NanoARC: nanovesicles with antioxidant and photoprotective activity against damage induced by UVB light in keratinocytes

APEZTEGUIA, G; ROMERO, EL; MORILLA, MJ

Congreso; LXIII Reunión científica anual de la Sociedad Argentina de Investigación Clínica SAIC; 2018

The development of malignant skin tumors is a major problem in the field of dermatology. The mechanisms of photocarcinogenesis are mainly due to UV solar radiation, which alters the DNA structure, the cellular homeostasis and induces reactive oxygen species (ROS). The extreme halophilic archaebacteria produce a unique group of polar (PA) and neutral membrane archaeolipids (NA) that help them to survive in high UV radiation exposure environments where they live. PAs are composed of saturated isoprenoid chains linked by ether bonds to the glycerol carbons in the sn 2,3 position and are highly resistant to hydrolytic, oxidative and enzymatic attack. The NA are carotenoids with high antioxidant activity. The nanoformulation of both types of lipids could generate a product with photoprotective activity of topical application. In this work, we optimize the biomass production of halophilic archaea by a simple batch growth. Then we implemented an extraction process of PA and NA using bio-solvents and we used it to produce nanovesicles (NanoARC). The antioxidant and photoprotective capacity of NanoARC were then evaluated on keratinocyte irradiated with UVB light.PA-NA extracts obtained with ecological solvents showed high DPPH scavenging ability with a Trolox Equivalent Antioxidant Capacity (TEAC) of 11 ± 5.6, that was superior to that reported for compounds such as a-tocopherol or ascorbic acid. Using PA-NA extract we prepared NanoARC (310 nm and -42 mV Z potential) that showed significant protection against the detrimental effects of cell destruction induced by UVB light (270 mJ/cm2) and ROS release measured by the carboxy-H 2 DCFDA dye. Besides, NanoARC inhibited UVB-induced apoptosis, as indicated by YO-PRO and propidium iodide staining. The results suggested that the halophilic archaebacteria is a sustainable source of unique biomaterials that can be extracted by ecological solvents and formulated in nanovesicles that can be propose as potential new photoprotective agents.