1 00:00:02,040 --> 00:00:07,120 Speaker 1: Welcome to brain Stuff from How Stuff Works. Hey brain Stuff, 2 00:00:07,160 --> 00:00:11,080 Speaker 1: I'm Lauren Vogelbaum, and today's episode is a brain Stuff classic, 3 00:00:11,600 --> 00:00:14,200 Speaker 1: How does Aspirin Work? I wrote this one for our 4 00:00:14,240 --> 00:00:16,759 Speaker 1: YouTube channel a while back while I was going through 5 00:00:16,840 --> 00:00:20,920 Speaker 1: a pain research phase, which yes, is just about as 6 00:00:20,920 --> 00:00:23,760 Speaker 1: goth as it sounds. It was performed for the podcast 7 00:00:23,800 --> 00:00:31,320 Speaker 1: by our former host, Christian Saga. Let's dive in, Hey 8 00:00:31,320 --> 00:00:34,159 Speaker 1: brain Stuff. It's Christian Sager here. There are lots of 9 00:00:34,200 --> 00:00:37,159 Speaker 1: ways to numb yourself to the minor aches and pains 10 00:00:37,240 --> 00:00:40,879 Speaker 1: that we humans accrew in our daily lives. But today 11 00:00:41,320 --> 00:00:45,959 Speaker 1: we're talking about aspirin. Why aspirin, Because although aspirin as 12 00:00:46,000 --> 00:00:49,879 Speaker 1: we know it has only existed since the late eighteen hundreds, 13 00:00:49,920 --> 00:00:53,960 Speaker 1: the plant that it was originally derived from, willow, is 14 00:00:54,080 --> 00:00:58,280 Speaker 1: probably the oldest known pain killer in history. Records of 15 00:00:58,320 --> 00:01:02,200 Speaker 1: people using willow leaves to relieve pain and fevers stretch 16 00:01:02,280 --> 00:01:07,399 Speaker 1: back six thousand years to ancient Assyria and sumer Willow 17 00:01:07,800 --> 00:01:12,360 Speaker 1: was also put to use in ancient Egypt, Babylon, and China, 18 00:01:12,480 --> 00:01:17,040 Speaker 1: and Hippocrates thought it was pretty rad especially for pain 19 00:01:17,360 --> 00:01:22,720 Speaker 1: during childbirth. In the seventeen and eighteen hundreds, scientists worked 20 00:01:22,880 --> 00:01:27,880 Speaker 1: on identifying, extracting, and purifying the active ingredient in willow, 21 00:01:27,920 --> 00:01:31,399 Speaker 1: which turned out to be a chemical they called salison, 22 00:01:31,680 --> 00:01:37,679 Speaker 1: which they further discovered your digestive system changes into salacilic acid, 23 00:01:38,080 --> 00:01:40,640 Speaker 1: which is what reacts with stuff in your body to 24 00:01:40,680 --> 00:01:45,360 Speaker 1: relieve pain, reduced fever, and swelling. More on how all 25 00:01:45,400 --> 00:01:49,640 Speaker 1: that works In a second, but first salacilic acid. It 26 00:01:49,680 --> 00:01:54,040 Speaker 1: was a pharmacological superstar. German chemists figured out how to 27 00:01:54,120 --> 00:01:58,080 Speaker 1: synthesize it on an industrial scale in the eighteen seventies, 28 00:01:58,120 --> 00:02:03,280 Speaker 1: effectively ending millennia of willow powder use. But it had 29 00:02:03,320 --> 00:02:08,240 Speaker 1: its drawbacks. Lots of patients couldn't stomach it literally, it 30 00:02:08,320 --> 00:02:11,040 Speaker 1: was really hard on the stomach lining The son of 31 00:02:11,160 --> 00:02:15,120 Speaker 1: one such patient, a chemist with Friedrich bear in Company 32 00:02:15,200 --> 00:02:18,160 Speaker 1: by the name of Felix Hoffman, thought it might be 33 00:02:18,280 --> 00:02:22,480 Speaker 1: less irritating if it was less acidic, so Hoffman converted 34 00:02:22,520 --> 00:02:26,960 Speaker 1: it to what bear in Company dubbed aspirin in eight 35 00:02:29,160 --> 00:02:33,160 Speaker 1: Aspirin has become the popular and less ridiculous to pronounce 36 00:02:33,320 --> 00:02:39,919 Speaker 1: name for Hoffman's chemical compound, a setal silic acid or salicylate. 37 00:02:40,440 --> 00:02:43,760 Speaker 1: It works as humanity finally figured out in the nineteen 38 00:02:43,880 --> 00:02:48,959 Speaker 1: seventies by preventing yourselves from using cyclo oxygen ase to 39 00:02:49,480 --> 00:02:53,919 Speaker 1: to create prostaglandins. And don't worry, I'm about to unpack 40 00:02:54,000 --> 00:02:57,040 Speaker 1: all of those words. Let's start with the idea that 41 00:02:57,240 --> 00:03:01,639 Speaker 1: lots of pain is useful evolutionarily speaking, when you feel 42 00:03:01,680 --> 00:03:04,080 Speaker 1: pain due to an injury like a burn or a 43 00:03:04,120 --> 00:03:07,440 Speaker 1: twisted ankle, it prompts you to take your hand away 44 00:03:07,440 --> 00:03:10,160 Speaker 1: from that hot thing real quick, or to keep your 45 00:03:10,160 --> 00:03:13,440 Speaker 1: weight off the ankle until it heals. It's it's useful, right. 