Scientists discovered a “second hit” in mamba venom that helps explain why some patients initially improve with antivenom, only to relapse into severe, painful spasms.
Certain mamba species initially paralyze muscles, then target another area of the nervous system, causing uncontrollable contractions after treatment reverses the initial paralysis.
The Hidden Threats Lurking in Mamba Venom
A groundbreaking study at The University of Queensland has uncovered a previously unknown and dangerous trait in the Black Mamba, one of the world’s most venomous snakes.
Professor Bryan Fry from UQ’s School of the Environment explained that the research showed the venoms of three mamba species are far more neurologically complex than once believed, shedding light on why antivenoms can sometimes fail to work effectively.
Two-Pronged Neurological Assault Mechanism
“The Black Mamba, Western Green Mamba, and Jameson’s Mamba don’t rely on a single type of venom; they target two separate areas of the nervous system simultaneously,” explained Professor Fry.
In bites from three of the four mamba species, victims typically suffer flaccid or limp paralysis due to postsynaptic neurotoxicity.
Why Antivenoms Can Occasionally Be Ineffective
Current antivenoms can counteract the flaccid paralysis, but this study revealed that the venoms of these three mamba species can subsequently target another part of the nervous system, triggering spastic paralysis through presynaptic toxicity.
Until now, we believed only the fourth species, the Eastern Green Mamba, could cause spastic paralysis.
“This discovery explains a long-standing clinical puzzle: some patients bitten by mambas initially respond to antivenom, regaining muscle tone and movement, only to later experience painful, uncontrollable spasms.
“The venom first blocks nerve signals to the muscles, but once antivenom is administered, it overstimulates them.”
“It’s as if you cure one condition, only to uncover a second one.”
A Lethal Danger Across Sub-Saharan Africa
Bites from mamba snakes (Dendroaspis species) pose a major danger in sub-Saharan Africa, causing around 30,000 deaths each year.
PhD candidate Lee Jones, who carried out the experimental studies on mamba venoms, emphasized that developing new antivenoms is essential for saving lives.
Unexpected Discoveries from Laboratory Research
“We aimed to compare the venom potencies among different mamba species,” Mr. Jones explained.
We anticipated seeing clear flaccid paralysis caused by postsynaptic effects and that antivenom would neutralize these effectively.
What surprised us was that the antivenom actually revealed the other half of the venom’s effects on presynaptic receptors.
We also discovered that venom activity varied depending on the snakes’ geographic origin, especially in Black Mamba populations from Kenya and South Africa.
“This makes treatment even more challenging across regions, as current antivenoms are not designed to address the complex differences in venom composition.”
Advancing Antivenoms and Improving Patient Treatment
Professor Fry stated that this research could lead to the development of specialized antivenoms with higher effectiveness.
“This is more than an academic finding—it’s a direct message to clinicians and antivenom producers,” Professor Fry explained.
“By recognizing the shortcomings of existing antivenoms and fully understanding venom behavior, we can guide more evidence-based approaches to snakebite treatment.”
“This type of applied venom research can enable doctors to make more informed decisions on the spot and, ultimately, save lives.”
The laboratory studies were conducted in partnership with the Monash Venom Group.
Read the original article on: SciTechDaily
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