Table 16

Effect of oral administration of black tea on bromodeoxyuridine incorporation into the DNA of established papillomas, keratoacanthomas, and squamous cell carcinomas in SKH-1 mice

Female SKH-1 mice (7–8 weeks old) were irradiated with UVB (30 mJ/cm2) twice weekly for 22 weeks, and UVB administration was stopped. Tumors were allowed to develop during the following 13 weeks, and tumor-bearing mice (17/group) were then treated with lyophilized black tea (6 mg tea solids/ml) or water as the drinking fluid for 11 weeks. Bromodeoxyuridine (50 mg/kg) was injected i.p., and the animals were killed 1 h later. Bromodeoxyuridine positive cells in each area of focal epidermal hyperplasia and in each tumor were counted and expressed as the number of positive cells per 100 cells counted. Each value is the mean ± SE, and the numbers in parentheses represent percentage of inhibition. (Taken from Ref. 341 .)

TreatmentNumber of miceBromodeoxyuridine labeling index
Focal epidermal hyperplasiaSquamous cell papillomasKeratoacanthomasNonmalignant tumorsSquamous cell carcinomasTotal tumors
Water1514.1 ± 1.533.9 ± 6.535.2 ± 2.935.0 ± 2.654.5 ± 4.340.2 ± 2.4
Black tea1414.3 ± 1.915.0 ± 4.419.5 ± 2.419.0 ± 2.135.2 ± 4.223.5 ± 2.3
(−1)(56)(45)(46)(35)(42)