Search

Background: Nasopharyngeal carcinoma (NPC), predominant in Southern China and Southeast Asia, is a malignant tumor that arises from the epithelial lining of the nasopharynx. Current NPC treatments result in unfavorable side effects. Natural compounds with anti-proliferative capabilities are gaining popularity as a way to mitigate the toxicity of radiation and synthetic antitumor drugs. Ponicidin, an ent-kaurane diterpenoid, has been demonstrated to possess several pharmacological activities, including antitumor, antibacterial, immunoregulatory, antiviral, and anti-inflammatory properties. Materials and Methods: In the current investigation, the anti-carcinogenic activity of Ponicidin against nasopharyngeal cell line C666-1, has been investigated. The influence of Ponicidin on cell viability, apoptotic induction, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) generation, and apoptotic markers has been examined. Doxorubicin was selected as the positive control for the experiments. Results: The effect of Ponicidin on the viability of C666-1 cells revealed that its cytotoxic potential increased in a dose-dependent pattern and the optimum concentration chosen for further experiments was 7.5 µM. The Ponicidin-treated cells demonstrated a significant increase in the amount of TBARS, whereas it reduced the activity of superoxide dismutase (SOD) and glutathione (GSH) levels, indicating augmented oxidative stress and lower antioxidant activity in the C666-1 cells. The acridine orange/ethidium bromide (AO/EtBr) staining technique was used to assess morphological changes with respect to apoptosis, which confirmed its apoptotic nature. Furthermore, Ponicidin elevated the ROS generation, modified the mitochondrial membrane permeability, elevated the apoptotic marker levels (caspase-3, caspase-9, and Bax) and reduced the Bcl-2 expression in C666-1 cell lines. Conclusion: The findings suggest that Ponicidin successfully inhibited cancer cell proliferation by following the mitochondrial apoptotic pathway and thus could be effectively utilized as a potent anti-cancer agent for the treatment of nasopharyngeal cancer. [ABSTRACT FROM AUTHOR]

Duck Tembusu virus (DTMUV) is a pathogenic flavivirus that has caused enormous economic losses in Southeast Asia. Our previous study showed that DTMUV could induce duck embryo fibroblast (DEF) apoptosis, but the specific mechanism was not clear. In this study, we confirmed that DTMUV could induce the apoptosis of DEFs by DAPI staining and TUNEL staining. Furthermore, we found that the expression levels of cleaved-caspase-3/7/8/9 were significantly upregulated after DTMUV infection. After treatment of cells with an inhibitor of caspase-8 or caspase-9, DTMUV-induced apoptosis rates were significantly decreased, indicating that the caspase-8-mediated death receptor apoptotic pathway and caspase-9-mediated mitochondrial apoptotic pathway were involved in DTMUV-induced apoptosis. Moreover, we found that DTMUV infection not only caused the release of mitochondrial cytochrome C (Cyt C) and the downregulation of the apoptosis-inhibiting protein Bcl-2 but also reduced the mitochondrial membrane potential (MMP) and the accumulation of intracellular reactive oxygen species (ROS). Key genes in the mitochondrial apoptotic pathway and death receptor apoptotic pathway were upregulated to varying degrees, indicating the activation of the mitochondrial apoptosis pathway and death receptor apoptosis pathway. In conclusion, this study clarifies the molecular mechanism of DTMUV-induced apoptosis and provides a theoretical basis for revealing the pathogenic mechanism of DTMUV infection. [ABSTRACT FROM AUTHOR]