Effect of Tomato Supplementation on Changes of Proteasome Concentration in Hepatocarcinogenesis

Serum concentration of proteasome in cancer patients is higher than normal individual, but whether proteasome concentration increased at precancer is still unknown. This study was conducted to investigate the alteration of proteasome concentration in vivo and how it is affected by tomato. This research used rats that were divided randomly into 5 groups: control group 1 (KK1), group of rats which were only given bidistilled water; control group 2 (KK2), group of rats that were given Pulvis Gummi Arabic (PGA) and palm oil; control group 3 (KK3), group of rats that were given tomato emulsion; group of treatment 1 (KP1), group of rats which were induced by N,2-Fluorenilasetamida (FAA); and group of treatment 2 (KP 2), group of rats that were induced by FAA and given tomato emulsion. The rats were killed in the fourth and eight weeks after treatment. Some parts of the liver were taken for histological examination and the rest were homogenized. The proteasome concentration was determined from liver homogenats and plasma by ELISA method. This study shows that proteasome concentration in plasma of KP1 group was significantly increased compare to all control and KP2 group after 8 weeks. Proteasome concentration in liver of KP1 rats was significantly increased compare to all control and KP2 group after 4 weeks. Histological examinations show signs of precancerous only among KP1 rats after 8 weeks of treatment and not in other groups. This study suggested that proteasome concentration in rats’ plasma increased in precancerous stage. Elevation of liver proteasome was detected before alteration of the liver cells and tomato emulsion showed protective effect in liver carcinogenesis.