Effect of resistance training plus enriched probiotic supplement on sestrin2, oxidative stress, and mitophagy markers in elderly male Wistar rats

Abstract

This study aimed to determine the effects of resistance training combined with a probiotic supplement enriched with vitamin D and leucine on sestrin2, oxidative stress, antioxidant defense, and mitophagy markers in aged Wistar rats. Thirty-five male rats were randomly assigned to two age groups (old with 18-24 months of age and young with 8-12 weeks of age) and then divided into five groups, including (1) old control (OC: n = 5 + 2 for reserve in all groups), (2) young control (YC: n = 5), (3) old resistance training (OR: n = 5), (4) old resistance training plus supplement (ORS: n = 5), and old supplement group (OS: n = 5). Training groups performed ladder climbing resistance training 3 times per week for 8 weeks. Training intensity was inserted progressively, with values equal to 65, 75, and 85, determining rats' maximal carrying load capacity. Each animal made 5 to 8 climbs in each training session, and the time of each climb was between 12 and 15 s, although the time was not the subject of the evaluation, and the climbing pattern was different in the animals. Old resistance plus supplement and old supplement groups received 1 ml of supplement 5 times per week by oral gavage in addition to standard feeding, 1 to 2 h post training sessions. Forty-eight hours after the end of the training program, 3 ml of blood samples were taken, and all rats were then sacrificed to achieve muscle samples. After 8 weeks of training, total antioxidant capacity and superoxide dismutase activity levels increased in both interventions. A synergistic effect of supplement with resistance training was observed for total antioxidant capacity, superoxide dismutase, and PTEN-induced kinase 1. Sestrin 2 decreased in intervention groups. These results suggest that resistance training plus supplement can boost antioxidant defense and mitophagy while potentially decreasing muscle strength loss.

Figure 1

Differences of variables between the intervention and control groups. Graph A shows multiple comparisons between study groups in TOS, B in TAC, C in SOD, D in Sesn₂, E in Parkin, and F in PINK. OC stands for old control, YC for young control, OS for old plus supplement, OR for old plus resistance training, and ORS for old plus supplement and resistance training. *Denotes significant within-group differences after-training period values (p = 0.033), ** (p = 0.002), ***(p < 0.001), and ns represents non-significant.

Figure 2

Grip strength in the absolute and relative values before and after the intervention and maximum carrying capacity in three stages among the training groups. OC stands for old control, YC for young control, OS for old plus supplement, OR for old plus resistance training, and ORS for old plus supplement and resistance training. Wk0 shows the baseline of MCC, Wk3 shows MCC at the end of the 3rd week, and Wk6 shows MCC at the end of the 6th week. A1 and A2 show the baseline of the grip strength before starting the protocol, B1 and B2 indicate post-intervention grip strength and C1 and C2 represent MCC in three stages, both in relative and absolute values, respectively. *Denotes significant within-group differences between after-training period values (p = 0.033),** (p = 0.002), ***(p < 0.001), and ns stands for non-significance.

Figure 3

Heatmap shows the correlation between Parkin, PINK, and TAC. Significance was set on (p ≤ 0.05). TAC and PINK stand for total antioxidant capacity and PTEN-Induced Kinase1, respectively.

Figure 4

Pearson correlation test between Sesn2 and Parkin, A; Sesn2 and TAC, B; Sesn2 and PINK, C; and Normality test, D. TAC stands for total antioxidant capacity, PINK for PTEN-Induced Kinase 1, and Sesn2 for sestrin2. The mean line and p-value were also reported in each panel of figure. *Denotes significant within-group differences between after-training period values (p = 0.033),** (p = 0.002), ***(p < 0.001), and ns stands for non-significant.

Figure 5

Cage used to accommodate rats .