More Good Reasons Not to Lick a Toad

A New Review of Chemicals Produced by the Toad Family, Bufonidae

Cane toad (Rhinella marinus)

As human diseases become alarmingly antibiotic resistant, identification of new pharmaceuticals is critical. The cane toad and other members of the Bufonidae family produce substances widely used in traditional folk medicine, but endangered family members, like Panama’s golden frog, Atelopus zeteki, may disappear before revealing their secrets. Smithsonian scientists and colleagues catalog the known chemicals produced by this amphibian family in the Journal of Ethnopharmacology highlighting this largely-unexplored potential for discovery.

“We’re slowly learning to breed members of this amphibian family decimated by the chytrid fungal disease,” said Roberto Ibañez, Panamanian staff scientist at the Smithsonian Tropical Research Institute (STRI) and in-country director of the Panama Amphibian Conservation and Rescue (PARC) project. “That’s buying us time to understand what kind of chemicals they produce, but it’s likely that animals in their natural habitats produce an even wider range of compounds.”

15 of 47 frog and toad species used in traditional medicine belong to the family Bufonidae. For millennia, secretions from their skin and from glands near their ears called parotid glands, as well as from their bones and muscle tissues have been used as remedies for infections, bites, cancer, heart disorders, hemorrhages, allergies, inflammation, pain and even AIDS.

Toxins of two common Asian toad species, Bufo gargarizans and Duttaphrynus melanostictus, produce the anticancer remedies known as Chan Su and Senso in China and Japan, respectively. Another preparation used to treat cancer and hepatitis, Huachansu or Cinobufacini, is regulated by the Chinese State Food and Drug Administration. In Brazil, the inner organs of the toad, Rhinella schneideri, are applied to horses to treat the parasite Habronema muscae. In Spain, extract from the toad Bufo bufo is used to treat hoof rot in livestock. In China, North and South Korea, ranchers use the meat of Bufo gargarizans to treat rinderpest.

Only a small proportion of the more than 580 species in the Bufonidae family have been screened by scientists. “In Panama, not only do we have access to an amazing diversity of amphibian species,” said Marcelino Gutiérrez, investigator at the Center for Biodiversity and Drug Discovery at Panama’s state research institute, Instituto de Investigaciones Cientificas y Servicios de Alta Tecnologia (INDICASAT),  “we’re developing new mass spectrometry and nuclear magnetic resonance spectroscopy techniques to make it easier and cheaper to elucidate the chemical structures of the alkaloids, steroids, peptides and proteins produced by these animals. We work closely with herpetologists so as not to further threaten populations of these species in the wild.” Their efforts to catalog chemicals produced by the Bufonidae included researchers from the University of Panama, Vanderbilt University, in Tennessee, U.S.A. and Acharya Nagarjuna University in Guntur, India.

Most of the chemicals produced by frogs and toads protect them against predators. Atelopus varius contains tetrodototoxin. Chiriquitoxin is found in Atelopus limosus, one of the first species that researches succeeded in breeding in captivity as well as in Atelopus glyphus and Atelopus chiriquiensis. An atelopidtoxin (zetekitoxin) from the Panamanian golden frog, Atelopus zeteki, appears to consist of two toxins. Toxins from a single frog skin can kill 130-1000 mice.

The golden frog, A. zeteki, Panama’s national frog, is the only species of the genus Atelopus that secretes zetekitoxins. Threatened by the chytrid fungal disease that infects the skin and causes heart attacks, with collection for the exotic pet trade and by habitat destruction, if golden frogs were to disappear, they would take this potentially valuable chemical with them.

More than 30 percent of amphibians in the world are in decline. Racing to stay ahead of the wave of disease spreading across Central America, Panama is leading the way in conservation efforts. The Smithsonian’s Panama Amphibian Rescue and Conservation project (PARC) identified several Atelopus species in danger of extinction, and are learning how to create the conditions needed to breed them in captivity. Not only do animal caretakers at their facilities in Gamboa and El Valle, Panama experiment to discover what the frogs eat, they also recreate the proper environment the entire frog life-cycle: egg laying, egg hatching and tadpole survival, to successfully breed Atelopus. Each species has unique requirements, making it an expensive challenge to create this Noah’s ark for amphibians.