46 00:03:14,160 --> 00:03:17,920 Speaker 1: Pain from an injury to anything but the nervous system 47 00:03:18,080 --> 00:03:24,360 Speaker 1: is called no susceptive pain. After specialized sensory neurons located 48 00:03:24,400 --> 00:03:28,960 Speaker 1: throughout your body called no susceptors, They alert your brain 49 00:03:29,040 --> 00:03:32,520 Speaker 1: to damage. With the help of the damaged tissue itself, 50 00:03:32,840 --> 00:03:36,040 Speaker 1: cells in the hurt areas start producing enzymes that work 51 00:03:36,080 --> 00:03:40,960 Speaker 1: together to create a few signal chemicals, including those prostaglandins 52 00:03:41,000 --> 00:03:46,880 Speaker 1: I mentioned a minute ago. Prostaglandins tell your no susceptors, no, hey, seriously, 53 00:03:47,160 --> 00:03:50,440 Speaker 1: there is a problem here. They make your no susceptors 54 00:03:50,680 --> 00:03:54,400 Speaker 1: increase the signal to your brain. You feel the pain 55 00:03:54,640 --> 00:03:58,880 Speaker 1: more acutely now Prostaglandins are also one of the chemicals 56 00:03:58,880 --> 00:04:02,880 Speaker 1: that cause inflammation in the tissue around a wound. They 57 00:04:02,920 --> 00:04:06,200 Speaker 1: make your blood vessels expand, flooding the damaged tissue with 58 00:04:06,400 --> 00:04:09,960 Speaker 1: all the immune systems stuff your body sends to protect 59 00:04:10,000 --> 00:04:13,320 Speaker 1: the wound from infection and to help it to heal. 60 00:04:14,080 --> 00:04:17,000 Speaker 1: All of this is great right up until it isn't. 61 00:04:17,040 --> 00:04:20,880 Speaker 1: After a certain point. You don't need continual acute pain 62 00:04:21,040 --> 00:04:24,520 Speaker 1: as a reminder that you're injured. We know, and some 63 00:04:24,680 --> 00:04:28,120 Speaker 1: non susceptive pain and swelling is warning us about stimuli 64 00:04:28,200 --> 00:04:32,560 Speaker 1: that we can't easily avoid, like headaches, arthritis, or period cramps. 65 00:04:33,000 --> 00:04:36,440 Speaker 1: In the case of arthritis, that inflammation can even cause 66 00:04:36,560 --> 00:04:40,440 Speaker 1: more damage in the long run. Here's where aspirin swoops 67 00:04:40,440 --> 00:04:43,440 Speaker 1: in to save the day. When you take aspirin, it's 68 00:04:43,440 --> 00:04:47,400 Speaker 1: absorbed by your digestive tract into your blood stream, which 69 00:04:47,440 --> 00:04:50,920 Speaker 1: takes it throughout your body, including places where cells are 70 00:04:50,960 --> 00:04:57,279 Speaker 1: excreting the enzymes necessary to produce prostaglandins. Molecules of aspirin 71 00:04:57,680 --> 00:05:01,839 Speaker 1: lock up with one of those enzymes, cyclo oxygenase too. 72 00:05:02,400 --> 00:05:06,520 Speaker 1: Once a molecule of cyclo oxygenase two is locked into 73 00:05:06,560 --> 00:05:11,240 Speaker 1: a molecule of aspirin, it can't help create prostaglandins, which 74 00:05:11,240 --> 00:05:15,200 Speaker 1: means fewer prostaglandins, which means that the pain signals to 75 00:05:15,240 --> 00:05:19,400 Speaker 1: your brain don't increase as much and the tissue in 76 00:05:19,440 --> 00:05:24,000 Speaker 1: the area doesn't swell as much. Hey, thanks thousands of 77 00:05:24,080 --> 00:05:30,599 Speaker 1: years of science. Today's episode was produced by Tyler Klang. 78 00:05:30,880 --> 00:05:33,000 Speaker 1: If you miss Christian and want to hear more from him, 79 00:05:33,160 --> 00:05:36,960 Speaker 1: check out his pop culture podcast super Context, And of course, 80 00:05:37,000 --> 00:05:39,919 Speaker 1: for more on this and lots of other anti inflammatory topics, 81 00:05:40,080 --> 00:05:53,960 Speaker 1: visit our home planet, how stuff works dot com.