Saikosaponin C

Biochem Biophys Res Commun. 2014 Mar 14;445(3):615-21.

Saikosaponin C inhibits lipopolysaccharide-induced apoptosis by suppressing caspase-3 activation and subsequent degradation of focal adhesion kinase in human umbilical vein endothelial cells.[Pubmed: 24565837]

Bacterial lipopolysaccharide (LPS) is an important mediator of inflammation and a potent inducer of endothelial cell damage and apoptosis. In this study, we investigated the protective effects of Saikosaponin C (SSc), one of the active ingredients produced by the traditional Chinese herb, Radix Bupleuri, against LPS-induced apoptosis in human umbilical endothelial cells (HUVECs).
METHODS AND RESULTS:
LPS triggered caspase-3 activation, which was found to be important in LPS-induced HUVEC apoptosis. Inhibition of caspase-3 also inhibited LPS-induced degradation of focal adhesion kinase (FAK), indicating that caspase-3 is important in LPS-mediated FAK degradation as well as in apoptosis in HUVECs. SSc significantly inhibited LPS-induced apoptotic cell death in HUVECs through the selective suppression of caspase-3. SSc was also shown to rescue LPS-induced FAK degradation and other cell adhesion signals. Furthermore, the protective effects of SSc against LPS-induced apoptosis were abolished upon pretreatment with a FAK inhibitor, highlighting the importance of FAK in SSc activity.
CONCLUSIONS:
Taken together, these results show that SSc efficiently inhibited LPS-induced apoptotic cell death via inhibition of caspase-3 activation and caspase-3-mediated-FAK degradation. Therefore, SSc represents a promising therapeutic candidate for the treatment of vascular endothelial cell injury and cellular dysfunction.

Life Sci. 2004 Dec 31;76(7):813-26.

Saikosaponin C induces endothelial cells growth, migration and capillary tube formation.[Pubmed: 15581913]

Saikosaponin C is one of the saikosaponins that are consisted in a Chinese herb, Radix Bupleuri. Recently, saikosaponins have been reported to have properties of cell growth inhibition, inducing cancer cells differentiation and apoptosis. However, Saikosaponin C had no correlation with cell growth inhibition. In this study, we investigated the role of Saikosaponin C on the growth of endothelial cells and angiogenesis.
METHODS AND RESULTS:
We found that Saikosaponin C yielded a potent effect on inducing human umbilical vein endothelial cells (HUVECs) viability and growth. In addition to inducing endothelial cells growth, Saikosaponin C also induced endothelial cells migration and capillary tube formation. The gene expression or activation of matrix metalloproteinase-2 (MMP-2), vascular endothelial growth factor (VEGF) and the p42/p44 mitogen-activated protein kinase (MAPK, ERK) that correlated with endothelial cells growth, migration and angiogenesis were also induced by Saikosaponin C.
CONCLUSIONS:
From these results, we suggest that Saikosaponin C may have the potential for therapeutic angiogenesis but is not suitable for cancer therapy.

J Neurochem . 2016 Mar;136(6):1232-1245.

A potential therapeutic effect of saikosaponin C as a novel dual-target anti-Alzheimer agent[Pubmed: 26710244]

Abstract Alzheimer's disease (AD) is a chronic neurodegenerative disease and the risk of developing it increases with advancing age. In this study, we investigated the protective effects of Saikosaponin C (SSc), one of the main bioactive components produced by the traditional Chinese herb, radix bupleuri, the root of Bupleurum falcatum, against AD in various neuronal models. Interestingly, we found that SSc has dual effects on AD by targeting amyloid beta (Aβ) and tau, two key proteins in AD. SSc significantly suppressed the release of both Aβ peptides 1-40 and 1-42 into cell culture supernatants, though it does not affect BACE1 activity and expression. SSc also inhibited abnormal tau phosphorylation at multiple AD-related residues. Moreover, SSc seems to have beneficial effects on cellular tau function; it accelerated nerve growth factor-mediated neurite outgrowth and increased the assembly of microtubules. In addition, SSc increased synaptic marker proteins such as synaptophysin and PSD-95. Considering its various biological activities, our results suggest that SSc might be a novel therapeutic tool for treating human AD and other neurodegenerative diseases. Tau and amyloid beta are two key features in Alzheimer's disease. Saikosaponin C, an active component of Bupleuri Radix, inhibits abnormal tau phosphorylation and amyloid beta production, thereby promoting synaptic integrity. Saikosaponin C also prevents amyloid beta-induced apoptosis in brain vascular endothelial cells. Therefore, Saikosaponin C may provide a new therapeutic strategy for treatment of neurodegenerative diseases, including Alzheimer's disease. Keywords: Alzheimer's disease; amyloid beta; neurodegenerative diseases; Saikosaponin C; tau; therapeutic tool.

