Table 13

Effect of topical applications of caffeine or EGCG on the formation of histologically characterized tumors in high-risk mice

High-risk UVB-pretreated SKH-1 mice (30/group) were treated topically with 100 μl acetone, caffeine (6.2 μmol) in 100 μl acetone, or EGCG (6.5 μmol) in 100 μl acetone once daily 5 days a week for 18 weeks. The numbers in parentheses represent percentage of inhibition. Each value represents the mean ± SE. (Taken from Ref. 324 .)

TreatmentNonmalignant tumorsSquamous cell carcinomas
Percentage of mice with tumorsTumors per mousePercentage of mice with tumorsTumors per mouse
Acetone827.21 ± 1.28641.18 ± 0.25
Caffeine774.03 ± 0.76a23b0.33 ± 0.12b
(6% ↓)(44% ↓)(64% ↓)(72% ↓)
EGCG703.27 ± 0.67b23b0.40 ± 0.18b
(15% ↓)(55% ↓)(64% ↓)(66% ↓)
  • a P < 0.05.

  • b P < 0.01.