Tenuigenin attenuates α-synuclein-induced cytotoxicity by down-regulating polo-like kinase 3.

BACKGROUND AND AIMS: Tenuigenin (Ten) is a Chinese herbal extract with antioxidative and antiinflammatory effects on toxin-induced cell models of Parkinson's disease (PD); however, its effects on α-synuclein toxicity-based PD models remain unknown. α-synuclein hyperphosphorylation is a key event in PD pathogenesis and potential target of therapeutic interventions. We tested whether Ten alleviates α-synuclein-induced cytotoxicity via reducing kinases that phosphorylate α-synuclein. METHODS: SH-SY5Y cells transiently transfected with wild-type or A53T mutant α-synuclein were used to evaluate the effect of Ten on the levels of α-synuclein phosphorylation-related kinases. Cells treated with 10 µM Ten for 24 h were measured for viability (proliferation and apoptosis assays) and cellular proteins harvested and fractioned. The levels of total and phosphorylated α-synuclein and five associated kinases (polo-like kinase [PLK] 1-3, casein kinase [CK] 1-2) were evaluated by Western blotting. RESULTS: Overexpression of either wild-type or A53T mutant α-synuclein decreased cell viability and increased α-synuclein phosphorylation. Ten treatment-protected cells from this α-synuclein-induced toxicity and dramatically reduced α-synuclein phosphorylation and PLK3 (but not other kinase) levels. CONCLUSION: In α-synuclein cell model of PD, Ten is effective in attenuating α-synuclein-induced toxicity and α-synuclein phosphorylation probably via targeting PLK3, suggesting it could be an efficient therapeutic drug to treat α-synuclein-related neurodegeneration.

[Callus cultivation and determination of gentiopicroside from Gentiana macrophylla].

OBJECTIVE: To explore and improve the utilization efficiency of Gentiana macrophylla resources. METHODS: The germination of Gentiona macrophylla seeds were used as explants to induce calluses; Cultured on various culture media and condition for callus induction and subculture by test; The content of gentiopicroside in callus was determined by HPLC. RESULTS: The optimum medium for callus was MS +2,4-D (1.0 mg/L) + 6-BA (0.5 mg/L), and MS +2,4-D (1.0 mg/L) +6-BA (0.5 mg/L) + NAA (0.5 mg/L) was the optimum for subculture,the optimum time of subculture was 30 d; The accumulated gentiopicroside reached the highest level with 0.78 mg/g DW when entered 28-30 d. CONCLUSION: The optimized culture method of callus of Gentiana. macrophylla is obtained; The growth curve of callus of Gentiona macrophylla turns on "S" appearance and the accumulated gentiopicroside increases along with the callus appreciation.