Polygonum hydropiperoides and P. spectabile are, commonly known as "erva-de-bicho", and traditionally used as anti-inflammatory, antihaemorrhoidal and anti-diarrhea. The pharmacognostic analysis indicated the content of loss on drying, of total ash and acid-insoluble ash ranged from 4.0 to 6.5%, 5.0 to 10.0% and 0.1 to 0.4%, respectively. The TLC analysis revealed the presence of triterpenes and/or steroids, coumarins, flavonoids, polyphenols, tannins and saponins in the four samples. The content of total polyphenols, tannins and flavonoids were 7.0%, 5.5% and 0.4%, respectively for P. spectabile. They were different from the three samples of P. hydropiperoides. The values observed were around 5.0%, 4.0% and 0.6% for two of them and 12.5%, 11.3% and 0,3% for the other one. These species are morphologically very similar and they are used indiscriminately for the production of herbal medicines. This study showed variations on the contents of polyphenols and tannins in samples of P. hydropiperoides collected in autumn and spring. These results represent the first parameters obtained for the quality control of P. hydropiperoides and P. spectabile.
Polygonum hydropiperoides; P. spectabile; quality control