Medicinal Ecology: Hosts, Parasites, and Antiparasitic as Interacting Ecological Agents

Abstract: Modern strategies for drug discovery against parasitic diseases are increasingly reliant on a reductionist mindset, focusing more on identifying a single protein target and associated susceptibility within a single parasite. Although this method was effective at discovering some successful antiparasitic compounds, it often neglects the context of the complex host-parasite ecological system. Shaped by coevolution among hosts, parasites, xenobiotics, and host-resident microbiota, these systems closely interact across interconnected chemical and biological gradients. Here, I propose medicinal ecology as a conceptual framework that views antiparasitic drugs as chemical interventions that shaped by and modify host–parasite–microbiota interactions within biologically constrained niches. In medicinal ecology, potential antiparasitic agents may be identified by exploring defense strategies evolved in similar host–parasite or relevant prey-predator ecological systems. Using parasitic helminths as an example, I contend that effective drug discovery and design, therapeutic success, and failure may be better understood within the ecological context of parasitism, including host physiological, behavioral, and physicochemical limitations, interactions among the host-associated biota, and parasite adaptation under exposure. Medicinal ecology addresses the limitations of current antiparasitic discovery programs, especially their low productivity in deploying new agents combined with reduced deployment times due to the evolution of drug resistance, which reductionist models do not fully account for early in the discovery pipeline. By targeting multifactorial and conserved ecological vulnerabilities in a specific host niche rather than isolated molecular events, medicinal ecology offers testable predictions for improved antiparasitic discovery programs, ecologically guided combination therapy, and better resistance management.