The chemical building blocks amphibians use to create toxic compounds come from sources including their diet, skin glands or symbiotic microorganisms. Toads in the genus Melanophryniscus sequester lipophilic alkaloids from their complex diet consisting of mites and ants. Researchers found that toxins found in a wild-caught species of Atelopus could not be isolated from frogs raised in captivity: another reason to conserve frog habitat and to begin to explore the possibility of releasing frogs bred in captivity back into the wild.

Learn more about amphibians by visiting the PARC blog and the Panama’s Fabulous Frogs exhibit at the Smithsonian’s Culebra Point Nature Center in Panama.

The Smithsonian Tropical Research Institute, headquartered in Panama City, Panama, is a part of the Smithsonian Institution. The Institute furthers the understanding of tropical nature and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems. Website. Promo video.

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Rodriguez, Candelario, Rollins-Smith, Louise, Ibanez, Roberto, Durant-Archibold, Armando, Gutiérrez, Marcelino. 2016. Toxins and pharmacologically active compounds from species of the family Bufonidae (Amphibia, Anura). Journal of Ethnopharmacology, doi:10.1016/j.jep.2016.12.021

Join us as together we Fight for Frogs

Brian swabs frogs in the field_Brian GratwickeFrogs matter. As a kid in nursery school, I remember observing tadpoles metamorphose into froglets right before our eyes in the classroom. It was like watching a magic trick over and over again. As I grew more interested in these cool little creatures, I learned that some frogs reproduce using pouches, others by swallowing their own eggs and regurgitating their young, others still by laying eggs that hatch directly into little froglets. It was like discovering not one magic trick, but an entire magical world—except this world was no illusion, it was real. My formative experiences both in the classroom and out rummaging around cold rainy ponds at night with my best friend and a headlamp spurred me into a career in the biological sciences. They also instilled in me a deep appreciation for the incredible diversity of life.

Panamanian golden frog_Brian GratwickeToday I am focused on conserving that incredible diversity specifically among amphibians in Panama, which is home to an astounding 214 amphibian species. Or at least it was. When a deadly amphibian chytrid fungus swept through, nine species disappeared entirely, including the country’s national animal, the beautiful Panamanian golden frog.

graphical abstractSince 2009, the Panama Amphibian Rescue and Conservation Project has spearheaded efforts to bring at-risk species into rescue pods to ride out the storm while we work on finding a cure. We’ve worked with partners to conduct several experiments in search of a cure and to better understand why some frogs resist infection and others do not. We have built new facilities that house highly endangered species of amphibians as part of a bigger global push to create an “Amphibian Ark.” These efforts and those of our colleagues around the world give me profound hope for our amphibian friends.

But we need your help.

Although frogs are the orchestral backdrop to every pond and forest, frogs have no voice to represent themselves, and they certainly can’t write checks. It’s up to professional conservationists, including the rescue project’s 12 talented conservationists in Panama, to save frogs so that others can enjoy them. This, however, requires money. From now until the end of August, our generous sponsor Golden Frog—a global online services provider with a terrific name—will match donations to the rescue project up to $20,000, helping us raise money critical to our fight for frogs. Your donations during the Fight for Frogs campaign will buy us equipment to care for the frogs in the rescue pods, help us continue to conduct experiments to find a cure, ensure crucial breakthroughs, and ultimately one day see the return of these incredible species to their home in the wild.

Together, let’s make a stand. Together, let’s #FightForFrogs.

The Panama Amphibian Rescue and Conservation Project is a project partnership between the Cheyenne Mountain Zoo, the Houston Zoo, Zoo New England and Smithsonian Institution. You can follow the Fight for Frogs campaign on Twitter using the #FightForFrogs hashtag or on the rescue project’s Facebook page.

