Ginsenoside Rh2 Enhances CD8⁺ T Cell-Mediated Anticancer Immunity in Hepatocellular Carcinoma

Background: Ginsenoside Rh2 (Rh2), a bioactive metabolite of Panax ginseng, has documented anticancer effects, but its role in cancer-immune crosstalk remains incompletely defined. Thus, we aimed to investigate the role of Rh2 in hepatocellular carcinoma (HCC) cells and immune regulation. Methods: We used a co-culture system of murine Hepa1-6 hepatocellular carcinoma cells or nonmalignant AML12 hepatocytes with primary splenocytes to model cancer-immune interactions during Rh2 exposure. Readouts included cell viability, nuclear morphology, and multiparameter flow cytometry. Results: In a co-culture system of Hepa1-6 cells and splenocytes, Rh2 decreased bulk cell viability and increased apoptosis in Hepa1-6 cells. CD8⁺ T cells exhibited enhanced effector features, with increased CD107a and IFN-γ expression following Rh2 treatment. Rh2 reduced PD-L1 expression on Hepa1-6 cells and splenocytes, and PD-1 expression on CD8⁺ T cells. Rh2 also reduced TGF-β1 and IL-6 levels in both Hepa1-6 cells and splenocytes, and decreased IL-10 levels in splenocytes. This was accompanied by a reduction in CD4⁺CD25⁺FOXP3⁺ regulatory T cells (Tregs). Conclusions: In a physiologically relevant cancer-immune context, Rh2 reprograms suppressive interactions by enhancing CD8⁺ T cell effector function, dampening PD-L1/PD-1 signaling, and reducing key immunosuppressive cytokines and Tregs. These coordinated effects position Rh2 as a candidate multi-target immunomodulatory agent for enhancing anticancer immunity.