Table 1.
Effect of treatment with sulforaphane (broccoli sprout extract) on the erythema induced by UV radiation
| Subject | Sex | Age, yr | Reduction in UVR-induced erythema at given UVB radiation dose, % |
Mean reduction in erythema, % | P value | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 300 mJ/cm2 | 400 mJ/cm2 | 500 mJ/cm2 | 600 mJ/cm2 | 700 mJ/cm2 | 800 mJ/cm2 | |||||
| 1 | M | 53 | 66.8 | 32.3 | 33.1 | 16.6 | 48.8 | 32.1 | 38.3 | 0.0029 |
| 2 | F | 32 | 69.1 | −1.4 | −5.5 | 56.5 | 15.4 | 8.7 | 23.8 | 0.1220 |
| 3 | F | 28 | 30.1 | 1.7 | 1.5 | −5.7 | 22.2 | 0.4 | 8.37 | 0.2102 |
| 4 | M | 41 | 60.0 | 107.5 | 37.1 | 115.7 | 58.9 | 89.5 | 78.1 | 0.0016 |
| 5 | F | 29 | 52.0 | 72.5 | 87.0 | 64.5 | 26.7 | 20.9 | 53.9 | 0.0038 |
| 6 | M | 48 | N/A | 61.4 | 1.1 | 45.9 | 11.7 | −2.5 | 23.5 | 0.1390 |
| 37.7 ± 11.2 (± SEM) | 0.025 | |||||||||
The six subjects (three men and three women) were studied under identical conditions over a 5-day period, as described under Materials and Methods. The pairs of adhesive vinyl templates were applied in the same paraspinal positions on 4 successive days, at 24-h intervals, and erythema index (a*) values were determined with the chromometer on each of the 16 circular (2.0-cm diameter) windows at each session. The means of the last eight values of each set of measurements obtained on 4 days were averaged, and these means were assumed to be the a* values for each spot before UVR (Pre-UVR). Immediately after the last measurements, the subjects were exposed to a range of doses of UV (311 nm), such that the eight pairs of adjacent spots received 100–800 mJ/cm2 in 100 mJ/cm2 increments. Twenty-four hours after UVR, the chromometer a* measurements were repeated (Post-UVR). Only results for the 300–800 mJ/cm2 UVR are shown (see text). On the first 3 days, one of each pair of spots was treated with 25 μl of BSE containing 200–400 nmol SF (in 80% acetone/20% water), and the other received 25 μl of solvent only. The effects of treatment on UVR-induced erythema a* were derived from the change in a* values (Δa*), i.e., (a*Post-UVR − a*Pre-UVR) for BSE and solvent-treated spots, and the percentage change expressed as follows: [(Δa* of treated spot/Δa*of control spot) × 100]. The P values were calculated using a two-sided Student t test and represent the comparison between an individual subject's average percent reduction (i.e., across all UVR doses administered) and no protection (i.e., 0% reduction in erythema). For the purpose of the t test, we assumed the standard deviation associated with no protection (0% reduction) was the same as that calculated for each individual. Consequently, in determining the significance of the mean percent reduction for all six subjects, the standard deviation associated with a no protection value (0%) was assumed to be equal to that of the individual subject responses.