Birdbrained Science: You’re putting WHAT on your face? 

Welcome back to Birdbrained Science! Today, we will cover neither birds, nor brains but a third thing — salmon sperm in your skincare. 

You probably won’t actually see any skincare products marketing that they include salmon sperm — instead, they’ll use words like “salmon DNA” or “PDRN.” PDRN is short for polydeoxyribonucleotide, which is a drug made of deoxyribonucleotides, or DNA fragments. Why am I calling it salmon sperm then? Because in order to source salmon DNA with the lowest risk of impurities, PDRN is “mainly extracted from the sperm cells of salmon trout or chum salmon.”  So yes, there is salmon sperm in your skincare. (Importantly, however, the sperm has been filtered and purified beforehand, so hopefully nobody is putting straight salmon sperm on their face. Do not come away from this article thinking that you should put unprocessed salmon sperm on your face).  

Sounds kind of crazy, doesn’t it? Humans have put all kinds of weird and strange things on their faces in the pursuit of beauty. But apparently, PDRN isn’t one of these weird things — or at least, not just one of those weird things. There’s actual scientific merit behind the idea that PDRN is good for your skin. Studies say it has lots of awesome anti-aging properties for your skin, including anti-inflammation, collagen synthesis, skin priming and revitalization, tissue regeneration and tissue damage prevention. This is by no means a conclusive list — studies also say PDRN is beneficial in treating diabetic foot ulcers — but in the interest of staying on topic, we won’t get much into that. 

But how exactly does it work? Skin aging is a very complicated process, made up of lots of involved smaller processes, so we can’t get into all of the details, but I’ll try to give a brief overview. 

We’ll start off with collagen. Collagen is a protein that plays a major role in skin structure, skin elasticity, skin cell formation and skin cell regeneration, and is also used in skincare products.  

Based on all that, you can probably guess that collagen is something you’d want a lot of if you want your skin to be healthy and youthful. You can also probably guess that less collagen leads to less youthful skin.  

There are various skin aging processes that ultimately decrease collagen synthesis, such as the activation of the MAPK and NF-κB pathways, and expression of matrix metalloproteinases (MMPs).  

PDRN, however, stops these processes pretty much right at the start. PDRN activates the adenosine A_2A receptor, which blocks the NF-κB and MAPK pathways, thus stopping them from limiting collagen production. PDRN also blocks MMP-1, further preventing a decrease in collagen production.  

PDRN also boosts collagen synthesis in another chain reaction, by first decreasing Fli1 (a collagen-gene repressor), which increases connective tissue growth factor (CTGF) expression, which also seems to allow for collagen production. 

Another aspect of skin aging is chronic inflammation.  

PDRN also addresses this through the activation of the A _2A receptor. The receptor stops many pro-inflammatory cytokines from getting released and instead allows for anti-inflammatory cytokines to be released, thus decreasing overall inflammation. 

Yet another process involved in the aging of skin is the increase in DNA damage and decrease in DNA synthesis. DNA damage releasing MMP-1, which PDRN prevents. Aside from preventing negative effects of DNA damage, PDRN also contributes to DNA synthesis by supporting salvage pathways.  

When DNA or RNA degrades, it leaves behind bases and nucleosides. Salvage pathways recycle these bases and nucleosides into nucleotides and reincorporates them back into DNA. PDRN supports this process by providing nucleotides and nucleosides for salvage pathways, which leads to more cell growth and reproduction, thus leading to faster tissue regeneration and wound healing.  

So there you have it — PDRN supports anti-aging skincare in multiple ways by stopping multiple different processes and helping out other ones.  

 There is a lot I had to cut from this  — turns out, there are a lot of details and processes involved in the aging of skin and attempts to prevent it. But it seems like PDRN manages to fight off quite a lot of processes involved in skin aging. So, as strange as it may be, salmon sperm really does benefit your skin.  

The majority of today’s content came from the 2022 review article “Polydeoxyribonucleotide: A promising skin anti-aging agent.” If you’re reading online and would like to learn more, you can find the link here. 

I usually try to end with a deeper reflective question, but I don’t really have any today pertaining to the topic at hand. I guess don’t knock it before you try it? Personally, despite the science, I will not be seeking to incorporate salmon sperm into my skincare, but I guess I can’t quite judge anyone who does. See you all in another two weeks!