Novel steroidal saponin isolated from Trillium tschonoskii maxim. exhibits anti-oxidative effect via autophagy induction in cellular and Caenorhabditis elegans models.
BACKGROUND
Emerging evidences indicate the important roles of autophagy in anti-oxidative stress, which is closely associated with cancer, aging and neurodegeneration.


OBJECTIVE
In the current study, we aimed to identify autophagy inducers with potent anti-oxidative effect from traditional Chinese medicines (TCMs) in PC-12 cells and C. elegans.


METHODS
The autophagy inducers were extensively screened in our herbal extracts library by using the stable RFP-GFP-LC3 U87 cells. The components with autophagic induction effect in Trillium tschonoskii Maxim. (TTM) was isolated and identified by using the autophagic activity-guided column chromatography and Pre-HPLC technologies, and MS and NMR spectroscopic analysis, respectively. The anti-oxidative effect of the isolated autophagy inducers was evaluated in H2O2-induced PC-12 cells and C. elegans models by measuring the viability of PC-12 cells and C. elegans, with quantitation on the ROS level in vitro and in vivo using H2DCFDA probe.


RESULTS
The total ethanol extract of TTM was found to significantly increase the formation of GFP-LC3 puncta in stable RFP-GFP-LC3 U87 cells. One novel steroidal saponin 1-O-[2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl-(1→2)-4-O-acetyl-α-L-arabinopyranosyl]-21-Deoxytrillenogenin, (Deoxytrillenoside CA, DTCA) and one known steroidal saponin 1-O-[2,3,4-tri-O-acetyl-α-L-rhamnopyranosyl-(1→2)-4-O-acetyl-α-L-arabinopyranosyl]-21-O-acetyl-epitrillenogenin (Epitrillenoside CA, ETCA) were isolated, identified and found to have novel autophagic effect. Both DTCA and ETCA could activate autophagy in PC-12 cells via the AMPK/mTOR/p70S6K signaling pathway in an Atg7-dependent. In addition, DTCA and ETCA could increase the cell viability and decrease the intracellular ROS level in H2O2-treated PC-12 cells and C. elegans, and the further study demonstrated that the induced autophagy contributes to their anti-oxidative effect.


CONCLUSION
Our current findings not only provide information on the discovery of novel autophagy activators from TTM, but also confirmed the anti-oxidative effect of the components from TTM both in vitro and in vivo.
['Wu|An-Guo|AG|', 'Teng|Jin-Feng|JF|', 'Wong|Vincent Kam-Wai|VK|', 'Zhou|Xiao-Gang|XG|', 'Qiu|Wen-Qiao|WQ|', 'Tang|Yong|Y|', 'Wu|Jian-Ming|JM|', 'Xiong|Rui|R|', 'Pan|Rong|R|', 'Wang|Yi-Ling|YL|', 'Tang|Bin|B|', 'Ding|Tian-Yi|TY|', 'Yu|Lu|L|', 'Zeng|Wu|W|', 'Qin|Da-Lian|DL|', 'Law|Betty Yuen-Kwan|BY|']
D000818:Animals D000975:Antioxidants D001343:Autophagy D000071193:Autophagy-Related Protein 7 D017173:Caenorhabditis elegans D002470:Cell Survival D004186:Disaccharidases D006801:Humans D006861:Hydrogen Peroxide D016716:PC12 Cells D010936:Plant Extracts D051381:Rats D017382:Reactive Oxygen Species D012503:Saponins D015398:Signal Transduction D058570:TOR Serine-Threonine Kinases D031446:Trillium
Trillium tschonoskii Maxim. Autophagy PC-12 C. elegans Deoxytrillenoside CA Epitrillenoside CA