Table 1.
Leucine supplementation studies in animal models of cancer cachexia. In dietary details, C—control diet and E—experimental diet.
| Author(s) | Animals | Dietary Details | Experimental Protocol | Major Effect(s) |
|---|---|---|---|---|
| Cruz et al., 2017 [124] | Walker-256 tumor model, female Wistar rats (n = 72, 90 days old, weighing 180–200 g) | C = 18% protein E = 18% protein + 3% leucine |
12 groups according to Walker-256 status, tumor growth period, and diet | Attenuated skeletal muscle and protein content loss |
| Cruz et al., 2020 [125] | Walker-256 tumor model, male Wistar rats (n = 72, 90 days old, weighing 350–380 g) | C = 18% protein E = 18% protein + 3% leucine |
4 groups according to Walker-256 status and diet | Attenuated energy production |
| Faber et al., 2008 [141] | C26 tumor model, male CD2F1 mice (6 to 7 weeks old) | C = 12.6% protein E = 15.1% protein ± 1.6% leucine and/or fish oil, or 21% protein ± 2.1% leucine and/or fish oil |
6 groups according to C26 status and diet (control, single nutrient additive, or combination) | Combined diet led to reduced inflammation and improved immune competence |
| Gomes-Marcondes et al., 2003 [126] | Walker-256 tumor model, male Wistar rats (n = 36, 25 days old) | C = 18% protein E = 15% protein + 3% leucine |
4 groups according to Walker-256 status and diet | Attenuation of lean carcass mass and muscle myosin loss |
| Liu et al., 2014 [144] | Panco02 tumor model, male C57BL/6 mice (n = 88, 6 to 8 weeks old—diet initiation, 23 weeks of age—tumor injection) | C = ~16% protein E = ~16% protein + 5% leucine |
At 6 to 8 weeks, 4 groups according to diet and calorie restriction. After 23 weeks, some mice were euthanized while the remainder were redistributed into 4 groups according to Panco02 status | Enhanced tumor growth |
| Peters et al., 2011 [128] | C26 tumor model, male CD2F1 mice (n = 38, 6–7 weeks old) | C = 8.7% of protein as leucine E = 9.6% or 14.8% of protein as leucine |
4 groups according to C26 status and diet (low and high leucine feeding) | Reduced skeletal muscle wasting |
| Plas et al., 2019 [138] | C26 tumor model, male CD2F1 mice (6–7 weeks old) | C = 12.6% protein E = 15.1% protein ± 1.6% leucine and/or fish oil |
53 groups according to C26 status and diet (control, single nutrient additive, or combination) | Combined diet reduced elevated plasma PGE-2 and PTHrP levels |
| Salomão et al., 2010 [130] | Walker-256 tumor model, male Wistar rats (n = 93, 21 days old) | C = 18% protein E = 18% protein + 3% leucine |
At 21 days, 4 groups according to exercise and diet. After 60 days, rats were redistributed into 8 groups according to Walker-256 status | Exercise and leucine supplementation in conjunction led to decreased negative alterations in protein turnover |
| Salomão et al., 2012 [129] | Walker-256 tumor model, male Wistar rats (n = 80, 35 ± 2 days old) | C = 18% protein E = 18% protein + 3% leucine or 4% glutamine, or both |
8 groups according to Walker-256 status, exercise, and diet | Exercise and leucine supplementation in conjunction led to decreased negative alterations in protein turnover and carcass nitrogen content |
| Toneto et al., 2016 [131] | Walker-256 tumor model, male Wistar rats (n = 20, 90 days old) | C = 18% protein E = 18% protein + 3% leucine |
4 groups according to Walker-256 status and diet | Attenuated cardiac failure |
| van Norren et al., 2009 [127] | C26 tumor model, male CD2F1 mice (6–7 weeks old) | C = 12.6% protein E = 15.1% protein ± 1.6% leucine and/or fish oil |
6 groups according to C26 status and diet (control, single-nutrient additive, or combination) | Reduced loss of carcass, skeletal muscle, and fat mass loss with leucine-rich diet alone, combined diet resulted in a greater reduction in cachectic symptoms and improved functional performance |
| Ventrucci et al., 2004 [132] | Walker-256 tumor model, pregnant female Wistar rats (n = 60, 45 days old) | C = 18% protein E = 15% protein + 3% leucine |
6 groups according to Walker-256 status, diet, and pair feeding | Reduced 20S, 19S, and 11S proteasome content and increased protein synthesis |
| Viana et al., 2016 [133] | Walker-256 tumor model, female Wistar rats (n = 35, 90 ± 10 days old, weighing 265 ± 10 g) | C = 18% protein E = 18% protein + 3% leucine |
4 groups according to Walker-256 status and diet | Alterations in 23 serum metabolites with no increase in tumor size |
| Viana et al., 2021 [134] | Walker-256 tumor model, male Wistar rats (n = 24, 12 weeks old) | C = 18% protein E = 18% protein + 3% leucine |
4 groups according to Walker-256 status and diet | Improved muscle strength and behavioral performance, no impact on walking test, inflammation status, or muscle oxidative capacity |