Phenolic-dependent anti-lipid peroxidative, antimodulatory and antioxidant activity of virgin coconut oil in vitro

The phenolic profile of virgin coconut oil (VCO) was studied using HPLC and was found to contain 4.04 x 10^-2 ppm gallic acid. Further test using Folin-Ciocalteu gave 3.658 mg/mL gallic acid equivalent (GAE). The same phenolic extract revealed a concentration-dependent activity against DPPH radical (IC50 = 14.9 mg/mL). Thiobarbituric acid reactive substances (TBARS) assay for the assessment of lipid peroxidation exhibited an IC50 of 4.32 x 10^-1 mg/mL GAE. Also, it demonstrated an IC50 at 2.31 x 10^-2 mg/mL GAE against nitric oxide (NO•). Stimulation of both hydroxyl (•OH) (SC50 = 1.29 mg/mL GAE) and H2O2 formation was observed. Cell viability test using alamarBlue® confirmed that 80%v/v VCO increased cell death of human hepatocarcinoma (Hep-G2) by 18.2% prior to treatment of H2O2. The data suggest that VCO may help inhibit general free radicals, lipid peroxidation and vasodilation-related diseases. Stimulation of H2O2 and •OH radicals are necessary in fighting pathogens and malignant cells.