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ObjectiveTo compare the effects of total alkaloids， matrine， and sophoridine extracted from Sophora alopecuroides on the activity of pheochromocytoma cells （PC12 cells）. MethodThe effect of S. alopecuroides total alkaloids， matrine， and sophoridine at concentrations of 2， 1， 0.5， 0.25， 0.125， and 0.062 5 g·L-1 on the proliferation of PC12 cells was evaluated using the 3-（4，5-dimethylthiazol-2-yl）-2，5-diphenyl tetrazolium bromide （MTT） assay. The lactate dehydrogenase （LDH） leakage rate was measured by enzyme-linked immunosorbent assay （ELISA）. Flow cytometry was used to assess cell apoptosis rate， cell cycle distribution， and intracellular Ca2+ levels. Real-time quantitative polymerase chain reaction （Real-time PCR） was performed to determine the mRNA transcription levels of B-cell lymphoma-2 （Bcl-2） and Bcl-2-associated X protein （Bax）. Protein expression levels of apoptosis-related proteins Caspase-3， Caspase-8， Bcl-2， and Bax were detected by Western blot. ResultCompared to the control group， S. alopecuroides total alkaloids， matrine， and sophoridine inhibited the proliferation of PC12 cells， increased LDH leakage rate， enhanced intracellular Ca2+ fluorescence intensity， and induced cell apoptosis in concentration-dependent manner （P<0.05， P<0.01）. Among them， S. alopecuroides total alkaloids had the strongest inhibitory effect on cell proliferation and induction of apoptosis in PC12 cells （P<0.01）. After treatment with S. alopecuroides total alkaloids， matrine， and sophoridine， the cell cycle progression of PC12 cells was arrested at G1/G0 in the S. alopecuroides total alkaloids group， and at G1/S in the matrine and sophoridine groups. The expression levels of Bax mRNA were significantly increased （P<0.05， P<0.01）， while the expression levels of Bcl-2 mRNA were significantly decreased （P<0.05， P<0.01）. All treatments significantly downregulated the expression of the anti-apoptotic protein Bcl-2 （P<0.05， P<0.01） and upregulated the expression of the pro-apoptotic proteins Bax， Caspase-3， and Caspase-8 （P<0.05， P<0.01）， with the most significant protein expression changes observed in the S. alopecuroides total alkaloids group. ConclusionAmong the S. alopecuroides total alkaloids， matrine， and sophoridine， S. alopecuroides total alkaloids exhibit the strongest inhibitory effect on the activity of PC12 cells， and its mechanism of action may be related to the inhibition of anti-apoptotic protein expression， upregulation of pro-apoptotic protein expression， and activation of the mitochondrial Caspase-8 apoptotic pathway.
RESUMEN
OBJECTI VE To establish the high performan ce liquid c hromatography（HPLC）fingerprint of carotenoid in Lycium barbarum，and to investigate the spectrum-effect relationship between its common peak and antioxidant activity. METHODS HPLC method was adopted. The fingerprints of carotenoid in 34 batches of L. barbarum from different producing areas were established by Similarity Evaluation System of TCM Fingerprint （2012 edition），and similarity evaluation and common peak identification were carried out. Taking scavenging rate of DPPH free radical as index ，in vitro antioxidant activity of carotenoid in L. barbarum was investigated. The spectrum-effect relationship between the common peaks of carotenoids in L. barbarum and antioxidant activity was analyzed by grey correlation method. RESULTS There were 4 common peaks in the fingerprints of carotenoids in 34 batches of L. barbarum ，and the similarity was not less than 0.903. Peak 1 was identified as zeaxanthin ，and peak 4 as zeaxanthin dipalmitate. The scavenging rates of them to DPPH free radical were 1.792％-3.160％. The common peaks of carotenoids in L. barbarum were positively correlated with scavenging rate of DPPH free radical ，and the correlation degree was greater than 0.6；the correlation degree of peak 2 and peak 4（zeaxanthin dipalmitate ）with scavenging rate of DPPH free radical was greater than 0.8. According to the correlation degree ，the contribution of each common peak to scavenging rate of DPPH free radical was determined as peak 2＞ peak 4（zeaxanthin dipalmitate ）＞peak 1（zeaxanthin）＞peak 3. CONCLUSIONS In this study ，HPLC fingerprint of carotenoid in L. barbarum is successfully established ，and two common peaks are identified. The chemical components represented by peak 2 and zeaxanthin palmitate may be the material basis of antioxidant activity of carotenoid in L. barbarum .