Astaxanthin ameliorates dopaminergic neuron damage in paraquat-induced SH-SY5Y cells and mouse models of Parkinson's disease.

Parkinson's disease (PD) is the second largest neurodegenerative disorder caused by the decreased number of dopaminergic (DAc) neurons in the substantia nigra pars compacta (SNpc). There is evidence that oxidative stress can contribute degeneration of DAc neurons in SNpc which is mainly caused by apoptotic cell death. Thus, suppressing oxidative stress and apoptosis of DAc neurons is an effective strategy to mitigate the progress of PD. Astaxanthin (AST) is a carotenoid, which mainly exists in marine organisms and is a powerful biological antioxidant. In this study, we aimed to determine the neuroprotective effect of AST on paraquat (PQ) -induced models of PD in vitro and in vivo. Here, we showed that AST significantly enhanced cell survival of SH-SY5Y cells against PQ toxicity by suppressing apoptotic cell death and oxidative stress. Moreover, we found that AST significantly ameliorated PQ-induced behavioral disorders associated with PD in C57BL/6 J mice and the damage to DAc neurons in the SNpc of mice. Lastly, we found that the neuroprotective effects of AST were conducted through inhibiting PQ-induced activation of MAPK signaling. In conclusion, our study indicates that AST had a strong protective effect on PQ-induced oxidative stress and antagonized apoptotic cell death in SH-SY5Y cells and PQ-induced mice PD model, which might provide new insights of AST for PD treatment.

Ponicidin Induces Apoptosis of Murine Melanoma by Inhibiting the NF-κB Signaling Pathway.

Ponicidin (PON), a diterpenoid extracted from the Chinese herb Rubescens, has been reported to be a therapeutic cytotoxic drug for the treatment of various types of human cancers. According to the statistics, the incidence of malignant melanoma is increasing year by year and the degree of malignancy is extremely high, so early treatment is very important. In the present study, we demonstrated the antitumor effect of PON on melanoma in vitro and in vivo. Cell Counting Kit-8 (CCK-8) assay was used to detect cell proliferation rate, crystal violet staining and TdT-mediated dUTP Nick-End Labeling (TUNEL) kit was used to detect cell apoptosis, and Western blotting was used to detect the expression of apoptotic indicators and related signaling pathway proteins. Finally, the tumor-bearing mouse model was constructed. Treating melanoma B16F0 and B16F10 cells with different concentrations (10 and 20 µmol/L) of PON magnificantly decreased cell viability. In addition, PON significantly activates the expression of pro-apoptotic proteins, including cleaved-poly(ADP-ribose)polymerase (PARP) (cl.PARP), Bak and Bim proteins, and also inhibits the expression of anti-apoptotic protein Mcl-1 and nuclear transcription factor nuclear factor-kappaB (NF-κB) in melanoma cells. Lastly, PON effectively inhibits the growth of mouse xenografts in vivo. These results suggest that PON induces apoptosis of melanoma cells may be achieved by inhibiting NF-κB signal pathway, but the specific mechanism remains to be further elucidated. Taken together, PON may serve as an effective potential drug for the treatment of melanoma.