One article said that TTX, in diluted form, had been used as something like an anti-seizure medicine in ancient China.
The ancients had all the medicines, especially the Orientals. They were very wise, but when man learned how to replicate the drugs, they saw money in it, and damn the side-effects. So here we are today, re-learning what the ancients knew but the costs are prohibitive for a lot of them. But don’t get me started! ;o]