Abstract 1592: Anti-cancer evaluation of various solvent extracts of blue honeysuckle berry (Lonicera caerulea L.) against prostate cancer cells

Prostate cancer (PCa) is the second most common cancer among men in the United Sates. It is estimated 1 in 6 men will be diagnosed with PCa and approximately 180,890 new cases are predicted in 2016 alone. Standard treatments for PCa include surgery, radiation, chemotherapy and hormonal therapy or a combination of these treatments. However, factors like patient health, drug resistance, specificity, and toxicity can result in poor disease prognosis. In order to overcome these limitations and improve patient prognosis, there is an urgent need to identify new anti-cancer agents with minimal side effects. Current studies are being focused on natural products and their components for alternative therapeutics. Blue Honeysuckle (Lonicera caerule L.) a berry native to northeast Asia, is known to be rich in Vitamin C and polyphenols such as anthocyanins, flavonoids, and phenolic acids. Polyphenols are found to have several therapeutic effects such as anti-inflammatory, antioxidant and antimicrobial properties. Our present study used sequential solvent extracts of Blue Honeysuckle (BHS) berry using Hexane, Ethyl Acetate, Methanol, and Water respectively. These fractions were used to assess various therapeutic effects of BHS on DU 145, PC-3, C4-2 and LNCaP PCa cell lines. The goal was to identify the most potent BHS fraction that is effective against PCa using pre-clinical studies. MTT assays were used to identify the anti-proliferative effects of various BHS fractions. The above indicated PCa cells were treated with different doses (10-150 µg/mL) of BHS factions over various time periods (24, 48, 72 hr). Our data revealed that Hexane extract (HE) exhibited the highest inhibition of cell viability in a time and dose-dependent manner. HE fraction showed to have an IC50 of 89.6 μg/mL for DU 145, 117.4 μg/mL for PC-3, 163.3 μg/mL for C4-2 and 140.84 for LNCaP cells. Moreover, BHS HE fraction showed a decrease in migration capacity and colony formation ability of PCa cells in vitro. Cellular senescence assay was performed to assess β-Galactosidase activity in PCa cells treated with BHS HE extract. All the PCa cell lines treated with 100 µg/mL of BHS HE showed increased senescence. Western blotting was performed to identify the potential anti-cancer mechanism of BHS against PCa using DU 145 and PC-3 cell lines. Results from this study indicated that DU 145 and PC-3 cell lines after 24 hr treatment with 100 μg/mL of various BHS fractions especially BHS HE showed an increase in apoptosis (Caspase 3,8,9 and PARP-1) and autophagy (LC3 A/B) markers. Furthermore, cell cycle analysis of DU 145 and PC-3 cells treated with BHS HE extract showed increased apoptotic cells. Further analysis of apoptotic and autophagy pathways modulated by BHS treatments are required to illustrate its potential underlying anti-cancer mechanisms in PCa. In conclusion, results from our study warrant further evaluation of BHS berry for potential PCa management. Citation Format: Syed M. Ali, Alex Ourth, Chun-Tao Che, Mian-Ying Wang, Gnanasekar Munirathinam. Anti-cancer evaluation of various solvent extracts of blue honeysuckle berry (Lonicera caerulea L.) against prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1592. doi:10.1158/1538-7445.AM2017-1592