| Contact angle differences | Young rats | Senescent rats | ||
| t-student | p | t-student | p | |
| Rats treated with polyphenols | ||||
| Catalase (GL = 22) | 38.55 | p < 0.001 | 49.86 | p < 0.001 |
| SOD (GL = 22) | 0.29 | NS | 13.54 | p < 0.001 |
| Rats treated with zinc | ||||
| Catalase (GL = 22) | 94.15 | p < 0.001 | 50.35 | p < 0.001 |
| SOD (GL = 22) | 1.90 | NS | 12.31 | p < 0.001 |