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.