Source, Etc

The name jaborandi is applied in South America, especially in Brazil, to a number of plants (belonging chiefly to the natural orders Rutaceœ and Piperaceœ) possessing salivant and sudorific properties. The leaflets of several species of Pilocarpus (N.O. Rutaceae) have been imported as jaborandi but the variety at present almost exclusively in commerce is obtained from P. microphyllus, Stapf.

The plant produces imparipinnate compound leaves, mostly with three pairs of leaflets which are collected, dried, and exported in large quantities to Liverpool, chiefly from Maranham; hence this variety is often distinguished as Maranham jaborandi.

Description

The leaflets are 2.5 to 4 cm. long, greyish green, coriaceous, glabrous, obovate, deeply emarginate at the apex and more or less asymmetrical with the exception of the terminal leaflet which is symmetrical. By transmitted light oil-glands are visible under a lens. Odour characteristic but not powerful; taste aromatic and pungent, a copious flow of saliva being produced. The rachis, if present, is slightly winged. The student should carefully observe

(a) The presence of oil-glands,

(b) The emarginate apex,

(c) The asymmetry of the leaflet.

Constituents

Jaborandi leaves contain volatile oil (about 0.5 per cent.) resin and the alkaloids pilocarpine, isopilocarpine and pilosine (carpiline). Of these alkaloids pilocarpine, C11H16N202, is the most important and the one upon which the therapeutical value of the leaves almost entirely depends. The proportion present is usually about 0 5 per cent.

Pilocarpine is crystalline (m. pt. 34°) and dextrorotatory; 001 gm. produces powerful sweating and salivation. Heating with alcoholic potash converts it into the racemic form, isopilocarpine, which has about one-tenth of the activity.

Pilosine occurs in very small proportion only.

Fig. 19.   Leaflet of Pilocarpus microphyllus. (Holmes.)

Fig. 19. - Leaflet of Pilocarpus microphyllus. (Holmes).

Pilocarpidine occurs in the leaves of P. Jaborandi, Holmes (see below); jaborine is non-existent. The therapeutical action of pilocarpine is not modified by the addition of isopilocarpine, pilosine, pilocarpidine or the resin; hence pilocarpine can well replace the drug for medicinal use (Jowett).

Assay

The total quantity of alkaloid in jaborandi may be determined by the following process: Moisten 10 gm. of the leaves in fine powder with 2 c.c. of solution of ammonia and 3 c.c. of chloroform, pack in a small percolator and percolate to exhaustion with ammoniacal chloroform. Shake out with diluted sulphuric acid, make alkaline, and shake out again with chloroform. Evaporate the chloroformic solution to dryness, dissolve the residue in 7 c.c. N/10 sulphuric acid and titrate back with N/50 solution of potassium hydroxide, using cochineal as indicator. Each c.c. of the acid indicates 0.02 gm. of alkaloid.

Uses

Jaborandi stimulates the nerve endings to the salivary, sweat, gastric, and other secreting glands, and induces therefore profuse salivation and perspiration. It is chiefly given as a powerful and rapid diaphoretic, and appears to be of most service in renal disease, eliminating both water and urea. Pilocarpine is used in ophthalmic surgery to contract the pupil of the eye; it is antagonistic to atropine.

Substitutes And Varieties

Swartzia sp. (N.O. Leguminosae); brownish green, glossy, midrib minutely hairy; very short, hairy petiolule, veinlets pellucid; about 3 cm. long but some only 0.5 long; substituted for P. microphyllus.

P. Jaborandi, Holmes; dull brownish green, 6-10 cm. long, oblong-lanceolate, margin revolute, apex emarginate, unequal at the base, upper surface glabrous with prominent lateral veinlets, under surface sometimes slightly hairy. Formerly official but now seldom imported; contain pilocarpine (about 0.5 per cent.), isopilocarpine and pilocarpidine.

P. pennatifolius, Lemaire; Paraguay Jaborandi; greyish green, pale and less coriaceous than P. Jaborandi; veinlets not prominent on the upper surface; usually equal at the base. Contain about 0.25 per cent. of alkaloid.

P. selloanus, Engler; imported from Rio Janeiro, closely resemble the above, but are more obovate.

P. trachylophus, Holmes; smaller than those of either P. Jaborandi or P. pennatifolius; dark olive green on the upper, yellowish green on the under surface, which is clothed with short curved hairs, similar ones being found scattered on the upper surface; contain about 0.4 per cent. of total alkaloid (Paul and Cownley, 1896), of which only 0.02 per cent. is possibly pilocarpine.

P. spicatus (?); Aracati Jaborandi; resemble bay leaves in size and shape; upper surface polished, veins scarcely visible, outline lanceolate, and the petiole short and twisted.

P. racemosus, Vahl; Guadeloupe Jaborandi; ovate, attaining 17 cm. or more in length; contain from 0.6 to 1.0 per cent. of total alkaloid, about one half of which appears to be pilocarpine.

Piper Jaborandi, Velley; large, thin, grey, papery leaves tapering towards both base and apex; usually mixed with the stems, which are swollen at the nodes.