Therapeutic impact of purified Trichoderma viride L-asparaginase in murine model of liver cancer and in vitro Hep-G2 cell line.

Background: Hepatocellular carcinoma (HCC) is among the common cancers, but difficult to diagnose and treat. L-asparaginase has been introduced in the treatment protocol of pediatric acute lymphoblastic leukemia (ALL) since the 1960s with a good outcome and increased survival rates to nearly 90%. Moreover, it has been found to have therapeutic potential in solid tumors. Production of glutaminase-free-L-asparaginase is of interest to avoid glutaminase-related toxicity and hypersensitivity. In the current study, an extracellular L-asparaginase that is free of L-glutaminase was purified from the culture filtrate of an endophytic fungus Trichoderma viride. The cytotoxic effect of the purified enzyme was evaluated in vitro against a panel of human tumor cell lines and in vivo against male Wister albino mice intraperitoneally injected with diethyl nitrosamine (200 mg/kg bw), followed by (after 2 weeks) oral administration of carbon tetrachloride (2 mL/kg bw). This dose was repeated for 2 months, and after that, the blood samples were collected to estimate hepatic and renal injury markers, lipid profiles, and oxidative stress parameters.

Results: L-asparaginase was purified from T. viride culture filtrate with 36 purification folds, 688.1 U/mg specific activity, and 38.9% yield. The highest antiproliferative activity of the purified enzyme was observed against the hepatocellular carcinoma (Hep-G2) cell line, with an IC₅₀ of 21.2 g/mL, which was higher than that observed for MCF-7 (IC₅₀ 34.2 g/mL). Comparing the DENA-intoxicated group to the negative control group, it can be demonstrated that L-asparaginase adjusted the levels of the liver function enzymes and the hepatic injury markers that had previously changed with DENA intoxication. DENA causes kidney dysfunction and altered serum albumin and creatinine levels as well. Administration of L-asparaginase was found to improve the levels of the tested biomarkers including kidney and liver function tests. L-asparaginase treatment of the DENA-intoxicated group resulted in a significant improvement in the liver and kidney tissues to near normal similar to the healthy control group.

Conclusion: The results suggest that this purified T. viride L-asparaginase may be able to delay the development of liver cancer and may be used as a potential candidate for future application in medicine as an anticancer medication.