Hanging from the canopy of trees in Soberania National Park, Panama, the coat of the world’s slowest mammal may become the medical community’s newest “bioprospect.” Fungi isolated from the hair of the Bradypus variegatus Three-toed sloths have been found to have anti-parasitic, anti-cancer, and anti-bacterial activity by a study published this past January in PloS one Journal.
Amid the matted-grime of the three-toed sloth lies a richly biodiverse environment. While the inner layer of the two-tiered coat consists of fine, soft hair, the outer layer is made up of courser, cracked hair. These fractured hairs serve as the home for an entire ecosystem; camouflaging green alga grows on this coat among a host of other micro- and macro-organisms.
Researchers have identified 84 fungal species from samples collected from nine sloths, including three new ones. All samples were of the phylum ascomycota, the same phylum of the mold that produces the antibiotic penicillin and the fungus that secretes the immunosuppressor Ciclosporin—an important drug in organ transplantation as well as rheumatoid arthritis and psoriasis.
The fungi were cultured on agar plates and tested for their bioactivity in vitro by the team of researchers from the Smithsonian Tropical Research Institute, UC Santa Cruz, and the University of Arizona.
The relationship between the fungi and sloths has yet to be explored, but the potential benefits to humans are promising. Using a BioMAP (antibiotic mode of action profile) antibiotic profile screen, out of 50 or so fungal extracts, 20 were active against at least one of 15 human bacterial strains. Furthermore, 15 fungi also showed bioactivity against the MCF-7 breast cancer cell line. The anti-parasitic applications include parasites Plasmodium falciparum that causes malaria and the parasite responsible for Chagas disease, Trypanosoma cruzi. New therapeutic solutions are needed to counter T. cruzi, since the side effects of current agents, nitrofurane and benznidazole, are fairly strong.
Also of significance is the action of the Lasiodplodia fungal species, which showed “potent and specific activity against Gram-negative bacteria.” Gram-negative bacteria contribute to the growing problem of drug resistance that is largely attributed to the overuse and misuse of antibiotics.
Although the results of the study are preliminary and may not amount to any substantive results during in vivo animal studies or in humans, it sheds a glimmer of hope for an untapped resource for tackling some of today’s most demanding clinical challenges.
“The pressing need for new medications continues to represent one of humanity’s greatest challenges,” the study reads.
“The high abundance and diversity of fungi associated with sloth hair, coupled with their bioactivity, may speak to a biological importance to sloths that is yet unexplored.”
With five other extant species across the neotropics, who knows what other medical applications might exist from this adorable beacon of laziness, as well as the vast diversity of Panama that is currently threatened by deforestation.
Ensuring the viability of ecosystems is a worthy goal, not only for the sake of the environment in itself, but for their broader social benefits, as Executive Director of the UN Environment Program Achim Steiner has expressed.
“We must help society understand how much we already depend on diversity of life to run our economies, our lives; but more importantly, what we are losing in terms of future potential,” he said in an interview with the CBC.
