Neuroprotective effects of polyphyllin VI against rotenone-induced toxicity in SH-SY5Y cells

BACKGROUND

A substantial body of evidence is drawing connections between Parkinson's disease (PD) and the phenomena of oxidative stress and mitochondrial dysfunction. Polyphyllin VI (PPVI), an active compound found in Rhizoma Paridis-commonly known as Chonglou (CL) in China, has been identified for its various pharmacological properties, including anti-tumor and anti-inflammatory effects.

OBJECTIVE

In the present study, an in vitro model of PD was established by treating SH-SY5Y cells with rotenone (ROT), to evaluate the potential neuroprotective effects of polyphyllin VI and its underlying mechanism.

METHODS

SH-SY5Y cells were treated with ROT to establish an in vitro model of PD. The effects of polyphyllin VI on cell viability were assessed using the resazurin assay. Cell morphology was examined using a microscope. The YO-PRO-1/PI was used to detect apoptosis. Mito-Tracker Red CMXRos, Mito-Tracker Green, and JC-1 were used to detect the effects of polyphyllin Ⅵ on mitochondrial viability, morphology, and function. Oxidative stress-related marker detection kits were used to identify the effects of polyphyllin VI on oxidative stress. Western blot analysis was employed to investigate the signaling pathways associated with neuroprotection.

RESULTS

PPVI increased ROT-induced SH-SY5Y cell viability and improved ROT-induced cellular morphological changes. PPVI ameliorated ROT-induced oxidative stress status, and attenuated mitochondrial function and morphological changes. PPVI may exert neuroprotective effects through FOXO3α/CREB1/DJ-1-related signaling pathways.

CONCLUSION

These preliminary findings suggested that PPVI possesses neuroprotective attributes in vitro, and it may be a potential candidate for PD treatment. However, extensive research is necessary to fully understand the mechanisms of PPVI and its effectiveness both in vitro and in vivo.

Polyphyllin Ⅵ inhibits colitis associated colorectal carcinogenesis in mice: Possible mechanisms

AIM: To investigate the effect of polyphyllin Ⅵ (PPLⅥ) on colitis associated colorectal carcinogenesis in mice and the underlying mechanisms.

METHODS: Fifty male Institute of Cancer Research (ICR) mice were randomly divided into five groups: a model group, three PPLⅥ-treated groups and a control group. The mice in the model group and three PPLⅥ-treated groups were given a single intraperitoneal injection of 1,2-dimethylhydrazine (DMH) at a dose of 15 mg/kg body weight. One week later, the mice were treated with 2% (w/v) dextran sodium sulfate (DSS) in their drinking water for 1 wk. This was followed by no further treatment for 1 wk. After another 1 wk of 2% DSS treatment, normal water was given for an additional 15 weeks. At week 9, the mice in PPLⅥ-treated groups were intraperitoneally injected with PPLⅥ (2.5, 5.0 and 10.0 mg/kg, respectively) every 3 d, for 12 wk. All mice were sacrificed at week 20 by ether overdose and colon samples were collected for histopathological examinations and Western blot analysis.

RESULTS: HE staining showed that the incidence of tumor formation was 90% in the mice treated with DMH/DSS; it decreased to 40% (4/10), 20% (2/10), and 10% (1/10) in mice treated with DMH/DSS plus 2.5, 5.0 and 10.0 mg/kg of PPLⅥ, respectively. PPLⅥ treatment increased the expression of cleaved Caspase3, Caspase9 and Bax and decreased the expression of Bcl-2 in colonic epithelial cells.

CONCLUSION: PPLⅥ can inhibit DMH/DSS-induced colon tumor formation in ICR mice partly through inducing apoptosis of abnormal colonic epithelial cells via the intrinsic pathway of apoptosis.