Tarantula Toxin Frees Pain Pathways For IBS, According To Study

One tarantula toxin, which is isolated from the Togo starbust tarantula, may give a better understanding about the pain mechanisms and could likely give rise to new treatments for irritable bowel syndrome or IBS. Considered as the worst nightmare for the arachnophobes, the findings made by the American researchers about the large, hairy tarantulas' toxin seem like a dream come true.

A tarantula toxin, which is unique from the Earth Tiger tarantula's venom, was reported to act by binding to the external region of the heat-sensitive TRPV1 protein, trapping the pore in its open condition. In this latest study conducted by David Julius from the University of California in San Francisco in 2010, 100 venoms from different scorpion, centipede and spider species were gathered and added to the  sensory neurons that are isolated from mice and rats and were kept alive in Petri dishes. A calcium imaging was used to find out which of these elicit increases in calcium ion concentration, which suggests neuronal activity, within the cells.

The tarantula toxin from the Togo starbust tarantula stimulated subsets of sensory neurons. Based on the research team's analysis, the venom was found to have two toxins -delta-theraphotoxin=Hm1b and delta-theraphotoxin-Hm1a. Aside from this, a synthetic type of Hm1a elicited robust reactions in cultured sensory neurons that suggests it is an active part of the venom, and that the tetrodotoxin is blocking the calcium ion concentration increases that it creates, indicating that the toxin acts on sodium channels, according to Medical News.

Since hypersensitivity to mechanical stimuli acts in persistent abdominal pain, which is a symptom of irritable bowel syndrome, gut-nerve preparations were also examined, and discovered that giving Hma1 increased the firing degree of mechanical-reactive cells and greatly lessened the activation threshold as well.  With these findings, the previously undetermined role for Na_v1.1 in nociceptors sensitive to mechanical pain were revealed.

The area of the Na_v1.1 protein that binds tarantula toxin was also characterized through the use of genetic engineering. From this, the researchers are hopeful that they can develop new treatments that can reduce the chronic pain being experienced by patients with irritable bowel syndrome through selectively blocking the channel, Adelaide Now reported.