Challenging the safety and efficiency of homeopathy: Ignatia amara as an example, ants as models

Homeopathic treatments are considered by the vast majority of the scientific community as non-effective, apart from a well-documented placebo effect. Nevertheless, some experimental results raise questions about their efficiency, and numerous practitioners still consider homeopathy as an efficient alternative treatment instead of usual pharmaceutical drugs. Homeopathy is thus nowadays debated among the general public, practitioners and medical schools, and is still used by many patients in search for “natural” treatments. It is therefore relevant to bring information to feed this debate and to investigate the efficiency and safety of homeopathic drugs. We examined on ants, used as biological models, the effects of a homeopathic drug, Ignatia amara, advocated to ease symptoms of stress. We tested the effects of thus drug on ant’s ethological and physiological traits (1) under normal condition, then (2) under a stressing situation. We found that (1) this drug was not without adverse effects but slightly impacted some ants’ traits; (2) this drug could reduce the adverse effects caused by the stressing situation. It nearly fully restored the ants’ locomotion, orientation ability, audacity, tactile perception, brood caring, social relationship, escaping behavior, cognition, and slightly the memory. No adaptation and no habituation to the effects of Ignatia amara occurred, and no dependence on its consumption developed. The causes and mechanisms of these effects remain unknown to us, but our results support the hypothesis that, in some given cases, for some specific health problems, and using adequate product(s) and dose(s), a homeopathic treatment based on Ignata amara extracts could help patients to recover from stress symptoms.