 40 species native to the tropical areas of Africa, Momordica species have become naturalized in tropical areas of North America.

The plants are vines, with slender, hairy, grooved, stems that may grow to 10 m in length. The leaves are simple, triangular, ovate or cordate, with 3 - 7 palmate lobes. Flowers are single, showy, yellow to orange in color, with 5 sepals and 5 petals. Fruits are up to 6 cm in length, pendulous, and covered with pointed, wart-like projections, turning yellow when ripe and splitting open to reveal numerous seeds with bright orange-red fleshy arils (Fig. 273).

Figure 273. Momordica charantia.

Toxic Principle and Mechanism of Action

Tetracyclic cucurbitane terpenoids (momordicin I,II), and at least 2 lectins are the toxins most responsible for the toxicity of the plant [1,2]. All parts of the plant are toxic with the exception of the fleshy ripe arils covering the seeds [3]. The compounds act as gastrointestinal irritants and in high doses may cause depression, muscle tremors, and seizures. Similar cucurbitane compounds are found in bryony (Bryonia spp.) and buffalo gourd (Cucurbita foetidissima), species of which are native to North America. Mormordica species have found wide use in herbal remedies and may have benefit in treating certain cancers [4].

Risk Assessment

Since fruits and seeds are attractive to some birds, the plant seeds are quite easily spread. The brightly colored fruits and seeds are also attractive to children and to pets especially where the vines are grown in gardens and along fences. Momordica poisoning is not frequently reported in dogs except in Florida where several instances of poisoning have occurred [3].

Clinical Signs

Vomiting, salivation, abdominal pain, and diarrhea are the most likely signs associated with Mormordica. Dogs that eat the ripe fruits reportedly develop convulsions and vomiting [3].

Severely affected animals may require sedation and intravenous fluid therapy to counteract dehydration and shock following severe diarrhea and vomiting.