One significant challenge in psychedelic research is finding all the chemicals of interest (such as alkaloids) in organisms like toads, frogs, kratom, magic mushrooms, etc. This task is complicated by the knowledge that an individual may not be representative of the entire species.
Scientists know that several factors influence the cocktail of compounds in toad secretions (aka venoms), for example. The age and size of a toad can influence the composition of its secretions.1 Also, the habitat a toad lives in exposes them to different predators and microorganisms that impact the chemical content of their secretions.1–3
A 2020 study published in Toxicon adds to the knowledge base about the influence of habitat on toad secretions. In the study, de Souza et al. analyzed the parotid gland secretions of Smooth-sided toads, Rhaebo guttatus, that live in two distinct regions of the Brazilian Amazon.4 Specifically, they compared their habitats and the levels of alkaloids and steroids in their secretions.
The collected toads (14 total) were rinsed with running water and milked by compressing their parotid glands. The secretions were dried in the dark in a desiccator for two days. Methanol extracts were made from the dried secretions and analyzed using liquid chromatography on UV and MS Detected Ultra-Chromatography Systems (UFLC-DAD-micrOTOF). The toads were not injured during the milking process and were released back into the wild.
The chromatogram peaks showed nine compounds in the extracts that were present at >/= 1.0%. The authors identified six of them based on previous studies in the literature. Unfortunately, the most abundant compound was one of those not identified. The six identified were:
- Ethenzamide (alkaloid)
- N’-methyl-5-hydroxytryptamine (N-methylserotonin) (alkaloid)
- Bufotenin (alkaloid)
- Dehydrobufotenine (alkaloid)
- 3β,16β-dihydroxybufa-8(14),20,22-trienolide (steroid)
- Bufatrienolide (steroid)
The chromatograms peaks clustered into two areas corresponding to the hydrophobic and hydrophilic compounds. The authors noted that this behavior is in agreement with the chemistry of the molecules and previous work in the literature. Further, they noted that their results indicated that the extracted alkaloids were in the hydrophilic group and the steroid compounds in the hydrophobic group. This is also in agreement with previous studies.
Interestingly, all the toad secretion samples from both regions contained the steroid compounds. However, the samples from the toads from the Amazon-Cerrado transition region contained none of the alkaloid compounds, while the toad samples from the southern Brazilian Amazon did. The authors said that these results agree with previous studies showing that diet, among other things, can influence the composition of amphibian poisons.5
So, overall for this study, the environment and diet may play a role in the composition of the parotid gland secretions of Rhaebo guttatus.
The researchers noted there was another difference between the two regional groups of toads that may have influenced the results. They explained, “[W]hile the collection site in the south of the Brazilian Amazon is an area of fully recovered vegetation and with very little human intervention, the collection site of the Amazon-Cerrado region has suffered several anthropic actions.”
So, human intervention further altered the habitat of the Amazon-Cerrado toads. One could hypothesize that this disturbance could not only affect the habitat, and thus the available food, but it may also put stress on the toads. This stress could conceivably cause them to produce different combinations and amounts of compounds in their secretions by way of currently unknown adaptative mechanisms.
Protecting Toads While Advancing Psychedelic Science
The cocktail of compounds nature presents can be complicated and subject to the effects of many variables. To get a complete inventory of the compounds in the secretions of a toad species, for example, psychedelic researchers must have an understanding of the variables and be able to control them. But this should be done under the overarching objective of taking care to protect the toads. This study shows that toads can be handled with care while milking, so they suffer no adverse effects and can be returned to their natural habitat. However, it is unclear if this is a sustainable method for harvesting toad secretions.
Ideally, toads will be milked only to help scientists understand the composition of their secretions. When that is understood, further research can develop synthetic methods for making each compound. This is a strategy that was suggested by the psychedelic thought leader and researcher Hamilton Morris at the World Bufo alvarius Congress in 2019. Creating formulations using selected compounds produced in the lab will give the desired outcomes without the unwanted side effects. In this manner, the wild toads are disturbed as little as possible