Daphnane-type diterpenoids from Stellera chamaejasme L. and their inhibitory activity against hepatocellular carcinoma cells

Daphnane-type diterpenoids, which are scarce in nature, exhibit potent growth-inhibitory activities against various cancer cells. To identify more daphnane-type diterpenoids, the phytochemical components in the root extracts of Stellera chamaejasme L. were analysed in this study using the Global Natural Products Social platform and the MolNetEnhancer tool. Three undescribed 1α-alkyldaphnane-type diterpenoids (1-3; named stelleradaphnanes A-C) and 15 known analogues were isolated and characterised. The structures of these compounds were determined using ultraviolet and nuclear magnetic resonance spectroscopy. The stereo configurations of the compounds were determined using electronic circular dichroism. Next, the growth-inhibitory activities of isolated compounds against HepG2 and Hep3B cells were examined. Compound 3 exhibited potent growth-inhibitory activities against HepG2 and Hep3B cells with half-maximal inhibitory concentration values of 9.73 and 15.97 μM, respectively. Morphological and staining analyses suggested that compound 3 induced apoptosis in HepG2 and Hep3B cells.

Vibsane-type diterpenoids from Viburnum odoratissimum inhibit hepatocellular carcinoma cells via the PI3K/AKT pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, with an elevated danger of metastasis and a short survival rate. Vibsane-type diterpenoids with novel structures possess marked antitumor activities against multiple cancer cells. However, the exact mechanism is poorly unclear.

PURPOSE

To assess the antitumor mechanism of vibsane-type diterpenoids derived from Viburnum odoratissimum (V. odoratissimum) against HCC cells in vitro and in vivo.

METHODS

The main constituents in the ethyl acetate extract of V. odoratissimum (EAVO) were identified by LC-MS/MS. The antiproliferative activity of EAVO in vitro was evaluated by MTT assays. Annexin V-FITC/PI, AO/EB, and Hoechst 33,258 staining were employed to detect apoptosis. JC-1 fluorescence dye was used to detect the mitochondrial membrane potential (MMP). The levels of intracellular ROS and mitochondrial superoxides were assessed by H₂DCF-DA and MitoSox staining, respectively. The levels of oxidative stress were determined by ROS Green™ H₂O₂ probe, hydroxyphenyl fluorescein (HPF), and the C11 BODIPY 581/591 fluorescent probe. Transcriptomics was performed to investigate the antitumor mechanism of EAVO in HCC. The molecular mechanism by which EAVO suppressed HCC cells was verified by Western blot, RT-PCR, and HTRF® KinEASE™-STK S3 kits. The efficacy and safety of EAVO in vivo were evaluated using Hep3B xenograft models.

RESULTS

Vibsane-type diterpenoids were the main constituents of EAVO by LC-MS/MS. EAVO suppressed proliferation, aggravated oxidative stress, and promoted apoptosis in HCC cells. Moreover, EAVO dramatically inhibited tumor growth in Hep3B xenograft models. Transcriptomics results indicated that EAVO inhibited HCC cell proliferation by regulating the PI3K/AKT pathway. Vibsanin B, vibsanol I, and vibsanin S isolated from EAVO was used to further verify the antitumor activity of vibsane-type diterpenoids subsequently. Interestingly, the kinase results showed that vibsanin B and vibsanol I exhibited vital AKT kinase inhibitory activities.

CONCLUSIONS

Collectively, this study provided a comprehensive mechanism overview of vibsane-type diterpenoids against HCC cells in vitro and in vivo. It also laid a foundation for further antitumor investigation of vibsane-type diterpenoids in V. odoratissimum.

Monoterpenoid coumarins and monoterpenoid phenylpropanoids from the root bark of Ailanthus altissima

Three new monoterpenoid coumarins, zantholin A (3), altissimacoumarin P-Q (5, 6), two new monoterpenoid phenylpropanoids, altissmaphenylpropanoids A-B (2, 4), along with two known compounds (7, 8), were obtained from aqueous EtOH extracts of the root bark of Ailanthus altissima.