Objective: Cigarette smoke contains harmful substances such as molecular compounds, reactive oxygen and nicotine compounds that can increase levels of Serum Glutamate-Pyruvate Transaminase (SGPT) and Serum Glutamic Oxaloacetic Transaminase (SGOT). Sweet orange peel extract is known to have good radical antioxidative potential and a hepatoprotective effect. This study purpose to know the effectiveness of sweet orange peel extract (Citrus sinensis) to improve the liver function of trials animal that induced by cigarette smoke. Methods: This research is experimental laboratory with pre-test and post-test with control group design. The research subjects were 25 white rats (Rattus novergicus) male Wistar strain that divided into 5 groups: P1 (negative control), P2 (positive control), P3 (sweet orange peel extract dose of 37,5 mg / kgBW), P4 (sweet orange peel extract dose of 75 mg / kgBW), P5 (sweet orange peel extract dose of 112,5 mg/kgBW). The differences in SGOT-SGPT levels of pre-test and posttest were conducted by Wilcoxon test. The inhibition of increased levels of SGOT-SGPT to determine the effectiveness of sweet orange extract to the improvement of liver function using Kruskal-Wallis test. Results: Significant differences and inhibition of increase of SGOT-SGPT level (p = 0,00). The most effective sweet orange peel extract inhibits elevated levels of SGOT-SGPT is group P5 (sweet orange peel extract dose of 112,5 mg / kgBW. Conclusion: The sweet orange peel extract (Citrus sinensis) can effectively improve the liver function of trials animal induced by cigarette smoke.
Key words: Sweet orange peel extract (Citrus sinensis), Liver function, Serum Glutamic Oxaloacetic Transaminase, Serum Glutamate-Pyruvate Transaminase, Cigarette smoke, Rattus novergicus.