Purpose: In the present study, we aimed to investigate the effects of tomato powder (TP) on glucose and lipid metabolism, as well as oxidative stress and the NF-κB, mTOR, and Nrf2 pathways during the aging process in healthy rats.
Methods and results: Male Wistar rats were randomly assigned to four groups as follows: (i) Control group 1 (n=15, 3-week old): rats were fed standard diet for 7 weeks; (ii) TP group 1 (n=15, 3-week old): rats were fed standard diet supplemented with TP for 7 weeks; (iii) Control group 2 (n=15, 8-week old): rats were fed standard diet for 69 weeks; and (iv) TP group 2 (8-week old): rats were fed standard diet supplemented with TP for 69 weeks. TP supplementation significantly reduced the hyperglycemia, hypertriglyceridemia, and hypercholesterolemia and improved liver function and kidney function in 77-week old rats compared with the control animals (P < 0.05). In addition, TP significantly decreased the serum and liver MDA levels (P < 0.003 and P < 0.001, respectively) while increasing the activities of liver SOD (P < 0.001), CAT (P < 0.008), and GPx (P < 0.01) compared with the control groups in both 10-week-old and 77-week-old rats (P < 0.05). Age-related increases in phosphorylation of NF-κBp65, mTOR, 4E-BP1, and P70S6K were observed in livers of 77-week-old rats compared to those of 10-week-old rats (P < 0.001). TP supplementation decreased the expression of NF-κBp65 and activation of mTOR, 4E-BP1, and P70S6K in livers of 77-week-old rats compared to the control animals. Moreover, TP supplementation significantly elevated Nrf2 expression in livers of both 10-week-old and 77-week-old rats (P < 0.05).
Conclusion: TP ameliorates age-associated inflammation and oxidative stress through the inhibition of NF-κBp65, mTOR pathways, and Nrf2 activation may explain the observed improvement in glucose and lipid metabolism as well as the improved liver and kidney functions.