Ashwagandha (Withania somnifera) targets liver cancer stem cells via inhibiting Hedgehog signaling pathway in hepatocellular carcinoma

Ashwagandha (W. somnifera), known for its broad health benefits, has shown potential in cancer prevention and treatment. The aim of this study was to investigate the potential effect of ashwagandha aqueous extract (ASH-AE) on cell proliferation and therapy resistance markers in hepatocellular carcinoma (HCC). An in vitro study was conducted using the HepG2 cell line. The HepG2 cells were divided into 4 groups according to the treatment regimen received. ASH-AE was extracted from the whole plant and characterized by GC-MS and HPLC. HepG2 cell viability was determined for all groups. The protein expression of cluster of differentiation 90 (CD90) was determined by flow cytometry technique. Also, the gene expression of Sonic Hedgehog (SHH), Patched 1(PTCH1) and ATP-binding cassette subfamily C1 (ABCC1) was assayed by qRT-PCR. The protein expression and localization of glioma-associated oncogene 1 (Gli1) in HepG2 cells were determined by immunocytochemistry (ICC) assay. The results indicated that ASH-AE either alone or in combination with sorafenib (SOR) significantly reduced HepG2 cell viability in a concentration dependent manner (P ˂0.001) with IC50 was 6.65 mg/ml for ASH-AE, 11.3 µM for SOR, and 5.6 mg/ml + 18.6 µM for ASH-AE in combination with SOR. Moreover, SOR significantly increased the percentage of CD90⁺ cells and Gli1 protein expression and nuclear translocation as well as ABCC1 gene expression compared to untreated cells. On the other hand, ASH-AE either alone or in combination with SOR significantly decreased the percentage of CD90⁺ cells and Gli1 expression and nuclear translocation as well as SHH, PTCH1 and ABCC1 gene expression compared to untreated cells and that treated with SOR. We concluded for the first time that the combination of SOR and ASH-AE generates antagonistic antitumor effect in HepG2 cells. Moreover, ASH-AE can inhibit proliferation of HepG2 cells and mitigate sorafenib-induced resistance-associated markers in HepG2 cells by targeting CD90⁺ cells via Hedgehog pathway modulation.