Antiviral and Cytotoxic Effects of Mycophenolic Acid

Mycophenolic acid, produced by various species of the genus Penicillium, has been shown to have both antibacterial and antifungal properties (see Korzybski, Kowszyk-Gindifer & Kurylowicz 1967). Mycophenolic acid was found to be antiviral in tissue culture. The Agar Diffusion Test (Herrmann et al. 1960) was employed, using 100 µg. per well. It gave zones of plaque inhibition of 40 to 60 mm. against vaccinia, herpes simplex, Semliki Forest, encephalomyocarditis, Coxsackie (Bl, conn. 5) and influenza (A-nws) viruses. The degree of inhibition against vaccinia virus compared favourably with that obtained with the known antivaccinial compounds iododeoxyuridine (80 mm.) and methisazone (75 mm.). When incorporated into the agar overlay in a normal plaque technique, it was found that the median plaque inhibitory concentration was 0.3 to 1 µg./ml. for vaccinia virus, the same as that obtained with iododeoxyuridine and methisazone.