In vitro anti-inflammatory and skin protective properties of Virgin coconut oil

Virgin coconut oil (VCO) has been traditionally used as moisturizer since centuries by people in the tropical region. Clinical studies have revealed that VCO improves the symptoms of skin disorders by moisturizing and soothing the skin. However, the mechanistic action of VCO and its benefits on skin has not been elucidated in vitro. The cytotoxicity (CTC₅₀) of VCO was 706.53 ± 2.1 and 787.15 ± 1.1 μg/mL in THP-1 (Human monocytes) and HaCaT (Human keratinocytes) cells respectively. VCO inhibited TNF-α (62.34 ± 3.2 %), IFN-γ (42.66 ± 2.9 %), IL-6 (52.07 ± 2.0 %), IL-8 (53.98 ± 1.8 %) and IL-5 (51.57 ± 2.6 %) respectively in THP-1 cells. Involucrin (INV) and filaggrin (FLG) content increased by 47.53 ± 2.1 % and 40.45 ± 1.2 % respectively in HaCaT cells. VCO increased the expression of Aquaporin-3 (AQP3), involucrin (INV) and filaggrin (FLG) and showed moderate UV protection in HaCaT cells. In vitro skin irritation studies in Reconstructed human epidermis (RHE) and NIH3T3 cells showed that VCO is a non skin irritant (IC₅₀ > 1000 μg/mL) and non phototoxic (PIF < 2). Our study demonstrated the anti inflammatory activity of VCO by suppressing inflammatory markers and protecting the skin by enhancing skin barrier function. This is the first report on anti-inflammatory and skin protective benefits of VCO in vitro. Overall, the results warrant the use of VCO in skin care formulations.