Preliminary Study On Inhibition Of Prostate Cancer Cell Proliferation In Vitro Of Prinsepia Utilis Royle Oil

Background:Prinsepia utilis Royle is a kind of wild plant of Rosaceae Prinsepia, it is treated as "Lucky Tree" and "flowers of the king" by the Naxi, Tibetan and Mosuo people. Prinsepia utilis royle oil is fatty oil obtained from the dried ripe fruit of Prinsepia utilis Royle, as a kind of special edible oil in the folk has been used for many years which is widely used in health care, skin care, beauty, the effect is very efficacious. Vapor chromatography combined with mass spectrometry（GC-MS） detection and analysis results show that Prinsepia utilis Royle oil contains lots of unsaturated fatty acids, mainly oleic acid and linoleic acid, total content up to 75%, the suppression tumor activity of oleic acid and linoleic acid have been identified. Cancer is one of the malignant disease which is seriously harmful to the safety of human life and property. Withing the progress of science、technology and the improvement of human living standards, more and more people are diagnosed with cancer. Prostate cancer（PCa） is a malignant tumor which is one of the main causes of death in today’s society of the male population. In western developed countries,the incidence and mortality of prostate cancer is the second after lung cancer. As entered the aging society, the prevalence of prostate cancer showed an increasing trend year by year in China.Objective:In this experiment, we select Prinsepia utilis Royle oil as the experimental drug,dealing with various tumor cells to research the proliferation inhibition of PC-3 cells and its mechanism, in order to lay a theoretical basis for the anticancer biological functiondevelopment of Prinsepia utilis Royle oil, and provide experimental basis and certain reference significance in vitro anti prostate cancer research.Method:This experiment using the Prinsepia utilis Royle oil by CO₂ supercritical fluid extraction method which has a higher quality as the object of study, cultured tumor cells,divided into experimental and control groups. According to the results of preliminary experiments, set the drug concentration as 25, 50, 100, 200, 300, 400, 500 μg/m L, control group with 0.1% DMSO, the other conditions are exactly the same. The experimental group and control group put in 5% CO₂, 37 ℃ incubator about 48 hours. Using four methyl azo thiazole salt（MTT）colorimetric assay to measure the inhibitory effect on proliferation of cancer cells. Using Inverted microscope to observe the inhibition effect on proliferation of different concentrations of Prinsepia utilis Royle oil for PC-3 cells. Using flow cytometry（FCM） analysis the different of the cycle of PC-3 cells before and after using Prinsepia utilis Royle oil. Using Western Blot to detect the change of cell cycle interest protein in experimental and control groups.Results:1、MTT assay studies have shown that Prinsepia utilis Royle oil can inhibit the growth of various tumor cells, which have a strong role in prostate cancer PC-3, breast cancer cell MDA-MB-453 and colon cancer CT-26, IC50 values of the three were 285μg/m L, 339 μg/m L, 277 μg/m L; with the incubation time increased, IC50 values of 24 h,48 h, 72 h acting on PC-3 cells were 46 mg/m L, 285 μg/m L, 120 μg/m L, and in a dose-time dependent effects.2、Inverted microscope find that Prinsepia utilis Royle oil can disrupt the normal cell morphology, cells of dosing group shrinkage, refraction becomes weak, cytoplasmic lipid droplets or particles occur frequently and with the concentration increased, shaped cells gradually increased, more and more swollen, irregularly shaped cell（dead cells） began to appear.3、Flowcytometry analysis showed that, with the drug concentration increased, S phase gradually increased, G0/G1 and G2/M phase gradually decreased. Compared withthe control group, the difference of the experimental groups was statistically significant（P< 0.01）.4、Western Blot showed that with the increase of drug concentration, the expression level of cyclin-dependent kinases 2 decreased. Compared with the control group was a statistically significant（P <0.05）.Conclusion:Prinsepia utilis Royle oil can inhibit the proliferation of a variety of tumor cell,especially for androgen-independent prostate cancer cells PC-3. The mechanism maybe by blocking cell cycle in the S phase and inhibiting the expression of cyclin-dependent kinases2, thus affecting the PC-3 cell cycle distribution, reducing its distribution in G0/G1 and G2/M phase, affecting DNA synthesis and replication, thereby inhibiting cell division and proliferation.