Selective Toxicity of Persian Gulf Sea Squirt (Phallusia nigra) Extract on Isolated Mitochondria Obtained from Liver Hepatocytes of Hepatocellular Carcinoma Induced Rat

Background: One of the deadliest types of liver cancer is hepatocellular carcinoma (HCC). The current treatment methods show poor tolerance and low efficacy. Phallusia nigra (P. nigra) is a kind of sea squirt or marine tunicate that lives in tropical seas around the world. As a marine animal, it contains natural bioactive products. It has been shown that P. nigra has some biological properties, including anti-inflammatory property. Objectives: In this study, we examined the selective toxicity of methanolic extracts obtained from body and wall of Persian Gulf P. nigra on isolated mitochondria obtained from liver hepatocytes of hepatocellular carcinoma-induced rats. Methods: For induction of HCC, the rats were injected with a single dose of diethyl nitrosamine (DEN) at 200 mg/kg, followed by dietary administration of 2-acetylaminofluorene (2-AAF) (0.02%) for 14 days. Then, the HCC induction was approved by histopathological evaluations, liver function markers (ALT, AST, and ALP), and determination of blood levels of liver cancer specific marker, i.e. alpha-fetoprotein (AFP). At the end, mitochondria isolated from cancerous and normal hepatocytes were applied for subsequent investigations. Results: Our results showed that different concentrations (250, 500, and 1000 μg/mL) of both extracts (from body and wall) significantly induced reactive oxygen species (ROS) formation, promoted mitochondrial swelling, decreased mitochondrial membrane potential (MMP), and increased cytochrome c release only in HCC hepatocyte mitochondria in a time and concentration dependent manner. No significant change in the above mentioned parameters was observed in the control hepatocyte mitochondria. Conclusions: Our results suggest that bioactive compounds of P. nigra could be promising anti-HCC molecules. However, further studies are needed including molecular identification tests, confirmatory in vivo experiments, and clinical trials.