Abstract: To study the anti-tumor effect of Cistanche deserticola in Balb/c mice, tumor-bearing nude mice subcutaneously inoculated with HepG2 liver cancer cells were administered with total glycosides (TG) of C. deserticola at different doses by gavage. The pathological changes in the liver and tumors, the proliferation capacity of splenic lymphocytes, and antioxidant indicators in the liver were detected. Metabolomics and 16S rDNA sequencing were used to analyze the changes in metabolites and microbial community composition in the intestinal contents of mice. Results showed that TG inhibited the growth of tumor in nude mice without affecting the normal growth and development of the mice and without any toxic side effects. As the dose of TG increased, the structure of hepatocytes in liver tissues became intact, the degree of pathological changes gradually reduced, the distribution of tumor cells became sparser, and the degree of vacuole deformation increased, which was accompanied by the occurrence of necrosis, indicating that TG could protect the liver and simultaneously inhibit the growth of tumor. TG alleviated liver lesions in mice, as evidenced by increased levels of catalase (CAT) and glutamic-pyruvic transaminase (GPT) and decreased levels of aspartate aminotransferase (GOT) and alkaline phosphatase (AKP). With increasing TG dose, the proliferative capacity of lymphocytes also increased, indicating that TG could exert an anti-liver cancer effect by improving immune function in mice. In addition, TG could inhibit the progression of liver cancer by regulating the levels of metabolites and improving the composition of the intestinal microbiota. Therefore, TG of C. deserticola has an anti-liver cancer effect by improving oxidative stress resistance, regulating immune capacity, improving the metabolic profile and regulating intestinal microbial balance.

Key words: Cistanche deserticola; total glycosides; anti-liver cancer; metabolomics; 16S rDNA sequencing