Photoprotective effects of methoxycinnamidopropyl polysilsesquioxane

Photochem Photobiol. 2011 Jul-Aug;87(4):920-4. doi: 10.1111/j.1751-1097.2011.00940.x. Epub 2011 Jun 13.


A new sunscreen ingredient, methoxycinnamidopropyl polysilsesquioxane (MCP-PSQ), which contains an UV-absorbing p-methoxycinnamoyl group, has been developed synthetically and evaluated using in vitro and in vivo approaches. Previous studies revealed that MCP-PSQ has a raising or boosting effect on the sun protection factor (SPF) of other sunscreen agents. In this study, we demonstrated that MCP-PSQ, an organic/inorganic hybrid compound, has photoprotective effects for human fibroblasts, and for hairless mouse and human skin. MCP-PSQ increases cell viability and suppresses the expression of p53 protein in fibroblasts after UV exposure. In addition, the numbers of sunburn cells and mast cells are reduced by topical application of MCP-PSQ on hairless mouse skin after UV irradiation. A 10% MCP-PSQ cream has higher and similar effects on SPF values for human skin compared to 5% titanium dioxide (TiO(2)) and 5% ethylhexyl methoxycinnamate (EHMC), respectively. The SPF value obtained using the MCP-PSQ cream did not drop after UV irradiation of the cream itself. However, higher dose of UV irradiation is required to guarantee the stability or photostability of the formulation. Further, there were no side effects such as erythema, edema, itch or tingling, suggesting that MCP-PSQ is a good sunscreen agent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption
  • Administration, Topical
  • Animals
  • Blotting, Western
  • Cell Survival / drug effects
  • Cell Survival / radiation effects
  • Cinnamates / pharmacology
  • Drug Stability
  • Electrophoresis, Polyacrylamide Gel
  • Female
  • Fibroblasts* / cytology
  • Fibroblasts* / drug effects
  • Fibroblasts* / radiation effects
  • Gene Expression / drug effects
  • Gene Expression / radiation effects
  • Humans
  • Hydrocarbons, Aromatic / chemical synthesis
  • Hydrocarbons, Aromatic / pharmacology*
  • Mice
  • Mice, Hairless
  • Silicon Compounds / chemical synthesis
  • Silicon Compounds / pharmacology*
  • Skin* / cytology
  • Skin* / drug effects
  • Skin* / radiation effects
  • Sunburn / prevention & control*
  • Sunscreening Agents / chemical synthesis
  • Sunscreening Agents / pharmacology*
  • Titanium / pharmacology
  • Tumor Suppressor Protein p53 / antagonists & inhibitors*
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism
  • Ultraviolet Rays / adverse effects


  • Cinnamates
  • Hydrocarbons, Aromatic
  • Silicon Compounds
  • Sunscreening Agents
  • Tumor Suppressor Protein p53
  • ethylhexyl methoxycinnamate
  • titanium dioxide
  • Titanium