Virion disruption by ozone-mediated reactive oxygen species.

It is well documented in the scientific literature that ozone-oxygen mixtures inactivate microorganisms including bacteria, fungi and viruses (Hoff, J.C., 1986. Inactivation of microbial agents by chemical disinfectants. EPA 600 S2-86 067. Office of Water, U.S. Environmental Protection Agency, Washington, DC; Khadre, M.A., Yousef, A.E., Kim, J.-G., 2001. Microbiological aspects of ozone applications in food: a review. J. Food Sci. 66, 1242-1252). In the current study, delivery and absorption of precisely known concentrations of ozone (in liquid media) were used to inactivate virus infectivity. An ozone-oxygen delivery system capable of monitoring and recording ozone concentrations in real time was used to inactivate a series of enveloped and non-enveloped viruses including herpes simplex virus type-1 (HHV-1, strain McIntyre), vesicular stomatitis Indiana virus (VSIV), vaccinia virus (VACV, strain Elstree), adenovirus type-2 (HAdV-2), and the PR8 strain of influenza A virus (FLUAVA/PR/8/34/H1N1; FLUAV). The results of the study showed that ozone exposure reduced viral infectivity by lipid peroxidation and subsequent lipid envelope and protein shell damage. These data suggest that a wide range of virus types can be inactivated in an environment of known ozone exposure.

Comparison of the total oxyradical scavenging capacity and oxygen radical absorbance capacity antioxidant assays.

Epidemiological studies have shown that phytochemicals in fruits and vegetables may decrease the incidence of cancer. The antioxidant activity of phytochemicals may be partially responsible for the reduced cancer risk. In this study, the antioxidant activity of several phytochemicals was compared using two different antioxidant assays: the oxygen radical absorbance capacity (ORAC) assay, which measures the decrease in fluorescence decay caused by antioxidants, and the total oxyradical scavenging capacity (TOSC) assay, which measures the decrease in ethylene production caused by antioxidants. TOSC and ORAC values were measured for 11 different phytochemicals, and values were expressed as micromol of Trolox equivalents/mg. As expected, a correlation was seen between the TOSC values and the ORAC values (R2 = 0.60). Quercitin, maritime pine bark extract (Pycnogenol, Horphag Research Ltd., Geneva, Switzerland), grape skin extract, and green tea polyphenols had the highest overall antioxidant activity of the 11 phytochemicals measured. Lemon fruit and citrus bioflavonoids had the lowest overall antioxidant activity. Rutin and alpha-lipoic acid had low ORAC values but high TOSC values when compared to the other phytochemicals. The correlation between the in vitro TOSC and ORAC antioxidant assays suggests that both assays may be useful in identifying phytochemicals with high antioxidant activity.