PAREIRA BRAVA 



301 



root, when cut with a knife, exhibits a glossy, waxy, rather than 

 woody surface. The transverse section shows four or five crenate, 

 concentric or more or less eccentric zones, separated from each other 

 by lighter lines of parenchymatous tissue. Each zone consists of a 

 varying number of wedge-shaped wood- 

 bundles with large pores alternating with 

 wide medullary rays. A similar abnormal 

 structure is found in many Menispermaceous 

 stems and roots. The innermost zone is 

 usually from 6 to 12 mm. in diameter. 



The drug has no odour, but a decidedly 

 bitter taste. 



The student should observe 



(a) The nearly black outer surface, 



(b) The crenate outline of the zones, 



(c) The waxy cut, 



(d) The bitter taste. 



Constituents. Pareira brava contains 

 about 2-5 per cent, of beberine (compare 

 bebeeru bark, p. 273), to which its bitter 

 taste is due ; to this 

 alkaloid the name pelo- 

 sine (derived from Cis- 

 sampelos) was given until 

 its identity with bebe- 

 rine was proved. An 

 unusually large quantity 

 (about 9 per cent), of 

 fatty acids, chiefly stea- 

 ric, is said to be present, 

 but this statement re- 

 quires confirmation. 

 Other constituents are 

 an amorphous alkaloid 

 (chondrodine), tannin 

 and starch. The genuine 



drug yields about 12 per cent, of (cold) aqueous extract and about 

 4 per cent, of ash. Spurious Pareira brava often yields much less 

 aqueous extract (see below). According to Fattis, in addition to 

 beberine, which is soluble in benzene, two other alkaloids insoluble in 

 benzene, one crystalline, the other amorphous, are present. 



Uses. Pareira brava is used in inflammatory affections of the 

 urinary tract ; it is considered to relieve pain and promote healing 

 and cessation of muco-purulent discharge. It is not much used now, 

 owing possibly to the substitution of other roots for the genuine drug. 



FIG. 151. True Pareira Brava. Portion of a root, 

 and transverse sections. (Bentley, after Hanbury.) 



