North American opossum: innate immunity against snake venom.

In the impression of everyone, opossum may be both foolish and ugly, and is rated by high school students as the most likely animal to be run over by a car. But in the eyes of scientists, its blood may be the key to fighting all kinds of snake venom.

A team of researchers conducted laboratory experiments in mice and found that a molecule in the blood of opossum North America called peptide neutralizes snake venom. The substance has detoxification effects on the venom of several venomous snakes, including the Western rhombohedral rattlesnake in the United States and the Indian mountain viper.

“Mice injected with snake venom showed no toxic symptoms,” said Claire Komives, a professor of chemical engineering at San Jose State University in California.

“It’s amazing that this peptide really works,” Komives said. On March 23, at the meeting of the American Chemical Society in Denver, she reported her preliminary findings to the participants.

Komives points out that since the 1940s, scientists have known that opossum is immune to snake venom. Other mammals, such as ground squirrels and badgers, also have natural immunity to snake venom.

Komives said that now her team has isolated an effective antivenom from opossum blood, which scientists can mass produce as a cheap universal antivenom for use in developing countries.

The World Health Organization estimates that as many as 94,000 people die each year from snake bites. Although many kinds of antivenom have been developed, each antivenom can only dissolve one kind of snake venom, so it is very expensive to develop a universal antivenom.

Not so fast?

Opossum research is exciting, but snake venom expert Zoltan Takacs warns that it’s not time to celebrate.

Snake venom contains thousands of different compounds, each of which has different ways of poisoning victims.

“Snake venom works in many ways. One group of toxins may attack nerve cells, the other may attack the muscular system, “said Takacs, who is also a new explorer in National Geographic.

“Once you have hundreds or more toxins in your body, you have to detoxify them, or at least neutralize the highly toxic ones, so as to prevent the symptoms of poisoning.”

Takacs is concerned that the peptide isolated from opossum blood may only neutralize one toxin, while other toxins may continue to cause damage to the body.

In addition, he said that specific compounds in snake venom may vary depending on snake species, sex, age and even geographical location. Therefore, although the acetic acid acts on a sample of viper venom under experimental conditions, this antidote is not necessarily effective for all viper venom. Every year, mountain vipers kill thousands of people in India.

On Takacs’question, Komives said he was right.

Nevertheless, she believes that her findings are also evident.

“It seems unreasonable that acetic acid can neutralize rattlesnake venom, but that’s the case.” She said in a subsequent e-mail.

One idea that a peptide can fight several snake venoms is a “very revolutionary” idea, says Robert Harrison, a snake venom expert at Liverpool Tropical Medical College in the United Kingdom.

Although this method is “innovative”, more experiments are needed, Harrison stressed, and he is currently working on a general antivenin program.

Crucial antivenom

Any research on snake venom and antivenom is important, Takacs said, and he has witnessed the devastating consequences of snake bites.

In rural Nepal, he had seen a man bitten by a cobra lying on a wheelbed. Antivenom and expensive medical devices are rare in Nepal. Therefore, although the man is still alive, he can only be in a state of respiratory paralysis. His brother sat next to him, squeezing air into his lungs with a rubber ball to keep him breathing. It’s not clear how the man ended up with Takacs.

Takacs says the first antivenin reagent came out 100 years ago. However, due to various obstacles, such as the complexity of snake venom compounds and the high cost of research, most regions of the world are still unable to resist snake bites.

“But it’s extremely rare to wake up healthy in the morning and die suddenly at the end of the day.” He said.