Aidong Wen

Triterpenoid Saponins from Ardisia pusilla and their Cytotoxic Activity

Three new triterpenoid saponins 3, 4 and 5, together with two known saponins, ardisiacrispin B (1) and ardisiacrispin A (2), were isolated from the whole plants of Ardisia pusilla A. DC. Their structures were elucidated by extensive spectral analysis and chemical evidence. Compound 3 is a hexaglycoside with a 13,28-epoxyoleanane type aglycone, while both 4 and 5 are triterpenoid tetraglycosides related to the olean-12-ene skeleton. Saponins 1-4 exhibited significant cytotoxicity against human glioblastoma U251MG cells, but did not affect the growth of primary cultured human astrocytes.

Cytotoxic Asterosaponins Capable of Promoting Polymerization of Tubulin from the Starfish Culcita novaeguineae

Four new asterosaponins, novaeguinosides A (1), B (2), C (3), and D (4), were isolated from the bioactive fraction of the starfish Culcita novaeguineae, as active compounds capable of promoting polymerization of tubulin. Their structures were elucidated by extensive spectroscopic studies and chemical evidence. Compounds 1 and 3 are characterized by sulfated side chains not previously found in asterosaponins, and 1 is the first example of a trisulfated asterosaponin. In the side chains of 2 and 4, the 26-carboxylic acid function is found as an amide derivative of taurine, which is a rare feature and first encountered among asterosaponins. All the asterosaponins showed cytotoxicity against two human tumor cell lines.

Triterpenoid saponins from Clematis tangutica and their cardioprotective activities.

Phytochemical investigation of the whole plants of Clematis tangutica led to the isolation of three new triterpenoid saponins (1-3), together with four known saponins (4-7). Their structures were determined by extensive spectral analysis and chemical evidences. Compounds 1-7 were evaluated for their cardioprotective activities in cardiomyocytes anoxia/reoxygenation (A/R) model. The results showed that those saponins exhibited cardioprotective effects by decreasing the levels of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH).

Triterpenoid saponins from the roots of Clematis argentilucida and their cytotoxic activity.

The reinvestigation of the n-BuOH extract of the roots of Clematis argentilucida led to the isolation of four new oleanane-type triterpenoid saponins, 1-4, four known saponins, 5-8, first isolated from the species, together with ten saponins, 9-18, reported in the preceding papers. The structures of saponins 1-8 were elucidated by extensive spectroscopic analysis and chemical evidences. The cytotoxicity of all the saponins were evaluated against human tumor HL-60, HepG-2, and SGC-7901 cell lines. The monodesmosidic saponins 4, 7, 8, and 14-18 exhibited cytotoxic activity against the three cell lines with IC50 values in the range of 0.87-19.48 µM.

Echinacoside Alleviates UVB Irradiation-Mediated Skin Damage via Inhibition of Oxidative Stress, DNA Damage, and Apoptosis

Ultraviolet B (UVB) irradiation has been known to cause skin damage, which is associated with oxidative stress, DNA damage, and apoptosis. Echinacoside is a phenylethanoid glycoside isolated from Herba Cistanches, which exhibits strong antioxidant activity. In this study, we evaluate the photoprotective effect of echinacoside on UVB-induced skin damage and explore the potential molecular mechanism. BALB/c mice and HaCaT cells were treated with echinacoside before UVB exposure. Histopathological examination was used to evaluate the skin damage. Cell viability, lactate dehydrogenase (LDH) levels, antioxidant enzyme activities, reactive oxygen species (ROS) generation, DNA damage, and apoptosis were measured as well. Western blot was used to measure the expression of related proteins. The results revealed that pretreatment of echinacoside ameliorated the skin injury; attenuated oxidative stress, DNA damage, and apoptosis caused by UVB exposure; and normalized the protein levels of ATR, p53, PIAS3, hnRNP K, PARP, and XPA. To summarize, echinacoside is beneficial in the prevention of UVB-induced DNA damage and apoptosis of the skin in vivo and in vitro.