Effect of High-intensity Interval Training and Loquat Leaf Extract Consumption on Liver Enzymes in Obese Men With Non-alcoholic Fatty Liver Disease

* Corresponding Author: Seyed Hamed Ghiyami Taklimi, PhD. Address: Department of Physical Education and Sports Science, Faculty of Educational Sciences and Psychology, Mohaghegh Ardabili University, Ardabil, Iran. Tel: +98 (913) 2627940 E-mail: hamedghiyami88@gmail.com 1. Department of Physical Education and Sports Science, Faculty of Educational Sciences and Psychology, Mohaghegh Ardabili University, Ardabil, Iran. 2. Department of Physical Education and Sports Science, Faculty of Social Sciences, Imam Khomeini International University, Qazvin, Iran. Mohammad Ebrahim Bahram1 , Roghayeh Afroundeh1 , *Seyed Hamed Ghiyami Taklimi1 , Abbas Sadeghi2 , Mahsa Gholamhosseini2


Introduction
n recent years, Non-alcoholic Fatty Liver Disease (NAFLD) has received a lot of attention as the most common liver disease and one of the most important causes of chronic liver disease in children and adults [1]. The main mechanism that leads to NAFLD is not fully known yet, but factors such as obesity, metabolic syndrome, lack of antioxidant resources in the body, genetics, unhealthy and sedentary lifestyle and poor nutrition can be effective in the development of this disease [4]. Loquat is a subtropical plant belonging to the Rosaceae family with high medicinal value. It has been reported that the extracts of its various tissues (leaves, seeds and fruits) have great therapeutic effects in terms of biological activity. Ursolic acid has several biological activities including anti-oxidation, anti-inflammatory, anti-cancer and liver protection [13]. On the other hand, exercise can have positive effects on the treatment, control and prevention of NAFLD. Exercise is one of the main regulators of hepatic metabolism by increasing beta oxidation and decreasing lipogenesis. Studies have shown that High Intensity Interval Training (HIIT) is a good strategy to reduce the plasma concentrations of liver enzymes, lipid profile, insulin resistance and fat content [27]. This study aims to assess whether 8 weeks of HIIT with Loquat Leaf Extract (LLE) supplementation can affect the liver enzymes of obese men with NAFLD.

Materials and Methods
This is a quasi-experimental study with a pre-test/posttest design using a control group. The study population consists of all patients with NAFLD referred to the digestive health clinics in Qazvin province of Iran. After sending invitations, 55 volunteered to participate in the study. Of them, 40 were randomly selected and entered into the study based on the inclusion criteria and under the supervision of a physician. They were randomly divided into four groups: HIIT (n=10), LLE (n=10), HIIT+LLE (n=10) and control (n=10). LLE was administered for 8 weeks, 2 capsules per day. Each capsule contained 250 mg of LLE (Choufarm, South Korea) [31]. Exercises were performed for 8 weeks, 3 sessions per week for 60 minutes with an intensity of 80-95% of heart rate reserve. Serum levels of AST, ALP, and ALT were measured by kits made by Pars Azmoun Company in Iran using enzymatic method before the intervention and 48 hours after the last training session and supplementation. Data analysis was performed using analysis of covariance and Tukey's post hoc test considering the significance level at 0.05.

Results
There was no significant difference between the studied groups in terms of age, weight, height, body mass index and body fat percentage (P≥0.05). The results of paired t-test showed that after eight weeks of HIIT and LLE consumption, serum ALT level significantly decreased in the HIIT+LLE (P=0.01) and HIIT (P=0.02) groups; serum AST level also significantly decreased in the in the HIIT+LLE (P=0.01) and HIIT (P=0.01) groups; se- rum ALP level also significantly decreased in the in the HIIT+LLE (P=0.01) and HIIT (P=0.001) groups. Analysis of covariance was used to compare the post-test scores of the groups whose results showed a significant difference between the groups in ALT (P=0.001), AST (P=0.001) and ALP (P=0.04) ( Table 1).

Conclusion
The results of this study regarding the effects of interval training are consistent with the results of Galedari etal [33] and Najafi et al. [34] but against the results of Saji et al. [37], Fealy et al. [38] and Hallsworth et al. [39]. This discrepancy may be due to difference in the duration, type, and intensity of training. In Saji et al's study, only resistance training was used while in Fealy et al's study, endurance training was in NAFLD patients [37,38]. HIIT increases lipid oxidation, insulin sensitivity, and basal metabolic rate; therefore, it is possible that decreased levels of ALT (long half-life with the highest amount in liver tissue) and AST (shorter half-life) reduces liver enzymes by increasing basal metabolic rate and increasing lipid oxidation [36]. Loquat also has high antioxidant properties which is highly related to the phenolics and flavonoids that can be found in this plant [40]. It seems that the possible effectiveness of LLE in improving liver enzymes can be related to the antioxidant properties of ursolic acid in the plant leaves. This acid inhibits lipid peroxidation of cellular membranes by having abundant antioxidant properties and neutralizing free radicals. Moreover, it exhibits anti-inflammatory activity by decreasing cellular levels of hydrogen peroxide and nitric oxide. Therefore, due to the antioxidant and anti-inflammatory properties of ursolic acid, a decrease in the activity of liver enzymes is predictable [23]. Possible mechanisms of action of ursolic acid include a significant response with increased apoptosis in the ROS pathway, inhibition of hyperlipidemia-induced IRE1α gene activation, and JNK phosphorylation reported in the liver of db/db mice [45]. Overall, based on the results it can be argued that simultaneous use of LLE and HIIT can be more beneficial in improving liver enzyme status than when they are used alone.
It seems that consumption of LLE along with performing HIIT leads to a decrease in the level of liver enzymes in men with NAFLD.

Conflicts of interest
The authors declared no conflict of interest.