Evaluation of Saudi Juniperus procera Extracts Cytotoxicity and Regulatory Mechanisms of Tumorigenesis Against Two Breast Cancer Cell Lines

Abstract

Background Breast cancer poses a major threat to female health worldwide. One of the medicinal plants used in traditional Saudi medicine is the Juniperus procera (Arar) plant, which is used to cure various illnesses, including cancer. Objectives The cytotoxic properties of Saudi J. procera extracts and their regulatory mechanisms against tumorigenesis in breast cancer were investigated. Methods The antioxidant capacities of the fruit and leaf extracts were detected by the 2,2′-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay and 2,2-diphenyl-1-1picrylhydrazyl (DPPH) assay. The cell viability of the extracts was determined by 3-(4,5-dimethylthiazoyl)-2,5-diphenyl-tetrazolium bromide assay. The cell migration was detected by a wound healing assay. The cell cycle and cell apoptosis were analyzed by flow cytometry. The reactive oxygen species (ROS) was evaluated using a DCFDA-cellular (the cell permeant reagent 2',7' –dichlorofluorescein diacetate) reactive oxygen species detection assay. The protein and gene expression levels were estimated by western blotting and Reverse transcription polymerase chain reaction (RT-PCR), respectively. Results Phytochemical analysis revealed a high content of phenolic and flavonoids in fruit and leaf extracts. Relative to leaf extract, the fruit extract showed higher antioxidant activities and exhibited more potent cytotoxic effects against two breast cancer cell lines: MCF-7 and MDA-MB-231. The fruit extract arrested the cell cycle of the tested cancer cell lines in S phase and G1 phase, and downregulated PI3K (phosphoinositide 3-kinase-protein kinase)/Akt (protein kinase B)/mTOR (Mammalian target of rapamycin) pathway. It also suppressed aromatase expression in MCF-7 but upregulated it in MDA-MB-231. Conclusion J procera fruit and leaf extracts have significant antitumor activities against MCF-7 and MDA-MB-231 breast cancer cell lines.