Optimization and characterization of antileukemic L-asparaginase produced by Fusarium solani endophyte

Abstract

Abstract L-asparaginase is an antileukemic enzyme that hydrolyzes L-asparagine into L-aspartic acid and ammonia, causing leukemia cell starvation and apoptosis in susceptible leukemic cell populations. Currently, L-asparaginase obtained from bacterial sources is constrained by several issues, including lesser productivity, stability, selectivity, and higher toxicity. The goal of this study is to provide fungal L-asparaginase with in-vitro effectiveness towards different human carcinomas. L-asparaginase from endophytic Fusarium solani (Gene Bank accession number MW209717) isolated from the roots of the medicinal plant Hedera helix L. was characterized and optimized experimentally for maximum L-asparaginase production in addition to evaluating its subsequent cytotoxicity towards acute monocytic leukemia and human skin fibroblast cell lines. The enzyme production was maximized using potato dextrose media at the 5th and 6th days of fermentation with incubation temperature 30 ℃ with 3% asparagine. Enzyme characterization studies revealed that the enzyme maintained its thermal stability with temperatures up to 60 ℃. Results revealed promising cytotoxic activity against acute monocytic leukemia with IC50 = 3.66 µg/ml with low cytotoxicity against tested normal human skin fibroblast cell line which suggested that it might have selective toxicity, and consequently it could be used as a less toxic alternative to the current formulations.