Biomass, resin and essential oil content and their variability in natural populations of the Chilean crude drug "bailahuen" (Haplopappus spp.)

Abstract

Bailahuen (Haplopappus rigidus, Haplopappus baylahuen, Haplopappus multifolius and Haplopappus taeda; Asteraceae) are medicinal shrubs native to the Andes Mountains of Chile widely used to treat hepatic ailments. At present, exploitation of bailahuen is based on wild collections, affecting the abundance of natural populations. Variability of biomass production and concentration of active compounds in different wild populations of the four Haplopappus species was studied in order to select the best plant material for cultivation. Resins were extracted with dichloromethane and essential oils by distillation. Biomass production of the populations was highest for H. baylahuen and H. rigidus compared with the other species, reaching between 0.56 and 1.61 kg and 1.11-1.48 kg per plant, respectively. No differences were found among populations of the same species. In some H. rigidus populations, the resin content was about a third of the dry weight, whereas plants of H. multifolius had mean values of about 8%. In H. baylahuen (11.3-27.7%) the resin content of leaves differed significantly among populations, whereas the essential oil ranged from 0.02-0.38 mL* 100g DM-1 in H. baylahuen, 0.03-0.5 mL* 100 g DM-1 for H. rigidus, and 0.08-0.35 mL* 100 g DM-1 for H. taeda. Resin content in stems differed only among H. baylahuen (6.3-15.5%) and H. rigidus (10.7-21.2%) populations. No significant differences in essential oil content among species could be detected because of the large amount of variation observed among populations. The variation between plants of the same population may indicate favorable selection potential for future breeding programs.