Topical Application of Glycolipids from Isochrysis galbana Prevents Epidermal Hyperplasia in Mice

Chronic inflammatory skin diseases such as psoriasis have a significant impact on society. Currently, the major topical treatments have many side effects, making their continued use in patients difficult. Microalgae have emerged as a source of bio-active molecules such as glycolipids with potent anti-inflammatory properties. We aimed to investigate the effects of a glycolipid (MGMG-A) and a glycolipid fraction (MGDG) obtained from the microalga Isochrysis galbana on a TPA-induced epidermal hyperplasia murine model. In a first set of experiments, we examined the preventive effects of MGMG-A and MGDG dissolved in acetone on TPA-induced hyperplasia model in mice. In a second step, we performed an in vivo permeability study by using rhodamine-containing cream, ointment, or gel to determinate the formulation that preserves the skin architecture and reaches deeper. The selected formulation was assayed to ensure the stability and enhanced permeation properties of the samples in an ex vivo experiment. Finally, MGDG-containing cream was assessed in the hyperplasia murine model. The results showed that pre-treatment with acetone-dissolved glycolipids reduced skin edema, epidermal thickness, and pro-inflammatory cytokine production (TNF-, IL-1, IL-6, IL-17) in epidermal tissue. The in vivo and ex vivo permeation studies showed that the cream formulation had the best permeability profile. In the same way, MGDG-cream formulation showed better permeation than acetone-dissolved preparation. MGDG-cream application attenuated TPA-induced skin edema, improved histopathological features, and showed a reduction of the inflammatory cell infiltrate. In addition, this formulation inhibited epidermal expression of COX-2 in a similar way to dexamethasone. Our results suggest that an MGDG-containing cream could be an emerging therapeutic strategy for the treatment of inflammatory skin pathologies such as psoriasis.