Background: Aging is a multifactorial phenomenon that is characterized by a decrease in physiological functions that increases with age. Free radicals cause oxidative stress, which plays a role in the aging process. The accumulation of reactive oxygen compounds increases matrix metalloproteinase-2. Collagen can be directly destroyed by reactive oxygen compounds or through the induction of MPPs. Tomato fruit is an antioxidant, which acts as a binder and damper of free radicals that activate collagen damage. This study aims to assess the effect of tomato juice on the expression of MMP-2 and type-1 collagen on the vaginal wall of the menopausal rat.
Methods: This was a true experimental study, using Sprague-Dawley rats and tomato juice (Solanum lycopersicum). Expression of MMP-2 and type-1 collagen was examined using immunohistochemistry staining. Twenty-four healthy female rats, aged 4 months weighing 150-200 grams, were divided into 4 groups, each group as many as 6 rats. The negative control group (NC) was a group of rats with a sham procedure, given aquades for 28 days. The positive control group (PC) was bilaterally ovariectomized rats, given aquades for 28 days. The first treatment group (P1) was bilaterally ovariectomized rats, given tomato juice with a dose of 11 g / 200 g BW / day. The second treatment group (P2) was bilaterally ovariectomized rats, given tomato juice with a dose of 15 g / 200 g BW / day. Data analysis used the One-way ANOVA statistical test (Î± = 0.05) and different tests between groups using Games-Howell and Tukey HSD. The association between tomato juice and the expression of MMP-2 and type-1 collagen used regression tests.
Results: This study found that the lowest expression of MMP-2 was NC group (2.07 Â± 0.84), and the highest was the PC group (5.72 Â± 1.91). The mean MMP-2 expression in the treatment groups was lower than the PC group but still higher than the NC group. There was a significant difference in MMP-2 expression between groups (p = 0,000). There was a negative correlation between tomato juice administration and MMP-2 expression (b = -0.592). The lowest type-1 collagen expression was PC group (3.83 Â± 1.44), and the highest was the P2 group (7.27 Â± 2.21). The mean type-1 collagen expression in the treatment groups was higher than the PC group. There were significant differences of type-1 collagen expression between groups (p = 0.012). There was a positive correlation between tomato juice administration and type-1 collagen expression (b = 0.682).
Conclusions: Tomato juice administration can reduce the expression of MMP-2 and increase the expression of type-1 collagen on the vaginal wall of the menopausal rat. The higher the dose of tomato juice, the higher the expression of type-1 collagen.