Mechanistic investigation of RHEI FLOS extract against hepatocarcinoma via the PI3K/Akt signaling pathway In vitro and Invivo

Ethnopharmacological relevance: Modern pharmacological studies have demonstrated the anti-HCC effects of Rheum palmatum L. and formulations. Anthocyanins have also been reported to have anti-HCC activity. However, the specific role and underlying mechanisms of Rhei Flos (RF)-derived anthocyanins in the treatment of HCC remain unexplored. An investigation of these mechanisms may provide new perspectives on the hepatoprotective properties of RF and substantiate its potential application for HCC treatment.

Aim of the study: We investigated if the anti-hepatocarcinoma mechanism of the RF extract was mediated by the PI3K/Akt signaling pathway in HepG2 human hepatoma cells and H22 tumor-bearing mice.

Materials and methods: Through cell functional assays, the effects of RF extract on the proliferation, invasion, migration, and Apoptosis of HepG2 cells were investigated.Western blotting was used to analyze the expression of key proteins and genes in the PI3K/Akt signaling pathway after RF extract treatment. Biochemical indicators, organ indices, tumor inhibition rates, histopathological analysis, immunofluorescence and Western blotting were used to evaluate the therapeutic effects of RF on H22 tumor-bearing mice.

Results: The RF extract significantly inhibited HepG2 cell viability and migration while promoting Apoptosis (P < 0.05 or P < 0.01). RF extract treatment significantly decreased the expression of Ki67 and NF-κB and the p-PI3K/PI3K, p-Akt/Akt, ratios p-mTOR/mTOR but increased the expression of PTEN, TNF-α, Bax, Caspase-8, Caspase-9, and Caspase-3 (P < 0.05 or P < 0.01).

Conclusion: RF extract exerts anti-hepatocarcinoma effects by modulating tumor-related growth factors, enhancing cellular immunity, and upregulating the expression of the tumor suppressor gene PTEN. The RF extract also inhibits the expression of PI3K, p-Akt, p-mTOR, NF-κB and Bcl-2 in the PI3K/Akt pathway, thereby promoting the expression of downstream Bax, caspase-9 and Caspase-3 and ultimately inducing tumor cell Apoptosis.

Anthocyanin; Hepatocellular carcinoma; Mechanism; PI3K/Akt signaling pathway; Rhei flos.