Apoptosis and pro-death autophagy induced by a spirostanol saponin isolated from Rohdea chinensis (Baker) N. Tanaka (synonym Tupistra chinensis Baker) on HL-60 cells
Authors: Xiaomin Yi
Limin Xiang
Yihai Wang
Xiangjiu He
Yuying Huang
Journal: Phytomedicine (2018)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: Apoptosis; Autophagy; Human acute promyelocytic leukemia; Rohdea chinensis; Spirostanol saponin.
Affiliations: School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, China; Guangdong Engineering Research Center for Lead Compounds & Drug Discovery, Guangzhou 510006, China., School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, China., School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, China; Guangdong Engineering Research Center for Lead Compounds & Drug Discovery, Guangzhou 510006, China. Electronic address: .

Abstract:  Background: Our previous study has revealed that the spirostanol saponins isolated from the rhizomes of Rohdea chinensis (Baker) N. Tanaka (synonym Tupistra chinensis Baker) (Convallariaceae) (a reputed folk medicine) exhibited potent antiproliferative activity. However, the underlying mechanism of purified saponins remains unclear. More studies are necessary to assess the apoptosis and autophagy activities of the saponins from R. chinensis and clarify their antiproliferative mechanisms. Purpose: The present study certificated the potential antiproliferative activity and mechanism of 5β-spirost-25(27)-en-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1→2)- β-D-xylopyranosyl-3-O-α-L-rhamnopyranoside (SPD), a spirostanol saponin from R. chinensis, against human acute promyelocytic leukemia cells (HL-60). Methods: The antiproliferative activity of SPD in vitro was evaluated by MTT assay compared with cis-dichlorodiammineplatinum (II). The autophagic activity was assessed using MDC staining and western blot, cell apoptosis inspection was detected by Annexin V-FITC/PI double staining and the mitochondrial membrane potential was detected by JC-1 fluorescence dye combined with flow cytometry. The potential mechanisms for protein levels of apoptosis and autophagy were evaluated by western blot. Results: Treatment of HL-60 cells with SPD resulted in growth inhibition (IC50 value of 2.0 ± 0.2 µM, after 48 h treatment) and induction of apoptosis and autophagy. Results from Annexin V-FITC/PI double-staining assay and mitochondrial membrane potential detection showed that apoptosis was happened after SPD treatment. The regulation of caspase-3, Bax, Bcl-2, PARP following SPD treatment contributed to the induction of mitochondria-dependent apoptosis. Meanwhile, SPD induced autophagy related with Akt/mTOR/p70S6K signaling and activated of AMPK signaling pathway. Furthermore, blocking autophagy with bafilomycin A1 reduced the cytotoxicity of SPD in HL-60 cells. Conclusion: The antiproliferative, apoptosis and pro-death autophagy activities of SPD suggested that spirostanol saponins from R. chinensis would be a potential cytotoxic candidate against acute promyelocytic leukemia. 

Retracted: No

PubPeer comments:
 The actin bands in Fig.5C and Fig. 6D look much more similar than you could expect with dimention changes. ![file] , 
 Two WB bands look very similar with different exposure time. ![file] , 
 Areas in two flow cytometry images in Fig. 4C are identical. Could the authors please check? ![file] , 
 No problem for concern #1. ,