Bioassay-guided extraction of Andrographis paniculata for intervention of in-vitro prostate cancer progression in metabolic syndrome environment

Abstract

Metabolic syndrome (MetS) is considered to be a risk factor for prostate cancer (PCa) progression. This disease has become one of the most significant healthcare issues, and the demands for a proactive curing strategy is essential. Plants and their bioactive compounds are promising sources for anticancer drug discovery. In this study, Andrographis paniculata (AP) or locally known as Hempedu Bumi has been selected due to its many reported medicinal values, particularly in the treatment of cancer, hyperglycemia and dysregulated lipid profile, and in the management of obesity. However, successful extraction of the active compounds from AP is crucial for maximum activity, which is influenced by extraction parameters particularly the solvent. Therefore, the current research aimed to discover the most potential AP extract as an agent to intervene PCa progression in metabolic syndrome environment. Strategically, bioassay-guided extraction of AP was conducted. Five AP extracts, each prepared with different solvent system using ultrasound-assisted extraction, designated as APE1 (aqueous), APE2 (absolute methanol), APE3 (absolute ethanol), APE4 (40 % methanol), and APE5 (60 % ethanol) were tested on in vitro MetS and PCa conditions utilizing the 3T3L1 adipocytes and DU145 cells, respectively. For extraction yield, APE4 (18.29 ± 2.02 %) resulted in the highest yield followed by, APE5 (15.78 ± 2.04 %), APE1 (14.76 ± 1.44 %), APE2 (8.81 ± 1.72 %), and APE3 (6.81 ± 0.24 %). Based on high-performance liquid chromatography analysis, APE2 was found to contain the highest andrographolide (andro) content at 1.34 ± 0.05 mg/mL. Similarly, the phenolic content of APE2 (8.85 ± 0.63 GAE/g DW) and APE3 (8.75 ± 0.06 GAE/g DW) significantly among the highest in this study. APE3 also displayed the highest flavonoid content at 11.52 ± 0.80 RE/ g DW. In the 1,1-diphenyl-2-picrylhydrazyl scavenging activity, APE2 resulted in the most potent activity (EC50 = 397.0 µg/mL). APE2 also exhibited the most potent antiproliferative action on DU145 PCa cell line with IC50 equivalent to 57.5 ± 11.8 µg/mL. APE2 and APE3 significantly inhibited the migration activity of DU145 after treatment with the concentration of 125 µg/mL for 24 hr. During adipogenesis inhibition in 3T3-L1 cells, APE3, APE4, and APE5 significantly reduced the lipid formation with a more considerable margin than APE2. Nevertheless, the inhibition by APE2 was still statistically significant compared to the untreated control. APE2 also demonstrated significantly higher insulin-sensitizing activity. Likewise, APE2, together with APE3 and APE5, simultaneously mimic insulin’s action. The bioassay-guided extraction resulted in APE2 as the most potential AP extract. Leptin (10 – 100 ng/mL) progressively induced the proliferation of DU145. Similarly, adipocyte conditioned media (CM) induced the growth of DU145 at 10 % concentration. Co-treatment of DU145 with leptin/CM and APE2 successively diminished the proliferative effects through cell cycle arrest and apoptotic event. In conclusion, an andrographolide-rich AP extract shows high potential to ameliorate PCa progression induced by MetS factors, particularly leptin.