Hepatocellular carcinoma (HCC) is one of the most aggressive malignancies worldwide, and its incidence associated with viral infection has increased in recent years. Amantadine is a tricyclic symmetric amine that can effectively protect against the hepatitis C virus. However, its antitumor properties remain unclear. In the present study, the effects of amantadine on tumor cell viability, cell cycle regulation and apoptosis were investigated. The growth of HepG2 and SMMC‑7721 cells (HCC cell lines) was detected by an MTT assay. Flow cytometry was used to investigate cell cycle regulation and apoptosis. Reverse transcription‑quantitative polymerase chain reaction and western blot analysis were also performed to examine the expression of cell cycle‑ and apoptosis‑related genes and proteins, including cyclin E, cyclin D1, cyclin‑dependent kinase 2 (CDK2), B‑cell lymphoma 2 (Bcl‑2) and Bax. Our results demonstrated that amantadine markedly inhibited the proliferation of HepG2 and SMMC‑7721 cells in a dose‑ and time‑dependent manner and arrested the cell cycle at the G0/G1 phase. The levels of the cell cycle‑related genes and proteins (cyclin D1, cyclin E and CDK2) were reduced by amantadine, and apoptosis was significantly induced. Amantadine treatment also reduced Bcl‑2 and increased the Bax protein and mRNA levels. Additionally, Bcl‑2/Bax ratios were lower in the two HCC cell lines following amantadine treatment. Collectively, these results emphasize the role of amantadine in suppressing proliferation and inducing apoptosis in HCC cells, advocating its use as a novel tumor-suppressive therapeutic candidate.

Abstract. Saussureae involucratae Flos is the primary component of the jiangu capsule, which also consists of 12 types of natural medicine. It is a traditional Chinese medicine used to treat a number of conditions including arthralgia, cold and sore muscles, stiff limbs, inconvenient flexion and activity limitation caused by different types of osteoarthritis. The present study was performed to assess the safety of the jiangu capsule following acute and chronic administration in mice and rats. In the acute study, mice were treated with the jiangu capsule orally at 16 g/kg/day, the highest dose, for 14 days. In the chronic oral toxicity study, rats were treated with 2, 4 and 8 g/kg/day of the jiangu capsule for 6 months. The general condition, body weight changes, food and water consumption, hematological and biochemical parameters, urinalysis, systematic anatomy and organ weights of the rats were monitored and histopathological examination was performed at the end of 3 and 6 months' daily administration, and following 14 days of withdrawal. There were no signs of toxicity in the general condition and body weight of the mice was not significantly affected by the treatment. Furthermore, necropsy findings for the animals in the acute and chronic toxicity studies demonstrated that no mortalities had occurred. The results of the current study indicate that treatment with the jiangu capsule did not induce mortality or any detectable abnormalities in mice and rats.