Role of oleanolic acid in relieving psoriasis and its underlying mechanism of action

Abstract

The present study aimed to determine whether oleanolic acid (Ole) could be used to treat psoriasis and its related underlying mechanism of action via in vitro analysis. HaCaT cells were stimulated with IL-22 to established an in vitro psoriasis cell model. MTT, flow cytometry and TUNEL assays, respectively. Transmission electron microscopy was used to observe the cell ultrastructure. LC3B protein expression levels were analyzed using immunofluorescence, other protein expression levels were determined using western blotting. Cell viability was significantly increased, while the apoptotic rate was significantly decreased in the model group (P < 0.001). In addition, Notch1, Hes1, beclin 1 and LC3B protein expression levels were significantly downregulated, while P62 protein expression levels were significantly upregulated in the model group compared with the control group (P < 0.001). Supplementation of Ole, the increased levels of proliferation were significantly suppressed, while cell apoptosis was significantly increased (P < 0.05) in a dose-dependent manner, which was discovered to occur via Notch1 upregulation. Notably, the transfection with small interfering RNA-Notch1 significantly reversed the effect of Ole treatment (P < 0.001) and the levels of autophagy were also decreased. In conclusion, the findings of the current study suggested that Ole may relieve psoriasis via upregulating Notch1, which subsequently regulates cell autophagy.

Keywords:
oleanolic acid; psoriasis; notch 1 receptor; HaCaT cells; autophagy