Flavonoid extract Kushenol a exhibits anti-proliferative activity in breast cancer cells via suppression of PI3K/AKT/mTOR pathway

PLGA-PEG-c(RGDfK)-Kushenol E Micelles With a Therapeutic Potential for Targeting Ovarian Cancer

Background: As a naturally derived inhibitor of autophagy, Kushenol E (KE) is a biprenylated flavonoid and is isolated from Sophora flavescens, which has been used for the treatment of cancer, hepatitis, and skin diseases. However, KE, as a poorly soluble drug, exhibited strong autophagy regulating activity in in vitro cancer cell lines, but no related studies have reported its antiovarian cancer property. Therefore, it is very beneficial to enhance the antineoplastic properties of KE by establishing an ovarian tumor-targeting nanoparticle system modified with tumor-homing c(RGDfK) peptides. Materials and Methods: In the current study, poly(lactic-co-glycolic acid)-poly(ethylene glycol)-modified with cyclic RGDfK peptide (PLGA-PEG-c(RGDfK))-KE micelles (PPCKM) were prepared to overcome the poor water solubility of KE to meet the requirement of tumor-active targeting. The effect of PPCKM on ovarian cancer was evaluated on SKOV-3 cells and xenograft models in BALB/c nude mice. Results: The PPCKM showed a higher drug cumulative release ratio (82.16 ± 7.69% vs. 34.96 ± 3.05%, at 1.5 h) with good morphology, particle size (93.41 ± 2.84 nm), and entrapment efficiency (89.7% ± 1.3%). The cell viability, migration, and apoptosis analysis of SKOV-3 cells demonstrated that PPCKM retained potent antitumor effects and promoted apoptosis at early and advanced stages with concentration-dependent. Based on the establishment of xenograft models in BALB/c nude mice, we discovered that PPCKM reduced tumor volume and weight, inhibited proliferating cell nuclear antigen (PCNA) and Ki67 expression, as well as promoted apoptosis by targeting the tumor site. Conclusion: The findings in this study suggest that PPCKM may serve as an effective therapeutic option for ovarian cancer.

Investigation of prunetrin induced G2/M cell cycle arrest and apoptosis via Akt/mTOR/MAPK pathways in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) stands as a leading cause of mortality, and despite recent advancements in the overall survival rates, the prognosis remains dismal. Prunetin 4-O-glucoside (Prunetrin or PUR), an active compound derived from Prunus sp., was explored for its impact on HepG2 and Huh7 cells. The cytotoxicity assessment revealed a notable reduction in cell viability in both cell lines, while exhibiting non-toxicity towards HaCaT cells. Colony formation studies underscored PUR's inhibitory effect on cell proliferation, dose-dependently. Mechanistically, PUR downregulated cell cycle proteins (CDC25c, Cdk1/CDC2, and Cyclin B1), inducing G2/M phase arrest, corroborated by flow cytometry. Western blot analyses exhibited dose-dependent cleavages of PARP and caspase 3, indicative of apoptosis. Treatment with the apoptotic inhibitor z-vmd-fmk provided evidence of PUR-induced apoptosis. Annexin V and PI flow cytometry further affirmed apoptotic induction. Enhanced expression of cleaved-caspase 9 and the pro-apoptotic protein Bak, coupled with reduced anti-apoptotic Bcl-xL, and affirmed PUR's induction of intrinsic apoptosis. Additionally, PUR activated the MAPK pathway, evidenced by elevated phospho p38 and phospho ERK expressions in both cell lines. Notably, a concentration-dependent decrease in mTOR and Akt expressions indicated PUR's inhibition of the Akt/mTOR pathway in HepG2 and Huh7 cells. These findings illuminate PUR's multifaceted impact, revealing its potential as a promising therapeutic agent against HepG2 and Huh7 cells through modulation of cell cycle, apoptosis, and key signaling pathways.

Estrogenic Prenylated Flavonoids in Sophora flavescens

Sophora flavescens is a medicinal herb distributed widely in Japan and it has been used to treat various diseases and symptoms. To explore its pharmacological use, we examined the estrogenic activity of four prenylated flavonoids, namely kurarinone, kushenols A and I, and sophoraflavanone G, which are characterized by the lavandulyl group at position 8 of ring A, but have variations in the hydroxyl group at positions 3 (ring C), 5 (ring A) and 4' (ring B). These prenylated flavonoids were examined via cell proliferation assays using sulforhodamine B, Western blotting, and RT-PCR, corresponding to cell, protein, and transcription assays, respectively, based on estrogen action mechanisms. All the assays employed here found weak but clear estrogenic activities for the prenylated flavonoids examined. Furthermore, the activities were inhibited by an estrogen receptor antagonist, suggesting that the activities were likely being mediated by the estrogen receptors. However, there were differences in the activity, attributable to the hydroxyl group at position 4', which is absent in kushenol A. While the estrogenic activity of kurarinone and sophoraflavanone G has been reported before, to the best of our knowledge, there are no such reports on kushenols A and I. Therefore, this study represents the first report of their estrogenic activity.