Assuming that the plant is found to have evidenced based use in treatments for Chagas and a pharmaceutical company or other entity moves to harvest the plant, as Ashleigh pointed out, it would likely impact the environment by creating jobs. While this is great for the economical environment, what about the physical biological environment? One negative effect could be the endangerment and/or extinction of the plant through mass harvesting. Additionally, what effect might this have on other plants/animals that share the environment with N. lobata? There could be biological (symbiotic) relationships that may be threatened and/or destroyed which could have rippling effects. Either way, the biodiversity would likely decrease for the country. That point here is that caution needs to be taken as there are several unknowns about the plants role in its environment.
As for who would most likely be harvesting the plant; it depends. If there is evidence/research based proof that the plant can be used as an effective treatment for Chagas, then I would imagine a pharmaceutical or other medical related company would be backing the harvesting in attempts to patent some form of drug. If, however, there is not enough evidence for it to be profitable to harvest the plant, I imagine it would stay with locals as the main harvesters (which I suspect would have less quick/drastic effects on the environment).