Bioassay-Guided extraction of andrographis paniculata for intervention of in-vitro prostate cancer progression in metabolic syndrome environment

BACKGROUND: Metabolic syndrome (MetS) is a risk factor for prostate cancer (PCa) progression. Thus, this life-threatening disease demands a proactive treatment strategy. Andrographis paniculata (AP) is a promising candidate with various medicinal properties. However, the bioactivity of AP is influenced by its processing conditions especially the extraction solvent.

OBJECTIVE: In the present study, bioassay-guided screening technique was employed to identify the best AP extract in the management of MetS, PCa, and MetS-PCa co-disease in vitro.

METHODS: Five AP extracts by different solvent systems; APE1 (aqueous), APE2 (absolute methanol), APE3 (absolute ethanol), APE4 (40% methanol), and APE5 (60% ethanol) were screened through their phytochemical profile, in-vitro anti-cancer, anti-obese, and anti-hyperglycemic properties. The best extract was further tested for its potential in MetS-induced PCa progression.

RESULTS: APE2 contained the highest andrographolide (1.34 ± 0.05 mg/mL) and total phenolic content (8.85 ± 0.63 GAE/gDW). However, APE3 has the highest flavonoid content (11.52 ± 0.80 RE/gDW). APE2 was also a good scavenger of DPPH radicals (EC50 = 397.0 µg/mL). In cell-based assays, among all extracts, APE2 exhibited the highest antiproliferative activity (IC50 = 57.5 ± 11.8 µg/mL) on DU145 cancer cell line as well as on its migration activity. In in-vitro anti-obese study, all extracts significantly reduced lipid formation in 3T3-L1 cells. The highest insulin-sensitizing and -mimicking actions were exerted by both APE2 and APE3. Taken together, APE2 showed collectively good activity in the inhibition of PCa progression and MetS manifestation in vitro, compared to other extracts. Therefore, APE2 was further investigated for its potential to intervene DU145 progression induced with leptin (10-100 ng/mL) and adipocyte conditioned media (CM) (10% v/v). Interestingly, APE2 significantly diminished the progression of the cancer cell that has been pre-treated with leptin and CM through cell cycle arrest at S phase and induction of cell death.

CONCLUSION: In conclusion, AP extracts rich with andrographolide has the potential to be used as an alternative to ameliorate PCa progression induced by factors highly expressed in MetS.