Hanging around.

Ecuador Cochran frog (Nymphargus griffithi)

Ecuador cochran frog (Nymphargus griffithi)

Cute Frog of the Week: March 25, 2013

The Ecuador cochran frog is a brightly colored frog found most often on vegetation next to streams in montane forests. Although its name points to Ecuador, it appears to have disappeared from its original region and is now found most commonly in Columbia. The Cochran frog population is currently in a decline due to habitat loss from deforestation for agricultural development, logging and human settlement. The introduction of alien predatory fish to the area and pollution resulting from the spraying of illegal crops has also had a negative effect on the species. Due to these factors, the IUCN has listed them as vulnerable on the IUCN Red List.

Photo by Lucas M. Bustamante via Arkive.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Stealing your heart.

Turquino Robber Frog (Eleutherodactylus turquinensis )

Turquino robber frog (Eleutherodactylus turquinensis )

Cute Frog of the Week: March 4, 2013

The turquino robber frog is a small frog, but large for Eleutherodactylids. It is a semi-aquatic frog found in small mountain streams in cloud forest and fragmented areas at high altitudes. Endemic to Cuba, this frog is known only from the Sierra del Turquino (Sierra Maestra Mountains) in eastern Cuba. These little robbers can be found on stream banks clinging to wet rocks in the splash zone, prepared to dive underwater for a quick getaway if needed. Due to habitat loss and their limited area of occupancy, this species is classified as critically endangered by the IUCN.

Photo by Ariel Rodriguez via Arkive.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Hops and spots.

Marañón poison frog (Excidobates mysteriosus)

Marañón poison frog (Excidobates mysteriosus)

Cute Frog of the Week: February 25, 2013

This little polka-dotted guy is actually one of the most distinctive poisonous frogs. Adults are black or brown, sporting fashionable white “polka-dots” that cover their entire body. This spotting is highly variable from frog to frog, with the exception of a single spot under the chin and an oval spot on the underside of the thighs. The species is known from a single location in the vicinity of Santa Rosa, Cajamarca, Peru and often lives in giant bromeliad flowers. Unfortunately, because of land destruction for coffee farms in the area around Santa Rosa, this species is losing its habitat and becoming severely threatened in the wild. Humans have also begun to want these beautiful amphibians as terrarium pets. These threats have caused the IUCN to classify the spotted frog as endangered by the IUCN.

Photo by Jean-Francois Brousseau via ARKive.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Frog Love on Valentine’s Day

This Valentine’s Day we asked some of the rescue project’s researchers why they love frogs. Here’s what we got back from a few biologists at the Smithsonian’s National Zoo. The common link? A life-long love of wildlife.

Matt Evans, biologist, Smithsoinan's National Zoo

Matt Evans, biologist, Smithsonian

“My favorite childhood memories revolve around my mother taking me down to the nearest stream and letting me get dirty playing with frogs and salamanders. I loved it so much, I get to do that for a living now! The diversity within all amphibians still amazes me as there is so much we still have  to learn. I consider being able to work on projects, which may help save frogs from extinction, to be the absolute coolest part of my job.”

Ed Smith, biologist, Smithsonian's National Zoo

Ed Smith, biologist, Smithsonian

“Since childhood it was snakes, not frogs, that were the focus of hours spent searching woodlands, streams and ponds. Unlike other more noticeable  creatures, snakes are decidedly unapparent; unless they happen to be eating a frog! Although, the thrill of finding a snake by following the plaintive screams of a leopard frog never diminished, what increased was my interest in the gradually disappearing prey. So, thanks in part to the appetite of a few alluring garter snakes the equally marvelous world of frogs, toads, salamanders, sirens, and hellbenders opened to me and now inform and enhance days at work and in the field.”

