Cytotoxicity and potential anticancer activities of herbal formulations from cultivated Ganoderma species in Nigeria against Human Hepatocellular Carcinoma

Domesticated wild Ganoderma species have emerged as a valuable adjunct in the treatment of specific cancers and tumors, offering new avenues for therapeutic intervention. However, many existing treatments for Human Hepatocellular Carcinoma (HepG2), which are mostly costly, are limited by cirrhosis. In contrast, natural compounds in Ganoderma have potential synergistic and low-toxicity properties that could enhance therapeutic outcomes. In this study, heavy metal analysis, anti-proliferation screening of extracts and formulations of three cultivated Ganoderma species against HepG2 and Vero cells, and cytoplasmic fluorescence imaging of cells tracked with Red CMTPX were conducted. Ganoderma isolates were identified using Polymerase chain reactions (PCR) with Internal transcribed spacer sequences (ITS1 and ITS4) using a GenBank BLAST. Heavy metals were at acceptable levels according to the WHO standard. Indeed, the effective anti-proliferative, cell-mediated cytotoxicity of these species was observed. The hot water extract of Ganoderma sessile, Ganoderma oregonense, and Ganoderma mbrekobenum combined formulation (MCF-11) exhibited potent cytotoxicity with an IC50 of 44.7 µg mL-1 against HEPG2 cells, while showing mild toxicity with IC50 of 158.4 µg mL-1 against Vero cells. Mycelia biomass formulation of G. mbrekobenum showed a remarkable value of IC50 < 30 µg mL-1. At 100 μg mL-1, the effect of MCF-11 on treated cells was evident, as the cells lost their typical morphology and the cytoplasm appeared shrunken and rounded, with reduced cell volume. However, extracts demonstrated dose-dependent toxicity, indicating anti-HepG2 potential.