Effect of hydroalcoholic extract of Aegle marmelos fruit on radical scavenging activity and exercise-endurance capacity in mice

Context: Aegle marmelos L. Corr (Rutaceae) is an important Indian Ayurvedic medicinal plant used for the treatment of various ailments. However, little information is available on the anti-fatigue properties of its fruit.

Objective: Evaluation of the physical endurance and exercise-induced oxidative stress modulating properties of A. marmelos fruit in mice.

Material and methods: Radical scavenging activity of the fruit hydroalcoholic extract was evaluated using in vitro systems. The extract was further evaluated for its endurance-enhancing properties at three oral doses (100, 200 and 400?mg/kg?b.wt) in BALB/c mice for 21?d using a swimming test.

Results and discussion: The extract exhibited significant scavenging activity against DPPH (IC₅₀, 351?±?37?µg/ml) and ABTS radicals (IC₅₀, 228?±?25?µg/ml), respectively, with the polyphenol content of 95?µg/mg extract. It also inhibited AAPH radical-induced oxidation of biomolecules such as BSA protein (63%), plasmid DNA (81%) and lipids (80.5%). Administration of extract resulted in an increase in the duration of swimming time to exhaustion by 23.4 and 47.5% for medium and higher doses, respectively. The extract significantly normalized the fatigue-related biochemical parameters and also down-regulated the swim stress-induced over-expression of heat shock protein-70 and up-regulated the skeletal muscle metabolic regulators (GLUT-4 and AMPK1-α) by 2- and 3-fold, respectively, at the higher dose in muscle tissues.

Conclusion: Our study demonstrates the anti-fatigue properties of A. marmelos fruit, most probably manifested by delaying the accumulation of serum lactic acid, increasing the fat utilization and up-regulating the skeletal muscle metabolic regulators.