Brian Gratwicke, rescue project international coordinator

Brian Gratwicke, rescue project international coordinator

“I fell in love with frogs growing up as a child in Zimbabwe. There was something exhilarating about discovering the translucent, musical jewels that are responsible for the familiar nocturnal soundtrack of my childhood. Unlike any computer games or TV shows, I will carry those first memories of catching frogs around a pond with me for the rest of my life. For me, seeing frogs in the wild stirs emotions of wonder and discovery, and they are accessible to everyone who is willing to take a little extra effort to open their eyes and look.”

–Brian Gratwicke, rescue project international coordinator

Nestled amongst the leaves.

La Loma robber frog (Pristimantis caryophyllaceus)

La Loma robber frog (Pristimantis caryophyllaceus)

Cute Frog of the Week: February 11, 2013

La Loma robber frog used to be found predominantly in the forests of Costa Rica, Panama and Colombia, yet recently this frog has been disappearing in increasing numbers. The deadly chytrid fungus, as well as habitat loss attributed to logging, farming and human encroachment, has had an impact on the wild populations of this species. The population effects have been the most drastic at lower altitudes, which is unusual, as most other species experience the heaviest declines at higher elevations. These small frogs prefer leaf litter and the low vegetation of primary moist and wet forests and rainforests. Leaves play an important role in the life cycle of these frogs, as females lay their eggs on leaves and brood them there. The la Loma robber frog is listed as a near threatened species on the IUCN Red List of Threatened Species.

Photo by Andreas Hertz via ARKive.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Small, but mighty.

Robber frog (Eleutherodactylus orientalis)

Robber frog (Eleutherodactylus orientalis)

Cute Frog of the Week: February 4, 2013

If you ever visit Cuba and spot this little yellow and black frog, watch out! The robber frog is toxic, and when touched can secrete painful toxins into the skin of other species, including humans. This terrestrial species is endemic and can only be found among leaf litter in hardwood forests of limestone soil, and sometimes on coffee and cacao plantations in Cuba. An increase in agriculture and tourism has resulted in the degradation of these critically-endangered frogs’ heavily restricted range.

Photo by Ariel Rodriguez via Arkive.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Next, to bend space and time.

Hellbender (Cryptobranchus alleganiensis)

Hellbender (Cryptobranchus alleganiensis)

Cute Amphibian of the Week: January, 28, 2013

The hellbender has the distinct honor of being the largest salamander in the United States, growing as large as two feet long. It can be found in rocky, clear creeks and rivers, usually where there are large rocks for shelter. Its mottled appearance allows the hellbender to almost perfectly blend into its surroundings, making it quite the crafty salamander. Despite its name, this species is not a fan of warm water and strictly avoids water with temperatures above 68 o Fahrenheit/20 o Celsius.

The principal threat to this species is habitat degradation since it is a habitat specialist with little tolerance of environmental change. While it may seem like the sensitive type, do not be fooled; this species knows how to defend itself when push comes to shove. Hellbenders produce skin secretions that are likely unpalatable to predators and lethal in mice. At the current time the species is listed as near threatened by the IUCN.

Follow the Smithsonian National Zoo’s hellbender work at http://www.salamanderscience.com/.

Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Cuban Frog Crisis

Oriente Mottled Frog (Eleutherodactylus simulans)

Oriente mottled frog (Eleutherodactylus simulans)

Cute Frog of the Week: January 21, 2013

The crisis facing this little Cuban native doesn’t involve missiles, but it does require immediate action to save this frog species from extinction. Characterized by its dark mottled brown pattern on its dorsal surface, the Oriente mottled frog (Eleutherodactylus simulans) blends well among the rocks, leaves and streambeds from which it is found. Recorded only in five small locations in Cuba, this terrestrial frog is currently classified as endangered by the IUCN. Due to habitat destruction from increasing deforestation within the country, the Oriente mottled frog population is clinging on to its existence.

Photo by Ariel Rodriguez via Arkive.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/