Red microalga Porphyridium cruentum produces a sulfated exopolysaccharide (EPS), which enables its survival in challenging intertidal and spray zones. Extracellular polysaccharide hyaluronic acid (HA) plays important roles in skin hydration, elasticity, and volume. However, with aging, HA decreases and loses effectiveness, reducing skin moisture retention and firmness, and increasing signs of aging. An effective topical alternative to injectable HA replacement remains a largely unmet need. An extract of Porphyridium cultivated in natural sunlight, rich in EPS and polydeoxyribonucleotides (PDRNs), significantly activated the ADORA2A receptor in a CHO model, as well as reduced inflammation and increased collagen and HA production, autophagic flux, and key autophagy gene expression in dermal fibroblast cultures. In a double-blind clinical trial with placebo and HA benchmark controls, the Porphyridium extract delivered significant HA-like skin plumpness, hydration, and radiance benefits, and reduced signs of aging. The extract generally equaled or exceeded the HA benchmark. Its meaningful, swift HA-like activity shows potential for a safe, natural, and arguably more powerful HA-like alternative.
Keywords: Porphyridium; cosmetic; exopolysaccharide; hyaluronic acid; microalga; natural PDRN; plumpness; radiance.