Ginsenoside Rh4 Facilitates the Sensitivity of Renal Cell Carcinoma to Ferroptosis via the NRF2 Pathway

Background: Renal cell carcinoma (RCC) is one of the most common malignancies of the urinary system and ferroptosis is considered as a promising therapeutic approach for treating RCC. Ginsenoside Rh4 (Rh4) was proved to have anticancer properties and play roles in ferroptosis. This study aimed to investigate the potential of ginsenoside Rh4 (Rh4) in enhancing the sensitivity of renal cell carcinoma (RCC) cells to ferroptosis and to elucidate the underlying mechanisms. Methods: RCC cell lines of 786-O and ACHN were treated with RAS-selective lethal 3 (RSL3) and/or Rh4. Cell-viability assays were used to determine how Rh4 affected the sensitivity of RCC cells to RSL3-induced ferroptosis. Quantitative real-time polymerase chain reaction was conducted to examine the levels of ferroptosis-related genes. Additionally, the knockdown of nuclear factor E2-related factor 2 (NRF2) was performed to investigate the role of NRF2 in mediating the effects of Rh4. Results: RSL3 suppressed the progression of RCC cells by inducing ferroptosis. Furthermore, Rh4 led to more RCC sensitivity to ferroptosis induced by RSL3. Rh4 downregulated the ferroptosis-related gene expression including superoxide dismutase 1 (p < 0.01), glutathione peroxidase 4 (p < 0.01), and catalase (p < 0.01), which was attenuated by NRF2 knockdown. This finding suggested that Rh4 exerted its sensitising effect on ferroptosis through the NRF2 pathway. Conclusions: Rh4 made RCC cells more sensitive to ferroptosis by inhibiting the NRF2 signaling and suppressing the expression of antioxidant enzymes. Therefore, combining Rh4 with ferroptosis-inducing reagents to treat RCC had potential therapeutic application.