2.5. Lipid Peroxidation Assay
OxiSelect
SKIN
Skin surface and hair lipids were collected from 3 points of the scalp by application of cotton disks (diameter 5.3 cm) soaked in diethyl ether, allowing contact for 2 min. Then, the freshly collected lipids were pooled, filtered, and evaporated. The content of malonyl dialdehyde (MDA) in the scalp skin and hair lipids was measured by a quantitative spectrophotometric method using OxiSelect TBARS Assay Kit (Cell Biolabs, Inc., MA, USA). The data were expressed in μmol/cm