Source, Etc

The fruits commonly known as Cocculus indicus are produced by Anamirta paniculata, Colebrooke (N.O. Menispermaceoe), a tall, woody, climbing shrub indigenous to Eastern India and the Malay Archipelago. They derive the name of Levant berries, by which they are sometimes known, from the fact of their having been formerly brought from India by way of Alexandria and the ports of the Levant.

The plant produces a pendulous panicle of flowers; the ovaries of the pistillate flowers are apocarpus, each carpel being gibbous and developing into a drupaceous fruit containing a single seed. The fruits are collected when ripe, and dried; they are exported chiefly from Bombay and Madras.

Description

Cocculus indicus of commerce consists of small dark brown or nearly black fruits, about 12 mm. in length. They are more or less distinctly reniform in shape, one side being flattened or even slightly concave, whilst the other is boldly arched. On the former the small scar left by the stalk can usually be distinguished, and near it is a minute prominence, the apex of the fruit. The gibbous dorsal surface of the carpel from which the fruit is formed develops much more rapidly than the ventral, and the apex of the fruit thus remains near to the base, the dorsal surface becoming conspicuously arched. The pericarp is rough and finely wrinkled, and although thin is hard and woody. It encloses a single, oily seed - so deeply hollowed out as to be cup-shaped. This cup-shaped hollow is completely filled by two parallel, lenticular ingrowths of the endocarp and mesocarp, which can easily be seen by cutting a fruit longitudinally through the median line of the carpel and removing the two halves of the seed, or less clearly by cutting the fruit transversely. The seed exhibits a crescent-shaped section when cut either longitudinally or transversely. Cocculus indicus has no odour; the pericarp is tasteless, but the seed is very bitter.

Fig. 49.   Cocculus indicus. A, vertical; B, transverse section; p, pericarp; n, base of fruit; E, seed; /, fold of pericarp. Magnified. (Moeller.)

Fig. 49. - Cocculus indicus. A, vertical; B, transverse section; p, pericarp; n, base of fruit; E, seed; /, fold of pericarp. Magnified. (Moeller).

The student should observe

(a) The sub-reniform shape of the fruit, and should cut it longitudinally and transversely, noting

(b) The shape of the seed,

(c) The characteristic ingrowths from the pericarp.

He should further notice that the seed is bitter, but the pericarp is almost tasteless. .

Constituents

The seed contains from 1 to 1.5 per cent, of an intensely bitter, crystalline principle, picrotoxin, accompanied by a crystalline but tasteless body, cocculin, and a large proportion of fat. Picrotoxin, C45H50O19 (m.p. 199°), contains no nitrogen and is therefore not alkaloidal, nor does it possess glucosidal properties. It is readily separable into toxic picrotoxinin, C15H1606, and non-toxic picrotin, C15H1807, but its further constitution is as yet unknown.

From the pericarp, which is tasteless, two alkaloids, menispermine and paramenispermine (Pelletier and Couerbe, 1833) have been isolated but they require re-investigation.

Uses

Cocculus indicus is now used almost exclusively for the preparation of picrotoxin, which is a powerful convulsive poison; it has been given internally to check the night-sweating of phthisis; and has also been employed to destroy pediculi. The power possessed by the fruits, when thrown into water, of stupefying fish has long been known, and is due to the picrotoxin contained in the seed. So susceptible are fish to the influence of picrotoxin, that they have been used as a means of detecting its presence. A number of other plants, however, share this property with Cocculus indicus.