What We Know About Salmon Sperm in Dermatology

It may not have an aesthetic-sounding appeal to most people, but salmon sperm is indeed one of the novel ingredients featured in products for human skin. Used topically after procedures like skin tightening and in fillers, polydeoxyribonucleotides (PDRNs) and purified polynucleotides (PNs) derived from salmon sperm are on the market. These products also reportedly enhance and promote skin regeneration.[1] This column will focus on the innovative approach to skin care involving purified polynucleotides derived from salmon sperm.
The Properties and Activities of PDRNs, PNs
PDRNs contain DNA fragments primarily derived from Pacific or chum salmon (Oncorhynchus keta), and salmon trout (Oncorhynchus mykiss) sperm cells.[2] Through preclinical and clinical trials, PDRN has demonstrated a wide range of salutary functions, including antiallodynic, antiapoptotic, anti-inflammatory, antimelanogenetic, antiosteonecrotic, antiosteoporotic, antiulcerative, bone-regenerative, tissue damage–preventive, and wound-healing activities through adenosine A2A receptor and salvage pathways activation. Indeed, PDRNs have been shown in vitro to spur the proliferation of preadipocytes and, in vivo, to be effective in treating wounds and ulcers.[3,4] In particular, atrophic, hypertrophic, surgical, and various acne scars have been treated with such injections.[2,5,6] PDRN is thought to affect cutaneous health more directly by facilitating angiogenesis, cellular functions, especially fibroblast stimulation, collagen production, soft-tissue regeneration, and skin revitalization. Further, it has been used successfully to treat hyperpigmentation.[7]
PNs, derived from the same fish species as PDRNs, have been used effectively to ameliorate skin elasticity, hydration, pore size, thickness, wrinkles, as well as pigmentation and, specifically, in treating periorbital rhytides and postsurgical scars.[5,6,8] Beyond skin rejuvenation, PNs have been recognized for effectiveness in treating stretch marks and achieving vulvovaginal revitalization; guidelines for its use have been established and implemented in recent years.[6,9,10] In South Korea, PNs have become a popular treatment for facial erythema even though preclinical and clinical data are sparse.[11] Nevertheless, the use of these novel substances is thought to foster tissue regeneration and a more natural rejuvenation than achieved through more traditional fillers.[6]
Skin Rejuvenation
Park and colleagues conducted a small study with five patients in 2016 in which long-chain polynucleotide filler was used for skin rejuvenation. Over a 2-week period, five Korean women received four injections of the filler (0.05 mL) on one side of the face. No adverse side effects were reported. In the patients in their 30s, pore and skin thickness significantly improved with treatment. For patients in their 40s, observable improvements were noted in melanin, sagging, skin tone, and wrinkles. Despite the small study size, the investigators concluded that this intradermal injection material is a safe and effective product for skin rejuvenation therapy.[1] The product is also available in Europe and reportedly spurs the regeneration of damaged tissues and yields a more natural appearance.[1]
A Hybrid HA-PN Filler
Given that the most common filling agent, hyaluronic acid (HA), is associated with multiple side effects, JH Kim and colleagues set out in 2020 to compare HA with a new HA-PN dermal filler that has displayed notable biocompatibility and promoted tissue regeneration. The investigators observed that the combination filler provoked greater cell migration in a wound healing assay and was more effective in promoting collagen production in human and mouse fibroblasts. To their knowledge, this was the first study showing the efficacy, safety, and durability of a hybrid HA-PN filler. They concluded that fillers containing both HA and PN were more effective than HA alone in suppressing cutaneous aging and may represent the next step in the evolution of dermal filling agents.[12]
Most Recent Findings
In August 2023, MJ Kim and colleagues became the first to report on the successful use of PNs derived from fish sperm as a volumizing treatment for fat atrophy in vivo (in the temple in one case, and the cheek in the other). Injections were made into the subcutaneous layer to treat iatrogenic volume loss resulting from lipolysis injections. In one case, a depression in the left temple of a 53-year-old female lipolysis patient was treated with a series of 1 cc PN injections in a 20 mg/mL concentration. At 1 month after the final series of injections (four treatments), significant clinical improvement was observed, with the result (barely visible depression) maintained at 11 months and 21 months after the last treatment. The second patient, a 34-year-old female, presented with two depressed areas on the left cheek 2 months after steroid injections for two acne lesions. A series of PN filler injections also with a concentration of 20 mg/mL was administered (four treatments) at 1-month intervals. Significant improvement was seen 2 months after the last treatment, with maintenance of complete healing noted at 5 months and 12 months after the final treatment. No adverse effects were reported in either case. The investigators concluded that long-chain PN fillers appear to be effective in treating depressions in the skin, but more data, particularly from controlled studies, is necessary to determine the safety and efficacy as a lone therapeutic approach for soft-tissue depression.[6]
A month later, Lee and colleagues reported on the results of their survey of clinicians in South Korea who use PNs in clinical practice. The goal was to understand current practices and perceptions of effectiveness in treating facial erythema. Of the 557 physicians who participated, 84.4% used PNs for facial erythema provoked by inflammatory facial dermatosis, 66.4% for facial erythema induced by repeated laser/microneedle radiofrequency, and 47.4% for facial erythema caused by steroid overuse. In these same classifications, 88.1%, 90%, and 83.7%, respectively, found PNs to be “highly effective” or “effective.” Survey respondents also characterized PNs as imparting wound healing/regeneration (95.8%), skin barrier protection (92.2%), hydration (90.5%), vascular stabilization (81.0%), and anti-inflammatory activity (79.5%).[11]
Conclusion
The use of salmon sperm cells is an example of the recent trend toward a cellular approach in which cutaneous components are activated with the intention of stimulating tissue regeneration. It is commonly used in Brazil and my Brazilian patients seem to know all about it. This innovative outlook is intriguing as are a spate of recently reported results. Nevertheless, much more evidence is required to ascertain safety and effectiveness in large sample sizes and, ideally, to establish maintenance of corrections over longer periods whether these ingredients are used in filling agents or topical formulations.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.
Dr. Baumann is a private practice dermatologist, researcher, author, and entrepreneur in Miami. She founded the division of cosmetic dermatology at the University of Miami in 1997. The third edition of her bestselling textbook, “Cosmetic Dermatology,” was published in 2022. Dr. Baumann has received funding for advisory boards and/or clinical research trials from Allergan, Galderma, Johnson & Johnson, and Burt’s Bees. She is the CEO of Skin Type Solutions, a SaaS company used to generate skin care routines in office and as a e-commerce solution. Write to her at [email protected].
 
Any views expressed above are the author’s own and do not necessarily reflect the views of MDedge or its affiliates.