Spirulina maxima L Asparaginase: Immobilization, Antiviral and antiproliferation activities

BACKGROUND: L-asparaginase (L-AsnA) enzyme has gained significant attention in the food, biocatalysts and pharmaceutics industry. It (L-AsnA) has been widely used in food processing industries as a promising acrylamide mitigating agent and as a therapeutic agent in the treatment of certain human cancers. OBJECTIVE: Based on US Patent (4,433,054; 1984), the L-asparaginase (L-AsnA) enzyme is immobilized by admixing the active enzyme on the polysaccharide to be in a gel form [1]. The storage stability of immobilized L-AsnA enzyme and its anti-proliferation and antiviral activity were determined. METHODS: In the present study, S. maxima was cultured at large scales (300 liter) for the production of enough extracellular L-asparaginase (L-AsnA) using modified (high N concentration) Zarrouk [2] medium as we reported in a previous study [3]. The L-AsnA was immobilized on natural polymers, as agar cake beads, agarose pieces and gelatin blocks, in order to evaluate the efficiency physical entrapment techniques. Anti-proliferation properties of L-AsnA against lung carcinoma A549, hepatocellular carcinoma Hep-G2 and prostate carcinoma PC3 human cancer cell lines was assessed by the MTT cell viability method. In addition, the antiviral activity against Coxsackie B3 (CSB3) Virus was assessed. RESULTS: The highest L-AsnA immobilized activity and immobilization yield were achieved with agar cakes bead. The purified S. maxima L-AsnA showed a good antiviral activity against Coxsackie B3 (CSB3) Virus in a dose dependent manner with an IC50 value 17.03 µg/ml. The antiviral mode of action is presumably due to their capability of inhibiting attachment, blocking the adsorption and penetration event of the viral replication cycle with 89.24%, 72.78% and 72.78%, respectively. Also, S. maxima L-AsnA showed anti-proliferation effect against lung carcinoma A549, hepatocellular carcinoma Hep-G2 and prostate carcinoma PC3 human cancer cell lines, with an IC50 of 22.54, 24.65 and 56.61 µg/ml, respectively. CONCLUSION: It is interesting to favor the L-asparaginase of S. maxima showed antiviral activity and anti-proliferation effect against different types of human cell lines. Thus, S. maxima microalgae might be a good source for L-AsnA enzymes and can be immobilized on natural polymers.