Abstract:

The protective effects of Chlamydomonas nivalis extract on NIH-3T3 cells under the oxidative stress and skin photodamage induced by UVB were evaluated. The cytotoxicity of the extract and the protective effect against hydrogen peroxide on NIH-3T3 cells were evaluated by MTT method. Chlamydomonas nivalis extract was applied to the dorsal skin of mice after UVB irradiation daily for 28 days to complete the photoaging model. Moreover, the skin was analyzed by H&E staining and Masson staining, then the expression of IL-1, IL-6 and TNF-α was analyzed by immunohistochemistry（IHC）. The results show that Chlamydomonas nivalis extract exhibits no obvious cytotoxicity for NIH-3T3 cells and increases the cell vitality under the oxidative stress. In animal experiment, the results of H&E staining show that UVB irradiation induces epidermis thickening and the collagen decreasing. The extract recovers the epidermis thickness and the collagen is increased. The increase of TNF-α and interleukin including IL-1 and IL-6 were induced by UVB, as shown in IHC results. The extract is shown to decrease the expression quantities of IL-1, IL-6 and TNF-α. Chlamydomonas nivalis extract protects the NIH-3T3 cells from oxidative stress induced by hydrogen peroxide and repairs the skin damage from UVB irradiation. It is speculated that the alleviative efficacy of Chlamydomonas nivalis extract may work by regulating oxidative stress and inflammation.

Key words: Chlamydomonas nivalis extract, NIH-3T3, oxidative stress, skin photodamage, protect