Antioxidant/Anti-Erythema Effect on Human Skin
Antioxidant/Anti-Erythema activity
Antioxidants react
with free radicals, reducing their concentration before they can react and do damage. An excess of free radicals is
associated with many conditions, and one of the most common is sunburn,
caused by excess UV exposure. Erythema is the medical term for skin
redness caused by UV and other inflammatory conditions. If an antioxidant reduces concentrations of excess free radicals,
then a reduction in sunburn or erythema should be observed after
exposure to UV irradiation. (Note, this effect is not the same as a sunscreen,
and Combray should not be used as a substitute for sunscreen. See How to Use Combray.)
Description of Study and Results
0.3%
(wt.) formulation of Oxofulleram in grape seed oil was applied to 25
human subjects for 24 hours with occluded patch prior to irradiation
with UVA and UVB dosage of 3 times the minimal erythema dose (MED), which is defined as the UV dosage where the first definiable edges of erythema are visible. 6 treatment and irradiation tests were
performed with each subject, for a total of 150 data points.
Irradiation levels of 3MED can be expected to give a response of 1 – 3
on the erythemal response scale.
The average sunburn response (erythema response) was decreased in 25 human subjects exposed to UV irradiation in a controlled clinical study. In 7 subjects, the erythema response was eliminated; in an additional 5 subjects, the response was 0.3 – 0.5 on the erythema response scale. The average response for all subjects over all data points was 0.73 (SD 0.8). On the erythema response scale, 1 indicates the first identifiable redness with defined edges, the light intensity corresponding to this is the MED.
 Figure 1. Average response on erythema scale for 25 subjects. Each data point represents average over the 6 values in the induction period; expected average value for 3MED is 1 - 3.
 Figure 2.
Decrease in erythema response with time over the 6 applications of the induction period. Values represent number of subjects scoring zero in erythema response scale. Formulation applied with 24 hour occluded patch twice per week for 3 weeks (at same location), followed by 3MED. Both the comparison from Application 1 to Application 3 and the deviation from expected values are statistically significant.
Irradiated site on the left has application of Oxofulleram (0.3%) in grape seed oil 24 hours prior to UV exposure. The left site would be graded 0 and the right 1 (first sign of clearly defined edges). This UV dosage would also correspond approximately to 1 MED.
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