Plants have long been a source of raw materials for making medicines, including both traditional therapies and conventional drugs. Yet chemicals produced by animals—especially the venom that some 15% to 30% of all species use for defense and hunting—remain largely untapped. The Food and Drug Administration has approved just a handful of drugs derived from venom, including the antihypertensive Captopril (from the Brazilian viper) and the diabetes medication exenatide (from the Gila monster).
But with more than 200,000 venomous species walking the earth, many new therapeutics await discovery, says chemical biologist Mandë Holford, an associate professor of chemistry at CUNY Hunter College. Holford studies the medicinal potential of peptides in venom from marine snails. She explains that isolating the potentially curative components in animal toxins is becoming less challenging because of the emergence of techniques that include transcriptomics, which allows scientists to survey a venom’s RNA sequence in hours instead of months. “That has been game changing. We now have the tools to mine these animals’ arsenals to understand what’s there and figure out how we can use it,” says Holford. “This will help us make more effective drugs, faster.”
Bufo toads
Scorned in Florida, where they are considered invasive pests and a threat to pets, bufo toads secrete chemicals used in a traditional Chinese medicine known as cinobufacini. They are currently in clinical trials as adjunctive treatments for several malignancies, including esophageal cancer and lymphoma.
Shrews
Few mammals produce venom, but the short-tailed shrew’s saliva contains a peptide called soricidin that paralyzes prey. A synthetic derivative of soricidin, called SOR-C13, is currently in a phase 1 trial for treatment of advanced ovarian, pancreatic and prostate tumors that no longer respond to treatment.
Pufferfish
Nerve pain is a common and serious side effect of cancer chemotherapy, with little or no effective form of prevention. A recent phase 2 trial found that chemotherapy patients with nerve pain who were treated with tetrodotoxin, derived from the deadly pufferfish, had reduced pain levels.
Scorpions
The venom of a scorpion known as the deathstalker contains a paralyzing agent called chlorotoxin, which has been shown to target cancerous glioma cells, ignoring healthy brain cells. Early clinical trials of a synthetic version of the toxin, paired with immunotherapy, are under way in patients with recurrent or worsening glioblastoma.
Sea anemones
A small study showed improvement in psoriasis in nine out of 10 patients treated with dalazatide, derived from toxins that sea anemones emit to hunt prey. Such chemicals may prove useful for other conditions, including inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis and neuroinflammations such as Alzheimer’s disease.
Honeybees
Honeybee venom is brimming with intriguing peptides and enzymes, and has shown promise as a treatment for Parkinson’s disease, Alzheimer’s disease, ALS, HIV and several cancers. In a recent study, honeybee venom and its major component, melittin, induced death of malignant cells in a mouse model of aggressive breast cancer.
