Fig. 2. Effect of crocetin on HO generation by H2O2 with UV irradiation. (A) ESR spin trapping measurement of HO generated by H2O2 with UV irradiation for 5 sec with CYPMPO (5.0 mM) as the spin trap in the presence of crocetin (0, 125, 250, 500, 1,000 µM). (B) The effects of crocetin on HO generation by H2O2 with UV irradiation. The signal intensity of the seventh peak of the spectrum was normalized as the relative height against the signal intensity of the control. Results are expressed as the percentage of the mean control value and are represented as mean ± SD. * significant difference (p<0.05) versus the corresponding control value. Fig. 3. ESRCT imaging in isolated SHRSPs brain following crocetin administration. Effects of administration of crocetin on 2D ESR imag es (z–x plane) of MCPROXYL distribution in isolated brain of SHRSPs. ESR was measured at 3, 5, 7, 9, 11, 13, 15, 17, 19 and 21 min afte r i.v. treatment with MCPROXYL (isolated 30 sec after the treatment). The color scale shows 32 colors (white and 100 being the maximum ESR signal). T he ESR images are reproduced in 32 colors with signals lower than 10% of the maximal signal intensity detected in all slices regarded as noise. Experimental condi tions are described in Materials and Methods. decreased the decay rate of the 2D ESR-CT image of MC-PROXYL in the isolated brain (Fig. 3). The signal decay rate of MC- PROXYL in this study was confirmed with preliminary data from a previous study using ESR-CT imaging with L-band ESR analysis. The signal decay rate constant of MC-PROXYL in brain of SHRSPs brain was significantly lower than that of the control (p<0.05) (Fig. 4). Crocetin analysis in plasma and brain. Crocetin was given to SHRSPs (n = 6) by oral administration at the same dose (100 mg/kg) used in the ESR experiments (Fig. 3 and 4). Plasma 184 doi: 10.3164/jcbn.1101 ©2011 JCBN