Arch Pharm Res. 1997 Oct;20(5):420-4.

Metabolism of saikosaponin c and naringin by human intestinal bacteria.[Pubmed: 18982483]

METHODS AND RESULTS:
By human intestinal bacteria, Saikosaponin C was transformed to four metabolites, prosaikogenin E1 (E1) prosaikogenin E2 (E2), prosaikogenin E3 (E3) and saikogenin E. Metabolic time course of Saikosaponin C was as follows; in early time, Saikosaponin C was converted to E1 and E2, and then these were transformed to saikogenin E via E3. Also, this metabolic pathway was similar to the metabolism of Saikosaponin C by rat intestinal bacteria.Bacteroides JY-6 andBacteroides YK-4, the bacteria isolated from human intestinal bacteria, could transform saiko-saponin c to E via E1 (or E2) and E3. However, these bacteria were not able to directly transform E1 and E2 to saikogenin E.
CONCLUSIONS:
Naringin was mainly transformed to naringenin by human intestinal bacteria. The minor metabolic pathway transformed naringin to naringenin via prunin. By JY-6 or YK-4, naringin was metabolized to naringenin only via prunin.

Planta Med. 2003 Aug;69(8):705-9.

Cytotoxicity and anti-hepatitis B virus activities of saikosaponins from Bupleurum species.[Pubmed: 14531019]

Saikosaponins, the main active constituents of Bupleurum spp., have been shown to possess immunomodulatory, hepatoprotective, anti-tumor and anti-viral activities. In this study, saikosaponins a, c and d were evaluated for cytotoxicity and anti-hepatitis B virus ( HBV) activities.
METHODS AND RESULTS:
Results showed that, with the exception of saikosaponins a and d, HBV-transfected human hepatoma cells (2.2.15 cells) cultured with Saikosaponin C showed a significantly lower level of HBeAg in culture medium. Saikosaponin C also possessed activity in inhibiting HBV DNA replication; this inhibitory effect was not due to the cytotoxicity of Saikosaponin C or its effect on 2.2.15 cell proliferation. Although saikosaponin d exhibited cytotoxicity on 2.2.15 cells, it failed to inhibit HBV multiplication. The cytotoxicity of saikosaponin d against HepG2 human hepatocellular carcinoma cells was due to the induction of apoptosis through the activation of caspases 3 and 7, which subsequently resulted in poly-ADP-ribose-polymerase (PARP) cleavage. DNA fragmentation was clearly noted at more than 6 h after HepG2 cells exposure to saikosaponin d.
CONCLUSIONS:
The present study concludes that Saikosaponin C exhibits anti-HBV activity and saikosaponin d possesses potent cytotoxicity against human hepatocellular carcinoma cells.

Molecules. 2016 Jan 28;21(2):153.

Binding between Saikosaponin C and Human Serum Albumin by Fluorescence Spectroscopy and Molecular Docking.[Pubmed: 26828474 ]

Saikosaponin C (SSC) is one of the major active constituents of dried Radix bupleuri root (Chaihu in Chinese) that has been widely used in China to treat a variety of conditions, such as liver disease, for many centuries.
METHODS AND RESULTS:
The binding of SSC to human serum albumin (HSA) was explored by fluorescence, circular dichroism (CD), UV-vis spectrophotometry, and molecular docking to understand both the pharmacology and the basis of the clinical use of SSC/Chaihu. SSC produced a concentration-dependent quenching effect on the intrinsic fluorescence of HSA, accompanied by a blue shift in the fluorescence spectra. The Stern-Volmer equation showed that this quenching was dominated by static quenching. The binding constant of SSC with HSA was 3.72 × 103 and 2.99 × 103 L·mol(-1) at 26 °C and 36 °C, respectively, with a single binding site on each SSC and HSA molecule. Site competitive experiments demonstrated that SSC bound to site I (subdomain IIA) and site II (subdomain IIIA) in HSA. Analysis of thermodynamic parameters indicated that hydrogen bonding and van der Waals forces were mostly responsible for SSC-HSA association. The energy transfer efficiency and binding distance between SSC and HSA was calculated to be 0.23 J and 2.61 nm at 26 °C, respectively.
CONCLUSIONS:
Synchronous fluorescence and CD measurements indicated that SSC affected HSA conformation in the SSC-HSA complex. Molecular docking supported the experimental findings in conformational changes, binding sites and binding forces, and revealed binding of SSC at the interface between subdomains IIA-IIB.