Determining the ability of astaxanthin to induce proliferation and skin protection from harmful environmental factors in vitro and in vivo

Abstract

Astaxanthin (ASX) is a carotenoid having the strongest antioxidant capacity. Haematocoocus pluvialis is the most commonly used source of ASX today. In this study, the authors obtained ASX from H. pluvialis by using Sacha Inchi oil. Then, the ability of ASX on stimulating proliferation of skin cells, protecting skin fibroblasts from H₂O₂ in vitro, and protecting mice skin from UV irradiation in vivo was tested. The results showed that ASX could be extracted in Sacha Inchi oil with a concentration of 225.54±21.56 µg/ml. ASX with a concentration of 1 µg/ml was non-toxic to the fibroblasts, induced proliferation with a concentration of (6.05±0.24)x10⁴  µg/ml (n=3) (1.44 times higher than that of the control), and quick migrated to the affected areas (after 36 hours). ASX 1 µg/ml protected the fibroblasts from the oxidative stress of H₂O₂. Comparing to the positive control (fibroblasts exposed to H₂O₂ only), the experimental group cells (induced by ASX 1 µg/ml first, then exposed to H₂O₂) did not express signs of oxidative stress: small nuclear size (259.6±29.1 µm² vs 314.5±30.5 µm²), low G0/G1 ratio (83.1±6.1% vs 90.6±5.2%) and didn’t express β-galactosidase. Furthermore, ASX 200 µg/ml protected mice skin from UV irradiation. After 4 weeks of continuous UV irradiation, mice skin applied with ASX every day did not express any aging signs such as wrinkles, thick epidermis, and solar elastosis. In conclusion, ASX extracted in Sacha Inchi oil stimulated proliferation and migration of fibroblast cells, and protected skin from oxidative radical H₂O₂ in vitro and UV irradiation in vivo.