Page 188 - 2025中醫藥與天然藥物聯合學術研討會-中醫藥與天然藥物的挑戰Ｘ機遇與未來大會手冊

PP-06

Edible and agricultural plant extracts as sources of natural product

candidates targeting NRF2 in HCC

1
2
3
Ying-Hsuan Lee, Yi-Siao Chen, Ying-Fei Lo, Chia-Hung Yen* ,1,2,4,5

1 Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan.
2 Ph.D. Program in Environmental and Occupational Medicine, College of Medicine,
Kaohsiung Medical University, Kaohsiung, Taiwan
3 Taiwan Seed Improvement And Propagation Station , Ministry of Agriculture
4 Drug Development and Value Creation Research Center, Kaohsiung Medical University,
Kaohsiung, Taiwan
5 Center for Cancer Research, Kaohsiung Medical University, Kaohsiung, Taiwan

* Email: chyen@kmu.edu.tw

Abstract
Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related mortality
worldwide, and therapeutic efficacy for advanced HCC remains limited. Aberrant activation of
NRF2 drives chemoresistance in hepatocellular carcinoma (HCC), and several natural
compounds have been reported as NRF2 inhibitors. However, existing candidates remain
limited by suboptimal potency and selectivity, poor pharmacokinetic or safety profiles, narrow
mechanisms prone to resistance, and a lack of systematic evaluation for combinatorial or multi-
target effects.These gaps highlight the need for large-scale, systematic screening to identify
safer and more effective NRF2 modulators with translational potential. A total of 445 plant
extracts(ethonalic extracts from 346 edible plants and 99 agricultural plants) were screened
using a luciferase reporter assay driven by the antioxidant response element (ARE) in stable
Huh7-ARE cells. Eleven hits underwent secondary dose–response testing, yielding six extracts
(P1–P6) with IC₅₀ values below 20 μg/mL. These were further assessed by cytotoxicity assays
(72 h, CC₅₀) in parental Huh7 cells, which confirmed detectable cytotoxicity (CC50 ranged
from 1.56-100 μg/mL) in all six candidates Western blotting revealed that for these 6 extracts,
reporter inhibition was not consistently associated with reduced total NRF2 protein, suggesting
distinct inhibitory mechanisms. Confocal imaging further revealed variable effects on NRF2
nuclear localization, with P2 showing the most consistent suppression of nuclear accumulation.
Selectivity analysis (CC₅₀/IC₅₀) indicated values > 1 for P1 and P2, suggesting that their
anticancer activity is more likely related to NRF2 inhibition rather than nonspecific cytotoxicity.
In summary, our screening pipeline identified P1 and P2 as promising NRF2-modulating
extracts. Derived from edible plants, they offer translational advantages, including potential
oral applicability, and warrant further investigation as adjunctive strategies for HCC.

Keywords: NRF2; Hepatocellular carcinoma; Natural products; Reporter assay