Table 1 Experimental design and treatment protocol (for a duration of 18 weeks)

I

Normal control (NC); received intraperitoneal injection of 0.9% w/v NaCl solution (1 ml/kg b.w.)

II

Diabetogenic (STZ); received a single dose of streptozotocin (STZ)

III

Diabetic hepatocellular carcinoma (STZ + DEN); following 2 weeks of STZ injection and after confirmation of increased glucose levels, this group received a single injection of diethylnitrosamine (DEN) to simulate diabetic HCC condition

IV

Treatment (STZ + DEN + asarone); following 2 weeks of STZ + DEN injections, this group received a mixture dose of alpha- and beta-asarone (50 µg/kg b.w.) in the ratio of 1:1. The asarone was administered orally for 5 days per week till the end of the study after preparing in 0.5% w/v sodium carboxymethyl cellulose solution (Das et al. 2019a; Chellian et al. 2017)

V

Treatment (STZ + DEN + metformin HCl); alike to group IV except that the test compound metformin HCl (250 mg/kg b.w.), which was freshly prepared in distilled water, substituted the asarone (Das et al. 2019a; DePeralta et al. 2016)