The Effect of Aerobic Exercise and Green Coffee on Liver Lipid Metabolism in Obese C57BL/6 Mice

Background and Purpose
Given the critical importance of liver health and its vital role in maintaining the body's metabolic homeostasis, it is imperative to investigate effective non-pharmacological interventions that can enhance hepatic function. Aerobic exercise training and green coffee bean supplementation have emerged as two promising modalities with potential synergistic effects on lipid metabolism. This study aimed to comprehensively evaluate the individual and combined effects of these interventions on hepatic lipid metabolism in a high-fat diet-induced obese C57BL/6 mouse model, which closely mimics human metabolic dysfunction.
The global epidemic of obesity and metabolic syndrome has underscored the urgent need for effective lifestyle interventions. Aerobic exercise has been well-documented to improve cardiovascular fitness and metabolic parameters through multiple pathways including enhanced mitochondrial biogenesis and improved insulin sensitivity. Concurrently, green coffee, rich in chlorogenic acids and other bioactive compounds, has demonstrated potent antioxidant and anti-inflammatory properties that may beneficially modulate lipid metabolism. However, the potential synergistic effects of combining these interventions on hepatic steatosis and related metabolic pathways remain insufficiently explored.
 
Materials and Methods
This experimental study employed a rigorous multi-group post-test design utilizing 28 male C57BL/6 mice (age: 4 weeks; initial weight: 13-15g) obtained from the Royan Institute. Animals were maintained under strictly controlled environmental conditions (12:12 light-dark cycle, 23°C ambient temperature, 50-60% humidity) with ad libitum access to water and a high-fat diet (60% fat, 20% protein, 20% carbohydrates) throughout the 22-week study period. The experimental protocol consisted of two distinct phases: A 12-week obesity induction phase where all animals received the high-fat diet; A subsequent 10-week intervention phase where animals were assigned into four experimental groups: 1) Green coffee supplementation group (GC); 2) Aerobic exercise training group (Ex); 3) Green coffee supplementation + Aerobic exercise training group (Ex+GC); and 4) High-fat diet control group (HFD).
The exercise protocol involved progressive treadmill running (5 sessions/week, 45 minutes/session) with intensity systematically increased from 15 m/min (weeks 1-2) to 23 m/min (weeks 9-10). Each session incorporated a standardized warm-up (3 minutes), main exercise bout (40 minutes), and cool-down period (2 minutes). Animals were acclimated to treadmill running prior to the intervention phase. Comprehensive metabolic assessments included anthropometric measurements (body weight, liver weight), biochemical analyses (fasting blood glucose, plasma insulin), and molecular analyses of key lipid metabolic regulators (Srebp1c, Acc1, Gpat1, Fasn, Cpt1, Ppara) were done using standard techniques.
 
Findings
The high-fat diet successfully induced metabolic dysfunction, with control animals exhibiting significant (P < 0.05) increases in body weight (45.2 ± 3.1g vs. baseline 14.3 ± 0.8g), liver weight (2.8 ± 0.3g vs. 0.9 ± 0.1g), fasting blood glucose (185 ± 12 mg/dL vs. 95 ± 8 mg/dL), and plasma insulin (3.8 ± 0.4 ng/mL vs. 0.9 ± 0.1 ng/mL) compared to baseline values.
All intervention groups demonstrated significant metabolic improvements compared to HFD controls:
Body Weight

GC group: 38.4 ± 2.7g (P = 0.0118)
Ex group: 35.1 ± 2.3g (P < 0.0001)
Ex+GC group: 32.6 ± 2.1g (P < 0.0001)

Liver Weight:

GC group: 2.1 ± 0.2g (P = 0.0283)
Ex group: 1.9 ± 0.2g (P = 0.0031)
Ex+GC group: 1.7 ± 0.1g (P < 0.0001)

Glucose Metabolism: All intervention groups showed significantly lower fasting glucose (P < 0.0001) and insulin levels (P < 0.0001) compared to HFD controls.
Molecular analyses revealed complex modulation of lipid metabolic pathways: in GC group, significant downregulation of Srebp1c (P < 0.001), Acc1 (P < 0.001), and Gpat1 (P < 0.001) but paradoxical upregulation of Fasn (P < 0.001) and downregulation of Cpt1/Ppara (P < 0.001) were seen. Consistent reduction in lipid synthesis enzymes (except Acc1) and beta-oxidation markers were observed in Ex group. And, in Ex+GC group, data demonstrated synergistic effects with approximately 2-fold greater reductions in lipid synthesis markers compared to single interventions.
Conclusion
This comprehensive investigation demonstrates that both aerobic exercise training and green coffee supplementation independently improve metabolic parameters in diet-induced obese mice, with the combined intervention yielding superior results. The findings suggest that these non-pharmacological approaches may represent an effective strategy for preventing hepatic steatosis and related metabolic disorders. The molecular data indicate complex interactions between these interventions and key regulatory pathways of lipid metabolism that warrant further investigation.
 Article Message
This study investigated the combined effects of regular aerobic exercise and green coffee consumption on hepatic lipid metabolism in high-fat diet-fed rats. The results demonstrated that both interventions independently improved liver fat content and regulated key enzymes involved in fatty acid synthesis and β-oxidation. However, the combination of aerobic exercise and green coffee supplementation showed the most significant benefits in optimizing hepatic lipid profiles and reducing metabolic risk factors.
The findings suggest that aerobic training can serve as an effective non-pharmacological approach for managing fatty liver disease and obesity-related metabolic disorders. Additionally, green coffee extract may mimic some beneficial effects of exercise, offering a potential complementary strategy for individuals with physical activity limitations. These results provide a foundation for future research on combined lifestyle and nutraceutical interventions to prevent and treat hepatic diseases.
 Ethical Considerations
This study was approved by the Royan Institute Ethics Committee (IR.ACECR.ROYAN.REC.1399.075) and conducted in accordance with international guidelines for animal research.
Funding
This research was fully supported by internal funding from the first author.
Authors' Contributions
Study design: SMM, MHN-E; Data collection: SS, ZG, FJG; Molecular analyses: ZS; Data interpretation: MA, SMM; Manuscript preparation: SS, SMM; Final approval: all authors.
Conflicts of Interest
The Authors Declare no Competing Financial or Professional Interests.