Red Dragon Fruit (Hylocereus Polyrhizus) Extract Decreases Lactic Acid Level and Creatine Kinase Activity in Rats Receiving Heavy Physical Exercise.

Heavy physical exercise causes relative hypoxia. In hypoxic condition, the cell's energy comes from anaerobic metabolism that produces lactic acid. An increment of oxygen need leads to ischemia-reperfusion, triggers free radical formation and damages muscles. Creatine kinase (CK) is a marker of muscle tissue damage. Red dragon fruit (RDF) has potential as antioxidant to reduce free radical formation.This study aims to determine RDF extract potential to reduce the lactic acid level and CK activity after heavy physical exercise.A total of 32 male rats (Rattus Norvegicus) were randomly divided into 4 groups: group NORDF, treated heavy physical exercise and distilled water; group RDF100, treated heavy physical exercise and at 100 mg/kg BW RDF extract; group RDF200, treated heavy physical exercise and at 200 mg/kg BW RDF extract and group RDF300, treated heavy physical exercise and at 300 mg/kg BW RDF extract. The rats swam for 20 minutes, 3 times a week for 3 weeks.RDF300 group showed lower lactic acid level and CK activity as compared to that of NORDF (p = 0.00) and RDF100 (p = 0.00) groups, but RDF300 are not significantly different for lactic acid (p = 0.45) and for CK (p = 0.68).Red dragon fruit extract has potential in lowering lactic acid level and CK activity in male rats receiving heavy physical exercise.