Calenduloside E

Front Pharmacol. 2017 Nov 23;8:862.

Calenduloside E Analogues Protecting H9c2 Cardiomyocytes Against H2O2-Induced Apoptosis: Design, Synthesis and Biological Evaluation.[Pubmed: 29218010 ]

Modulation of apoptosis is therapeutically effective in cardiomyocytes damage. Calenduloside E (CE), a naturally occurring triterpenoid saponin, is a potent anti-apoptotic agent. However, little is known about its synthetic analogues on the protective effects in apoptosis of cardiomyocytes.
METHODS AND RESULTS:
The present research was performed to investigate the potential protective effect of CE analogues against H2O2-induced apoptosis in H9c2 cardiomyocytes and the underlying mechanisms. Sixteen novel CE anologues have been designed, synthesized and biological evaluation. Among the 16 CE anologues, as well as the positive control CE tested, compound 5d was the most effective in improving cardiomyocytes viability. Pretreatment with anologue 5d inhibited ROS generation, maintained the mitochondrial membrane potential and reduced apoptotic cardiomyocytes. Moreover, exposure to H2O2 significantly increased the levels of Bax, cleaved caspase-3, and cleaved PARP, and decreased the level of Bcl-2, resulting in cell apoptosis. Pretreatment with anologue 5d (0.02-0.5 μg/mL) dose-dependently upregulated antiapoptotic proteins and downregulated proapoptotic proteins mentioned above during H2O2-induced apoptosis.
CONCLUSIONS:
These results suggested that CE analogues provide protection to H9c2 cardiomyocytes against H2O2-induced oxidative stress and apoptosis, most likely via anti-apoptotic mechanism, and provided the basis for the further optimization of the CE analogues.

Molecules. 2019 Aug 17;24(16). pii: E2985.

Inhibitory Effects of Ginsenoside Ro on the Growth of B16F10 Melanoma via Its Metabolites.[Pubmed: 31426477]

Ginsenoside Ro (Ro), a major saponin derived and isolated from Panax ginseng C.A. Meyer, exerts multiple biological activities. However, the anti-tumour efficacy of Ro remains unclear because of its poor in vitro effects.
METHODS AND RESULTS:
In this study, we confirmed that Ro has no anti-tumour activity in vitro. We explored the anti-tumour activity of Ro in vivo in B16F10 tumour-bearing mice. The results revealed that Ro considerably suppressed tumour growth with no significant side effects on immune organs and body weight. Zingibroside R1, chikusetsusaponin IVa, and Calenduloside E, three metabolites of Ro, were detected in the plasma of Ro-treated tumour-bearing mice and showed excellent anti-tumour effects as well as anti-angiogenic activity. The results suggest that the metabolites play important roles in the anti-tumour efficacy of Ro in vivo. Additionally, the haemolysis test demonstrated that Ro has good biocompatibility.
CONCLUSIONS:
Taken together, the findings of this study demonstrate that Ro markedly suppresses the tumour growth of B16F10-transplanted tumours in vivo, and its anti-tumour effects are based on the biological activity of its metabolites. The anti-tumour efficacy of these metabolites is due, at least in part, to its anti-angiogenic activity.

Nan Fang Yi Ke Da Xue Xue Bao. 2019 Aug 30;39(8):904-910.

Calenduloside E inhibits lipopolysaccharide-induced inflammatory response by inhibiting activation of ROS-mediated JAK1-stat3 signaling pathway in RAW264.7 cells.[Pubmed: 31511209 ]

To investigate the effect of Calenduloside E on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 cells and explore the underlying molecular mechanism.
METHODS AND RESULTS:
CCK-8 assay was used to examine the effect of different concentrations of Calenduloside E (0-30 μg/mL) on the viability of RAW264.7 cells. The release of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in RAW264.7 cells in response to pretreatment with 6, 8, and 10 μg/mL Calenduloside E for 2 h followed by stimulation with 100 ng/mL LPS was detected using enzyme-linked immunosorbent assay (ELISA). The expression levels of iNOS and COX-2 and the activation of JAK-stats, MAPKs and NF-кB signaling pathways in the treated cells were determined using Western blotting. A reactive oxygen species (ROS) detection kit was used to detect ROS production in the cells, and the nuclear translocation of the transcription factor stat3 was observed by laser confocal microscopy. Calenduloside E below 20 μg/mL did not significantly affect the viability of RAW264.7 cells. Calenduloside E dose-dependently decreased the expression levels of iNOS and COX-2 induced by LPS, inhibited LPS-induced release of TNF-α and IL-1β, and suppressed LPS-induced JAK1-stat3 signaling pathway activation and stat3 nuclear translocation. Calenduloside E also significantly reduced ROS production induced by LPS in RAW264.7 cells.
CONCLUSIONS:
Calenduloside E inhibits LPS-induced inflammatory response by blocking ROS-mediated activation of JAK1-stat3 signaling pathway in RAW264.7 cells.

Front Pharmacol. 2018 May 23;9:532.

Targets Fishing and Identification of Calenduloside E as Hsp90AB1: Design, Synthesis, and Evaluation of Clickable Activity-Based Probe.[Pubmed: 29875664 ]

Calenduloside E (CE), a natural triterpenoid compound isolated from Aralia elata, can protect against ox-LDL-induced human umbilical vein endothelial cell (HUVEC) injury in our previous reports. However, the exact targets and mechanisms of CE remain elusive.
METHODS AND RESULTS:
For the sake of resolving this question, we designed and synthesized a clickable activity-based probe (CE-P), which could be utilized to fish the functional targets in HUVECs using a gel-based strategy. Based on the previous studies of the structure-activity relationship (SAR), we introduced an alkyne moiety at the C-28 carboxylic group of CE, which kept the protective and anti-apoptosis activity. Via proteomic approach, one of the potential proteins bound to CE-P was identified as Hsp90AB1, and further verification was performed by pure recombinant Hsp90AB1 and competitive assay. These results demonstrated that CE could bind to Hsp90AB1. We also found that CE could reverse the Hsp90AB1 decrease after ox-LDL treatment. To make our results more convincing, we performed SPR analysis and the affinity kinetic assay showed that CE/CE-P could bind to Hsp90AB1 in a dose-dependent manner.
CONCLUSIONS:
Taken together, our research showed CE could probably bind to Hsp90AB1 to protect the cell injury, which might provide the basis for the further exploration of its cardiovascular protective mechanisms. For the sake of resolving this question, we designed and synthesized a clickable activity-based probe (CE-P), which could be utilized to fish the functional targets in HUVECs using a gel-based strategy.