Background
Prolonged exposure of free radicals, or known as reactive oxygen species (ROS), in hepatic cells may cause oxidative stress. Without proper treatment, it can induce liver injury and fatal hepatic disease, including cirrhosis. Red betel (Piper crocatum Ruiz and Pav) is one of Indonesia's medicinal plants that has been known to exhibit antioxidant, anti-inflammatory activities. This study aims to determine hepatoprotective effect of red betel leaves extract (RBLE) towards liver injury. Method: Hydrogen peroxide-induced HepG2 cells were used as liver injury model·H2O2-induced HepG2 cells were treated with 25 µg/mL and 100 µg/mL RBLE. Several parameters were observed, including TNF-α level through ELISA; necrotic, apoptotic, dead, live cells; and ROS level through flow cytometry analysis; and GPX gene expression through qPCR. Result: The study showed that treatment with RBLE were able to decrease TNF-α level; necrotic and death cells percentage; as well as ROS level. On the other hand, it were able to increase apoptotic and live cells percentage; as well as GPX gene expression. Low concentration (25 µg/mL) of RBLE treatment exhibited stronger anti-inflammatory activity as it was resulted in the lower TNF-α level and were able to switched hepatic cell death pathway from necrosis to apoptosis as shown by the shifted of apoptotic cells and necrotic cells percentage. This lead to lower death cells and ultimately improve live cells percentage. Meanwhile high concentration of RBLE (100 µg/mL) exhibited stronger antioxidant properties as indicated by lower ROS level and higher GPX gene expression.
Conclusion
Overall, this study was able to demonstrate hepatoprotective effect of RBLE towards liver injury model through its anti-inflammatory and antioxidant activities.