Mechanism Study On Bitter Apricot Oil Induced HaCaT Cell Apoptosis And NF-κB Pathway Inhibition

Psoriasis is a chronic immune-mediated inflammatory skin disease that affects approximately 2% of the world’s population. Conventional therapeutic approaches are not effective or necessarily safe for treating symptoms due to the serious side effects and resistance to currently prescribed drugs. Traditionally, in oriental medicine, apricot seed(Semen Armeniacae amarum) is used to treat skin diseases. However, the underlying mechanism of action has not been systematically elucidated.Bitter apricot essential oil(BAEO) is the volatiles mixture extracted from almond seeds.In the present study, the anti-proliferation effects, apoptosis-inducing effects and inner mechanism by setting HaCat as the research target after stimulating it with BAEO were evaluated and investigated.Methods:(1) Portraying the growth curve to detect the anti-proliferation effects to HaCaT cells of BAEO and the comparing medicine methotrexate.(2) Using Western blot assay to identify changes of expression of associated protein:caspase3/8/9, PARP, Bcl-2, Bax, NF-κB, IκB and IKK.(3) Adopting anti-denaturation assay to detect the anti-inflammatory activity of BAEO.The results are as following:(1) Bitter almond oil and methotrexate can cause obvious inhibiting effect to the proliferation of HaCat in dose and time-dependent manner. And the cytotoxicity of bitter almond oil is stronger than that of methotrexate.(2) BAEO is able to induce cell apoptosis. The protein expression index of both Apoptosis related key protein,caspase3/8/9 and PARP, shows down-regulation and cleaved band appears, the apoptosis of cell has been significantly inhibited after adding caspase specific inhibitor. Being mutual antagonistic apoptosis-related protein, the expression index of Bax shows up-regulation and down-regulation for Bcl-2. The expression indexes of NF-κB p65, IκB-α and IKKα/β show down, up and down-regulation, respectively. Results above illustrate that BAEO induce cell apoptosis in both intrinsic and extrinsic pathways.(3) BAEO and the control drug acetylsalicylic acid both present good activity inhibiting protein degeneration in concentration-dependent manner via detecting anti-inflammatory activity of BAEO with anti-denaturation assay.The result shows that BAEO can inhibit the cell proliferation of HaCat significantly and induce apoptosis in both intrinsic and extrinsic pathways. BAEO has the initialanti-inflammatory activity. All the results suggest that BAEO is a naturally occurring material from plants that functions as a potent pro-apoptotic medcine for human keratinocytes. Thus,it is a promising candidate to treat psoriasis.